Bronwyn is an Associate Professor of Immunology and Director of Undergraduate Programs (Faculty of Science). She is a core member of the Centre for Health Technologies (Key University Research Strength).
Bronwyn's major research interest is investigating the role of macrophages in the development of autoimmunity. She is currently conducting expression and functional studies of SLC11A1, a gene specifically expressed in antigen-presenting cells (macrophages and dendritic cells) that modulates the immune cell balance to influence the development of autoimmune disease. A greater understanding of the expression and function of this gene may provide novel avenues for modulating macrophage and dendritic cell function and consequently stop the development of autoimmune disease.
With funding from the Juvenile Diabetes Research Foundation (JDRF) Bronwyn is currently investigating the use of novel parasite antigens to prevent the initiation of autoimmunity. This work was prompted by epidemiological observations that in regions where parasitic worm infections are endemic there is a very low incidence of autoimmune disease. Our group has been able to prevent autoimmune diabetes in a rodent model using parasite secretions and we are now planning to test individual molecules within the secretions for their efficacy in preventing autoimmune disease. This project may ultimately lead to novel therapeutic strategies to prevent diabetes, and perhaps more broadly, autoimmunity per se.
Bronwyn is also conducting preliminary research to identify novel biomarkers of hypoglycaemia in exhaled air with the objective of developing a reliable, noninvasive means of detecting impending hypoglycaemia. This work was prompted by anecdotal evidence that some dogs owned by Type 1 diabetics can alert there owners to impending hypoglycaemia even when the dogs cannot see their owners. The stimulus for the dog‚Äôs behaviour is likely compounds that transit from the blood into exhaled air to provide a breath signature of hypoglycaemia.
Australasian Society for Immunology
Australian Diabetes Society
Transplantation Society of Australia and New Zealand
Can supervise: YES
Bronwyn‚Äôs research area is the immunology of autoimmune disease.
Bronwyn is investigating the role of macrophages in the development of autoimmune disease, specifically type 1 (juvenile-onset, insulin-dependent) diabetes.
She is also involved in NHMRC-funded research investigating the liver-directed gene therapy of diabetes.
With funding from JDRF Bronwyn is currently investigating the use of novel parasite antigens to prevent the initiation of autoimmunity in Type 1 diabetes.
Bronwyn is also conducting preliminary research to identify novel biomarkers of hypoglycaemia in exhaled air with the objective of developing a reliable, noninvasive means of detecting impending hypoglycaemia.
Bronwyn coordinates the advanced Immunology subject (Immunology 2) offered by the Faculty of Science.
Ren, B., La, Q.T., O'Brien, B.A., Nassif, N.T., Tan, Y., Gerace, D., Martiniello-Wilks, R., Torpy, F., Dane, A.P., Alexander, I.E. & Simpson, A.M. 2018, 'Partial pancreatic transdifferentiation of primary human hepatocytes in the livers of a humanised mouse model.', The journal of gene medicine, vol. 20, no. 5, p. e3017.View/Download from: UTS OPUS or Publisher's site
Gene therapy is one treatment that may ultimately cure type 1 diabetes. We have previously shown that the introduction of furin-cleavable human insulin (INS-FUR) to the livers in several animal models of diabetes resulted in the reversal of diabetes and partial pancreatic transdifferentiation of liver cells. The present study investigated whether streptozotocin-diabetes could be reversed in FRG mice in which chimeric mouse-human livers can readily be established and, in addition, whether pancreatic transdifferentiation occurred in the engrafted human hepatocytes.Engraftment of human hepatocytes was confirmed by measuring human albumin levels. Following delivery of the empty vector or the INS-FUR vector to diabetic FRG mice, mice were monitored for weight and blood glucose levels. Intraperitoneal glucose tolerance tests (IPGTTs) were performed. Expression levels of pancreatic hormones and transcription factors were determined by a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry.Diabetes was reversed for a period of 60 days (experimental endpoint) after transduction with INS-FUR. IPGTTs of the insulin-transduced animals were not significantly different from nondiabetic animals. Immunofluorescence microscopy revealed the expression of human albumin and insulin in transduced liver samples. Quantitative RT-PCR showed expression of human and mouse endocrine hormones and -cell transcription factors, indicating partial pancreatic transdifferentiation of mouse and human hepatocytes. Nonfasting human C-peptide levels were significantly higher than mouse levels, suggesting that transdifferentiated human hepatocytes made a significant contribution to the reversal of diabetes.These data show that human hepatocytes can be induced to undergo partial pancreatic transdifferentiation in vivo, indicating that the technology holds promise for the treatment of type 1 diabetes.
