ORCID Profile
0000-0003-4690-2571
Current Organisations
Københavns Universitet
,
Rockefeller University
,
IT University of Copenhagen
,
Peter Doherty Institute
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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.
Cellular Immunology | Immunology | Gene Expression (incl. Microarray and other genome-wide approaches) | Immunology not elsewhere classified | Receptors and Membrane Biology |
Human Biological Preventatives (e.g. Vaccines) | Expanding Knowledge in the Biological Sciences | Immune System and Allergy
Publisher: Cold Spring Harbor Laboratory
Date: 11-03-2021
DOI: 10.1101/2021.03.10.434884
Abstract: CD1c presents lipid-based antigens to CD1c-restricted T cells which are thought to be a major component of the human T cell pool. The study of CD1c-restricted T cells, however, is h ered by the presence of an abundantly expressed CD1c-binding partner on blood cells distinct to the T cell receptor (TCR), confounding analysis of TCR-mediated CD1c tetramer staining. Here, we identify the CD36 family (CD36, CD36-L1 and CD36-L2) as novel ligands for CD1c, CD1b and CD1d proteins, and show that CD36 is the receptor responsible for non-TCR-mediated CD1c tetramer staining of blood cells. Moreover, CD36-blockade enables tetramer-based identification of CD1c-restricted T cells and clarifies identification of CD1b- and CD1d-restricted T cells. We use this technique to characterise CD1c-restricted T cells ex vivo and show erse phenotypic features, TCR repertoire and antigen-specific subsets. Accordingly, this work will enable further studies into the biology of CD1 and human CD1-restricted T cells. CD1 molecules bind CD36 family members and blockade of this interaction facilitates the study of CD1-restricted T cells.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-02-2020
Abstract: In contrast to the well-studied αβ T cells, which recognize peptide antigens presented by major histocompatibility complex (MHC) and MHC-like molecules, how γδ T cells recognize antigens remains largely a mystery. One major class of γδ T cells, designated Vγ9Vδ2 + , is activated by small, phosphorylated nonpeptide antigens, or phosphoantigens, produced by microbes and cancer cells. Rigau et al. found that these cells needed the combination of two immunoglobulin superfamily members, butyrophilin 2A1 (BTN2A1) and BTN3A1, on their cell surface to recognize these phosphoantigens. BTN2A1 directly binds the Vγ9 + domain of the T cell receptor (TCR), whereas a second ligand, potentially BTN3A1, binds the Vδ2 and γ-chain regions on the opposite side of the TCR. A better understanding of this unexpected form of T cell antigen recognition should inform and enhance future γδ T cell–mediated immunotherapies. Science , this issue p. eaay5516
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543536
Abstract: Supplementary Tables
Publisher: The American Association of Immunologists
Date: 03-2020
Abstract: Mucosal-associated invariant T (MAIT) cells are important for immune responses against microbial infections. Although known to undergo marked numerical changes with age in humans, our understanding of how MAIT cells are altered during different phases across the human life span is largely unknown. Although also abundant in the tissues, our study focuses on MAIT cell analyses in blood. Across the human life span, we show that naive-like MAIT cells in umbilical cord blood switch to a central/effector memory-like profile that is sustained into older age. Whereas low-grade levels of plasma cytokine/chemokine were apparent in older donors (& y old), surprisingly, they did not correlate with the ex vivo MAIT hyperinflammatory cytokine profile observed in older adults. Removal of MAIT cells from older in iduals and an aged environment resulted in the reversal of the baseline effector molecule profile comparable with MAIT cells from younger adults. An upregulated basal inflammatory profile accounted for reduced Escherichia coli–specific responses in aged MAIT cells compared with their young adult counterparts when fold change in expression levels of GzmB, CD107a, IFN-γ, and TNF was examined. However, the magnitude of antimicrobial MR1-dependent activation remained as potent and polyfunctional as with younger adults. Paired TCRαβ analyses of MAIT cells revealed large clonal expansions in older adults and tissues that rivalled, remarkably, the TCRαβ repertoire ersity of virus-specific CD8+ T cells. These data suggest that MAIT cells in older in iduals, although associated with large clonal TCRαβ expansions and increased baseline inflammatory potential, demonstrate plasticity and provide potent antimicrobial immunity.
