ORCID Profile
0000-0002-5634-9637
Current Organisations
CSIRO Clayton
,
CSIRO
,
Monash University
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Publisher: Elsevier BV
Date: 03-2009
Publisher: Elsevier BV
Date: 09-2023
Publisher: Humana Press
Date: 2011
DOI: 10.1007/978-1-61779-289-2_12
Abstract: Fluorescence microscopy is an important and fundamental tool for biomedical research. Optical microscopy is almost non-invasive and allows highly spatially resolved images of organisms, cells, macromolecular complexes, and biomolecules to be obtained. Generally speaking, the architecture of the observed structures is not significantly modified and the environmental conditions can be kept very close to physiological reality. The development of fluorescence microscopy was revolutionized with the invention of laser scanning confocal microscopy (LSCM). With its unique three-dimensional representation and analysis capabilities, this technology gives us a more real view of the world.This chapter introduces the reader to the methodology of setting up basic experiments for use with a laser scanning confocal microscope. There are practical guidelines about s le preparation for both fixed and living specimens, as well as ex les of some of the applications of confocal microscopy.
Publisher: Wiley
Date: 23-01-2006
Publisher: Elsevier BV
Date: 07-2004
Publisher: SAGE Publications
Date: 09-10-2018
Abstract: We examined the clinical relevance of urinary concentrations of B-cell–activating factor of the tumour necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) in systemic lupus erythematosus (SLE). We quantified urinary BAFF (uBAFF) by enzyme-linked immunosorbent assay in 85 SLE, 28 primary Sjögren syndrome (pSS), 40 immunoglobulin A nephropathy (IgAN) patients and 36 healthy controls (HCs). Urinary APRIL (uAPRIL) and monocyte chemoattractant protein 1 (uMCP-1) were also quantified. Overall and renal SLE disease activity were assessed using the Systemic Lupus Erythematosus Disease Activity Index 2000. uBAFF was detected in 12% (10/85) of SLE patients, but was undetectable in HCs, IgAN and pSS patients. uBAFF was detectable in 28% (5/18) of SLE patients with active nephritis vs 5/67 (7%) of those without ( p = 0.03), and uBAFF was significantly higher in active renal patients ( p = 0.02) and more likely to be detected in patients with persistently active renal disease. In comparison, uAPRIL and uMCP-1 were detected in 32% (25/77) and 46% (22/48) of SLE patients, respectively. While no difference in proportion of s les with detectable uAPRIL was observed between SLE, HCs and IgAN patients, both uAPRIL and uMCP-1 were significantly detectable in higher proportions of patients with active renal disease. uBAFF was detectable in a small but a significant proportion of SLE patients but not in other groups tested, and was higher in SLE patients with active renal disease.
Publisher: Wiley
Date: 02-2002
DOI: 10.1046/J.1365-2567.2002.01362.X
Abstract: Caveolin is a generic term for a family of proteins that include caveolin-1, -2 and -3. Although the distribution of these proteins varies between cells, caveolin-1 and -2 are commonly found coating membrane invaginations known as caveolae. Studies on human and murine cells suggest that caveolin/caveolae can be found in neutrophils, macrophages and mast cells, in which they are involved in the uptake of pathogens, but not in lymphocyte cell lines. Expression of caveolin-1, -2 and -3 in bovine immune cells was investigated using confocal microscopy and Western blotting. Staining for caveolin-1 was evident in all peripheral blood mononuclear cells (PBMC) and in CD4+, CD8+ and CD21+ lymphocytes, monocytes, macrophages and monocyte-derived dendritic cells (DC). In addition, the caveolin-1 antibody detected a protein with a molecular weight of approximately 22[?]000 in all PBMC, macrophages and DC, as well as in bovine aortic endothelial (BAE)-1 cells and human endothelial cells by Western blotting. In macrophages and DC, caveolin co-localized with the endoplasmic reticulum--Golgi intermediate compartment (ERGIC) and to a lesser extent with Golgi, but not with endoplasmic reticulum. Staining was not seen on the plasma membrane in any bovine immune cells, suggesting the absence of caveolae, while in BAE-1 cells staining was predominantly on the cell membrane. Caveolin-2 could not be detected in any bovine cells by confocal microscopy or Western blotting, while caveolin-3 was detected in all bovine cells by Western blotting, but not by confocal microscopy. These data provide evidence for the presence of caveolin in bovine lymphocytes and antigen-presenting cells.
Publisher: Hindawi Limited
Date: 10-2003
DOI: 10.1046/J.1462-5822.2003.00313.X
Abstract: Respiratory syncytial virus (RSV) is the most common cause of severe lower respiratory tract infection in infants and the elderly. There is currently no effective antiviral treatment for the infection, but advances in our understanding of RSV uptake, especially the role of surfactant proteins, the attachment protein G and the fusion protein F, as well as the post-binding events, have revealed potential targets for new therapies and vaccine development. RSV infection triggers an intense inflammatory response, mediated initially by the infected airway epithelial cells and antigen-presenting cells. Humoral and cell-mediated immune responses are important in controlling the extent of infection and promoting viral clearance. The initial innate immune response may play a critical role by influencing the subsequent adaptive response generated. This review summarizes our current understanding of RSV binding and uptake in mammalian cells and how these initial interactions influence the subsequent innate immune response generated.