Alvarado, R, To, J, Lund, ME, Pinar, A, Mansell, A, Robinson, MW, O'Brien, BA, Dalton, JP & Donnelly, S 2017, 'The immune modulatory peptide FhHDM-1 secreted by the helminth Fasciola hepatica prevents NLRP3 inflammasome activation by inhibiting endolysosomal acidification in macrophages.', FASEB journal : official publication of the Federation of American Societies for Experimental Biology, vol. 31, no. 1, pp. 85-95.View/Download from: UTS OPUS or Publisher's site
The NLRP3 inflammasome is a multimeric protein complex that controls the production of IL-1, a cytokine that influences the development of both innate and adaptive immune responses. Helminth parasites secrete molecules that interact with innate immune cells, modulating their activity to ultimately determine the phenotype of differentiated T cells, thus creating an immune environment that is conducive to sustaining chronic infection. We show that one of these molecules, FhHDM-1, a cathelicidin-like peptide secreted by the helminth parasite, Fasciola hepatica, inhibits the activation of the NLRP3 inflammasome resulting in reduced secretion of IL-1 by macrophages. FhHDM-1 had no effect on the synthesis of pro-IL-1. Rather, the inhibitory effect was associated with the capacity of the peptide to prevent acidification of the endolysosome. The activation of cathepsin B protease by lysosomal destabilization was prevented in FhHDM-1-treated macrophages. By contrast, peptide derivatives of FhHDM-1 that did not alter the lysosomal pH did not inhibit secretion of IL-1. We propose a novel immune modulatory strategy used by F. hepatica, whereby secretion of the FhHDM-1 peptide impairs the activation of NLRP3 by lysosomal cathepsin B protease, which prevents the downstream production of IL-1 and the development of protective T helper 1 type immune responses that are detrimental to parasite survival.-Alvarado, R., To, J., Lund, M. E., Pinar, A., Mansell, A., Robinson, M. W., O'Brien, B. A., Dalton, J. P., Donnelly, S. The immune modulatory peptide FhHDM-1 secreted by the helminth Fasciola hepatica prevents NLRP3 inflammasome activation by inhibiting endolysosomal acidification in macrophages.
Tanaka, A., To, J., O'Brien, B., Donnelly, S. & Lund, M. 2017, 'Selection of reliable reference genes for the normalisation of gene expression levels following time course LPS stimulation of murine bone marrow derived macrophages.', BMC Immunology, vol. 18, no. 1, pp. 1-12.View/Download from: UTS OPUS or Publisher's site
Macrophages are key players in the initiation, perpetuation and regulation of both innate and adaptive immune responses. They largely perform these roles through modulation of the expression of genes, especially those encoding cytokines. Murine bone marrow derived macrophages (BMDMs) are commonly used as a model macrophage population for the study of immune responses to pro-inflammatory stimuli, notably lipopolysaccharide (LPS), which may be pertinent to the human situation. Evaluation of the temporal responses of LPS stimulated macrophages is widely conducted via the measurement of gene expression levels by RT-qPCR. While providing a robust and sensitive measure of gene expression levels, RT-qPCR relies on the normalisation of gene expression data to a stably expressed reference gene. Generally, a normalisation gene(s) is selected from a list of "traditional" reference genes without validation of expression stability under the specific experimental conditions of the study. In the absence of such validation, and given that many studies use only a single reference gene, the reliability of data is questionable.The stability of expression levels of eight commonly used reference genes was assessed during the peak (6 h) and resolution (24 h) phases of the BMDM response to LPS. Further, this study identified two additional genes, which have not previously been described as reference genes, and the stability of their expression levels during the same phases of the inflammatory response were validated. Importantly, this study demonstrates that certain "traditional" reference genes are in fact regulated by LPS exposure, and, therefore, are not reliable candidates as their inclusion may compromise the accuracy of data interpretation. Testament to this, this study shows that the normalisation of gene expression data using an unstable reference gene greatly affects the experimental data obtained, and, therefore, the ultimate biological conclusions drawn.This study reaffirms ...