Publisher: Springer Science and Business Media LLC
Date: 06-09-2016
Publisher: Elsevier BV
Date: 11-2022
Publisher: Proceedings of the National Academy of Sciences
Date: 23-04-2021
Abstract: Neutralizing antibodies are important for immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and as therapeutics for the prevention and treatment of COVID-19. We identified high-affinity nanobodies against SARS-CoV-2 receptor-binding domain and found that nanobody cocktails consisting of two noncompeting nanobodies were able to block ACE2 engagement with RBD variants present in human populations and potently neutralize both wild-type SARS-CoV-2 and the N501Y D614G variant at low concentrations. Prophylactic administration of nanobody cocktails reduced viral loads in mice infected with the N501Y D614G SARS-CoV-2 virus, showing that nanobody cocktails are useful as prophylactic agents against SARS-CoV-2.
Publisher: Rockefeller University Press
Date: 07-10-2013
DOI: 10.1084/JEM.20130958
Abstract: Mucosal-associated invariant T cells (MAIT cells) express a semi-invariant T cell receptor (TCR) α-chain, TRAV1-2–TRAJ33, and are activated by vitamin B metabolites bound by the major histocompatibility complex (MHC)–related class I–like molecule, MR1. Understanding MAIT cell biology has been restrained by the lack of reagents to specifically identify and characterize these cells. Furthermore, the use of surrogate markers may misrepresent the MAIT cell population. We show that modified human MR1 tetramers loaded with the potent MAIT cell ligand, reduced 6-hydroxymethyl-8-d-ribityllumazine (rRL-6-CH2OH), specifically detect all human MAIT cells. Tetramer+ MAIT subsets were predominantly CD8+ or CD4−CD8−, although a small subset of CD4+ MAIT cells was also detected. Notably, most human CD8+ MAIT cells were CD8α+CD8β−/lo, implying predominant expression of CD8αα homodimers. Tetramer-sorted MAIT cells displayed a TH1 cytokine phenotype upon antigen-specific activation. Similarly, mouse MR1–rRL-6-CH2OH tetramers detected CD4+, CD4−CD8− and CD8+ MAIT cells in Vα19 transgenic mice. Both human and mouse MAIT cells expressed a broad TCR-β repertoire, and although the majority of human MAIT cells expressed TRAV1-2–TRAJ33, some expressed TRAJ12 or TRAJ20 genes in conjunction with TRAV1-2. Accordingly, MR1 tetramers allow precise phenotypic characterization of human and mouse MAIT cells and revealed unanticipated TCR heterogeneity in this population.
Publisher: Springer Science and Business Media LLC
Date: 25-09-2023
Publisher: Wiley
Date: 13-01-2022
DOI: 10.1111/IMCB.12519
Abstract: MHC‐related protein 1 (MR1) presents microbial riboflavin metabolites to mucosal‐associated invariant T (MAIT) cells for surveillance of microbial presence. MAIT cells express a semi‐invariant T‐cell receptor (TCR), which recognizes MR1–antigen complexes in a pattern‐recognition‐like manner. Recently, erse populations of MR1‐restricted T cells have been described that exhibit broad recognition of tumor cells and appear to recognize MR1 in association with tumor‐derived self‐antigens, though the identity of these antigens remains unclear. Here, we have used TCR gene transfer and engineered MR1‐expressing antigen‐presenting cells to probe the MR1 restriction and antigen reactivity of a range of MR1‐restricted TCRs, including model tumor‐reactive TCRs. We confirm MR1 reactivity by these TCRs, show differential dependence on lysine at position 43 of MR1 (K43) and demonstrate competitive inhibition by the MR1 ligand 6‐formylpterin. TCR‐expressing reporter lines, however, failed to recapitulate the robust tumor specificity previously reported, suggesting an importance of accessory molecules for MR1‐dependent tumor reactivity. Finally, MR1‐mutant cell lines showed that distinct residues on the α1/α2 helices were required for TCR binding by different MR1‐restricted T cells and suggested central but distinct docking modes by the broad family of MR1‐restricted αβ TCRs. Collectively, these data are consistent with recognition of distinct antigens by erse MR1‐restricted T cells.
Publisher: Rockefeller University Press
Date: 26-08-2022
DOI: 10.1084/JEM.20210828
Abstract: Mucosal-associated invariant T (MAIT) cells detect microbial infection via recognition of riboflavin-based antigens presented by the major histocompatibility complex class I (MHC-I)–related protein 1 (MR1). Most MAIT cells in human peripheral blood express CD8αα or CD8αβ coreceptors, and the binding site for CD8 on MHC-I molecules is relatively conserved in MR1. Yet, there is no direct evidence of CD8 interacting with MR1 or the functional consequences thereof. Similarly, the role of CD8αα in lymphocyte function remains ill-defined. Here, using newly developed MR1 tetramers, mutated at the CD8 binding site, and by determining the crystal structure of MR1–CD8αα, we show that CD8 engaged MR1, analogous to how it engages MHC-I molecules. CD8αα and CD8αβ enhanced MR1 binding and cytokine production by MAIT cells. Moreover, the CD8–MR1 interaction was critical for the recognition of folate-derived antigens by other MR1-reactive T cells. Together, our findings suggest that both CD8αα and CD8αβ act as functional coreceptors for MAIT and other MR1-reactive T cells.