Publisher: Wiley
Date: 25-11-2015
DOI: 10.1002/ART.39328
Abstract: Knowledge of interleukin-38 (IL-38), formerly IL-1 family member 10, is sparse, but Il1f10 polymorphisms are associated with inflammatory diseases, and recombinant IL-38 inhibits inflammatory responses similar to those reported in the context of systemic lupus erythematosus (SLE). We undertook this study to explore the function of endogenous IL-38 in human peripheral blood mononuclear cells (PBMCs) as well as its abundance in serum in a well-characterized cohort of SLE patients. Serum IL-38 and IL-10 levels were quantified by enzyme-linked immunosorbent assay in 142 SLE patients at ≤3 consecutive visits and in 28 healthy volunteers. To assess IL-38 function, we silenced IL-38 in PBMCs from healthy donors using IL-38 small interfering RNA (siRNA). IL-38 (63-5,928 pg/ml) was detectable in 16% of 372 serum s les. IL-38 abundance was significantly higher in s les from SLE patients than in s les from healthy controls (P = 0.004) and 11-fold higher in patients with active disease (SLE Disease Activity Index 2000 [SLEDAI-2K] score of ≥4) than in those with inactive disease (SLEDAI-2K score of <4) (P = 0.044). Importantly, IL-38 detection was associated with increased risk of renal lupus (relative risk [RR] 1.6, P = 0.027) and central nervous system lupus (RR 2.3, P = 0.034), and detectable baseline IL-38 entailed a 1.6-fold increased risk of subsequently meeting criteria for persistently active disease (P = 0.0097). Longitudinal time-adjusted mean IL-38 concentration was also 6-fold higher in patients with persistently active disease than in those without (P = 0.023). Remarkably, PBMCs treated with IL-38 siRNA produced up to 28-fold more of the proinflammatory mediators IL-6, CCL2, and APRIL than did control siRNA-transfected cells upon stimulation with Toll-like receptor agonists. Similarly, in SLE patients, the antiinflammatory cytokine IL-10 was 5-fold more abundant when IL-38 was detectable. This is the first study of the function of endogenous IL-38, and the data suggest that IL-38 may be protective in SLE. A strong association between IL-38 and SLE severity suggests that IL-38 expression is driven by processes linked to SLE pathogenesis. Exploitation of the regulatory effects of IL-38 may represent a promising therapeutic strategy in SLE.
Publisher: BMJ
Date: 10-2018
DOI: 10.1136/LUPUS-2018-000277
Abstract: To characterise the clinical relevance of urinary macrophage migration inhibitory factor (uMIF) concentrations in patients with systemic lupus erythematosus (SLE). MIF, adjusted for urine creatinine, was quantified by ELISA in urine s les from 64 prospectively recruited patients with SLE. Serum MIF and urinary monocyte chemoattractant protein 1 (uMCP-1) were quantified by ELISA in a subset of patients (n = 39). Disease activity was assessed using the SLE Disease Activity Index-2000 (SLEDAI-2K) score. uMIF was detectable in all patients with SLE. uMIF was positively correlated with overall SLEDAI-2K, was significantly higher in patients with SLE with high disease activity (SLEDAI-2K≥10) compared with those with inactive disease (SLEDAI-2K ), and this association remained significant after adjusting for ethnicity, flare and use of immunosuppressants. uMIF was also significantly higher in SLE patients with flare of disease, although not confirmed in multivariable analysis. No significant differences in uMIF levels were observed according to the presence of renal disease activity, as assessed by renal SLEDAI-2K or biopsy-confirmed lupus nephritis. In contrast, uMCP-1 was significantly higher in SLE patients with active renal disease. uMIF expression was not associated with irreversible organ damage accrual or glucocorticoid use. These data suggest uMIF as a potential overall but not renal-specific SLE biomarker, whereas uMCP-1 is a renal-specific SLE biomarker.
Publisher: Wiley
Date: 2003
DOI: 10.1046/J.1365-2567.2003.01557.X
Abstract: Exposing bovine dendritic cells (DC) and macrophages (MPhi) to Salmonella typhimurium at a ratio of 1 cell to 10 bacteria had a cytotoxic effect that was not evident with a ratio of 1000 cells to 1 bacterium. This lower dose was considered to mimic more closely the in vivo situation and a comparison was made with this model of the consequences of infection for MPhi and DC. DC infected with S. typhimurium up-regulated cell surface expression of major histocompatibility class I (MHC-I), MHC-II, CD40, CD80 and CD86. In contrast, infected MPhi did not exhibit detectable changes in expression of cell surface molecules, except for a marginal increase in CD40. mRNA transcription for tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6 and inducible nitric oxide synthase was up-regulated in both infected DC and infected MPhi, although mRNA transcription for granulocyte-macrophage colony-stimulating factor and IL-12p40 was up-regulated only in infected DC and for IL-10 was only in infected MPhi. Infected DC had an increased ability to stimulate both allogeneic and antigen-specific T-cell responses compared to non-infected controls. In contrast, infected MPhi showed an increased ability to induce allogeneic responses but this was less than seen for DC and no enhancement of ability to induce antigen-specific T cell responses was seen. Thus, in a low-dose infection model that does not result in the cytotoxicity of a substantial percentage of antigen presenting cells, bovine MPhi and DC respond differently to infection with S. typhimurium and this could have important implications for the development of the immune response.
Publisher: Frontiers Media SA
Date: 2013
Publisher: Proceedings of the National Academy of Sciences
Date: 20-01-2009
Abstract: Many currently used and candidate vaccine adjuvants are particulate in nature, but their mechanism of action is not well understood. Here, we show that particulate adjuvants, including biodegradable poly(lactide- co -glycolide) (PLG) and polystyrene microparticles, dramatically enhance secretion of interleukin-1β (IL-1β) by dendritic cells (DCs). The ability of particulates to promote IL-1β secretion and caspase 1 activation required particle uptake by DCs and NALP3. Uptake of microparticles induced lysosomal damage, whereas particle-mediated enhancement of IL-1β secretion required phagosomal acidification and the lysosomal cysteine protease cathepsin B, suggesting a role for lysosomal damage in inflammasome activation. Although the presence of a Toll-like receptor (TLR) agonist was required to induce IL-1β production in vitro, injection of the adjuvants in the absence of TLR agonists induced IL-1β production at the injection site, indicating that endogenous factors can synergize with particulates to promote inflammasome activation. The enhancement of antigen-specific antibody production by PLG microparticles was independent of NALP3. However, the ability of PLG microparticles to promote antigen-specific IL-6 production by T cells and the recruitment and activation of a population of CD11b + Gr1 − cells required NALP3. Our data demonstrate that uptake of microparticulate adjuvants by DCs activates the NALP3 inflammasome, and this contributes to their enhancing effects on innate and antigen-specific cellular immunity.