Donnelly, S., Huston, W.M., Johnson, M., Tiberti, N., Saunders, B., O'Brien, B., Burke, C., Labbate, M. & Combes, V. 2017, 'Targeting the master regulator mTOR: a new approach to prevent the neurological of consequences of parasitic infections?', Parasites & Vectors, vol. 10, no. 1, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
A systematic analysis of 240 causes of death in 2013 revealed that parasitic diseases were responsible for more than one million deaths. The vast majority of these fatalities resulted from protozoan infections presenting with neurological sequelae. In the absence of a vaccine, development of effective therapies is essential to improving global public health. In 2015, an intriguing strategy to prevent cerebral malaria was proposed by Gordon et al. 2015 mBio, 6:e00625. Their study suggested that inhibition of the mammalian target of rapamycin prevented experimental cerebral malaria by blocking the damage to the blood brain barrier and stopping the accumulation of parasitized red blood cells and T cells in the brain. Here, we hypothesize that the same therapeutic strategy could be adopted for other protozoan infections with a brain tropism, to prevent cerebral parasitosis by limiting pathogen replication and preventing immune mediated destruction of brain tissue.
Lund, M.E., Greer, J., Dixit, A., Alvarado, R., McCauley-Winter, P., To, J., Tanaka, A., Hutchinson, A.T., Robinson, M.W., Simpson, A.M., O'Brien, B.A., Dalton, J.P. & Donnelly, S. 2016, 'A parasite-derived 68-mer peptide ameliorates autoimmune disease in murine models of Type 1 diabetes and multiple sclerosis.', Scientific Reports, vol. 6, pp. 1-11.View/Download from: UTS OPUS or Publisher's site
Helminth parasites secrete molecules that potently modulate the immune responses of their hosts and, therefore, have potential for the treatment of immune-mediated human diseases. FhHDM-1, a 68-mer peptide secreted by the helminth parasite Fasciola hepatica, ameliorated disease in two different murine models of autoimmunity, type 1 diabetes and relapsing-remitting immune-mediated demyelination. Unexpectedly, FhHDM-1 treatment did not affect the proliferation of auto-antigen specific T cells or their production of cytokines. However, in both conditions, the reduction in clinical symptoms was associated with the absence of immune cell infiltrates in the target organ (islets and the brain tissue). Furthermore, after parenteral administration, the FhHDM-1 peptide interacted with macrophages and reduced their capacity to secrete pro-inflammatory cytokines, such as TNF and IL-6. We propose this inhibition of innate pro-inflammatory immune responses, which are central to the initiation of autoimmunity in both diseases, prevented the trafficking of autoreactive lymphocytes from the periphery to the site of autoimmunity (as opposed to directly modulating their function per se), and thus prevented tissue destruction. The ability of FhHDM-1 to modulate macrophage function, combined with its efficacy in disease prevention in multiple models, suggests that FhHDM-1 has considerable potential as a treatment for autoimmune diseases.
