ORCID Profile
0000-0002-8457-8242
Current Organisations
University College London
,
Walter and Eliza Hall Institute of Medical Research
,
Monash University
,
Moorfields Eye Hospital NHS Foundation Trust
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Analytical Chemistry | Analytical Spectrometry | Chemical Characterisation of Materials
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Biological Sciences | Expanding Knowledge in the Medical and Health Sciences |
Related Links
Publications
Cell cycle progression dictates the requirement for BCL2 in natural killer cell survival
Publisher: Rockefeller University Press
Date: 05-01-2017
DOI: 10.1084/JEM.20160869
Abstract: Natural killer (NK) cells are innate lymphoid cells with antitumor functions. Using an N-ethyl-N-nitrosourea (ENU)–induced mutagenesis screen in mice, we identified a strain with an NK cell deficiency caused by a hypomorphic mutation in the Bcl2 (B cell lymphoma 2) gene. Analysis of these mice and the conditional deletion of Bcl2 in NK cells revealed a nonredundant intrinsic requirement for BCL2 in NK cell survival. In these mice, NK cells in cycle were protected against apoptosis, and NK cell counts were restored in inflammatory conditions, suggesting a redundant role for BCL2 in proliferating NK cells. Consistent with this, cycling NK cells expressed higher MCL1 (myeloid cell leukemia 1) levels in both control and BCL2-null mice. Finally, we showed that deletion of BIM restored survival in BCL2-deficient but not MCL1-deficient NK cells. Overall, these data demonstrate an essential role for the binding of BCL2 to BIM in the survival of noncycling NK cells. They also favor a model in which MCL1 is the dominant survival protein in proliferating NK cells.
Dual Targeting of CDK4/6 and BCL2 Pathways Augments Tumor Response in Estrogen Receptor–Positive Breast Cancer
Publisher: American Association for Cancer Research (AACR)
Date: 08-2020
DOI: 10.1158/1078-0432.CCR-19-1872
Abstract: Although cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors significantly extend tumor response in patients with metastatic estrogen receptor–positive (ER+) breast cancer, relapse is almost inevitable. This may, in part, reflect the failure of CDK4/6 inhibitors to induce apoptotic cell death. We therefore evaluated combination therapy with ABT-199 (venetoclax), a potent and selective BCL2 inhibitor. BCL2 family member expression was assessed following treatment with endocrine therapy and the CDK4/6 inhibitor palbociclib. Functional assays were used to determine the impact of adding ABT-199 to fulvestrant and palbociclib in ER+ breast cancer cell lines, patient-derived organoid (PDO), and patient-derived xenograft (PDX) models. A syngeneic ER+ mouse mammary tumor model was used to study the effect of combination therapy on the immune system. Triple therapy was well tolerated and produced a superior and more durable tumor response compared with single or doublet therapy. This was associated with marked apoptosis, including of senescent cells, indicative of senolysis. Unexpectedly, ABT-199 resulted in Rb dephosphorylation and reduced G1–S cyclins, most notably at high doses, thereby intensifying the fulvestrant albociclib–induced cell-cycle arrest. Interestingly, a CRISPR/Cas9 screen suggested that ABT-199 could mitigate loss of Rb (and potentially other mechanisms of acquired resistance) to palbociclib. ABT-199 did not abrogate the favorable immunomodulatory effects of palbociclib in a syngeneic ER+ mammary tumor model and extended tumor response when combined with anti-PD1 therapy. This study illustrates the potential for targeting BCL2 in combination with CDK4/6 inhibitors and supports investigation of combination therapy in ER+ breast cancer.
XIAP discriminates between type I and type II FAS-induced apoptosis
Publisher: Springer Science and Business Media LLC
Date: 22-07-2009
DOI: 10.1038/NATURE08229
The 2019 Lasker Award: T cells and B cells, whose life and death are essential for function of the immune system.
Publisher: Springer Science and Business Media LLC
Date: 17-10-2019
Elevated Mcl-1 inhibits thymocyte apoptosis and alters thymic selection
Publisher: Springer Science and Business Media LLC
Date: 29-06-2012
DOI: 10.1038/CDD.2012.84
Antiapoptotic Mcl-1 is critical for the survival and niche-filling capacity of Foxp3+ regulatory T cells
Publisher: Springer Science and Business Media LLC
Date: 14-07-2013
DOI: 10.1038/NI.2649
Characterization of Blimp-1 function in effector regulatory T cells
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.JAUT.2018.04.003
Abstract: Regulatory T (T
Acquisition of the Recurrent Gly101Val Mutation in BCL2 Confers Resistance to Venetoclax in Patients with Progressive Chronic Lymphocytic Leukemia
Publisher: American Association for Cancer Research (AACR)
Date: 03-2019
DOI: 10.1158/2159-8290.CD-18-1119
Abstract: Why CLL recurs in patients who achieve remission with the BCL2 inhibitor venetoclax has been unknown. We provide the first description of an acquired point mutation in BCL2 arising recurrently and exclusively in venetoclax-treated patients. The mutation reduces venetoclax binding and is sufficient to confer resistance. See related commentary by Thangava el and Byrd, p. 320. This article is highlighted in the In This Issue feature, p. 305
Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.OPHTHA.2022.09.009
Abstract: The LiGHT trial has shown selective laser trabeculoplasty (SLT) to be clinically and cost-effective as a primary treatment of open-angle glaucoma (OAG) and ocular hypertension (OHT) at 3 years. This paper reports health-related quality of life (HRQL) and clinical effectiveness of initial treatment with SLT compared to intra-ocular pressure (IOP) lowering eye drops, after 6 years of treatment. Prospective multicentre randomized controlled trial. Treatment-naïve eyes with OAG or OHT, initially treated with SLT or IOP-lowering drops. Patients were randomly allocated to initial SLT or eye drops. Eye specific target IOP and monitoring intervals were based on international guidelines. After the initial 3 years of the trial, patients in the SLT arm were permitted a 3 The primary outcome was HRQL at 6 years secondary outcomes were clinical effectiveness and safety. Of the 692 patients completing 3 years in the LiGHT trial, 633 (91.5%) entered the extension and 524 patients completed 6 years in the trial (82.8% of those entering the extension phase, 73% of those initially randomised). At 6 years, there were no significant differences in HRQL for EQ-5D, GUI and GQL-15 (all p>0.05). The SLT arm had better GSS scores than the drops arm (83.6 (SD 18.1) vs 81.3 (SD 17.3), respectively). 69.8% of eyes in the SLT arm remained at or below target IOP without the need for medical or surgical treatment. More eyes in the drops arm exhibited disease progression (26.8% vs 19.6%, respectively, p=0.006). Trabeculectomy was required in 32 eyes in the drops arm compared to 13 eyes in the SLT arm (p<0.001) there were more cataract surgeries in the drops arm (95 compared to 57 eyes, p=0.03). There were no serious laser-related adverse events. SLT is a safe treatment for OAG and OHT, providing better long-term disease control than initial drop therapy, with reduced need for incisional glaucoma and cataract surgery over 6 years.
Erratum: Consortium biology in immunology: the perspective from the Immunological Genome Project
Publisher: Springer Science and Business Media LLC
Date: 04-07-2014
DOI: 10.1038/NRI3714
Control of Cell Survival and Apoptosis
Publisher: Elsevier
Date: 2016
Controlling the thymic microenvironment.
Publisher: Elsevier BV
Date: 04-2005
DOI: 10.1016/J.COI.2005.02.001
Abstract: T-cell development in the thymus is a stepwise process, mediated by a variety of stromal cells in different regions of the organ. Although the cellular composition of the thymic microenvironment has been known for over a decade, the molecular cues that govern its formation are only beginning to be understood. Stromal-derived chemokines attract T-cell precursors to the thymus and direct maturing thymocytes to appropriate niches for their further development. Reciprocal signals from developing T cells provide crosstalk that is essential for establishment and maintenance of the thymic microenvironment. Elucidation of the molecular players involved and their context within the organ is the challenge for the field today. This knowledge could then be translated to clinical restoration of thymic function and T-cell reconstitution.
Uhrf to Treg cells: reinforcing the mucosal peacekeepers
Publisher: Springer Science and Business Media LLC
Date: 19-05-2014
DOI: 10.1038/NI.2893
Mesenchymal stromal cell apoptosis is required for their therapeutic function
Publisher: Springer Science and Business Media LLC
Date: 11-11-2021
DOI: 10.1038/S41467-021-26834-3
Abstract: Multipotent mesenchymal stromal cells (MSCs) ameliorate a wide range of diseases in preclinical models, but the lack of clarity around their mechanisms of action has impeded their clinical utility. The therapeutic effects of MSCs are often attributed to bioactive molecules secreted by viable MSCs. However, we found that MSCs underwent apoptosis in the lung after intravenous administration, even in the absence of host cytotoxic or alloreactive cells. Deletion of the apoptotic effectors BAK and BAX prevented MSC death and attenuated their immunosuppressive effects in disease models used to define MSC potency. Mechanistically, apoptosis of MSCs and their efferocytosis induced changes in metabolic and inflammatory pathways in alveolar macrophages to effect immunosuppression and reduce disease severity. Our data reveal a mode of action whereby the host response to dying MSCs is key to their therapeutic effects findings that have broad implications for the effective translation of cell-based therapies.
An Unbiased Linkage Approach Reveals That the p53 Pathway Is Coupled to NK Cell Maturation
Publisher: The American Association of Immunologists
Date: 15-08-2017
Abstract: Natural killer cells constitute potent innate lymphoid cells that play a major role in both tumor immunosurveillance and viral clearance via their effector functions. A four-stage model of NK cell functional maturation has been established according to the expression of CD11b and CD27, separating mature NK (mNK) cells into distinct populations that exhibit specific phenotypic and functional properties. To identify genetic factors involved in the regulation of NK cell functional maturation, we performed a linkage analysis on F2 (B6.Rag1−/− × NOD.Rag1−/− intercross) mice. We identified six loci on chromosomes 2, 4, 7, 10, 11, and 18 that were linked to one or more mNK cell subsets. Subsequently, we performed an in silico analysis exploiting mNK cell subset microarray data, highlighting various genes and microRNAs as potential regulators of the functional maturation of NK cells. Together, the combination of our unbiased genetic linkage study and the in silico analysis positions genes known to affect NK cell biology along the specific stages of NK cell functional maturation. Moreover, this approach allowed us to uncover a novel candidate gene in the regulation of NK cell maturation, namely Trp53. Using mice deficient for Trp53, we confirm that this tumor suppressor regulates NK cell functional maturation. Additional candidate genes revealed in this study may eventually serve as targets for the modulation of NK cell functional maturation to potentiate both tumor immunosurveillance and viral clearance.