Publisher: Elsevier BV
Date: 10-2007
Publisher: The American Association of Immunologists
Date: 15-10-2012
Abstract: Autophagy controls IL-1β secretion by regulating inflammasome activation and by targeting pro–IL-1β for degradation. In this article, we show that inhibition of autophagy, either with the PI3K inhibitors 3-methyladenine, wortmannin, and LY294002 or with small interfering RNA against autophagy proteins augmented the secretion of IL-23 by human and mouse macrophages and dendritic cells in response to specific TLR agonists. This process occurred at the transcriptional level and was dependent on reactive oxygen species and IL-1R signaling it was abrogated with an IL-1R antagonist or with IL-1–neutralizing Abs, whereas treatment with either rIL-1α or IL-1β induced IL-23 secretion. Dendritic cells treated with LPS and 3-methyladenine secreted enhanced levels of both IL-1β and IL-23, and supernatants from these cells stimulated the innate secretion of IL-17, IFN-γ, and IL-22 by γδ T cells. These data demonstrate that autophagy has a potentially pivotal role to play in the induction and regulation of inflammatory responses by innate immune cells, largely driven by IL-1 and its consequential effects on IL-23 secretion.
Publisher: Wiley
Date: 25-04-2006
Abstract: Mannose receptor (MR) is the best characterised member of a family of four endocytic molecules that share a common domain structure a cysteine-rich (CR) domain, a fibronectin-type II (FNII) domain and tandemly arranged C-type lectin-like domains (CTLD, eight in the case of MR). Two distinct lectin activities have been described for MR. The CR domain recognises sulphated carbohydrates while the CTLD mediate binding to mannose, fucose or N-acetylglucosamine. FNII domains are known to be important for collagen binding and this has been studied in the context of two members of the MR family, Endo180 and the phospholipase A2 receptor. Here, we have investigated whether the broad and effective lectin activity mediated by the CR domain and CTLD of MR is favoured to the detriment of FNII-mediated interaction(s). We show that MR is able to bind and internalise collagen in a carbohydrate-independent manner and that MR deficient macrophages have a marked defect in collagen IV and gelatin internalisation. These data have major implications at the molecular level as there are now three distinct ligand-binding sites described for MR. Furthermore our findings extend the range of endogenous ligands recognised by MR, a molecule firmly placed at the interface between homeostasis and immunity.
Publisher: Informa UK Limited
Date: 10-05-2016
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.JAUT.2015.05.010
Abstract: Patients with inflammatory autoimmune diseases are routinely treated with synthetic glucocorticoids to suppress immunopathology. A crucial outcome of glucocorticoid exposure is induction of glucocorticoid-induced leucine zipper (GILZ), a protein with multiple functions that include inhibition of key immune cell signalling pathways. Here we report that GILZ maintains a threshold for activation of Th17 responses and IL-17-dependent pathology. GILZ expression was deficient in lesional skin of psoriasis patients and was negatively correlated with the pro-inflammatory cytokines IL-23, IL-17A and IL-22, and with STAT3 expression. Deficiency of GILZ in mice resulted in excessive inflammation and pro-inflammatory cytokine expression in the imiquimod model of psoriasis, and dendritic cells lacking GILZ produced greater IL-1, IL-23 and IL-6 in response to imiquimod stimulation in vitro. These cytokines stimulate Th17 cell differentiation, and we found unchallenged GILZ-deficient mice to have spontaneous production of IL-17A and IL-22 in vivo. We also identified a T cell-intrinsic role for GILZ in limiting Th17 cell formation in vitro in response to Th17-promoting cytokines IL-1β and IL-23. Addition of IL-6 under these conditions suppressed GILZ, allowing T cell proliferation and expression of Th17 genes, whereas exogenous delivery of GILZ using a cell-permeable fusion protein restored regulation of Th17 cell proliferation. Thus, GILZ has a non-redundant function to constrain pathogenic Th17 responses, with clinical implications for psoriasis.
Publisher: Elsevier
Date: 2015
Publisher: Frontiers Media SA
Date: 11-11-2015
Publisher: Elsevier BV
Date: 05-2019
Abstract: Produced by many cell types, macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with critical and supporting roles in many disease states and conditions. Its disease associations, myriad functions, receptors, and downstream signaling have been the subject of considerable research, yet many questions remain. Moreover, the relevance of MIF's partially functionally redundant family member, D-dopachrome tautomerase (D-DT), also remains to be further characterized. Here, we discuss recent discoveries demonstrating direct roles of MIF in supporting NLR Family Pyrin Domain-Containing 3 (NRLP3) inflammasome activation, as well as acting as a molecular chaperone for intracellular proteins. These findings may offer new clues to understanding MIF's multiple functions, and assist the development of putative MIF-targeting therapeutics for a variety of pathologies.
Publisher: Springer Science and Business Media LLC
Date: 06-10-2016
DOI: 10.1038/SREP34604
Abstract: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the development of autoantibodies to nuclear antigens and inflammatory responses mediated by multiple cytokines. Although previous studies have determined clinical associations between SLE and the anti-inflammatory cytokines IL-10 and IL-37, their role in the disease, or their potential as biomarkers, remains unclear. We examined serum levels of IL-10 and IL-37 in a large cohort of SLE patients, with detailed longitudinal clinical data. We demonstrate a statistically significant association of serum IL-10 with disease activity, with higher levels in active compared to inactive disease. High first visit IL-10 was predictive of high subsequent disease activity patients with IL-10 in highest quartile at first visit were 3.6 times more likely to have active disease in subsequent visits. Serum IL-37 was also higher in SLE patients compared to control, and was strongly associated with Asian ethnicity. However, IL-37 was not statistically significantly associated with disease activity. IL-37 was significantly reduced in patients with organ damage but this association was attenuated in multivariable analysis. The data suggest that IL-10, but not IL-37, may have potential as a biomarker predictive for disease activity in SLE.