Lund, ME, To, J, O'Brien, BA & Donnelly, S 2016, 'The choice of phorbol 12-myristate 13-acetate differentiation protocol influences the response of THP-1 macrophages to a pro-inflammatory stimulus', JOURNAL OF IMMUNOLOGICAL METHODS, vol. 430, pp. 64-70.View/Download from: UTS OPUS or Publisher's site
Ren, B., Tao, C., Swan, M.A., Joachim, N., Martiniello-Wilks, R., Nassif, N.T., O'Brien, B.A. & Simpson, A.M. 2016, 'Pancreatic Transdifferentiation and Glucose-Regulated Production of Human Insulin in the H4IIE Rat Liver Cell Line', INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, vol. 17, no. 4.View/Download from: UTS OPUS or Publisher's site
Gerace, D., Martiniello-Wilks, R., O'Brien, B.A. & Simpson, A.M. 2015, 'The use of beta-cell transcription factors in engineering artificial beta cells from non-pancreatic tissue', GENE THERAPY, vol. 22, no. 1, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
Alvarado, R., O'Brien, B., Tanaka, A., Dalton, J.P. & Donnelly, S. 2015, 'A parasitic helminth-derived peptide that targets the macrophage lysosome is a novel therapeutic option for autoimmune disease', IMMUNOBIOLOGY, vol. 220, no. 2, pp. 262-269.View/Download from: UTS OPUS or Publisher's site
Archer, N.S., Nassif, N.T. & O'Brien, B.A. 2015, 'Genetic variants of SLC11A1 are associated with both autoimmune and infectious diseases: systematic review and meta-analysis.', Genes and immunity, vol. 16, no. 4, pp. 275-283.View/Download from: UTS OPUS or Publisher's site
A systematic review and meta-analyses were undertaken to investigate the association of SLC11A1 genetic variants with disease occurrence. Literature searching indentified 109 publications to include in the meta-analyses assessing the association of 11 SLC11A1 variants with autoimmune and infectious disease. The (GT)n promoter alleles 2 and 3 (rs534448891), which alter SLC11A1 expression, were significantly associated with tuberculosis (OR=1.47 (1.30-1.66), OR=0.76 (0.65-0.89), respectively) and infectious disease (OR=1.25 (1.10-1.42), OR=0.83 (0.74-0.93), respectively). However, although no association was observed with autoimmune disease, a modest significant association was observed with type 1 diabetes (allele 2 OR=0.94 (0.89-0.98)). On the basis of a stronger association of (GT)n allele 2 with tuberculosis, compared with the protective effect of allele 3, we hypothesise that allele 2 is likely the disease-causing variant influencing disease susceptibility. Significant associations were observed between the 469+14G/C polymorphism (rs3731865) and autoimmune disease (OR=1.30 (1.04-1.64)) and rheumatoid arthritis (OR=1.60 (1.20-2.13)) and between the -237C/T polymorphism (rs7573065) and inflammatory bowel disease (OR=0.60 (0.43-0.84)). Further, significant associations were identified between the 469+14G/C, 1730G/A and 1729+55del4 polymorphisms (rs3731865, rs17235409 and rs17235416, respectively) and both infectious disease per se and tuberculosis. These findings show a clear association between variants in the SLC11A1 locus and autoimmune and infectious disease susceptibility.
Lawandi, J, Tao, C, Ren, B, Williams, P, Ling, D, Swan, MA, Nassif, NT, Torpy, FR, O'Brien, BA & Simpson, AM 2015, 'Reversal of diabetes following transplantation of an insulin-secreting human liver cell line: Melligen cells.', Molecular therapy. Methods & clinical development, vol. 2, p. 15011.View/Download from: UTS OPUS or Publisher's site
As an alternative to the transplantation of islets, a human liver cell line has been genetically engineered to reverse type 1 diabetes (TID). The initial liver cell line (Huh7ins) commenced secretion of insulin in response to a glucose concentration of 2.5 mmol/l. After transfection of the Huh7ins cells with human islet glucokinase, the resultant Melligen cells secreted insulin in response to glucose within the physiological range; commencing at 4.25 mmol/l. Melligen cells exhibited increased glucokinase enzymatic activity in response to physiological glucose concentrations, as compared with Huh7ins cells. When transplanted into diabetic immunoincompetent mice, Melligen cells restored normoglycemia. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that both cell lines expressed a range of -cell transcription factors and pancreatic hormones. Exposure of Melligen and Huh7ins cells to proinflammatory cytokines (TNF-, IL-1, and IFN-) affected neither their viability nor their ability to secrete insulin to glucose. Gene expression (microarray and qRT-PCR) analyses indicated the survival of Melligen cells in the presence of known -cell cytotoxins was associated with the expression of NF-B and antiapoptotic genes (such as BIRC3). This study describes the successful generation of an artificial -cell line, which, if encapsulated to avoid allograft rejection, may offer a clinically applicable cure for T1D.