Publisher: American Association for Cancer Research (AACR)
Date: 05-03-2021
DOI: 10.1158/2326-6066.CIR-20-0817
Abstract: Merkel cell carcinomas (MCC) are immunogenic skin cancers associated with viral infection or UV mutagenesis. To study T-cell infiltrates in MCC, we analyzed 58 MCC lesions from 39 patients using multiplex-IHC/immunofluorescence (m-IHC/IF). CD4+ or CD8+ T cells comprised the majority of infiltrating T lymphocytes in most tumors. However, almost half of the tumors harbored prominent CD4/CD8 double-negative (DN) T-cell infiltrates (& % DN T cells), and in 12% of cases, DN T cells represented the majority of T cells. Flow cytometric analysis of single-cell suspensions from fresh tumors identified DN T cells as predominantly Vδ2− γδ T cells. In the context of γδ T–cell inflammation, these cells expressed PD-1 and LAG3, which is consistent with a suppressed or exhausted phenotype, and CD103, which indicates tissue residency. Furthermore, single-cell RNA sequencing (scRNA-seq) identified a transcriptional profile of γδ T cells suggestive of proinflammatory potential. T-cell receptor (TCR) analysis confirmed clonal expansion of Vδ1 and Vδ3 clonotypes, and functional studies using cloned γδ TCRs demonstrated restriction of these for CD1c and MR1 antigen-presenting molecules. On the basis of a 13-gene γδ T–cell signature derived from scRNA-seq analysis, gene-set enrichment on bulk RNA-seq data showed a positive correlation between enrichment scores and DN T-cell infiltrates. An improved disease-specific survival was evident for patients with high enrichment scores, and complete responses to anti–PD-1/PD-L1 treatment were observed in three of four cases with high enrichment scores. Thus, γδ T–cell infiltration may serve as a prognostic biomarker and should be explored for therapeutic interventions. See related Spotlight on p. 600
Publisher: Springer Science and Business Media LLC
Date: 26-09-2016
DOI: 10.1038/NI.3565
Abstract: Mucosal-associated invariant T cells (MAIT cells) detect microbial vitamin B2 derivatives presented by the antigen-presenting molecule MR1. Here we defined three developmental stages and checkpoints for the MAIT cell lineage in humans and mice. Stage 1 and stage 2 MAIT cells predominated in thymus, while stage 3 cells progressively increased in abundance extrathymically. Transition through each checkpoint was regulated by MR1, whereas the final checkpoint that generated mature functional MAIT cells was controlled by multiple factors, including the transcription factor PLZF and microbial colonization. Furthermore, stage 3 MAIT cell populations were expanded in mice deficient in the antigen-presenting molecule CD1d, suggestive of a niche shared by MAIT cells and natural killer T cells (NKT cells). Accordingly, this study maps the developmental pathway and checkpoints that control the generation of functional MAIT cells.
Publisher: Springer Science and Business Media LLC
Date: 29-09-2013
DOI: 10.1038/NI.2713
Abstract: The T cell repertoire comprises αβ and γδ T cell lineages. Although it is established how αβ T cell antigen receptors (TCRs) interact with antigen presented by antigen-presenting molecules, this is unknown for γδ TCRs. We describe a population of human Vδ1(+) γδ T cells that exhibit autoreactivity to CD1d and provide a molecular basis for how a γδ TCR binds CD1d-α-galactosylceramide (α-GalCer). The γδ TCR docked orthogonally, over the A' pocket of CD1d, in which the Vδ1-chain, and in particular the germ line-encoded CDR1δ loop, dominated interactions with CD1d. The TCR γ-chain sat peripherally to the interface, with the CDR3γ loop representing the principal determinant for α-GalCer specificity. Accordingly, we provide insight into how a γδ TCR binds specifically to a lipid-loaded antigen-presenting molecule.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-12-2019
Abstract: The ligands bound by γδ T cell receptors (TCRs) are less well characterized than those of their αβ TCR cousins, which are antigens presented by major histocompatibility complex (MHC) and related proteins. Le Nours et al. identified a phenotypically erse γδ T cell subset in human tissues that reacts to MHC-related protein 1 (MR1), which presents vitamin B derivatives. A crystal structure of a γδ TCR–MR1–antigen complex revealed that some of these TCRs can bind underneath the MR1 antigen-binding cleft instead of recognizing the presented antigen. This work thus uncovers an additional ligand for γδ T cells and reconceptualizes the nature of T cell antigen recognition. Science , this issue p. 1522
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543539
Abstract: Supplementary Figures
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543536.V1
Abstract: Supplementary Tables
Publisher: American Society for Clinical Investigation
Date: 23-08-2021
Publisher: Proceedings of the National Academy of Sciences
Date: 29-11-2021
Abstract: Alongside αβ T cells and B cells, γδ T cells comprise a major component of the adaptive immune system, although a lack of bona fide ligands has hindered understanding of their function. γδ T cells are key mediators of epithelial immune surveillance and have a purported capacity for employing erse ligand engagement mechanisms beyond the dogmas of conventional αβ T cell–human leukocyte antigen restriction. Here, we found blood- and gut-resident Vδ1/2 − γδ T cells bound to MR1 tetramers in a metabolite-independent mechanism distinct from mucosal-associated invariant T cells and provide insight into a unique antibody-like MR1 recognition mode. This reshapes our understanding of the ligand recognition principles of γδ T cells and how they differ from αβ T cells.