Publisher: Wiley
Date: 15-01-2013
DOI: 10.1038/ICB.2012.82
Abstract: Autophagy is a cellular mechanism for the sequestration and degradation of intracellular pathogens and compromised organelles, particularly damaged mitochondria. Autophagy also clears other cellular components, such as inflammasomes and cytokines, thus providing an important means of regulating inflammation. Defects in autophagy have been found by genetic association studies to confer susceptibility to several autoimmune and inflammatory disorders, particularly inflammatory bowel disease. Thus, the manipulation of autophagy in disease situations is of growing interest for therapeutic targeting however, the involvement of autophagy in cellular homoeostasis, in normal immune function and in inflammation is manifold. An appreciation of the intricacies of the contributions of this process to inflammation, and how these are altered by various immune and environmental stimuli, is essential for the understanding and interpretation of studies of inflammation and the design of therapeutics exploiting the manipulation of autophagy. This review focuses on the known roles of autophagy in the induction and maintenance of inflammation and on its role in the aetiology and regulation of inflammatory and autoimmune disorders.
Publisher: Wiley
Date: 31-08-2023
DOI: 10.1111/IMCB.12686
Abstract: Dysregulation of innate immune responses can result in chronic inflammatory conditions. Glucocorticoids, the current frontline therapy, are effective immunosuppressive drugs but come with a trade‐off of cumulative and serious side effects. Therefore, alternative drug options with improved safety profiles are urgently needed. Sulforaphane, a phytochemical derived from plants of the brassica family, is a potent inducer of phase II detoxification enzymes via nuclear factor‐erythroid factor 2–related factor 2 (NRF2) signaling. Moreover, a growing body of evidence suggests additional erse anti‐inflammatory properties of sulforaphane through interactions with mediators of key signaling pathways and inflammatory cytokines. Multiple studies support a role for sulforaphane as a negative regulator of nuclear factor kappa‐light chain enhancer of activated B cells (NF‐κB) activation and subsequent cytokine release, inflammasome activation and direct regulation of the activity of macrophage migration inhibitory factor. Significantly, studies have also highlighted potential steroid‐sparing activity for sulforaphane, suggesting that it may have potential as an adjunctive therapy for some inflammatory conditions. This review discusses published research on sulforaphane, including proposed mechanisms of action, and poses questions for future studies that might help progress our understanding of the potential clinical applications of this intriguing molecule.
Publisher: Springer Science and Business Media LLC
Date: 02-05-2023
Publisher: Wiley
Date: 20-06-2006
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.MOLIMM.2017.02.013
Abstract: Autophagy is a ubiquitous cellular mechanism for the targeted lysosomal degradation of various cytosolic constituents, from proteins to organelles. As an essential homeostatic mechanism, autophagy is upregulated in response to numerous environmental and pharmacological stimuli, including starvation, where it facilitates the recycling of essential amino acids. In addition, autophagy plays specific roles within the immune system it serves as a source of peptides for antigen presentation, a mechanism for the engulfment and degradation of intracellular pathogens and as a key regulator of inflammatory cytokines. In particular, autophagy has been shown to play a number of roles in regulating inflammasome activation, from the removal of inflammasome-activating endogenous signals, to the sequestration and degradation of inflammasome components. Autophagy also plays a role in determining the fate of IL-1β, which is concentrated in autophagosomes. This review discusses a growing body of literature that suggests autophagy is a critical regulator of inflammasome activation and the subsequent release of IL-1 family cytokines.
Publisher: Oxford University Press (OUP)
Date: 04-2013
DOI: 10.1189/JLB.1012543
Abstract: Review of the activation of inflammasome processes IL-1β and IL-18, which synergize with IL-23 to promote IL-17 production, by IL-17-secreting γδ T and Th17 cells. NLRs are members of the PRR family that sense microbial pathogens and mediate host innate immune responses to infection. Certain NLRs can assemble into a multiprotein complex called the inflammasome, which activates casapse-1 required for the cleavage of immature forms of IL-1β and IL-18 into active, mature cytokines. The inflammasome is activated by conserved, exogenous molecules from microbes and nonmicrobial molecules, such as asbestos, alum, or silica, as well as by endogenous danger signals, such as ATP, amyloid-β, and sodium urate crystals. Activation of the inflammasome is a critical event triggering IL-1-driven inflammation and is central to the pathology of autoinflammatory diseases, such as gout and MWS. Recent studies have also shown IL-1 or IL-18, in synergy with IL-23, can promote IL-17-prduction from Th17 cells and γδ T cells, and this process can be regulated by autophagy. IL-1-driven IL-17 production plays a critical role in host protective immunity to infection with fungi, bacteria, and certain viruses. However, Th17 cells and IL-17-seceting γδ T cells, activated by inflammasome-derived IL-1 or IL-18, have major pathogenic roles in many autoimmune diseases. Consequently, inflammasomes are now major drug targets for many autoimmune and chronic inflammatory diseases, as well as autoinflammatory diseases.