Lund, M.E., O'Brien, B., Hutchinson, A.T., Robinson, M.W., Simpson, A.M., Dalton, J.P. & Donnelly, S.M. 2014, 'Secreted proteins from the helminth Fasciola hepatica inhibit the initiation of autoreactive T cell responses and prevent diabetes in the NOD mouse', PLoS One, vol. 9, no. 1, p. e86289.View/Download from: UTS OPUS or Publisher's site
Infections with helminth parasites prevent/attenuate auto-inflammatory disease. Here we show that molecules secreted by a helminth parasite could prevent Type 1 Diabetes (T1D) in nonobese diabetic (NOD) mice. When delivered at 4 weeks of age (coincident with the initiation of autoimmunity), the excretory/secretory products of Fasciola hepatica (FhES) prevented the onset of T1D, with 84% of mice remaining normoglycaemic and insulitis-free at 30 weeks of age. Disease protection was associated with suppression of IFN-? secretion from autoreactive T cells and a switch to the production of a regulatory isotype (from IgG2a to IgG1) of autoantibody. Following FhES injection, peritoneal macrophages converted to a regulatory M2 phenotype, characterised by increased expression levels of Ym1, Arg-1, TGF and PD-L1. Expression of these M2 genetic markers increased in the pancreatic lymph nodes and the pancreas of FhES-treated mice. In vitro, FhES-stimulated M2 macrophages induced the differentiation of Tregs from splenocytes isolated from nave NOD mice. Collectively, our data shows that FhES contains immune-modulatory molecules that mediate protection from autoimmune diabetes via the induction and maintenance of a regulatory immune environment.
Robinson, MW, Dalton, JP, O'Brien, B & Donnelly, SM 2013, 'Fasciola hepatica: The therapeutic potential of a worm secretome', International Journal For Parasitology, vol. 43, no. 3-4, pp. 283-291.View/Download from: UTS OPUS or Publisher's site
The success of helminth parasites is partly related to their ability to modulate host immune responses towards an anti-inflammatory/regulatory phenotype. This ability resides with the molecules contained in the secretome of various helminths that have been shown to interact with host immune cells and influence their function. Consequently, there exists a unique opportunity to exploit these molecules for the prophylactic and therapeutic treatment of human pro- and auto-inflammatory disorders (for example septic shock, transplant rejection and autoimmune disease). In this review, we describe the mechanisms used by the trematode parasite, Fasciola hepatica, to modulate the immune responses of its host and discuss the potent immune-modulatory effects of three individual molecules within the secretome; namely cathepsin L1, peroxiredoxin and helminth defence molecule. With a focus on the requirements from industry, we discuss the strategies by which these molecules may be clinically developed to control human immune responses in a way that is conducive to the prevention of immune-mediated diseases.
Gerace, D., Ren, B., Hawthorne, W., Byrne, M., Phillips, P., O'Brien, B., Nassif, N., Alexander, I. & Simpson, A.M. 2013, 'Pancreatic transdifferentiation in porcine liver following lentiviral delivery of human furin-cleavable insulin', Transplantation Proceedings, vol. 45, no. 5, pp. 1869-1874.View/Download from: UTS OPUS or Publisher's site
Type I diabetes mellitus (TID) results from the autoimmune destruction of the insulin-producing pancreatic -cells. Gene therapy is one strategy being actively explored to cure TID by affording non--cells the ability to secrete insulin in response to physiologic stimuli. In previous studies, we used a novel surgical technique to express furin-cleavable human insulin (INS-FUR) in the livers of streptozotocin (STZ)-diabetic Wistar rats and nonobese diabetic (NOD) mice with the use of the HMD lentiviral vector. Normoglycemia was observed for 500 and 150 days, respectively (experimental end points). Additionally, some endocrine transdifferentiation of the liver, with storage of insulin in granules, and expression of some -cell transcription factors (eg, Pdx1, Neurod1, Neurog3, Nkx2-2, Pax4) and pancreatic hormones in both studies. The aim of this study was to determine if this novel approach could induce liver to pancreatic transdifferentiation to reverse diabetes in pancreatectomized Westran pigs. Nine pigs were used in the study, however only one pig maintained normal fasting blood glucose levels for the period from 10 to 44 days (experimental end point). This animal was given 2.8 10(9) transducing units/kg of the lentiviral vector expressing INS-FUR. A normal intravenous glucose tolerance test was achieved at 30 days. Reverse-transcription polymerase chain reaction analysis of the liver tissue revealed expression of several -cell transcription factors, including the key factors, Pdx-1 and Neurod1, pancreatic hormones, glucagon, and somatostatin; however, endogenous pig insulin was not expressed.