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543542
Abstract: RNA-seq and scRNA-seq count data and TCR contigs
Publisher: The American Association of Immunologists
Date: 15-11-2018
Abstract: Mucosal-associated invariant T (MAIT) cells are characterized by a semi-invariant TCR that recognizes vitamin B metabolite Ags presented by the MHC-related molecule MR1. Their Ag restriction determines a unique developmental lineage, imbuing a tissue-homing, preprimed phenotype with antimicrobial function. A growing body of literature indicates that MR1-restricted T cells are more erse than the MAIT term implies. Namely, it is increasingly clear that TCR α- and TCR β-chain ersity within the MR1-restricted repertoire provides a potential mechanism of Ag discrimination, and context-dependent functional variation suggests a role for MR1-restricted T cells in erse physiological settings. In this paper, we summarize MR1-restricted T cell biology, with an emphasis on TCR ersity, Ag discrimination, and functional heterogeneity.
Publisher: Springer Science and Business Media LLC
Date: 07-03-2018
DOI: 10.1038/S41598-018-22130-1
Abstract: Mucosal-associated invariant T (MAIT) cells are T cells that recognise vitamin-B derivative Ag presented by the MHC-related-protein 1 (MR1) antigen-presenting molecule. While MAIT cells are highly abundant in humans, their role in tumour immunity remains unknown. Here we have analysed the frequency and function of MAIT cells in multiple myeloma (MM) patients. We show that MAIT cell frequency in blood is reduced compared to healthy adult donors, but comparable to elderly healthy control donors. Furthermore, there was no evidence that MAIT cells accumulated at the disease site (bone marrow) of these patients. Newly diagnosed MM patient MAIT cells had reduced IFNγ production and CD27 expression, suggesting an exhausted phenotype, although IFNγ-producing capacity is restored in relapsed/refractory patient s les. Moreover, immunomodulatory drugs Lenalidomide and Pomalidomide, indirectly inhibited MAIT cell activation. We further show that cell lines can be pulsed with vitamin-B derivative Ags and that these can be presented via MR1 to MAIT cells in vitro , to induce cytotoxic activity comparable to that of natural killer (NK) cells. Thus, MAIT cells are reduced in MM patients, which may contribute to disease in these in iduals, and moreover, MAIT cells may represent new immunotherapeutic targets for treatment of MM and other malignancies.
Publisher: Rockefeller University Press
Date: 21-07-2014
DOI: 10.1084/JEM.20140484
Abstract: Mucosal-associated invariant T (MAIT) cells express an invariant T cell receptor (TCR) α-chain (TRAV1-2 joined to TRAJ33, TRAJ20, or TRAJ12 in humans), which pairs with an array of TCR β-chains. MAIT TCRs can bind folate- and riboflavin-based metabolites restricted by the major histocompatibility complex (MHC)-related class I−like molecule, MR1. However, the impact of MAIT TCR and MR1-ligand heterogeneity on MAIT cell biology is unclear. We show how a previously uncharacterized MR1 ligand, acetyl-6-formylpterin (Ac-6-FP), markedly stabilized MR1, potently up-regulated MR1 cell surface expression, and inhibited MAIT cell activation. These enhanced properties of Ac-6-FP were attributable to structural alterations in MR1 that subsequently affected MAIT TCR recognition via conformational changes within the complementarity-determining region (CDR) 3β loop. Analysis of seven TRBV6-1+ MAIT TCRs demonstrated how CDR3β hypervariability impacted on MAIT TCR recognition by altering TCR flexibility and contacts with MR1 and the Ag itself. Ternary structures of TRBV6-1, TRBV6-4, and TRBV20+ MAIT TCRs in complex with MR1 bound to a potent riboflavin-based antigen (Ag) showed how variations in TRBV gene usage exclusively impacted on MR1 contacts within a consensus MAIT TCR-MR1 footprint. Moreover, differential TRAJ gene usage was readily accommodated within a conserved MAIT TCR-MR1-Ag docking mode. Collectively, MAIT TCR heterogeneity can fine-tune MR1 recognition in an Ag-dependent manner, thereby modulating MAIT cell recognition.