Publisher: Wiley
Date: 2018
DOI: 10.1002/CTI2.1042
Publisher: Oxford University Press (OUP)
Date: 25-03-2011
DOI: 10.1111/J.1365-2249.2011.04381.X
Abstract: A growing body of evidence points to autophagy as an essential component in the immune response to tuberculosis. Autophagy is a direct mechanism of killing intracellular Mycobacterium tuberculosis and also acts as a modulator of proinflammatory cytokine secretion. In addition, autophagy plays a key role in antigen processing and presentation. Autophagy is modulated by cytokines it is stimulated by T helper type 1 (Th1) cytokines such as tumour necrosis factor (TNF)-α and interferon (IFN)-γ, and is inhibited by the Th2 cytokines interleukin (IL)-4 and IL-13 and the anti-inflammatory cytokine IL-10. Vitamin D, via cathelicidin, can also induce autophagy, as can Toll-like receptor (TLR)-mediated signals. Autophagy-promoting agents, administered either locally to the lungs or systemically, could have a clinical application as adjunctive treatment of drug-resistant and drug-sensitive tuberculosis. Moreover, vaccines which effectively induce autophagy could be more successful in preventing acquisition or reactivation of latent tuberculosis.
Publisher: Wiley
Date: 03-2010
Abstract: Adjuvants are essential for enhancing and directing immunity to vaccine antigens. Most adjuvants in clinical use are particulates, but how they drive innate and adaptive immune responses is unclear. A major recent advance was the demonstration that particulate adjuvants promote activation of the NLRP3 inflammasome. The mechanisms underlying this activation have been partly resolved and the role of NLRP3 in particulate adjuvant-induced adaptive immunity is currently the subject of intense interest.
Publisher: Wiley
Date: 2019
DOI: 10.1002/CTI2.1045
Publisher: Wiley
Date: 21-06-2022
DOI: 10.1111/IMCB.12562
Abstract: Studies have highlighted a critical role for autophagy in the regulation of multiple cytokines. Autophagy inhibits the release of interleukin (IL)‐1 family cytokines, including IL‐1α, IL‐1β and IL‐18, by myeloid cells. This, in turn, impacts the release of other cytokines by myeloid cells, as well as other cells of the immune system, including IL‐22, IL‐23, IL‐17 and interferon‐γ. Here, we assessed the impact of genetic depletion of the autophagy gene Atg7 in myeloid cells on acute and chronic inflammation. In a model of acute lipopolysaccharide‐induced endotoxemia, loss of autophagy in myeloid cells resulted in increased release of proinflammatory cytokines, both locally and systemically. By contrast, loss of Atg7 in myeloid cells in the Lyn −/− model of lupus‐like autoimmunity resulted in reduced systemic release of IL‐6 and IL‐10, with no effects on other cytokines observed. In addition, Lyn −/− mice with autophagy‐deficient myeloid cells showed reduced expression of autoantibodies relevant to systemic lupus erythematosus, including anti‐histone and anti‐Smith protein. In vitro , loss of autophagy, through pharmacological inhibition or small interfering RNA against Becn1 , inhibited IL‐10 release by human and mouse myeloid cells. This effect was evident at the level of Il10 messenger RNA expression. Our data highlight potentially important differences in the role of myeloid cell autophagy in acute and chronic inflammation and demonstrate a direct role for autophagy in the production and release of IL‐10 by macrophages.
Publisher: Wiley
Date: 2019
DOI: 10.1002/CTI2.1047
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.
Publisher: Elsevier BV
Date: 09-2005
Publisher: Wiley
Date: 12-08-2014
DOI: 10.1111/BPH.12768
Publisher: BMJ
Date: 07-11-2022
DOI: 10.1136/THORAX-2021-218555
Abstract: Severe neutrophilic asthma is resistant to treatment with glucocorticoids. The immunomodulatory protein macrophage migration inhibitory factor (MIF) promotes neutrophil recruitment to the lung and antagonises responses to glucocorticoids. We hypothesised that MIF promotes glucocorticoid resistance of neutrophilic inflammation in severe asthma. We examined whether sputum MIF protein correlated with clinical and molecular characteristics of severe neutrophilic asthma in the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) cohort. We also investigated whether MIF regulates neutrophilic inflammation and glucocorticoid responsiveness in a murine model of severe asthma in vivo. MIF protein levels positively correlated with the number of exacerbations in the previous year, sputum neutrophils and oral corticosteroid use across all U-BIOPRED subjects. Further analysis of MIF protein expression according to U-BIOPRED-defined transcriptomic-associated clusters (TACs) revealed increased MIF protein and a corresponding decrease in annexin-A1 protein in TAC2, which is most closely associated with airway neutrophilia and NLRP3 inflammasome activation. In a murine model of severe asthma, treatment with the MIF antagonist ISO-1 significantly inhibited neutrophilic inflammation and increased glucocorticoid responsiveness. Coimmunoprecipitation studies using lung tissue lysates demonstrated that MIF directly interacts with and cleaves annexin-A1, potentially reducing its biological activity. Our data suggest that MIF promotes glucocorticoid-resistance of neutrophilic inflammation by reducing the biological activity of annexin-A1, a potent glucocorticoid-regulated protein that inhibits neutrophil accumulation at sites of inflammation. This represents a previously unrecognised role for MIF in the regulation of inflammation and points to MIF as a potential therapeutic target for the management of severe neutrophilic asthma.
Publisher: Elsevier BV
Date: 03-2011
Publisher: Springer Science and Business Media LLC
Date: 12-09-2010
DOI: 10.1038/NI.1935
Publisher: Elsevier BV
Date: 03-2002
DOI: 10.1016/S1471-4906(01)02161-5
Abstract: Caveolae are small, cholesterol-rich, hydrophobic membrane domains, characterized by the presence of the protein caveolin and involved in several cellular processes, including clathrin-independent endocytosis, the regulation and transport of cellular cholesterol, and signal transduction. Recently, caveolae have been identified as providing a novel route by which several pathogens are internalized by antigen-presenting cells and as centers for signal transduction. Here, we review the distribution and role of caveolae and caveolin in mammalian immune cells.