Ren, B., O'Brien, B., Byrne, M., Ch'ng, E., Gatt, P.N., Swan, M.A., Nassif, N., Wei, M., Gijsbers, R., Debyser, Z. & Simpson, A.M. 2013, 'Long-term reversal of diabetes in non-obese diabetic mice by liver-directed gene therapy.', The Journal of gene Medicine, vol. 15, no. 1, pp. 28-41.View/Download from: UTS OPUS or Publisher's site
Background Type 1 diabetes (T1D) results from an autoimmune attack against the insulin-producing -cells of the pancreas. The present study aimed to reverse T1D by gene therapy. Methods We used a novel surgical technique, which involves isolating the liver from the circulation before the delivery of a lentiviral vector carrying furin-cleavable human insulin (INS-FUR) or empty vector to the livers of diabetic non-obese diabetic mice (NOD). This was compared with the direct injection of the vector into the portal circulation. Mice were monitored for body weight and blood glucose. Intravenous glucose tolerance tests were performed. Expression of insulin and pancreatic transcription factors was determined by the reverse transcriptase-polymerase chain reaction and immunohistochemistry and immunoelectron microscopy was used to localise insulin. Results Using the novel surgical technique, we achieved long-term transduction (42% efficiency) of hepatocytes, restored normoglycaemia for 150 days (experimental endpoint) and re-established normal glucose tolerance. We showed the expression of -cell transcription factors, murine insulin, glucagon and somatostatin, and hepatic storage of insulin in granules. The expression of hepatic markers, C/EBP-, G6PC, AAT and GLUI was down-regulated in INS-FUR-treated livers. Liver function tests remained normal, with no evidence of intrahepatic inflammation or autoimmune destruction of the insulin-secreting liver tissue. By comparison, direct injection of INS-FUR reduced blood glucose levels, and no pancreatic transdifferentiation or normal glucose tolerance was observed.
Simpson, A.M., Ren, B., O'Brien, B.A. & Nassif, N.T. 2013, 'Response to the letter to the editor by M. Elsner et al: "comment on Binhai Ren et al (2013;15:28-41). Long term reversal of diabetes in non-obese diabetic mice by liver-directed gene therapy".', The journal of gene medicine, vol. 15, no. 8-9, pp. 309-310.View/Download from: UTS OPUS or Publisher's site
Robinson, M.W., Alvarado, R., To, J., Hutchinson, A.T., Dowdell, S.N., Lund, M.E., Turnbull, L., Whitchurch, C.B., O'Brien, B., Dalton, J.P. & Donnelly, S.M. 2012, 'A helminth cathelicidin-like protein suppresses antigen processing and presentation in macrophages via inhibition of lysosomal vATPase', Faseb Journal, vol. 26, no. 11, pp. 4614-4627.View/Download from: UTS OPUS or Publisher's site
We previously reported the identification of a novel family of immunomodulatory proteins, termed helminth defense molecules (HDMs), that are secreted by medically important trematode parasites. Since HDMs share biochemical, structural, and functional characteristics with mammalian cathelicidin-like host defense peptides (HDPs), we proposed that HDMs modulate the immune response via molecular mimicry of host molecules. In the present study, we report the mechanism by which HDMs influence the function of macrophages. We show that the HDM secreted by Fasciola hepatica (FhHDM-1) binds to macrophage plasma membrane lipid rafts via selective interaction with phospholipids and/or cholesterol before being internalized by endocytosis. Following internalization, FhHDM-1 is rapidly processed by lysosomal cathepsin L to release a short C-terminal peptide (containing a conserved amphipathic helix that is a key to HDM function), which then prevents the acidification of the endolysosomal compartments by inhibiting vacuolar ATPase activity. The resulting endolysosomal alkalization impedes macrophage antigen processing and prevents the transport of peptides to the cell surface in conjunction with MHC class II for presentation to CD4(+) T cells. Thus, we have elucidated a novel mechanism by which helminth pathogens alter innate immune cell function to assist their survival in the host.