Publisher: Springer Science and Business Media LLC
Date: 19-07-2023
DOI: 10.1038/S41467-023-39936-X
Abstract: RNA-binding proteins (RBPs) are key players regulating RNA processing and are associated with disorders ranging from cancer to neurodegeneration. Here, we present a proteomics workflow for large-scale identification of RBPs and their RNA-binding regions in the mammalian brain identifying 526 RBPs. Analysing brain tissue from males of the Huntington’s disease (HD) R6/2 mouse model uncovered differential RNA-binding of the alternative splicing regulator RBM5. Combining several omics workflows, we show that RBM5 binds differentially to transcripts enriched in pathways of neurodegeneration in R6/2 brain tissue. We further find these transcripts to undergo changes in splicing and demonstrate that RBM5 directly regulates these changes in human neurons derived from embryonic stem cells. Finally, we reveal that RBM5 interacts differently with several known huntingtin interactors and components of huntingtin aggregates. Collectively, we demonstrate the applicability of our method for capturing RNA interactor dynamics in the contexts of tissue and disease.
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543539.V1
Abstract: Supplementary Figures
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.BBMT.2014.11.003
Abstract: Immunosuppressive pretransplantation conditioning is essential for donor cell engraftment in allogeneic bone marrow transplantation (BMT). The role of residual postconditioning recipient immunity in determining engraftment is poorly understood. We examined the role of recipient perforin in the kinetics of donor cell engraftment. MHC-mismatched BMT mouse models demonstrated that both the rate and proportion of donor lymphoid cell engraftment and expansion of effector memory donor T cells in both spleen and BM were significantly increased within 5 to 7 days post-BMT in perforin-deficient (pfn(-/-)) recipients, compared with wild-type. In wild-type recipients, depletion of natural killer (NK) cells before BMT enhanced donor lymphoid cell engraftment to that seen in pfn(-/-) recipients. This demonstrated that a perforin-dependent, NK-mediated, host-versus-graft (HVG) effect limits the rate of donor engraftment and T cell activation. Radiation-resistant natural killer T (NKT) cells survived in the BM of lethally irradiated mice and may drive NK cell activation, resulting in the HVG effect. Furthermore, reduced pretransplant irradiation doses in pfn(-/-) recipients permitted long-term donor lymphoid cell engraftment. These findings suggest that suppression of perforin activity or selective depletion of recipient NK cells before BMT could be used to improve donor stem cell engraftment, in turn allowing for the reduction of pretransplant conditioning.
Publisher: Wiley
Date: 2022
DOI: 10.1002/CTI2.1424
Abstract: Following infection with SARS‐CoV‐2, virus‐specific antibodies are generated, which can both neutralise virions and clear infection via Fc effector functions. The importance of IgG antibodies for protection and control of SARS‐CoV‐2 has been extensively reported. By comparison, other antibody isotypes including IgA have been poorly characterised. Here, we characterised plasma IgA from 41 early convalescent COVID‐19 subjects for neutralisation and Fc effector functions. Convalescent plasma IgA from 60% of the cohort had the capacity to inhibit the interaction between wild‐type RBD and ACE2. Furthermore, a third of the cohort induced stronger IgA‐mediated ACE2 inhibition than matched IgG when tested at equivalent concentrations. Plasma IgA and IgG from this cohort broadly recognised similar RBD epitopes and had similar capacities to inhibit ACE2 from binding to 22 of the 23 prevalent RBD mutations assessed. However, plasma IgA was largely incapable of mediating antibody‐dependent phagocytosis in comparison with plasma IgG. Overall, convalescent plasma IgA contributed to the neutralising antibody response of wild‐type SARS‐CoV‐2 RBD and various RBD mutations. However, this response displayed large heterogeneity and was less potent than IgG.