Publisher: Wiley
Date: 03-11-2020
DOI: 10.1111/IMCB.12413
Publisher: Frontiers Media SA
Date: 07-06-2018
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.CYTO.2011.08.022
Abstract: Autophagy is a highly conserved homoeostatic mechanism for the lysosomal degradation of cytosolic constituents, including long-lived macromolecules, organelles and intracellular pathogens. Autophagosomes are formed in response to a number of environmental stimuli, including amino acid deprivation, but also by both host- and pathogen-derived molecules, including toll-like receptor ligands and cytokines. In particular, IFN-γ, TNF-α, IL-1, IL-2, IL-6 and TGF-β have been shown to induce autophagy, while IL-4, IL-10 and IL-13 are inhibitory. Moreover, autophagy can itself regulate the production and secretion of cytokines, including IL-1, IL-18, TNF-α, and Type I IFN. This review discusses the potentially pivotal roles of autophagy in the regulation of inflammation and the coordination of innate and adaptive immune responses.
Publisher: Elsevier
Date: 2017
Publisher: Wiley
Date: 11-2009
DOI: 10.1002/0471142735.IM1414S87
Abstract: Macroautophagy is a conserved intracellular homeostatic mechanism for the degradation of cytosolic constituents. Autophagy can promote cell survival by providing essential amino acids from the breakdown of macromolecules during periods of nutrient deprivation, and can remove damaged or excess organelles, such as mitochondria and peroxisomes. More recently, autophagy has been shown to play an important role in innate and adaptive immune responses to pathogenic bacteria in macrophages and dendritic cells. This unit presents protocols for the measurement of autophagy in macrophages. Curr. Protoc. Immunol . 87:14.14.1‐14.14.13. © 2009 by John Wiley & Sons, Inc.
Publisher: Wiley
Date: 22-07-2014
DOI: 10.1038/ICB.2014.56
Abstract: The hypothalamic-pituitary-adrenal (HPA) axis is an important regulator of the stress response. In healthy in iduals, the HPA axis maintains an equilibrium, ensuring that endogenous glucocorticoid (GC) levels remain within the normal range. However, hypofunction of the HPA axis may have a role in the development of inflammatory diseases, such as rheumatoid arthritis (RA). Glucocorticoid-induced leucine zipper (GILZ) is an anti-inflammatory protein, the expression of which is upregulated by GC. Although GILZ mediates the anti-inflammatory effects of GC, it may not be associated with the adverse effects that are frequently caused by exogenous GC administration. This has raised interest in GILZ potentiation as a therapeutic approach in diseases such as RA, which may mimic the anti-inflammatory effects of GC without causing harmful side effects. This review will outline the involvement of the HPA axis in RA, as a prelude to highlighting emerging evidence regarding the role of GILZ in inflammation control and RA.
Publisher: Hindawi Limited
Date: 29-07-2013
DOI: 10.1111/CMI.12161
Abstract: Mycobacteria are a genus of bacteria that range from the non-pathogenic Mycobacterium smegmatis to Mycobacterium tuberculosis, the causative agent of tuberculosis in humans. Mycobacteria primarily infect host tissues through inhalation or ingestion. They are phagocytosed by host macrophages and dendritic cells. Here, conserved pathogen-associated molecular patterns (PAMPs) on the surface of mycobacteria are recognized by phagocytic pattern recognition receptors (PRRs). Several families of PRRs have been shown to non-opsonically recognize mycobacterial PAMPs, including membrane-bound C-type lectin receptors, membrane-bound and cytosolic Toll-like receptors and cytosolic NOD-like receptors. Recently, a possible role for intracellular cytosolic PRRs in the recognition of mycobacterial pathogens has been proposed. Here, we discuss currentideas on receptor-mediated recognition of mycobacterial pathogens by macrophages and dendritic cells.
Publisher: Wiley
Date: 31-08-2020
DOI: 10.1111/IMCB.12376
Publisher: Wiley
Date: 04-2021
DOI: 10.1111/IMCB.12454
Publisher: American Society of Hematology
Date: 11-01-2007
DOI: 10.1182/BLOOD-2006-10-052977
Abstract: Natural killer (NK) cells directly lyse tumor or viral-infected cells but also an important role for NK cell cytotoxicity in regulating the extent of immune responses is emerging. Here, we show that autologous human macrophages activated NK cell proliferation and cytokine secretion, increased expression of activating receptors, and primed NK cell cytotoxicity against susceptible target cells. Ligation of NK cell 2B4, and not NKp30 (known to be important for DC-mediated NK cell activation), is critical for this macrophage-mediated NK cell activation. Reciprocally, however, NK cells regulated macrophage activity by directly killing macrophages stimulated by high doses of LPS. Cytolysis was triggered by NKG2D recognition of stress-inducible class I major histocompatibility complex (MHC)–like ligands on macrophages: high doses of LPS induced transcription and surface expression of ULBP1, ULBP2, and ULBP3 and surface expression of constitutively transcribed MICA. Thus, these data suggest a new function for NK cell cytotoxicity in eliminating overstimulated macrophages. Additionally, these interactions define, for the first time, 2 distinct activating NK cell synapses: lytic and nonlytic. Triggering NK cell proliferation and cytokine secretion, but not cytolysis, specifically associated with synaptic accumulation of macrophage F-actin and NK cell 2B4, while macrophages were killed when NK cell F-actin and macrophage ICAM-1 accumulated around a central cluster of NK cell NKG2D/DAP10.