-Robinson, M. W., Alvarado, R., To, J., Hutchinson, A. T., Dowdell, S. N., Lund, M., Turnbull, L., Whitchurch, C. B., O'Brien, B. A., Dalton, J. P., Donnelly, S. A helminth cathelicidin-like protein suppresses antigen processing and presentation in macrophages via inhibition of lysosomal vATPase
Feller, J.M., Simpson, A.M., Nelson, M., Swan, M.A., O'Connell, P.J., Hawthorne, W.J., Tao, C.Z. & O'Brien, B. 2008, 'Growth-promoting effect of Rh(D) antibody on human pancreatic islet cells', Journal of Clinical Endocrinology and Metabolism, vol. 93, no. 9, pp. 3560-3567.View/Download from: UTS OPUS or Publisher's site
Context/Objective: Hyperinsulinism with islet cell hyperplasia is a frequent complication, of unknown cause, in hemolytic disease of the newborn, occurring in Rh(D)-positive infants of Rh-isoimmunized Rh(D)-negative mothers, but not in infants with other hemolytic disorders. We investigated the possibility that trans-placentally acquired anti-D Ig is the cause of both conditions. Design: Monolayer cultures of human islet cells were exposed to sera from Rh-isoimmunized mothers and newborns, where jaundice, hyperinsulinism, and hypoglycemia in the infant had ensued. Parallel cultures with anti-D, specific anti-D monoclonal antibodies, normal human Ig (15 Î¼g/ml), and serum controls were also undertaken. Islet cell proliferation was determined by [ 3H]thymidine incorporation. Insulin storage and chronic and acute insulin secretion to glucose were analyzed by RIA. Rh(D) surface antigen expression was determined on islet cells by flow cytometric analysis. Results: Islet cell proliferation and insulin secretion were significantly greater in coculture with test sera (P < 0.01; n = 8) and with anti-D (P < 0.001; n = 8), compared with either controls or Ig. After 8 d of growth, the static incubation experiment showed a 3.5-fold response to glucose stimulus in all sera. Rh(D) antigen expression was detected on the islet cell surface by flow cytometry, and islet cell morphology was normal. Colocalization of the proliferation marker Ki67 with insulin by immunofluorescent staining further indicated that Rh(D) antibody promoted islet growth. Conclusions: The anti-Rh(D) islet cell proliferative effect generates neonatal hyperinsulinism in Rh isoimmunization. Anti-Rh(D) may have application for islet cell proliferation in diabetes mellitus treatment for Rh(D)-positive subjects. Further analysis is required. Copyright © 2008 by The Endocrine Society.
Simpson, A.M. & O'Brien, B. 2008, 'Diabetes therapy by lentiviral hepatic insulin gene expression without transofrmation of liver. Reply to Elsner M, Jorns A, Lenzen S (letter)', Diabetologia, vol. 51, pp. 696-696.
O'Brien, B., Archer, N.S., Simpson, A.M., Torpy, F.R. & Nassif, N. 2008, 'Association of SLC11A1 promoter polymorphisms with the incidence of autoimmune and inflammatory diseases: A meta-analysis', Journal Of Autoimmunity, vol. 31, no. 1, pp. 42-51.View/Download from: UTS OPUS or Publisher's site
Solute carrier family 11 member a1 (SLC11A1) exerts pleiotropic effects on macrophage function. Expression of SLC11A1 is regulated by a (GT)(n) microsatellite promoter repeat polymorphism of which nine alleles have been described. Enhanced activation of
Lawandi, J., O'Brien, B. & Simpson, A.M. 2007, 'An Insulin Secreting Liver Cell Line, Tao, Is Resistant To The Cytotoxic Effects Of Pro-inflammatory Cytokines Via Nf-kb-dependent Pathways', Journal Of Gene Medicine, vol. 9, no. 6, pp. 527-527.