Genetic lesions in T‐cell tolerance and thresholds for autoimmunity
Publisher: Wiley
Date: 16-03-2005
DOI: 10.1111/J.0105-2896.2005.00253.X
Abstract: The cause of common organ-specific autoimmune diseases is poorly understood because of genetic and cellular complexity in humans and animals. Recent advances in the understanding of the mechanisms of the defects underlying autoimmune disease in autoimmune polyendocrinopathy syndrome type 1 and non-obese diabetic mice suggest that failures in central tolerance play a key role in predisposition towards organ-specific autoimmunity. The lessons from such rare monogenic autoimmune disorders and well-characterized polygenic traits demonstrate how subtle quantitative trait loci can result in large changes in the susceptibility to autoimmunity. These data allow us to propose a model relating efficiency of thymic deletion to T-cell tolerance and susceptibility to autoimmunity.
Overexpression of Lmo2 initiates T-lymphoblastic leukemia via impaired thymocyte competition
Publisher: Rockefeller University Press
Date: 15-03-2023
DOI: 10.1084/JEM.20212383
Abstract: Cell competition has recently emerged as an important tumor suppressor mechanism in the thymus that inhibits autonomous thymic maintenance. Here, we show that the oncogenic transcription factor Lmo2 causes autonomous thymic maintenance in transgenic mice by inhibiting early T cell differentiation. This autonomous thymic maintenance results in the development of self-renewing preleukemic stem cells (pre-LSCs) and subsequent leukemogenesis, both of which are profoundly inhibited by restoration of thymic competition or expression of the antiapoptotic factor BCL2. Genomic analyses revealed the presence of Notch1 mutations in pre-LSCs before subsequent loss of tumor suppressors promotes the transition to overt leukemogenesis. These studies demonstrate a critical role for impaired cell competition in the development of pre-LSCs in a transgenic mouse model of T cell acute lymphoblastic leukemia (T-ALL), implying that this process plays a role in the ontogeny of human T-ALL.
The acetyltransferase KAT7 is required for thymic epithelial cell expansion, expression of AIRE target genes, and thymic tolerance.
Publisher: No publisher found
Date: 2022
DOI: 10.1126/SCIIMMUNOL.ABB6032
Abstract: The autoimmune regulator (AIRE) induces the transcription of thousands of peripheral tissue genes (PTGs) in thymic epithelial cells (TECs) to mediate immunological tolerance. The chromatin state required for optimal AIRE function in TECs and how this state is induced remains unclear. We tested the role of the histone acetyltransferase, KAT7 (also known as HBO1 or MYST2), which is essential for acetylation of histone 3 lysine 14, in TEC differentiation, AIRE-mediated PTG expression, and thymic tolerance. We find that KAT7 is required for optimal expansion of medullary TEC and has a major role in the expression of AIRE-dependent PTGs, associated with enhanced chromatin accessibility at these gene loci in TECs. Mice with TEC-specific
Consortium biology in immunology: the perspective from the Immunological Genome Project
Publisher: Springer Science and Business Media LLC
Date: 07-09-2012
DOI: 10.1038/NRI3300
Abstract: Although the field has a long collaborative tradition, immunology has made less use than genetics of 'consortium biology', wherein groups of investigators together tackle large integrated questions or problems. However, immunology is naturally suited to large-scale integrative and systems-level approaches, owing to the multicellular and adaptive nature of the cells it encompasses. Here, we discuss the value and drawbacks of this organization of research, in the context of the long-running 'big science' debate, and consider the opportunities that may exist for the immunology community. We position this analysis in light of our own experience, both positive and negative, as participants of the Immunological Genome Project.
A Genetic and Functional Relationship between T Cells and Cellular Proliferation in the Adult Hippocampus
Publisher: Public Library of Science (PLoS)
Date: 14-12-2010
Deletion of self-reactive CCR7– thymocytes in the absence of MHC expression on thymic epithelial cells
Publisher: Springer Science and Business Media LLC
Date: 24-04-2019
Developmental kinetics, turnover, and stimulatory capacity of thymic epithelial cells
Publisher: American Society of Hematology
Date: 12-2006
DOI: 10.1182/BLOOD-2006-02-004531
Abstract: Despite the importance of thymic stromal cells to T-cell development, relatively little is known about their biology. Here, we use single-cell analysis of stromal cells to analyze extensive changes in the number and composition of thymic stroma throughout life, revealing a surprisingly dynamic population. Phenotypic progression of thymic epithelial subsets was assessed at high resolution in young mice to provide a developmental framework. The cellular and molecular requirements of adult epithelium were studied, using various mutant mice to demonstrate new cross talk checkpoints dependent on RelB in the cortex and CD40 in the medulla. With the use of Ki67 and BrdU labeling, the turnover of thymic epithelium was found to be rapid, but then diminished on thymic involution. The various defects in stromal turnover and composition that accompanied involution were rapidly reversed following sex steroid ablation. Unexpectedly, mature cortical and medullary epithelium showed a potent capacity to stimulate naive T cells, comparable to that of thymic dendritic cells. Overall, these studies show that the thymic stroma is a surprisingly dynamic population and may have a more direct role in negative selection than previously thought.
Primary Selective Laser Trabeculoplasty for Open-Angle Glaucoma and Ocular Hypertension
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.OPHTHA.2019.04.012
Abstract: To report clinical efficacy, predictors of success, and safety of primary selective laser trabeculoplasty (SLT) used in treatment-naive patients with open-angle glaucoma (OAG) or ocular hypertension (OHT). Post hoc analysis of a multicenter, prospective, randomized, controlled trial. Treatment-naive patients with OAG or OHT. Patients randomized to SLT or topical medication and treated to predefined target intraocular pressures (IOPs) requiring ≥20% IOP reduction from baseline for all disease severity levels. Initial (early) absolute IOP-lowering at 2 months. Achievement of drop-free disease-control: meeting target IOP without disease progression or need for additional topical medication over 36 months after SLT. Predictors of early absolute IOP-lowering and drop-free disease-control after single initial SLT. Frequency of laser-related complications. A total of 611 eyes (195 OHT and 416 OAG) of 355 patients received SLT, and 622 eyes (185 OHT and 437 OAG) of 362 patients received topical medication at baseline. Early absolute IOP-lowering after SLT was no different between OHT and OAG eyes (adjusted mean difference = -0.05 mmHg 95% confidence interval [CI], -0.6 to 0.5 mmHg P = 0.85). No difference was noted in early absolute IOP-lowering between topical medication and primary SLT (adjusted mean difference = -0.1 mmHg 95% CI, -0.6 to 0.4 mmHg P = 0.67). Early absolute IOP-lowering with primary SLT was positively associated with baseline IOP (coefficient 0.58 95% CI, 0.53-0.63 P 5 mmHg from pretreatment IOP) with 1 eye requiring treatment. Primary SLT achieved comparable early absolute IOP-lowering in OHT versus OAG eyes. Drop-free disease-control was achieved in approximately 75% eyes at 36 months after 1 or 2 SLTs, the majority of these after single SLT. These analyses are exploratory but support primary SLT to be effective and safe in treatment-naive OAG and OHT eyes.
CIS is a potent checkpoint in NK cell–mediated tumor immunity
Publisher: Springer Science and Business Media LLC
Date: 23-05-2016
DOI: 10.1038/NI.3470
Abstract: The detection of aberrant cells by natural killer (NK) cells is controlled by the integration of signals from activating and inhibitory ligands and from cytokines such as IL-15. We identified cytokine-inducible SH2-containing protein (CIS, encoded by Cish) as a critical negative regulator of IL-15 signaling in NK cells. Cish was rapidly induced in response to IL-15, and deletion of Cish rendered NK cells hypersensitive to IL-15, as evidenced by enhanced proliferation, survival, IFN-γ production and cytotoxicity toward tumors. This was associated with increased JAK-STAT signaling in NK cells in which Cish was deleted. Correspondingly, CIS interacted with the tyrosine kinase JAK1, inhibiting its enzymatic activity and targeting JAK for proteasomal degradation. Cish(-/-) mice were resistant to melanoma, prostate and breast cancer metastasis in vivo, and this was intrinsic to NK cell activity. Our data uncover a potent intracellular checkpoint in NK cell-mediated tumor immunity and suggest possibilities for new cancer immunotherapies directed at blocking CIS function.
Selective laser trabeculoplasty versus drops for newly diagnosed ocular hypertension and glaucoma: the LiGHT RCT
Publisher: National Institute for Health and Care Research
Date: 06-2019
DOI: 10.3310/HTA23310
Abstract: Newly diagnosed open-angle glaucoma (OAG) and ocular hypertension (OHT) are habitually treated with intraocular pressure (IOP)-lowering eyedrops. Selective laser trabeculoplasty (SLT) is a safe alternative to drops and is rarely used as first-line treatment. To compare health-related quality of life (HRQoL) in newly diagnosed, treatment-naive patients with OAG or OHT, treated with two treatment pathways: topical IOP-lowering medication from the outset (Medicine-1st) or primary SLT followed by topical medications as required (Laser-1st). We also compared the clinical effectiveness and cost-effectiveness of the two pathways. A 36-month pragmatic, unmasked, multicentre randomised controlled trial. Six collaborating specialist glaucoma clinics across the UK. Newly diagnosed patients with OAG or OHT in one or both eyes who were aged ≥ 18 years and able to provide informed consent and read and understand English. Patients needed to qualify for treatment, be able to perform a reliable visual field (VF) test and have visual acuity of at least 6 out of 36 in the study eye. Patients with VF loss mean deviation worse than –12 dB in the better eye or –15 dB in the worse eye were excluded. Patients were also excluded if they had congenital, early childhood or secondary glaucoma or ocular comorbidities if they had any previous ocular surgery except phacoemulsification, at least 1 year prior to recruitment or any active treatment for ophthalmic conditions if they were pregnant or if they were unable to use topical medical therapy or had contraindications to SLT. SLT according to a predefined protocol compared with IOP-lowering eyedrops, as per national guidelines. The primary outcome was HRQoL at 3 years [as measured using the EuroQol-5 Dimensions, five-level version (EQ-5D-5L) questionnaire]. Secondary outcomes were cost and cost-effectiveness, disease-specific HRQoL, clinical effectiveness and safety. Of the 718 patients enrolled, 356 were randomised to Laser-1st (initial SLT followed by routine medical treatment) and 362 to Medicine-1st (routine medical treatment only). A total of 652 (91%) patients returned the primary outcome questionnaire at 36 months. The EQ-5D-5L score was not significantly different between the two arms [adjusted mean difference (Laser-1st – Medicine-1st) 0.01, 95% confidence interval (CI) –0.01 to 0.03 p = 0.23] at 36 months. Over 36 months, the proportion of visits at which IOP was within the target range was higher in the Laser-1st arm (93.0%, 95% CI 91.9% to 94.0%) than in the Medicine-1st arm (91.3%, 95% CI 89.9% to 92.5%), with IOP-lowering glaucoma surgery required in 0 and 11 patients, respectively. There was a 97% probability of Laser-1st being more cost-effective than Medicine-1st for the NHS, at a willingness to pay for a quality-adjusted life-year of £20,000, with a reduction in ophthalmology costs of £458 per patient (95% of bootstrap iterations between –£585 and –£345). An unmasked design, although a limitation, was essential to capture any treatment effects on patients’ perception. The EQ-5D-5L questionnaire is a generic tool used in multiple settings and may not have been the most sensitive tool to investigate HRQoL. Compared with medication, SLT provided a stable, drop-free IOP control to 74.2% of patients for at least 3 years, with a reduced need for surgery, lower cost and comparable HRQoL. Based on the evidence, SLT seems to be the most cost-effective first-line treatment option for OAG and OHT, also providing better clinical outcomes. Longitudinal research into the clinical efficacy of SLT as a first-line treatment will specify the long-term differences of disease progression, treatment intensity and ocular surgery rates between the two pathways. Current Controlled Trials ISRCTN32038223. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment Vol. 23, No. 31. See the NIHR Journals Library website for further project information.