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.22543542.V1
Abstract: RNA-seq and scRNA-seq count data and TCR contigs
Publisher: Springer Science and Business Media LLC
Date: 12-08-2019
DOI: 10.1038/S41590-019-0444-8
Abstract: In recent years, a population of unconventional T cells called 'mucosal-associated invariant T cells' (MAIT cells) has captured the attention of immunologists and clinicians due to their abundance in humans, their involvement in a broad range of infectious and non-infectious diseases and their unusual specificity for microbial riboflavin-derivative antigens presented by the major histocompatibility complex (MHC) class I-like protein MR1. MAIT cells use a limited T cell antigen receptor (TCR) repertoire with public antigen specificities that are conserved across species. They can be activated by TCR-dependent and TCR-independent mechanisms and exhibit rapid, innate-like effector responses. Here we review evidence showing that MAIT cells are a key component of the immune system and discuss their basic biology, development, role in disease and immunotherapeutic potential.
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.IMMUNI.2015.12.005
Abstract: A characteristic of mucosal-associated invariant T (MAIT) cells is the expression of TRAV1-2(+) T cell receptors (TCRs) that are activated by riboflavin metabolite-based antigens (Ag) presented by the MHC-I related molecule, MR1. Whether the MR1-restricted T cell repertoire and associated Ag responsiveness extends beyond these cells remains unclear. Here, we describe MR1 autoreactivity and folate-derivative reactivity in a discrete subset of TRAV1-2(+) MAIT cells. This recognition was attributable to CDR3β loop-mediated effects within a consensus TRAV1-2(+) TCR-MR1-Ag footprint. Furthermore, we have demonstrated differential folate- and riboflavin-derivative reactivity by a erse population of "atypical" TRAV1-2(-) MR1-restricted T cells. We have shown that TRAV1-2(-) T cells are phenotypically heterogeneous and largely distinct from TRAV1-2(+) MAIT cells. A TRAV1-2(-) TCR docks more centrally on MR1, thereby adopting a markedly different molecular footprint to the TRAV1-2(+) TCR. Accordingly, ersity within the MR1-restricted T cell repertoire leads to differing MR1-restricted Ag specificity.
Publisher: Springer Science and Business Media LLC
Date: 06-02-2017
DOI: 10.1038/NI.3679
Abstract: The major-histocompatibility-complex-(MHC)-class-I-related molecule MR1 can present activating and non-activating vitamin-B-based ligands to mucosal-associated invariant T cells (MAIT cells). Whether MR1 binds other ligands is unknown. Here we identified a range of small organic molecules, drugs, drug metabolites and drug-like molecules, including salicylates and diclofenac, as MR1-binding ligands. Some of these ligands inhibited MAIT cells ex vivo and in vivo, while others, including diclofenac metabolites, were agonists. Crystal structures of a T cell antigen receptor (TCR) from a MAIT cell in complex with MR1 bound to the non-stimulatory and stimulatory compounds showed distinct ligand orientations and contacts within MR1, which highlighted the versatility of the MR1 binding pocket. The findings demonstrated that MR1 was able to capture chemically erse structures, spanning mono- and bicyclic compounds, that either inhibited or activated MAIT cells. This indicated that drugs and drug-like molecules can modulate MAIT cell function in mammals.
Publisher: Springer Science and Business Media LLC
Date: 15-02-2016
DOI: 10.1038/NCOMMS10570
Abstract: Crucial to Natural Killer T (NKT) cell function is the interaction between their T-cell receptor (TCR) and CD1d-antigen complex. However, the ersity of the NKT cell repertoire and the ensuing interactions with CD1d-antigen remain unclear. We describe an atypical population of CD1d–α-galactosylceramide (α-GalCer)-reactive human NKT cells that differ markedly from the prototypical TRAV10-TRAJ18-TRBV25-1 + type I NKT cell repertoire. These cells express a range of TCR α- and β-chains that show differential recognition of glycolipid antigens. Two atypical NKT TCRs (TRAV21-TRAJ8-TRBV7–8 and TRAV12-3-TRAJ27-TRBV6-5) bind orthogonally over the A′-pocket of CD1d, adopting distinct docking modes that contrast with the docking mode of all type I NKT TCR-CD1d-antigen complexes. Moreover, the interactions with α-GalCer differ between the type I and these atypical NKT TCRs. Accordingly, erse NKT TCR repertoire usage manifests in varied docking strategies and specificities towards CD1d–α-GalCer and related antigens, thus providing far greater scope for erse glycolipid antigen recognition.