Publisher: Elsevier BV
Date: 08-2000
DOI: 10.1016/S0165-2427(00)00205-1
Abstract: Melanin-concentrating hormone (MCH) and alpha-melanocyte stimulating hormone (alpha-MSH) are widespread vertebrate neuropeptides. In teleost fish the peptides are involved in the hormonal control of skin pigmentation, but they have also been shown to modulate corticosteroid secretion in both fish and mammals. alpha-MSH has additional potent anti-inflammatory actions in mammals and both peptides stimulate leucocyte phagocytosis in rainbow trout in vitro. The effects of these peptides on phagocytosis and the release of immunomodulatory factors by rainbow trout head kidney leucocytes were investigated in vitro. Neither MCH nor alpha-MSH had any effect on the adherence of phagocytes to glass slides or the activity of isolated phagocytes. When added to mixed leucocyte suspensions, however, MCH (50 and 100nM) and alpha-MSH (1 and 10nM) significantly increased the percentage of cells undergoing phagocytosis and MCH (50nM), but not alpha-MSH, stimulated the phagocytic index. In subsequent experiments, isolated phagocytes were exposed to supernatants derived from mixed leucocyte suspensions exposed to MCH (50 and 100nM) and alpha-MSH (1 and 10nM). Supernatants from leucocytes exposed to all doses of the peptides significantly increased the percentage phagocytosis and those from cells stimulated with MCH (100nM) and alpha-MSH (1 and 10nM) increased the phagocytic index of the phagocytes. The results suggest that cells other than phagocytes are required for MCH and alpha-MSH to exert their stimulatory effects on trout phagocytic cells through the release of one or more macrophage-activating factors.
Publisher: Oxford University Press (OUP)
Date: 18-05-2010
DOI: 10.1111/J.1365-2249.2010.04146.X
Abstract: Tumour necrosis factor (TNF) is a potent inflammatory cytokine that plays an important role in immunity to numerous bacterial infections, including Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) in humans. Infliximab, adalimumab, certolizumab pegol and etanercept are anti-TNF agents used to treat a range of inflammatory/autoimmune diseases, such as rheumatoid arthritis. The use of some of these drugs has been linked to reactivation TB. In addition to blocking TNF-mediated immune responses, some anti-TNF drugs have been found to interfere with innate immune responses, such as phagolysosomal maturation and monocyte apoptosis, as well as cell-mediated responses, including interferon-γ secretion by memory T cells, complement-mediated lysis of Mtb-reactive CD8+ T cells and increased regulatory T cell activity. This review summarizes some of the reported effects of TNF blockers on immune cell responses in the context of the observed clinical data on TB reactivation in patients on anti-TNF therapy.
Publisher: Elsevier BV
Date: 09-2007
DOI: 10.1016/J.IMMUNI.2007.07.022
Abstract: Autophagy is a recently recognized immune effector mechanism against intracellular pathogens. The role of autophagy in innate immunity has been well established, but the extent of its regulation by the adaptive immune response is less well understood. The T helper 1 (Th1) cell cytokine IFN-gamma induces autophagy in macrophages to eliminate Mycobacterium tuberculosis. Here, we report that Th2 cytokines affect autophagy in macrophages and their ability to control intracellular M. tuberculosis. IL-4 and IL-13 abrogated autophagy and autophagy-mediated killing of intracellular mycobacteria in murine and human macrophages. Inhibition of starvation-induced autophagy by IL-4 and IL-13 was dependent on Akt signaling, whereas the inhibition of IFN-gamma-induced autophagy was Akt independent and signal transducer and activator of transcription 6 (STAT6) dependent. These findings establish a mechanism through which Th1-Th2 polarization differentially affects the immune control of intracellular pathogens.
Publisher: Elsevier BV
Date: 12-2000
DOI: 10.1016/S0165-2427(00)00235-X
Abstract: Immune-neuroendocrine interactions in fish, as in mammals, have become a focus of considerable interest, with the modulation of immune responses by hormones receiving particular attention. Cortisol, growth hormone (GH), prolactin (PRL), reproductive hormones, melanin-concentrating hormone (MCH) and proopiomelanocortin (POMC)-derived peptides have all been shown to influence immune functions in a number of fish species. This review summarises the known effects of these hormones on the fish immune system, as well as the often complex interactions between different hormones. The possible implications for fish health, with respect to aquaculture and the changes in immunocompetence that take place during different stages in the fish life cycle are also discussed.
Publisher: AME Publishing Company
Date: 12-2017
Publisher: Oxford University Press (OUP)
Date: 15-12-2008
DOI: 10.1086/593174
Abstract: Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine that mediates inflammation in response to various pathogens, including Mycobacterium tuberculosis, but is also a key factor in the pathogenesis of rheumatoid arthritis and other autoimmune diseases. Three TNF-alpha-suppressing drugs have been approved to treat selected autoimmune diseases 2 are monoclonal antibodies against TNF-alpha (adalimumab and infliximab), and the other is a soluble TNF receptor/Fc fusion protein (etanercept). TNF blockers have been shown to increase the risk of reactivation of latent tuberculosis, and this risk is higher in patients treated with the monoclonal antibodies. We studied the effects of TNF-alpha blockers on the maturation of mycobacteria-containing phagosomes in human macrophages. All 3 drugs had an inhibitory effect on IFN-gamma-induced phagosome maturation in phorbolmyristate acetate-differentiated human THP-1 cells. Adalimumab and infliximab, but not etanercept, suppressed phagosome maturation in primary human peripheral blood monocyte-derived macrophages in the presence or absence of IFN-gamma. Treatment of macrophages with TNF-alpha led to increased maturation of phagosomes containing Mycobacterium bovis bacillus Calmette-Guérin or M. tuberculosis H37Rv. These results suggest a role for TNF-alpha in activating phagosome maturation and highlight a mechanism through which TNF-alpha blockade can affect the host response to mycobacteria.