Statistical analysis plan for the Laser-1st versus Drops-1st for Glaucoma and Ocular Hypertension Trial (LiGHT): a multi-centre randomised controlled trial
Publisher: Springer Science and Business Media LLC
Date: 11-11-2015
Combined immune checkpoint blockade as a therapeutic strategy for BRCA1 -mutated breast cancer
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-06-2017
DOI: 10.1126/SCITRANSLMED.AAL4922
Abstract: BRCA1 -mutated tumors may be particularly vulnerable to dual checkpoint inhibition.
The NF-[kappa]B1 transcription factor prevents the intrathymic development of CD8 T cells with memory properties
Publisher: Wiley
Date: 29-11-2012
How do thymic epithelial cells die?
Publisher: Springer Science and Business Media LLC
Date: 16-03-2018
Dual roles for LUBAC signaling in thymic epithelial cell development and survival.
Publisher: Springer Science and Business Media LLC
Date: 11-08-2021
Defects in the Bcl-2-regulated apoptotic pathway lead to preferential increase of CD25lowFoxp3+ anergic CD4+ T cells
Publisher: The American Association of Immunologists
Date: 15-08-2011
Abstract: Defects in the Bcl-2–regulated apoptotic pathway inhibit the deletion of self-reactive T cells. What is unresolved, however, is the nature and fate of such self-reactive T cells escaping deletion. In this study, we report that mice with such defects contained increased numbers of CD25lowFoxp3+ cells in the thymus and peripheral lymph tissues. The increased CD25lowFoxp3+ population contained a large fraction of cells bearing self-reactive TCRs, evident from a prominent increase in self-superantigen–specific Foxp3+Vβ5+CD4+ T cells in BALB/c Bim−/− mice compared with control animals. The survival rate of the expanded CD25lowFoxp3+ cells was similar to that of CD25highFoxp3+ CD4 T cells in vitro and in vivo. IL-2R stimulation, but not TCR ligation, upregulated CD25 on CD25lowFoxp3+CD4+ T cells in vitro and in vivo. The expanded CD25lowFoxp3+CD4+ T cells from Bim−/− mice were anergic but also had weaker regulatory function than CD25highFoxp3+ CD4+ T cells from the same mice. Analysis of Bim−/− mice that also lacked Fas showed that the peripheral homeostasis of this expanded population was in part regulated by this death receptor. In conclusion, these results show that self-reactive T cell escapees from thymic deletion in mice defective in the Bcl-2–regulated apoptotic pathway upregulate Foxp3 and become unresponsive upon encountering self-Ag without necessarily gaining potent regulatory function. This clonal functional ersion may help to curtail autoaggressiveness of escaped self-reactive CD4+ T cells and thereby safeguard immunological tolerance.
PD-1 cooperates with AIRE-mediated tolerance to prevent lethal autoimmune disease
Publisher: Proceedings of the National Academy of Sciences
Date: 08-04-2022
Abstract: A variety of mechanisms safeguard the body from autoimmune reactions, yet how these processes cooperate is largely unclear. Using a range of mouse genetic models, we uncover a critical tolerogenic axis between the autoimmune regulator, AIRE, and the immune checkpoint molecule, PD-1. Their combined loss induced an early-onset lethal autoimmune syndrome driven by autoreactive CD4 + T cells that could not be restrained by regulatory T cells. These data shed light on how central and peripheral tolerance mechanisms work together, and highlight thymic function as a potentially key modifier of responses to anti–PD-1 therapies.
P53 Efficiently Suppresses Tumor Development in the Complete Absence of Its Cell-Cycle Inhibitory and Proapoptotic Effectors p21, Puma, and Noxa
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.CELREP.2013.04.012
Abstract: Activation of apoptosis through transcriptional induction of Puma and Noxa has long been considered to constitute the critical (if not sole) process by which p53 suppresses tumor development, although G1/S boundary cell-cycle arrest via induction of the CDK inhibitor p21 has also been thought to contribute. Recent analyses of mice bearing mutations that impair p53-mediated induction of select target genes have indicated that activation of apoptosis and G1/S cell-cycle arrest may, in fact, be dispensable for p53-mediated tumor suppression. However, the expression of Puma, Noxa, and p21 was not abrogated in these mutants, only reduced therefore, the possibility that the reduced levels of these critical effectors of p53-mediated apoptosis and G1/S-cell-cycle arrest sufficed to prevent tumorigenesis could not be excluded. To resolve this important issue, we have generated mice deficient for p21, Puma, and Noxa (p21-/-puma-/-noxa-/- mice). Cells from these mice were deficient in their ability to undergo p53-mediated apoptosis, G1/S cell-cycle arrest, and senescence. Nonetheless, these animals remained tumor free until at least 500 days, in contrast to p53-deficient mice, which had all succumbed to lymphoma or sarcoma by 250 days. Interestingly, DNA lesions induced by γ-irradiation persisted longer in p53-deficient cells compared to wild-type or p21-/-puma-/-noxa-/- cells, and the former failed to transcriptionally activate several p53 target genes implicated in DNA repair. These results demonstrate beyond a doubt that the induction of apoptosis, cell-cycle arrest, and possibly senescence is dispensable for p53-mediated suppression of spontaneous tumor development and indicate that coordination of genomic stability and possibly other processes, such as metabolic adaptation, may instead be critical.
Can you rely on Treg cells on the rebound?
Publisher: Wiley
Date: 12-2014
Abstract: FoxP3(+) regulatory T (Treg) cells comprise a highly dynamic population that restrains autoreactivity. Although complete or long-term depletion of Foxp3(+) CD4(+) Treg cells in adult mice has been shown to result in chronic inflammation and autoimmune disease, the impact of transient Treg-cell depletion on self-reactive responses is poorly defined. A new study published in this issue of the European Journal of Immunology [Eur. J. Immunol. 2014. 44: 3621-3631] shows that, although transient depletion of Treg cells in mice is swiftly followed by recovery of Treg-cell numbers, the "rebounded" population fails to maintain tolerance, culminating in severe autoimmune gastritis. This commentary explores new questions about the quantitative and qualitative aspects of Treg-cell function in immunological tolerance raised by this study and others.
Stromal Cells Provide the Matrix for Migration of Early Lymphoid Progenitors Through the Thymic Cortex
Publisher: The American Association of Immunologists
Date: 15-10-2002
DOI: 10.4049/JIMMUNOL.169.8.4354
Abstract: During steady state lymphopoiesis in the postnatal thymus, migration of precursors outward from the deep cortex toward the capsule is required for normal differentiation. Such migration requires, at a minimum, expression of adhesive receptors on the migrating lymphoid cells, as well as a stable matrix of their ligands persisting throughout the region of migration. In this study, we address the nature of this adhesive matrix. Although some precursor stages bound efficiently to extracellular matrix ligands, a specific requirement for the cell surface ligand VCAM-1 was also found. In situ analysis revealed that early precursors are found in intimate contact with a matrix formed by stromal cells in the cortex, a proportion of which expresses VCAM-1. In vivo administration of an anti-VCAM-1 Ab resulted in decreased thymic size and altered distribution of early precursors within the cortex. These results indicate that precursors migrating outward through the cortex may use a cellular, rather than extracellular, matrix for adhesion, and suggest that the VCAM-1+ subset of cortical stroma may play a crucial role in supporting the migration of early precursors in the steady state thymus.
The transcriptional landscape of αβ T cell differentiation
Publisher: Springer Science and Business Media LLC
Date: 05-05-2013
DOI: 10.1038/NI.2590
The thymic epithelial microRNA network elevates the threshold for infection-associated thymic involution via miR-29a mediated suppression of the IFN-α receptor
Publisher: Springer Science and Business Media LLC
Date: 18-12-2011
DOI: 10.1038/NI.2193
Unresponsiveness to inhaled antigen is governed by conventional dendritic cells and overridden during infection by monocytes
Publisher: American Association for the Advancement of Science (AAAS)
Date: 08-10-2020
DOI: 10.1126/SCIIMMUNOL.ABB5439
Abstract: Immunity to inhaled antigens is governed by inflammatory signals that alter the composition of DC subsets within the NALTs.
Venetoclax treatment in patients with cancer has limited impact on circulating T and NK cells
Publisher: American Society of Hematology
Date: 15-06-2023
DOI: 10.1182/BLOODADVANCES.2022008221
Abstract: Venetoclax is an effective treatment for certain blood cancers, such as chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML). However, most patients relapse while on venetoclax and further treatment options are limited. Combining venetoclax with immunotherapies is an attractive approach however, a detailed understanding of how venetoclax treatment impacts normal immune cells in patients is lacking. In this study, we performed deep profiling of peripheral blood (PB) cells from patients with CLL and AML before and after short-term treatment with venetoclax using mass cytometry (cytometry by time of flight) and found no impact on the concentrations of key T-cell subsets or their expression of checkpoint molecules. We also analyzed PB from patients with breast cancer receiving venetoclax long-term using a single-cell multiomics approach (cellular indexing of transcriptomes and epitopes by sequencing) and functional assays. We found significant depletion of B-cell populations with low expression of MCL-1 relative to other immune cells, attended by extensive transcriptomic changes. By contrast, there was less impact on circulating T cells and natural killer (NK) cells, with no changes in their subset composition, transcriptome, or function following venetoclax treatment. Our data indicate that venetoclax has minimal impact on circulating T or NK cells, supporting the rationale of combining this BH3 mimetic drug with cancer immunotherapies for more durable antitumor responses.