Publisher: The American Association of Immunologists
Date: 05-2014
Abstract: Current views emphasize TCR ersity as a key feature that differentiates the group 1 (CD1a, CD1b, CD1c) and group 2 (CD1d) CD1 systems. Whereas TCR sequence motifs define CD1d-reactive NKT cells, the available data do not allow a TCR-based organization of the group 1 CD1 repertoire. The observed TCR ersity might result from donor-to-donor differences in TCR repertoire, as seen for MHC-restricted T cells. Alternatively, ersity might result from differing CD1 isoforms, Ags, and methods used to identify TCRs. Using CD1b tetramers to isolate clones recognizing the same glycolipid, we identified a previously unknown pattern of V gene usage (TRAV17, TRBV4-1) among unrelated human subjects. These TCRs are distinct from those present on NKT cells and germline-encoded mycolyl lipid–reactive T cells. Instead, they resemble the TCR of LDN5, one of the first known CD1b-reactive clones that was previously thought to illustrate the ersity of the TCR repertoire. Interdonor TCR conservation was observed in vitro and ex vivo, identifying LDN5-like T cells as a distinct T cell type. These data support TCR-based organization of the CD1b repertoire, which consists of at least two compartments that differ in TCR sequence motifs, affinity, and coreceptor expression.
Publisher: American Association for Cancer Research (AACR)
Date: 04-04-2023
DOI: 10.1158/2326-6066.C.6550308
Abstract: Abstract Merkel cell carcinomas (MCC) are immunogenic skin cancers associated with viral infection or UV mutagenesis. To study T-cell infiltrates in MCC, we analyzed 58 MCC lesions from 39 patients using multiplex-IHC/immunofluorescence (m-IHC/IF). CD4 sup + /sup or CD8 sup + /sup T cells comprised the majority of infiltrating T lymphocytes in most tumors. However, almost half of the tumors harbored prominent CD4/CD8 double-negative (DN) T-cell infiltrates ( % DN T cells), and in 12% of cases, DN T cells represented the majority of T cells. Flow cytometric analysis of single-cell suspensions from fresh tumors identified DN T cells as predominantly Vδ2 sup − /sup γδ T cells. In the context of γδ T–cell inflammation, these cells expressed PD-1 and LAG3, which is consistent with a suppressed or exhausted phenotype, and CD103, which indicates tissue residency. Furthermore, single-cell RNA sequencing (scRNA-seq) identified a transcriptional profile of γδ T cells suggestive of proinflammatory potential. T-cell receptor (TCR) analysis confirmed clonal expansion of Vδ1 and Vδ3 clonotypes, and functional studies using cloned γδ TCRs demonstrated restriction of these for CD1c and MR1 antigen-presenting molecules. On the basis of a 13-gene γδ T–cell signature derived from scRNA-seq analysis, gene-set enrichment on bulk RNA-seq data showed a positive correlation between enrichment scores and DN T-cell infiltrates. An improved disease-specific survival was evident for patients with high enrichment scores, and complete responses to anti–PD-1/PD-L1 treatment were observed in three of four cases with high enrichment scores. Thus, γδ T–cell infiltration may serve as a prognostic biomarker and should be explored for therapeutic interventions. i See related Spotlight on p. 600 /i /
Publisher: Wiley
Date: 22-04-2014
DOI: 10.1002/CYTO.A.22475
Publisher: Wiley
Date: 25-03-2018
DOI: 10.1111/IMCB.12021
Publisher: American Association for Cancer Research (AACR)
Date: 11-04-2018
DOI: 10.1158/2326-6066.C.6550308.V1
Abstract: Abstract Merkel cell carcinomas (MCC) are immunogenic skin cancers associated with viral infection or UV mutagenesis. To study T-cell infiltrates in MCC, we analyzed 58 MCC lesions from 39 patients using multiplex-IHC/immunofluorescence (m-IHC/IF). CD4 sup + /sup or CD8 sup + /sup T cells comprised the majority of infiltrating T lymphocytes in most tumors. However, almost half of the tumors harbored prominent CD4/CD8 double-negative (DN) T-cell infiltrates ( % DN T cells), and in 12% of cases, DN T cells represented the majority of T cells. Flow cytometric analysis of single-cell suspensions from fresh tumors identified DN T cells as predominantly Vδ2 sup − /sup γδ T cells. In the context of γδ T–cell inflammation, these cells expressed PD-1 and LAG3, which is consistent with a suppressed or exhausted phenotype, and CD103, which indicates tissue residency. Furthermore, single-cell RNA sequencing (scRNA-seq) identified a transcriptional profile of γδ T cells suggestive of proinflammatory potential. T-cell receptor (TCR) analysis confirmed clonal expansion of Vδ1 and Vδ3 clonotypes, and functional studies using cloned γδ TCRs demonstrated restriction of these for CD1c and MR1 antigen-presenting molecules. On the basis of a 13-gene γδ T–cell signature derived from scRNA-seq analysis, gene-set enrichment on bulk RNA-seq data showed a positive correlation between enrichment scores and DN T-cell infiltrates. An improved disease-specific survival was evident for patients with high enrichment scores, and complete responses to anti–PD-1/PD-L1 treatment were observed in three of four cases with high enrichment scores. Thus, γδ T–cell infiltration may serve as a prognostic biomarker and should be explored for therapeutic interventions. i See related Spotlight on p. 600 /i /
Publisher: Wiley
Date: 2021
DOI: 10.1002/CTI2.1242
Publisher: Wiley
Date: 10-2019
Abstract: These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring ex les of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer‐reviewed by leading experts in the field, making this an essential research companion.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 15-06-2021
DOI: 10.1126/SCIIMMUNOL.ABG4176
Abstract: CD1 molecules bind CD36 family members, and blocking this interaction facilitates staining and study of CD1-restricted T cells.