Publisher: Public Library of Science (PLoS)
Date: 10-01-2022
DOI: 10.1371/JOURNAL.PPAT.1010166
Abstract: A hallmark of Listeria (L . ) monocytogenes pathogenesis is bacterial escape from maturing entry vacuoles, which is required for rapid bacterial replication in the host cell cytoplasm and cell-to-cell spread. The bacterial transcriptional activator PrfA controls expression of key virulence factors that enable exploitation of this intracellular niche. The transcriptional activity of PrfA within infected host cells is controlled by allosteric coactivation. Inhibitory occupation of the coactivator site has been shown to impair PrfA functions, but consequences of PrfA inhibition for L . monocytogenes infection and pathogenesis are unknown. Here we report the crystal structure of PrfA with a small molecule inhibitor occupying the coactivator site at 2.0 Å resolution. Using molecular imaging and infection studies in macrophages, we demonstrate that PrfA inhibition prevents the vacuolar escape of L . monocytogenes and enables extensive bacterial replication inside spacious vacuoles. In contrast to previously described spacious Listeria -containing vacuoles, which have been implicated in supporting chronic infection, PrfA inhibition facilitated progressive clearance of intracellular L . monocytogenes from spacious vacuoles through lysosomal degradation. Thus, inhibitory occupation of the PrfA coactivator site facilitates formation of a transient intravacuolar L . monocytogenes replication niche that licenses macrophages to effectively eliminate intracellular bacteria. Our findings encourage further exploration of PrfA as a potential target for antimicrobials and highlight that intra-vacuolar residence of L . monocytogenes in macrophages is not inevitably tied to bacterial persistence.
Publisher: Informa UK Limited
Date: 04-2012
DOI: 10.4161/AUTO.19496
Publisher: BMJ
Date: 26-11-2015
DOI: 10.1136/ANNRHEUMDIS-2015-207744
Abstract: Systemic lupus erythematosus (SLE) is a serious multisystem autoimmune disease, mediated by disrupted B cell quiescence and typically treated with glucocorticoids. We studied whether B cells in SLE are regulated by the glucocorticoid-induced leucine zipper (GILZ) protein, an endogenous mediator of anti-inflammatory effects of glucocorticoids. We conducted a study of GILZ expression in blood mononuclear cells of patients with SLE, performed in vitro analyses of GILZ function in mouse and human B cells, assessed the contributions of GILZ to autoimmunity in mice, and used the nitrophenol coupled to keyhole limpet haemocyanin model of immunisation in mice. Reduced B cell GILZ was observed in patients with SLE and lupus-prone mice, and impaired induction of GILZ in patients with SLE receiving glucocorticoids was associated with increased disease activity. GILZ was downregulated in naïve B cells upon stimulation in vitro and in germinal centre B cells, which contained less enrichment of H3K4me3 at the GILZ promoter compared with naïve and memory B cells. Mice lacking GILZ spontaneously developed lupus-like autoimmunity, and GILZ deficiency resulted in excessive B cell responses to T-dependent stimulation. Accordingly, loss of GILZ in naïve B cells allowed upregulation of multiple genes that promote the germinal centre B cell phenotype, including lupus susceptibility genes and genes involved in cell survival and proliferation. Finally, treatment of human B cells with a cell-permeable GILZ fusion protein potently suppressed their responsiveness to T-dependent stimuli. Our findings demonstrated that GILZ is a non-redundant regulator of B cell activity, with important potential clinical implications in SLE.
Publisher: American Thoracic Society
Date: 11-2018
Publisher: Wiley
Date: 28-07-2014
DOI: 10.1002/ART.38689
Publisher: Wiley
Date: 02-11-2006
Publisher: Elsevier BV
Date: 10-2008
DOI: 10.1016/J.VACCINE.2008.07.059
Abstract: Bovine tuberculosis (bTB) is increasing in incidence in the UK. Effective control strategies could involve vaccination BCG, either alone or in prime-boost strategies, remains the most effective vaccine against bovine tuberculosis. However, BCG vaccination of cattle would require development of diagnostic tests able to accurately discriminate Mycobacterium bovis-infected from BCG-vaccinated animals. Herein, we demonstrate that the detection of secreted IFN-gamma following short term culture (4h) of whole blood with purified protein derived from M. bovis (PPD-B) allows such discrimination. This reflects, in part, the differential kinetics of IFN-gamma secretion in infected compared to vaccinated cattle. This is the first study to demonstrate that accurate, rapid distinction of BCG-vaccinated from M. bovis-infected cattle can be achieved in a short time period without the need for production of M. bovis-specific antigens, complex antigen mixtures or extensive laboratory procedures. We were also able to detect PPD-specific IFN-gamma release during short term culture of blood from a number of humans with active TB indicating that this test may have wider application and is potentially useful for the rapid diagnosis of disease in humans.
Publisher: Informa UK Limited
Date: 02-01-2016
Publisher: Portland Press Ltd.
Date: 12-2007
DOI: 10.1042/BSS0740141
Publisher: Hindawi Limited
Date: 05-2006
DOI: 10.1111/J.1462-5822.2006.00705.X
Abstract: A marquee feature of the powerful human pathogen Mycobacterium tuberculosis is its macrophage parasitism. The intracellular survival of this microorganism rests upon its ability to arrest phagolysosome biogenesis, avoid direct cidal mechanisms in macrophages, and block efficient antigen processing and presentation. Mycobacteria prevent Rab conversion on their phagosomes and elaborate glycolipid and protein trafficking toxins that interfere with Rab effectors and regulation of specific organellar biogenesis in mammalian cells. One of the major Rab effectors affected in this process is the type III phosphatidylinositol 3-kinase hVPS34 and its enzymatic product phosphatidylinositol 3-phosphate (PI3P), a regulatory lipid earmarking organellar membranes for specific trafficking events. PI3P is also critical for the process of autophagy, recently recognized as an effector of innate and adaptive immunity. Induction of autophagy by physiological, pharmacological or immunological signals, including the major antituberculosis Th1 cytokine IFN-gamma and its downstream effector p47 GTPase LRG-47, can overcome mycobacterial phagosome maturation block and inhibit intracellular M. tuberculosis survival. This review summarizes the findings centred around the PI3P-nexus where the mycobacterial phagosome maturation block and execution stages of autophagy intersect.
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for James Harris.