Author response: Removing unwanted variation with CytofRUV to integrate multiple CyTOF datasets
Publisher: eLife Sciences Publications, Ltd
Date: 09-2020
Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial
Publisher: Elsevier BV
Date: 04-2019
Thymus and Tolerance in Transplantation
Publisher: Elsevier
Date: 2004
Proliferative arrest and rapid turnover of thymic epithelial cells expressing Aire
Publisher: Rockefeller University Press
Date: 10-2007
DOI: 10.1084/JEM.20070795
Abstract: Expression of autoimmune regulator (Aire) by thymic medullary epithelial cells (MECs) is critical for central tolerance of self. To explore the mechanism by which such a rare cell population imposes tolerance on the large repertoire of differentiating thymocytes, we examined the proliferation and turnover of Aire+ and Aire− MEC subsets through flow cytometric analysis of 5-bromo-2′deoxyuridine (BrdU) incorporation. The Aire+ MEC subset was almost entirely postmitotic and derived from cycling Aire− precursors. Experiments using reaggregate thymic organ cultures revealed the presence of such precursors among Aire− MECs expressing low levels of major histocompatibility complex class II and CD80. The kinetics of BrdU decay showed the Aire+ population to have a high turnover. Aire did not have a direct impact on the ision of MECs in vitro or in vivo but, rather, induced their apoptosis. We argue that these properties strongly favor a “terminal differentiation” model for Aire function in MECs, placing strict temporal limits on the operation of any in idual Aire+ MEC in central tolerance induction. We further speculate that the speedy apoptosis of Aire-expressing MECs may be a mechanism to promote cross-presentation of the array of peripheral-tissue antigens they produce.
Differential Responsiveness of Innate-like IL-17– and IFN-γ–Producing γδ T Cells to Homeostatic Cytokines
Publisher: The American Association of Immunologists
Date: 15-01-2016
Abstract: γδ T cells respond to molecules upregulated following infection or cellular stress using both TCR and non-TCR molecules. The importance of innate signals versus TCR ligation varies greatly. Both innate-like IL-17–producing γδ T (γδT-17) and IFN-γ–producing γδ T (γδT-IFNγ) subsets tune the sensitivity of their TCR following thymic development, allowing robust responses to inflammatory cytokines in the periphery. The remaining conventional γδ T cells retain high TCR responsiveness. We determined homeostatic mechanisms that govern these various subsets in the peripheral lymphoid tissues. We found that, although innate-like γδT-17 and γδT-IFNγ cells share elements of thymic development, they erge when it comes to homeostasis. Both exhibit acute sensitivity to cytokines compared with conventional γδ T cells, but they do not monopolize the same cytokine. γδT-17 cells rely exclusively on IL-7 for turnover and survival, aligning them with NKT17 cells IL-7 ligation triggers proliferation, as well as promotes survival, upregulating Bcl-2 and Bcl-xL. γδT-IFNγ cells instead depend heavily on IL-15. They display traits analogous to memory CD8+ T cells and upregulate Bcl-xL and Mcl-1 upon cytokine stimulation. The conventional γδ T cells display low sensitivity to cytokine-alone stimulation and favor IL-7 for their turnover, characteristics reminiscent of naive αβ T cells, suggesting that they may also require tonic TCR signaling for population maintenance. These survival constraints suggest that γδ T cell subsets do not directly compete with each other for cytokines, but instead fall into resource niches with other functionally similar lymphocytes.
Generalized Resistance to Thymic Deletion in the NOD Mouse
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.IMMUNI.2004.10.014
Abstract: The cause of common polygenic autoimmune diseases is not understood because of genetic and cellular complexity. Here, we pinpoint the action of a subset of autoimmune susceptibility loci in the NOD mouse strain linked to D1mit181, D2mit490, D7mit101, and D15mit229, which cause a generalized resistance to thymic deletion in vivo that applies equally to Aire-induced organ-specific gene products in the thymic medulla and to systemic antigens expressed at high levels throughout the thymus and affects CD4(+), CD4(+)8(+), and CD4(+)25(+) thymocytes. Resistance to thymic deletion does not reflect a general deficit in TCR signaling to calcineurin- or ERK-induced genes, imbalance in constitutive regulators of apoptosis, nor excessive signaling to prosurvival genes but is distinguished by failure to induce the proapoptotic gene and protein, Bim, during in vivo encounter with high-avidity autoantigen. These findings establish defects in thymic deletion and Bim induction as a key mechanism in the pathogenesis of autoimmunity.
CARD11 is dispensable for homeostatic responses and suppressive activity of peripherally-induced FOXP3+ regulatory T cells.
Publisher: Wiley
Date: 26-06-2019
DOI: 10.1111/IMCB.12268
Abstract: FOXP3
Homeostatic control of regulatory T cell diversity
Publisher: Springer Science and Business Media LLC
Date: 31-01-2014
DOI: 10.1038/NRI3605
Abstract: Regulatory T (TReg) cells constitute an essential counterbalance to adaptive immune responses. Failure to maintain appropriate TReg cell numbers or function leads to autoimmune, malignant and immunodeficient conditions. Dynamic homeostatic processes preserve the number of forkhead box P3-expressing (FOXP3(+)) TReg cells within a healthy range, with high rates of cell ision being offset by apoptosis under steady-state conditions. Recent studies have shown that TReg cells become specialized for different environmental contexts, tailoring their functions and homeostatic properties to a wide range of tissues and immune conditions. In this Review, we describe new insights into the molecular controls that maintain the steady-state homeostasis of TReg cells and the cues that drive TReg cell adaptation to inflammation and/or different locations. We highlight how differing local milieu might drive context-specific TReg cell function and restoration of immune homeostasis, and how dysregulation of these processes can precipitate disease.
BAX requires VDAC2 to mediate apoptosis and to limit tumor development
Publisher: Cold Spring Harbor Laboratory
Date: 16-02-2018
DOI: 10.1101/266668
Abstract: Intrinsic apoptosis is critical for normal physiology including the prevention of tumor formation. BAX and BAK are essential for mediating this process and for the cytotoxic action of many anticancer drugs. BAX and BAK are thought to act in a functionally redundant manner and are considered to be regulated similarly. From an unbiased genome-wide CRISPR/Cas9 screen, we identified VDAC2 (voltage-dependent anion channel 2) as essential for BAX, but not BAK, to function. The genetic deletion of VDAC2 abrogated the association of BAX and BAK with mitochondrial complexes that contain VDAC1, VDAC2 and VDAC3. By disrupting its localization to mitochondria, BAX is rendered completely ineffective. Moreover, we defined an interface unique to VDAC2 that is required to drive BAX activity. Consequently, interfering with this interaction or deleting VDAC2 phenocopied the loss of BAX , including impairing the killing of tumor cells by anti-cancer agents such as the BCL-2 inhibitor venetoclax. Furthermore, the ability of BAX to prevent tumor formation was attenuated in the absence of VDAC2 . Taken together, our studies show for the first time that BAX-mediated apoptosis, but not BAK-mediated apoptosis, is critically dependent on VDAC2, hence revealing the differential regulation of BAX and BAK.
Early immune pressure imposed by tissue resident memory T cells sculpts tumour evolution in non-small cell lung cancer
Publisher: Cold Spring Harbor Laboratory
Date: 21-04-2021
DOI: 10.1101/2021.04.20.440373
Abstract: Tissue-resident memory T cells (T RM ) provide immune defence against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts T RM activation and how the immune pressure exerted by T RM affects developing tumours in humans. We performed deep profiling of lung cancers arising in never-smokers (NS) and ever-smokers (ES), finding evidence of enhanced T RM immunosurveillance in ES lung. Only tumours arising in ES patients underwent clonal immune escape, even when evaluating cancers with similar tumour mutational burden to NS patients, suggesting that the timing of immune pressure exerted by T RM is a critical factor in the evolution of tumour immune evasion. Tumours grown in T cell quiescent NS lungs displayed little evidence of immune evasion and had fewer neoantigens with low ersity, paradoxically making them amenable to treatment with agonist of the costimulatory molecule, ICOS. These data demonstrate local environmental insults enhance T RM immunosurveillance of human tissue, shape the evolution of tumour immunogenicity and that this interplay informs effective immunotherapeutic modalities.
Single-cell multiomics reveal the scale of multilayered adaptations enabling CLL relapse during venetoclax therapy
Publisher: American Society of Hematology
Date: 17-11-2022
Abstract: Venetoclax (VEN) inhibits the prosurvival protein BCL2 to induce apoptosis and is a standard therapy for chronic lymphocytic leukemia (CLL), delivering high complete remission rates and prolonged progression-free survival in relapsed CLL but with eventual loss of efficacy. A spectrum of subclonal genetic changes associated with VEN resistance has now been described. To fully understand clinical resistance to VEN, we combined single-cell short- and long-read RNA-sequencing to reveal the previously unappreciated scale of genetic and epigenetic changes underpinning acquired VEN resistance. These appear to be multilayered. One layer comprises changes in the BCL2 family of apoptosis regulators, especially the prosurvival family members. This includes previously described mutations in BCL2 and lification of the MCL1 gene but is heterogeneous across and within in idual patient leukemias. Changes in the proapoptotic genes are notably uncommon, except for single cases with subclonal losses of BAX or NOXA. Much more prominent was universal MCL1 gene upregulation. This was driven by an overlying layer of emergent NF-κB (nuclear factor kappa B) activation, which persisted in circulating cells during VEN therapy. We discovered that MCL1 could be a direct transcriptional target of NF-κB. Both the switch to alternative prosurvival factors and NF-κB activation largely dissipate following VEN discontinuation. Our studies reveal the extent of plasticity of CLL cells in their ability to evade VEN-induced apoptosis. Importantly, these findings pinpoint new approaches to circumvent VEN resistance and provide a specific biological justification for the strategy of VEN discontinuation once a maximal response is achieved rather than maintaining long-term selective pressure with the drug.
The lymphotoxin pathway regulates Aire-independent expression of ectopic genes and chemokines in thymic stromal cells.
Publisher: The American Association of Immunologists
Date: 15-04-2008
DOI: 10.4049/JIMMUNOL.180.8.5384
Abstract: Medullary thymic epithelial cells (mTEC) play an important and unique role in central tolerance, expressing tissue-restricted Ags (TRA) which delete thymocytes autoreactive to peripheral organs. Since deficiencies in this cell type or activity can lead to devastating autoimmune diseases, it is important to understand the factors which regulate mTEC differentiation and function. Lymphotoxin (LT) ligands and the LTβR have been recently shown to be important regulators of mTEC biology however, the precise role of this pathway in the thymus is not clear. In this study, we have investigated the impact of this signaling pathway in greater detail, focusing not only on mTEC but also on other thymic stromal cell subsets. LTβR expression was found in all TEC subsets, but the highest levels were detected in MTS-15+ thymic fibroblasts. Rather than directing the expression of the autoimmune regulator Aire in mTEC, we found LTβR signals were important for TRA expression in a distinct population of mTEC characterized by low levels of MHC class II (mTEClow), as well as maintenance of MTS-15+ fibroblasts. In addition, thymic stromal cell subsets from LT-deficient mice exhibit defects in chemokine production similar to that found in peripheral lymphoid organs of Lta−/− and Ltbr−/− mice. Thus, we propose a broader role for LTα1β2-LTβR signaling in the maintenance of the thymic microenvironments, specifically by regulating TRA and chemokine expression in mTEClow for efficient induction of central tolerance.