Publisher: Springer Science and Business Media LLC
Date: 21-05-2019
DOI: 10.1038/S41467-019-10198-W
Abstract: Mucosal-associated invariant T (MAIT) cells express an invariant TRAV1/TRAJ33 TCR-α chain and are restricted to the MHC-I-like molecule, MR1. Whether MAIT cell development depends on this invariant TCR-α chain is unclear. Here we generate Traj33 -deficient mice and show that they are highly depleted of MAIT cells however, a residual population remains and can respond to exogenous antigen in vitro or pulmonary Legionella challenge in vivo. These residual cells include some that express Trav1 + TCRs with conservative Traj -gene substitutions, and others that express Trav1 - TCRs with a broad range of Traj genes. We further report that human TRAV1-2 - MR1-restricted T cells contain both MAIT-like and non-MAIT-like cells, as judged by their TCR repertoire, antigen reactivity and phenotypic features. These include a MAIT-like population that expresses a public, canonical TRAV36 + TRBV28 + TCR. Our findings highlight the TCR ersity and the resulting potential impact on antigen recognition by MR1-restricted T cells.
Publisher: Wiley
Date: 20-09-2019
DOI: 10.1002/CPIM.90
Abstract: Mucosal-associated invariant T (MAIT) cells are a subset of unconventional T cells restricted by the major histocompatibility complex (MHC) class I-like molecule MHC-related protein 1 (MR1). MAIT cells are found throughout the body, especially in human blood and liver. Unlike conventional T cells, which are stimulated by peptide antigens presented by MHC molecules, MAIT cells recognize metabolite antigens derived from an intermediate in the microbial biosynthesis of riboflavin. MAIT cells mediate protective immunity to infections by riboflavin-producing microbes via the production of cytokines and cytotoxicity. The discovery of stimulating MAIT cell antigens allowed for the development of an analytical tool, the MR1 tetramer, that binds specifically to the MAIT T cell receptor (TCR) and is becoming the gold standard for identification of MAIT cells by flow cytometry. This article describes protocols to characterize the phenotype of human MAIT cells in blood and tissues by flow cytometry using fluorescently labeled human MR1 tetramers alongside antibodies specific for MAIT cell markers. © 2019 by John Wiley & Sons, Inc. The main protocols include: Basic Protocol 1: Determining the frequency and steady-state surface phenotype of human MAIT cells Basic Protocol 2: Determining the activation phenotype of human MAIT cells in blood Basic Protocol 3: Characterizing MAIT cell TCRs using TCR-positive reporter cell lines Alternate protocols are provided for determining the absolute number, transcription factor phenotype, and TCR usage of human MAIT cells and determining activation phenotype by staining for intracellular markers, measuring secreted cytokines, and measuring fluorescent dye dilution due to proliferation. Additional methods are provided for determining the capacity of MAIT cells to produce cytokine independently of antigen using plate-bound or bead-immobilized CD3/CD28 stimulation and determining the MR1-Ag dependence of MAIT cell activation using MR1-blocking antibody or competitive inhibition. For TCR-positive reporter cell lines, methods are also provided for evaluating the MAIT TCR-mediated MR1-Ag response, determining the capacity of the reporter lines to produce cytokine independently of antigen, determining the MR1-Ag dependence of the reporter lines, and evaluating the MR1-Ag response of the reporter lines using IL-2 secretion. Support Protocols describe the preparation of PBMCs from human blood, the preparation of single-cell suspensions from tissue, the isolation of MAIT cells by FACS and MACS, cloning MAIT TCRα and β chain genes and MR1 genes for transduction, generating stably and transiently transfected cells lines, generating a stable MR1 knockout antigen-presenting cell line, and generating monocyte-derived dendritic cells.
Start Date: 2021
End Date: 12-2023
Amount: $489,715.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2021
End Date: 12-2024
Amount: $462,948.00
Funder: Australian Research Council
View Funded Activity