Proapoptotic Bak and Bax guard against fatal systemic and organ-specific autoimmune disease
Publisher: Proceedings of the National Academy of Sciences
Date: 24-01-2013
Abstract: Dysregulation of the “intrinsic” apoptotic pathway is associated with the development of cancer and autoimmune disease. Bak and Bax are two proapoptotic members of the Bcl-2 protein family with overlapping, essential roles in the intrinsic apoptotic pathway. Their activity is critical for the control of cell survival during lymphocyte development and homeostasis, best demonstrated by defects in thymic T-cell differentiation and peripheral lymphoid homeostasis caused by their combined loss. Because most bak −/− bax −/− mice die perinatally, the roles of Bax and Bak in immunological tolerance and prevention of autoimmune disease remain unclear. We show that mice reconstituted with a Bak/Bax doubly deficient hematopoietic compartment develop a fatal systemic lupus erythematosus-like autoimmune disease characterized by hypergammaglobulinemia, autoantibodies, lymphadenopathy, glomerulonephritis, and vasculitis. Importantly, these mice also develop a multiorgan autoimmune disease with autoantibodies against most solid glandular structures and evidence of glandular atrophy and necrotizing vasculitis. Interestingly, similar albeit less severe pathology was observed in mice containing a hematopoietic compartment deficient for only Bak, a phenotype reminiscent of the disease seen in patients with point mutations in BAK . These studies demonstrate a critical role for Bak and an ancillary role for Bax in safeguarding immunological tolerance and prevention of autoimmune disease. This suggests that direct activators of the intrinsic apoptotic pathway, such as BH3 mimetics, may be useful for treatment of erse autoimmune diseases.
Chronically stimulated human MAIT cells are unexpectedly potent IL-13 producers
Publisher: Wiley
Date: 19-07-2019
DOI: 10.1111/IMCB.12281
Transgenic Expression of GM-CSF in T Cells Causes Disseminated Histiocytosis
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.AJPATH.2013.09.014
Abstract: Recent studies highlight surprising roles for granulocyte-macrophage colony-stimulating factor (GM-CSF) production by T cells. T-cell-derived GM-CSF is required for the differentiation of monocyte-derived inflammatory dendritic cells during inflammation and for the pathogenicity of IL-17 producing T helper cells in autoimmunity. To gain further insight into these findings, we engineered in vivo overexpression of GM-CSF specifically in T cells, under the control of the Lck promoter. Lck-GM-CSF transgenic mice displayed a dramatic phenotype, characterized by splenomegaly, lymphadenopathy, thymic atrophy, and multiple abnormalities in blood cell populations. Thymocyte differentiation was severely affected, and there was a dramatic increase in regulatory T cells in the thymus and peripheral lymphoid organs. Lck-GM-CSF transgenic mice developed a disseminated histiocytosis and had increased circulating IL-17 producing T helper cells-related cytokines. The pathological characteristics in Lck-GM-CSF transgenic mice resemble those of histiocytic human diseases, such as Langerhans cell histiocytosis. The etiology of many histiocytic disorders is unknown, but our findings suggest that over-production of GM-CSF by T cells could be a pathogenic factor and raise the possibility that GM-CSF may represent a novel therapeutic target.
Comparison of Short-term Postoperative Hypotony Rates of 23-gaugevs25-gauge Needles in Formation of the Scleral Tract for Baerveldt Tube Insertion into the Anterior Chamber
Publisher: Jaypee Brothers Medical Publishing
Date: 2018
Physiological restraint of Bak by Bcl-xL is essential for cell survival
Publisher: Cold Spring Harbor Laboratory
Date: 15-05-2016
Abstract: Due to the myriad interactions between prosurvival and proapoptotic members of the Bcl-2 family of proteins, establishing the mechanisms that regulate the intrinsic apoptotic pathway has proven challenging. Mechanistic insights have primarily been gleaned from in vitro studies because genetic approaches in mammals that produce unambiguous data are difficult to design. Here we describe a mutation in mouse and human Bak that specifically disrupts its interaction with the prosurvival protein Bcl-x L . Substitution of Glu75 in mBak (hBAK Q77) for leucine does not affect the three-dimensional structure of Bak or killing activity but reduces its affinity for Bcl-x L via loss of a single hydrogen bond. Using this mutant, we investigated the requirement for physical restraint of Bak by Bcl-x L in apoptotic regulation. In vitro, Bak Q75L cells were significantly more sensitive to various apoptotic stimuli. In vivo, loss of Bcl-x L binding to Bak led to significant defects in T-cell and blood platelet survival. Thus, we provide the first definitive in vivo evidence that prosurvival proteins maintain cellular viability by interacting with and inhibiting Bak.
Transcriptomes of the B and T Lineages Compared by Multiplatform Microarray Profiling
Publisher: The American Association of Immunologists
Date: 03-2011
Abstract: T and B lymphocytes are developmentally and functionally related cells of the immune system, representing the two major branches of adaptive immunity. Although originating from a common precursor, they play very different roles: T cells contribute to and drive cell-mediated immunity, whereas B cells secrete Abs. Because of their functional importance and well-characterized differentiation pathways, T and B lymphocytes are ideal cell types with which to understand how functional differences are encoded at the transcriptional level. Although there has been a great deal of interest in defining regulatory factors that distinguish T and B cells, a truly genomewide view of the transcriptional differences between these two cells types has not yet been taken. To obtain a more global perspective of the transcriptional differences underlying T and B cells, we exploited the statistical power of combinatorial profiling on different microarray platforms, and the breadth of the Immunological Genome Project gene expression database, to generate robust differential signatures. We find that differential expression in T and B cells is pervasive, with the majority of transcripts showing statistically significant differences. These distinguishing characteristics are acquired gradually, through all stages of B and T differentiation. In contrast, very few T versus B signature genes are uniquely expressed in these lineages, but are shared throughout immune cells.
Potent efficacy of MCL-1 inhibitor-based therapies in preclinical models of mantle cell lymphoma.
Publisher: Springer Science and Business Media LLC
Date: 26-11-2019
DOI: 10.1038/S41388-019-1122-X
Abstract: Apoptosis-regulating BCL-2 family members, which can promote malignant transformation and resistance to therapy, have become prime therapeutic targets, as illustrated by the striking efficacy in certain lymphoid malignancies of the BCL-2-specific inhibitor venetoclax. In other lymphoid malignancies, however, such as the aggressive mantle cell lymphoma (MCL), cell survival might rely instead or also on BCL-2 relative MCL-1. We have explored MCL-1 as a target for killing MCL cells by both genetic and pharmacologic approaches. In several MCL cell lines, MCL-1 knockout with an inducible CRISPR/Cas9 system triggered spontaneous apoptosis. Accordingly, most MCL cell lines proved sensitive to the specific MCL-1 inhibitor S63845, and MCL-1 inhibition also proved efficacious in an MCL xenograft model. Furthermore, its killing efficacy rose on combination with venetoclax, the BCL-X
Unbiased analysis, enrichment and purification of thymic stromal cells.
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.JIM.2007.09.010
Abstract: The microenvironment of the thymus consists of functionally discrete niches composed of distinct stromal cell subsets. Clinically relevant changes affecting T-cell differentiation occur within these niches with age and injury caused by irradiation and chemotherapy treatments. The study of thymic stromal cells has been h ered by the technical difficulty in isolating significant numbers of this important population. Here we present an improved protocol for enzymatic isolation of stromal cells that enables comparative flow cytometric analyses and their purification for downstream cellular or molecular analysis. Fractions analyzed throughout enzymatic digestion of the thymus revealed that various stromal subsets are isolated at characteristic intervals. This highlights the importance of pooling all cells isolated from the thymus for numerical and phenotypic analysis to avoid biased representation of subpopulations. We also describe refined magnetic bead separation techniques that yield almost pure preparations of CD45(-) stroma. Sorting of these suspensions using defined markers enabled purification of the major epithelial subsets, confirmed by keratin staining and PCR analysis. This three-step procedure represents a rapid, reproducible method for the unbiased purification of the stromal cells that direct thymic T-cell differentiation.
Single-cell RNA sequencing approaches for tracing T cell development
Publisher: The American Association of Immunologists
Date: 15-07-2021
Abstract: T cell development occurs in the thymus, where uncommitted progenitors are directed into a range of sublineages with distinct functions. The goal is to generate a TCR repertoire erse enough to recognize potential pathogens while remaining tolerant of self. Decades of intensive research have characterized the transcriptional programs controlling critical differentiation checkpoints at the population level. However, greater precision regarding how and when these programs orchestrate differentiation at the single-cell level is required. Single-cell RNA sequencing approaches are now being brought to bear on this question, to track the identity of cells and analyze their gene expression programs at a resolution not previously possible. In this review, we discuss recent advances in the application of these technologies that have the potential to yield unprecedented insight to T cell development.
Molecular control of the lymphocyte death timer
Publisher: Cold Spring Harbor Laboratory
Date: 27-10-2023
CCR7 Signals Are Essential for Cortex–Medulla Migration of Developing Thymocytes
Publisher: Rockefeller University Press
Date: 09-08-2004
DOI: 10.1084/JEM.20040643
Abstract: Upon TCR-mediated positive selection, developing thymocytes relocate within the thymus from the cortex to the medulla for further differentiation and selection. However, it is unknown how this cortex–medulla migration of thymocytes is controlled and how it controls T cell development. Here we show that in mice deficient for CCR7 or its ligands mature single-positive thymocytes are arrested in the cortex and do not accumulate in the medulla. These mutant mice are defective in forming the medullary region of the thymus. Thymic export of T cells in these mice is compromised during the neonatal period but not in adulthood. Thymocytes in these mice show no defects in maturation, survival, and negative selection to ubiquitous antigens. TCR engagement of immature cortical thymocytes elevates the cell surface expression of CCR7. These results indicate that CCR7 signals are essential for the migration of positively selected thymocytes from the cortex to the medulla. CCR7-dependent cortex–medulla migration of thymocytes plays a crucial role in medulla formation and neonatal T cell export but is not essential for maturation, survival, negative selection, and adult export of thymocytes.
A Phase Ib Dose-Escalation and Expansion Study of the BCL2 Inhibitor Venetoclax Combined with Tamoxifen in ER and BCL2–Positive Metastatic Breast Cancer
Publisher: American Association for Cancer Research (AACR)
Date: 03-2019
DOI: 10.1158/2159-8290.CD-18-1151
Abstract: In the first clinical study to evaluate venetoclax in a solid tumor, we demonstrate that combining venetoclax with endocrine therapy has a tolerable safety profile and elicits notable activity in ER and BCL2-positive metastatic breast cancer. These findings support further investigation of combination therapy for patients with BCL2-positive tumors. See related commentary by Drago et al., p. 323. This article is highlighted in the In This Issue feature, p. 305
Early immune pressure imposed by tissue resident memory T cells sculpts tumour evolution in non-small cell lung cancer
Publisher: Research Square Platform LLC
Date: 20-04-2021
DOI: 10.21203/RS.3.RS-432815/V1
Abstract: Tissue-resident memory T cells (TRM) provide immune defence against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts TRM activation and how the immune pressure exerted by TRM affects developing tumours in humans. We performed deep profiling of lung cancers arising in never-smokers (NS) and ever-smokers (ES), finding evidence of enhanced TRM immunosurveillance in ES lung. Only tumours arising in ES patients underwent clonal immune escape, even when evaluating cancers with similar tumour mutational burden to NS patients, suggesting that the timing of immune pressure exerted by TRM is a critical factor in the evolution of tumour immune evasion. Tumours grown in T cell quiescent NS lungs displayed little evidence of immune evasion and had fewer neoantigens with low ersity, paradoxically making them amenable to treatment with agonist of the costimulatory molecule, ICOS. These data demonstrate local environmental insults enhance TRM immunosurveillance of human tissue, shape the evolution of tumour immunogenicity and that this interplay informs effective immunotherapeutic modalities.
The Mitochondrial Apoptotic Effectors BAX/BAK Activate Caspase-3 and -7 to Trigger NLRP3 Inflammasome and Caspase-8 Driven IL-1β Activation
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.CELREP.2018.10.103
Abstract: Intrinsic apoptosis resulting from BAX/BAK-mediated mitochondrial membrane damage is regarded as immunologically silent. We show here that in macrophages, BAX/BAK activation results in inhibitor of apoptosis (IAP) protein degradation to promote caspase-8-mediated activation of IL-1β. Furthermore, BAX/BAK signaling induces a parallel pathway to NLRP3 inflammasome-mediated caspase-1-dependent IL-1β maturation that requires potassium efflux. Remarkably, following BAX/BAK activation, the apoptotic executioner caspases, caspase-3 and -7, act upstream of both caspase-8 and NLRP3-induced IL-1β maturation and secretion. Conversely, the pyroptotic cell death effectors gasdermin D and gasdermin E are not essential for BAX/BAK-induced IL-1β release. These findings highlight that innate immune cells undergoing BAX/BAK-mediated apoptosis have the capacity to generate pro-inflammatory signals and provide an explanation as to why IL-1β activation is often associated with cellular stress, such as during chemotherapy.
MCL-1 is essential for survival but dispensable for metabolic fitness of FOXP3+ regulatory T cells
Publisher: Springer Science and Business Media LLC
Date: 07-2020
Thymic generation and regeneration
Publisher: Wiley
Date: 10-09-2003
DOI: 10.1034/J.1600-065X.2003.00077.X
Abstract: The thymus is a complex epithelial organ in which thymocyte development is dependent upon the sequential contribution of morphologically and phenotypically distinct stromal cell compartments. It is these microenvironments that provide the unique combination of cellular interactions, cytokines, and chemokines to induce thymocyte precursors to undergo a differentiation program that leads to the generation of functional T cells. Despite the indispensable role of thymic epithelium in the generation of T cells, the mediators of this process and the differentiation pathway undertaken by the primordial thymic epithelial cells are not well defined. There is a lack of lineage-specific cell-surface-associated markers, which are needed to characterize putative thymic epithelial stem cell populations. This review explores the role of thymic stromal cells in T-cell development and thymic organogenesis, as well as the molecular signals that contribute to the growth and expansion of primordial thymic epithelial cells. It highlights recent advances in these areas, which have allowed for a lineage relationship amongst thymic epithelial cell subsets to be proposed. While many fundamental questions remain to be addressed, collectively these works have broadened our understanding of how the thymic epithelium becomes specialized in the ability to support thymocyte differentiation. They should also facilitate the development of novel, rationally based therapeutic strategies for the regeneration and manipulation of thymic function in the treatment of many clinical conditions in which defective T cells have an important etiological role.
Caspase-8 has dual roles in regulatory T cell homeostasis balancing immunity to infection and collateral inflammatory damage
Publisher: American Association for the Advancement of Science (AAAS)
Date: 25-03-2022
DOI: 10.1126/SCIIMMUNOL.ABN8041
Abstract: Targeting the potent immunosuppressive properties of FOXP3 + regulatory T cells (T regs ) has substantial therapeutic potential for treating autoimmune and inflammatory diseases. Yet, the molecular mechanisms controlling T reg homeostasis, particularly during inflammation, remain unclear. We report that caspase-8 is a central regulator of T reg homeostasis in a context-specific manner that is decisive during immune responses. In mouse genetic models, targeting caspase-8 in T regs led to accumulation of effector T regs resistant to apoptotic cell death. Conversely, inflammation induced the MLKL-dependent necroptosis of caspase-8–deficient lymphoid and tissue T regs , which enhanced immunity to a variety of chronic infections to promote clearance of viral or parasitic pathogens. However, improved immunity came at the risk of lethal inflammation in overwhelming infections. Caspase-8 inhibition using a clinical-stage compound revealed that human T regs have heightened sensitivity to necroptosis compared with conventional T cells. These findings reveal a fundamental mechanism in T regs that could be targeted to manipulate the balance between immune tolerance versus response for therapeutic benefit.
Dietary tryptophan deficiency promotes gut RORγt+ Treg cells at the expense of Gata3+ Treg cells and alters commensal microbiota metabolism
Publisher: Elsevier BV
Date: 03-2023
Cell death and thymic tolerance
Publisher: Wiley
Date: 30-04-2017
DOI: 10.1111/IMR.12532
Abstract: The differentiation of hematopoietic precursors into the many functionally distinct T-cell types produced by the thymus is a complex process. It proceeds through a series of stages orchestrated by a variety of thymic microenvironments that shape the T-cell developmental processes. Numerous cytokine and cell surface receptors direct thymocyte differentiation but the primary determinant of cell fate is the engagement of the T-cell antigen receptor (TCR). The strength of the TCR signal and the maturation stage of the thymocyte receiving it can direct the various differentiation programs or, alternatively, end the process by inducing cell death. The regulation of thymocyte death is critical for the efficiency of thymic T-cell differentiation and the preservation of immune tolerance. A detailed knowledge of mechanisms that eliminate thymocytes from the T-cell repertoire is essential to understand the "logic" of T-cell selection in the thymus. This review focuses on the central role of the BCL-2 family of proteins in the apoptotic checkpoints that punctuate thymocyte differentiation and the consequences of defects in these processes.
Nfkb2 variants reveal a p100-degradation threshold that defines autoimmune susceptibility
Publisher: Rockefeller University Press
Date: 27-10-2020
DOI: 10.1084/JEM.20200476
Abstract: NF-κB2 100 (p100) is an inhibitor of κB (IκB) protein that is partially degraded to produce the NF-κB2 52 (p52) transcription factor. Heterozygous NFKB2 mutations cause a human syndrome of immunodeficiency and autoimmunity, but whether autoimmunity arises from insufficiency of p52 or IκB function of mutated p100 is unclear. Here, we studied mice bearing mutations in the p100 degron, a domain that harbors most of the clinically recognized mutations and is required for signal-dependent p100 degradation. Distinct mutations caused graded increases in p100-degradation resistance. Severe p100-degradation resistance, due to inheritance of one highly degradation-resistant allele or two subclinical alleles, caused thymic medullary hypoplasia and autoimmune disease, whereas the absence of p100 and p52 did not. We inferred a similar mechanism occurs in humans, as the T cell receptor repertoires of affected humans and mice contained a hydrophobic signature of increased self-reactivity. Autoimmunity in autosomal dominant NFKB2 syndrome arises largely from defects in nonhematopoietic cells caused by the IκB function of degradation-resistant p100.
Immune homeostasis in health and disease
Publisher: Wiley
Date: 05-2018
DOI: 10.1111/IMCB.12043
Aire mediates thymic expression and tolerance of pancreatic antigens via an unconventional transcriptional mechanism
Publisher: Wiley
Date: 06-12-2012
Abstract: The autoimmune regulator (Aire), mediates central tolerance of peripheral self. Its activity in thymic epithelial cells (TECs) directs the ectopic expression of thousands of tissue-restricted antigens (TRAs), causing the deletion of autoreactive thymocytes. The molecular mechanisms orchestrating the breadth of transcriptional regulation by Aire remain unknown. One prominent model capable of explaining both the uniquely high number of Aire-dependent targets and their specificity posits that tissue-specific transcription factors induced by Aire directly activate their canonical targets, exponentially adding to the total number of Aire-dependent TRAs. To test this "Hierarchical Transcription" model, we analysed mice deficient in the pancreatic master transcription factor pancreatic and duodenal homeobox 1 (Pdx1), specifically in TECs (Pdx1(ΔFoxn1) ), for the expression and tolerance of pancreatic TRAs. Surprisingly, we found that lack of Pdx1 in TECs did not reduce the transcription of insulin or somatostatin, or alter glucagon expression. Moreover, in a model of thymic deletion driven by a neo-TRA under the control of the insulin promoter, Pdx1 in TECs was not required to affect thymocyte deletion or the generation of regulatory T (Treg) cells. These findings suggest that the capacity of Aire to regulate expression of a huge array of TRAs relies solely on an unconventional transcriptional mechanism, without intermediary transcription factors.
Keratinocyte growth factor (KGF) is required for postnatal thymic regeneration
Publisher: American Society of Hematology
Date: 15-03-2006
DOI: 10.1182/BLOOD-2005-07-2831
Abstract: Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor family that mediates epithelial cell proliferation and differentiation in a variety of tissues, including the thymus. We studied the role of KGF in T-cell development with KGF-/- mice and demonstrated that thymic cellularity and the distribution of thymocyte subsets among KGF-/-, wildtype (WT), and KGF+/- mice were similar. However, KGF-/- mice are more vulnerable to sublethal irradiation (450 cGy), and a significant decrease was found in thymic cellularity after irradiation. Defective thymopoiesis and peripheral T-cell reconstitution were found in KGF-/- recipients of syngeneic or allogeneic bone marrow transplant, but using KGF-/- mice as a donor did not affect T-cell development after transplantation. Despite causing an early developmental block in the thymus, administration of KGF to young and old mice enhanced thymopoiesis. Exogenous KGF also accelerated thymic recovery after irradiation, cyclophosphamide, and dexamethasone treatment. Finally, we found that administering KGF before bone marrow transplantation (BMT) resulted in enhanced thymopoiesis and peripheral T-cell numbers in middle-aged recipients of an allogeneic BM transplant. We conclude that KGF plays a critical role in postnatal thymic regeneration and may be useful in treating immune deficiency conditions. (Blood. 2006 :2453-2460)
Blockade of the co-inhibitory molecule PD-1 unleashes ILC2-dependent antitumor immunity in melanoma
Publisher: Springer Science and Business Media LLC
Date: 07-06-2021
Ubiquitination of MHC Class II Is Required for Development of Regulatory but Not Conventional CD4+ T Cells
Publisher: The American Association of Immunologists
Date: 09-2020
Abstract: MHC class II (MHC II) displays peptides at the cell surface, a process critical for CD4+ T cell development and priming. Ubiquitination is a mechanism that dictates surface MHC II with the attachment of a polyubiquitin chain to peptide-loaded MHC II, promoting its traffic away from the plasma membrane. In this study, we have examined how MHC II ubiquitination impacts the composition and function of both conventional CD4+ T cell and regulatory T cell (Treg) compartments. Responses were examined in two models of altered MHC II ubiquitination: MHCIIKRKI/KI mice that express a mutant MHC II unable to be ubiquitinated or mice that lack membrane-associated RING-CH 8 (MARCH8), the E3 ubiquitin ligase responsible for MHC II ubiquitination specifically in thymic epithelial cells. Conventional CD4+ T cell populations in thymus, blood, and spleen of MHCIIKRKI/KI and March8−/− mice were largely unaltered. In MLRs, March8−/−, but not MHCIIKRKI/KI, CD4+ T cells had reduced reactivity to both self– and allogeneic MHC II. Thymic Treg were significantly reduced in MHCIIKRKI/KI mice, but not March8−/− mice, whereas splenic Treg were unaffected. Neither scenario provoked autoimmunity, with no evidence of immunohistopathology and normal levels of autoantibody. In summary, MHC II ubiquitination in specific APC types does not have a major impact on the conventional CD4+ T cell compartment but is important for Treg development.
Visualization and Identification of IL-7 Producing Cells in Reporter Mice
Publisher: Public Library of Science (PLoS)
Date: 10-11-2009
Analysis of thymic stromal cell populations using flow cytometry.
Publisher: Elsevier BV
Date: 02-2002
DOI: 10.1016/S0022-1759(01)00493-8
Abstract: The complexity of the lymphostromal interplay that is essential to alphabetaT-cell development is reflected by the heterogeneity of both lymphocytes and thymic stromal cells. While panels of monoclonal antibodies have described many of the cellular components of these microenvironments, the means to quantify stromal cell subsets using flow cytometry remains poorly defined. This study refines and compares various stromal cell isolation procedures and determines the effects of various digestion enzymes on important surface molecules. Three- and four-color flow cytometry is used to correlate established and novel stromal cell markers to define thymic fibroblasts, epithelium and a unique subset of thymic endothelium that express MHC class II. This work provides a basis for the purification of thymic stromal cells for further phenotypic, functional and genetic analysis.
Role for CCR7 Ligands in the Emigration of Newly Generated T Lymphocytes from the Neonatal Thymus
Publisher: Elsevier BV
Date: 02-2002
DOI: 10.1016/S1074-7613(02)00267-4
Abstract: Most T lymphocytes are generated within the thymus. It is unclear, however, how newly generated T cells relocate out of the thymus to the circulation. The present study shows that a CC chemokine CCL19 attracts mature T cells out of the fetal thymus organ culture. Another CC chemokine CCL21, which shares CCR7 with CCL19 but has a unique C-terminal extension containing positively charged amino acids, failed to show involvement in thymic emigration. Neonatal appearance of circulating T cells was defective in CCL19-neutralized mice as well as in CCR7-deficient mice but not in CCL21-neutralized mice. In the thymus, CCL19 is predominantly localized in the medulla including endothelial venules. These results indicate a CCL19- and CCR7-dependent pathway of thymic emigration, which represents a major pathway of neonatal T cell export.
Deep profiling of apoptotic pathways with mass cytometry identifies a synergistic drug combination for killing myeloma cells
Publisher: Springer Science and Business Media LLC
Date: 27-01-2020
Characterisation of mice lacking all functional isoforms of the pro-survival BCL-2 family member A1 reveals minor defects in the haematopoietic compartment
Publisher: Springer Science and Business Media LLC
Date: 13-01-2017
DOI: 10.1038/CDD.2016.156
Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre, randomised controlled trial: design and methodology
Publisher: BMJ
Date: 13-09-2017
DOI: 10.1136/BJOPHTHALMOL-2017-310877
Abstract: The Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial aims to establish whether initial treatment with selective laser trabeculoplasty (SLT) is superior to initial treatment with topical medication for primary open-angle glaucoma (POAG) or ocular hypertension (OHT). The LiGHT Trial is a prospective, unmasked, multicentre, pragmatic, randomised controlled trial. 718 previously untreated patients with POAG or OHT were recruited at six collaborating centres in the UK between 2012 and 2014. The trial comprises two treatment arms: initial SLT followed by conventional medical therapy as required, and medical therapy without laser therapy. Randomisation was provided online by a web-based randomisation service. Participants will be monitored for 3 years, according to routine clinical practice. The target intraocular pressure (IOP) was set at baseline according to an algorithm, based on disease severity and lifetime risk of loss of vision at recruitment, and subsequently adjusted on the basis of IOP control, optic disc and visual field. The primary outcome measure is health-related quality of life (HRQL) (EQ-5D five-level). Secondary outcomes are treatment pathway cost and cost-effectiveness, Glaucoma Utility Index, Glaucoma Symptom Scale, Glaucoma Quality of Life, objective measures of pathway effectiveness, visual function and safety profiles and concordance. A single main analysis will be performed at the end of the trial on an intention-to-treat basis. The LiGHT Trial is a multicentre, pragmatic, randomised clinical trial that will provide valuable data on the relative HRQL, clinical effectiveness and cost-effectiveness of SLT and topical IOP-lowering medication. ISRCTN32038223, Pre-results.
Correction
Publisher: Rockefeller University Press
Date: 04-10-2004
Genetic Inversion in Mast Cell-Deficient Wsh Mice Interrupts Corin and Manifests as Hematopoietic and Cardiac Aberrancy
Publisher: Elsevier BV
Date: 12-2008
The Immunological Genome Project: networks of gene expression in immune cells
Publisher: Springer Science and Business Media LLC
Date: 10-2008
DOI: 10.1038/NI1008-1091
Abstract: The Immunological Genome Project combines immunology and computational biology laboratories in an effort to establish a complete 'road map' of gene-expression and regulatory networks in all immune cells.
The thymic medulla: who needs it?
Publisher: Wiley
Date: 27-08-2013
DOI: 10.1038/ICB.2013.44
Gene Dosage–limiting Role of Aire in Thymic Expression, Clonal Deletion, and Organ-specific Autoimmunity
Publisher: Rockefeller University Press
Date: 18-10-2004
DOI: 10.1084/JEM.20040581
Abstract: Inactivation of the autoimmune regulator (Aire) gene causes a rare recessive disorder, autoimmune polyendocrine syndrome 1 (APS1), but it is not known if Aire-dependent tolerance mechanisms are susceptible to the quantitative genetic changes thought to underlie more common autoimmune diseases. In mice with a targeted mutation, complete loss of Aire abolished expression of an insulin promoter transgene in thymic epithelium, but had no effect in pancreatic islets or the testes. Loss of one copy of Aire diminished thymic expression of the endogenous insulin gene and the transgene, resulting in a 300% increase in islet-reactive CD4 T cells escaping thymic deletion in T cell receptor transgenic mice, and dramatically increased progression to diabetes. Thymic deletion induced by antigen under control of the thyroglobulin promoter was abolished in Aire homozygotes and less efficient in heterozygotes, providing an explanation for thyroid autoimmunity in APS1. In contrast, Aire deficiency had no effect on thymic deletion to antigen controlled by a systemic H-2K promoter. The sensitivity of Aire-dependent thymic deletion to small reductions in function makes this pathway a prime candidate for more subtle autoimmune quantitative trait loci, and suggests that methods to increase Aire activity would be a potent strategy to lower the incidence of organ-specific autoimmunity.
Location, location, location! Rewiring IL ‐2 circuits defines context‐specific outcomes
Publisher: Wiley
Date: 05-08-2022
DOI: 10.1111/IMCB.12573
Abstract: Here, we highlight a recent publication by Whyte et al. that reveals erse immune outcomes of interleukin (IL)-2 expression in distinct microenvironments. Their definition of context-dependent IL-2 networks paves the way for the development of tissue-specific therapies that enlist the potent immuno-modulatory activity of IL-2.
Removing unwanted variation with CytofRUV to integrate multiple CyTOF datasets
Publisher: eLife Sciences Publications, Ltd
Date: 07-09-2020
DOI: 10.7554/ELIFE.59630
Abstract: Mass cytometry (CyTOF) is a technology that has revolutionised single-cell biology. By detecting over 40 proteins on millions of single cells, CyTOF allows the characterisation of cell subpopulations in unprecedented detail. However, most CyTOF studies require the integration of data from multiple CyTOF batches usually acquired on different days and possibly at different sites. To date, the integration of CyTOF datasets remains a challenge due to technical differences arising in multiple batches. To overcome this limitation, we developed an approach called CytofRUV for analysing multiple CyTOF batches, which includes an R-Shiny application with diagnostic plots. CytofRUV can correct for batch effects and integrate data from large numbers of patients and conditions across batches, to confidently compare cellular changes and correlate these with clinically relevant outcomes.
The BH3-Only Proteins Bim and Puma Cooperate to Impose Deletional Tolerance of Organ-Specific Antigens
Publisher: Elsevier BV
Date: 09-2012
ImmGen at 15
Publisher: Springer Science and Business Media LLC
Date: 23-06-2020
Distinct subpopulations of DN1 thymocytes exhibit preferential αβ or γδ T lineage potential
Publisher: Cold Spring Harbor Laboratory
Date: 28-02-2022
DOI: 10.1101/2022.02.25.481936
Abstract: The αβ and γδ T cell lineages are both are thought to differentiate in the thymus from common uncommitted progenitors. The earliest stage of T cell development is known as known as CD4 - CD8 - double negative 1 (DN1). These thymocytes have previously been revealed to be a heterogenous mixture of cells, which of only the CD117 + fraction have been proposed to be true T cell progenitors that progress to the DN2 and DN3 thymocyte stages, at which point the development of the αβ and γδ T cell lineages erge. However, recently, it has been shown that at least some γδ T cells are actually derived from a subset of CD117 - DN thymocytes. Along with other ambiguities, this suggests that T cell development may not be as straightforward as previously thought. To better understand early T cell development, particularly the heterogeneity of DN1 thymocytes, we performed single cell RNA sequence (scRNAseq) of mouse DN and γδ thymocytes and show that the various DN stages are indeed comprised of transcriptionally erse subpopulations of cells. We also show that multiple subpopulations of DN1 thymocytes exhibit preferential development towards the γδ lineage. Furthermore, specific γδ-primed DN1 subpopulations preferentially develop into IL-17 or IFNγ-producing γδ T cells. We show that DN1 subpopulations that only give rise to IL-17-producing γδ T cells already express many of the transcription factors associated with type 17 immune cell differentiation, while the DN1 subpopulations that can give rise to IFNγ-producing γδ T cell already express transcription factors associated with type 1 immune cell differentiation.
Effects of castration on thymocyte development in two different models of thymic involution
Publisher: The American Association of Immunologists
Date: 09-2005
DOI: 10.4049/JIMMUNOL.175.5.2982
Abstract: Age-associated thymic involution is accompanied by decreased thymic output. This adversely affects general immune competence and T cell recovery following cytoreductive treatments such as chemotherapy. A causal link between increasing sex steroids and age-related thymic atrophy is well established. Although castration has been demonstrated to regenerate the atrophied thymus, little is known about how this is initiated or the kinetics of thymocyte regeneration. The present study shows that although castration impacts globally across thymocyte development in middle-aged mice, the regenerative effects are initiated in the immature triple-negative compartment and early T lineage progenitors (ETP). Specifically, there was a reduction in number of ETP with age, which was restored following castration. There was, however, no change in ETP reconstitution potential in ETP at this age or following castration. Furthermore, in a chemotherapy-induced model of thymic involution, we demonstrate castration enhances intrathymic proliferation and promotes differentiation through the triple-negative program. Clinically, reversible sex steroid ablation is achieved hormonally, and thus presents a means of ameliorating immune inadequacies, for ex le, following chemotherapy for bone marrow transplantation. By improving our understanding of the kinetics of thymic recovery, this study will allow more appropriate timing of therapy to achieve maximal reconstitution, especially in the elderly.
BIM deficiency protects NOD mice from diabetes by diverting thymocytes to regulatory T cells
Publisher: American Diabetes Association
Date: 06-05-2015
DOI: 10.2337/DB14-1851
Abstract: Because regulatory T-cell (Treg) development can be induced by the same agonist self-antigens that induce negative selection, perturbation of apoptosis will affect both negative selection and Treg development. But how the processes of thymocyte deletion versus Treg differentiation bifurcate and their relative importance for tolerance have not been studied in spontaneous organ-specific autoimmune disease. We addressed these questions by removing a critical mediator of thymocyte deletion, BIM, in the NOD mouse model of autoimmune diabetes. Despite substantial defects in the deletion of autoreactive thymocytes, BIM-deficient NOD (NODBim−/−) mice developed less insulitis and were protected from diabetes. BIM deficiency did not impair effector T-cell function however, NODBim−/− mice had increased numbers of Tregs, including those specific for proinsulin, in the thymus and peripheral lymphoid tissues. Increased levels of Nur77, CD5, GITR, and phosphorylated IκB-α in thymocytes from NODBim−/− mice suggest that autoreactive cells receiving strong T-cell receptor signals that would normally delete them escape apoptosis and are erted into the Treg pathway. Paradoxically, in the NOD model, reduced thymic deletion ameliorates autoimmune diabetes by increasing Tregs. Thus, modulating apoptosis may be one of the ways to increase antigen-specific Tregs and prevent autoimmune disease.
Dynamic molecular monitoring reveals that SWI–SNF mutations mediate resistance to ibrutinib plus venetoclax in mantle cell lymphoma
Publisher: Springer Science and Business Media LLC
Date: 19-11-2018
DOI: 10.1038/S41591-018-0243-Z
Abstract: Ibrutinib plus venetoclax is a highly effective combination in mantle cell lymphoma. However, strategies to enable the evaluation of therapeutic response are required. Our prospective analyses of patients within the AIM study revealed genomic profiles that clearly dichotomized responders and nonresponders. Mutations in ATM were present in most patients who achieved a complete response, while chromosome 9p21.1-p24.3 loss and/or mutations in components of the SWI-SNF chromatin-remodeling complex were present in all patients with primary resistance and two-thirds of patients with relapsed disease. Circulating tumor DNA analysis revealed that these alterations could be dynamically monitored, providing concurrent information on treatment response and tumor evolution. Functional modeling demonstrated that compromise of the SWI-SNF complex facilitated transcriptional upregulation of BCL2L1 (Bcl-xL) providing a selective advantage against ibrutinib plus venetoclax. Together these data highlight important insights into the molecular basis of therapeutic response and provide a model for real-time assessment of innovative targeted therapies.
Characterization of a novel human BFL-1-specific monoclonal antibody.
Publisher: Springer Science and Business Media LLC
Date: 12-11-2019
Recipient BCL2 inhibition and NK cell ablation form part of a reduced intensity conditioning regime that improves allo-bone marrow transplantation outcomes
Publisher: Springer Science and Business Media LLC
Date: 12-11-2019
Multilineage potential and self-renewal define an epithelial progenitor cell population in the adult thymus.
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.CELREP.2014.07.029
Abstract: Thymic epithelial cells (TECs) are critical for T cell development and self-tolerance but are gradually lost with age. The existence of thymic epithelial progenitors (TEPCs) in the postnatal thymus has been inferred, but their identity has remained enigmatic. Here, we assessed the entire adult TEC compartment in order to reveal progenitor capacity is retained exclusively within a subset of immature thymic epithelium displaying several hallmark features of stem rogenitor function. These adult TEPCs generate mature cortical and medullary lineages in a stepwise fashion, including Aire+ TEC, within fetal thymus reaggregate grafts. Although relatively quiescent in vivo, adult TEPCs demonstrate significant in vitro colony formation and self-renewal. Importantly, 3D-cultured TEPCs retain their capacity to differentiate into cortical and medullary TEC lineages when returned to an in vivo thymic microenvironment. No other postnatal TEC subset exhibits this combination of properties. The characterization of adult TEPC will enable progress in understanding TEC biology in aging and regeneration.
VDAC2 enables BAX to mediate apoptosis and limit tumor development
Publisher: Springer Science and Business Media LLC
Date: 26-11-2018
DOI: 10.1038/S41467-018-07309-4
Abstract: Intrinsic apoptosis is critical to prevent tumor formation and is engaged by many anti-cancer agents to eliminate tumor cells. BAX and BAK, the two essential mediators of apoptosis, are thought to be regulated through similar mechanisms and act redundantly to drive apoptotic cell death. From an unbiased genome-wide CRISPR/Cas9 screen, we identified VDAC2 (voltage-dependent anion channel 2) as important for BAX, but not BAK, to function. Genetic deletion of VDAC2 abrogated the association of BAX and BAK with mitochondrial complexes containing VDAC1, VDAC2, and VDAC3, but only inhibited BAX apoptotic function. Deleting VDAC2 phenocopied the loss of BAX in impairing both the killing of tumor cells by anti-cancer agents and the ability to suppress tumor formation. Together, our studies show that efficient BAX-mediated apoptosis depends on VDAC2, and reveal a striking difference in how BAX and BAK are functionally impacted by their interactions with VDAC2.
The life and death of immune cell types: The role of BCL-2 anti-apoptotic molecules
Publisher: Wiley
Date: 17-10-2017
DOI: 10.1038/ICB.2017.72
Abstract: Targeting survival mechanisms of immune cells may provide an avenue for immune intervention to d en unwanted responses (e.g. autoimmunity, immunopathology and transplant rejection) or enhance beneficial ones (e.g. immune deficiency, microbial defence and cancer immunotherapy). The selective survival mechanisms of the various immune cell types also avails the possibility of specific tailoring of such interventions. Here, we review the role of the BCL-2 anti-apoptotic family members (BCL-2, BCL-XL, BCL-W, MCL-1 and A1) on cell death/survival of the major immune cell types, for ex le, T, NK, B, dendritic cell (DC) lineages. There is both selectivity and redundancy among this family. Selectivity comes partly from the expression levels in each of the cell types. For ex le, plasmacytoid DC express abundant BCL-2 and are susceptible to BCL-2 antagonism or deficiency, whereas conventional DC express abundant A1 and are susceptible to A1 deficiency. There is, however, also functional redundancy for ex le, overexpression of MCL-1 can override BCL-2 antagonism in plasmacytoid DC. Moreover, susceptibility to another anti-apoptotic family member can be unmasked, when one or other member is removed. These dual principles of selectivity and redundancy should guide the use of antagonists for manipulating immune cells.
Single-Cell Profiling of the Intrinsic Apoptotic Pathway by Mass Cytometry (CyTOF)
Publisher: Springer US
Date: 2022
DOI: 10.1007/978-1-0716-2553-8_8
Abstract: Mass cytometry time-of-flight (CyTOF) is a technology for the study of complex biological processes at the single-cell level. The technology enables measurement of >50 protein moieties on the surface and inside the cell. The power of CyTOF lies in the application of purpose-built panels of antibody probes that resolve features of key biological processes in a cell. Here, we describe this technology's use to profile changes in the intrinsic apoptotic (cell death) protein machinery at a single-cell level. We provide a comprehensive overview of a tailor-made set of cell survival/death antibodies, ideal staining conditions, and high-dimensional data analysis.
Danger-free autoimmune disease in Aire-deficient mice
Publisher: Proceedings of the National Academy of Sciences
Date: 13-11-2007
Abstract: The danger theory of immune tolerance asserts that environmental factors hold primacy over lymphocyte autoreactivity in initiating autoimmune disease. We sought to test this contention using the Aire-deficient mouse model of the human disease, autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy, a multiorgan autoimmune disorder rooted in a lesion in thymic tolerance. Compound screens stimulating a broad range of innate immune system pathways failed to show any modulation of disease characteristics in Aire −/− mice on either the C57BL/6 or NOD genetic backgrounds. Furthermore, deficiency in the Toll-like receptor adaptor Myd88 increased the lifespan of NOD. aire −/− mice but did not prevent the initiation of autoimmunity. Finally, germ-free NOD. aire −/− mice exhibited autoimmunity in all organs normally targeted in this model, indicating that microbial conditioning is not required for activation of autoreactive T cells relevant to this disease. Together, these data suggest that the stochastic genesis of dangerous T cell clones can initiate autoimmune disease without the need for environmental stimulation, underlining the importance of Aire-dependent thymic deletion.
Related Organisations
University College London
Location: United Kingdom of Great Britain and Northern Ireland
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Location: United Kingdom of Great Britain and Northern Ireland
Walter And Eliza Hall Institute Of Medical Research
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Location: United Kingdom of Great Britain and Northern Ireland
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End Date: 2019
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View Funded ActivityThe Cell Death Mechanisms The Control Regulatory T Cell Homeostasis
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View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE200100053
Start Date: 06-2020
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