Ren, B., O'Brien, B., Swan, M.A., Koina, M.E., Nassif, N., Wei, M.Q. & Simpson, A.M. 2007, 'Long-term Correction Of Diabetes In Rats After Lentiviral Hepatic Insulin Gene Therapy', Diabetologia, vol. 50, no. 9, pp. 1910-1920.View/Download from: UTS OPUS or Publisher's site
Aims/hypothesis Type 1 diabetes results from the autoimmune destruction of pancreatic beta cells. Exogenous insulin therapy cannot achieve precise physiological control of blood glucose concentrations, and debilitating complications develop. Lentiviral v
O'Brien, B, Geng, X, Orteu, CH, Huang, Y, Ghoreishi, M, Zhang, Y, Bush, JA, Li, G, Finegood, DT & Dutz, JP 2006, 'A deficiency in the in vivo clearance of apopototic cells is a feature of the NOD mouse', Journal of Autoimmunity, vol. 26, no. 2, pp. 104-115.View/Download from: UTS OPUS or Publisher's site
Deficiencies in apoptotic cell clearance have been linked to autoimmunity. Here we examined the time-course of peritoneal macrophage phagocytosis of dying cells following the direct injection of apoptotic thymocytes into the peritoneum of NOD mice and BALB/c controls. Macrophages from NOD mice demonstrated a profound defect in the phagocytosis of apoptotic thymocytes as compared to control macrophages. Nonobese diabetic mice also demonstrated a decrease in the clearance of apoptotic cell loads following an apoptotic stimulus to thymocytes (dexamethasone) when compared to BALB/c or NOR controls. Further, NOD mice demonstrated an increase in apoptotic cell load following an apoptotic stimulus to keratinocytes (ultraviolet light, UVB) when compared to control strains. Animals deficient in macrophage phagocytosis of apoptotic debris often manifest an autoimmune phenotype characterized by the production of antinuclear autoantibodies (ANA). We determined whether increased apoptotic cell loads (through repeated exposure to UVB irradiation) could accelerate such autoimmune phenomena in young NOD mice. Following repeated UVB irradiation, NOD mice, but not BALB/c or NOR controls, developed ANA. We propose that abnormalities in apoptotic cell clearance by macrophages predispose NOD mice to autoimmunity.
Ren, B., O'Brien, B., Swan, M.A. & Simpson, A.M. 2005, 'In vivo delivery of the human insulin gene results in long-term reversal of streptozotocin-induced type 1 diabetes in rats', Journal Of Gene Medicine, vol. 7, no. 8, pp. 1124-1124.
O'Brien, B, Huang, Y, Geng, X, Dutz, JP & Finegood, DT 2002, 'Phagocytosis of apoptotic cells by macrophages from NOD mice is reduced', Diabetes, vol. 51, no. 8, pp. 2481-2488.View/Download from: UTS OPUS or Publisher's site
Macrophages limit inflammatory responses by clearing apoptotic cells. Deficiencies in apoptotic cell phagocytosis have been linked to autoimmunity. In this study, we determined the efficiency with which macrophages from diabetes-prone NOD and diabetes-resistant NOR, Idd5, Balb/c, and C57BL/6 mice phagocytose apoptotic thymocytes and NIT-1 insulinoma cells. Peritoneal and bone marrow-derived macrophages from NOD mice engulfed fewer apoptotic thymocytes than macrophages from Balb/c mice (P < 0.05). Peritoneal macrophages from NOR and Idd5 NOD congenic mice were more proficient at engulfment than their NOD counterparts. Annexin V blockade diminished apoptotic thymocyte clearance and heat-labile serum factors augmented clearance. Binding of apoptotic thymocytes to NOD macrophages was also reduced, suggesting that the deficiency in phagocytosis may be partly attributable to a recognition defect. Peritoneal macrophages from female Balb/c and NOD mice were equally efficient in the engulfment of microspheres, suggesting that the phagocytic deficiency observed in NOD mice was specific for apoptotic cells. In summary, we have demonstrated a deficiency in phagocytic function of macrophages from NOD mice. Normal and diabetes-prone neonatal rodents have a wave of -cell apoptosis coincident with the onset of target organ inflammation. A constitutive defect in the clearance of apoptotic -cells may be contributory to the initiation of autoimmunity.
O'Brien, B., Finegood, D.T., Fieldus, W.E. & Field, C.J. 2002, 'Clearance of apoptotic beta-cells is reduced in neonatal autoimmune diabetes-prone rats', Cell Death and Differentiation, vol. 9, no. 4, pp. 457-464.View/Download from: UTS OPUS or Publisher's site
The kinetics of -cell death in neonatal diabetes-prone (BBdp) and diabetes-resistant (BBdr) BioBreeding rats was investigated using both direct (histochemical) and indirect (mathematical modelling) techniques. In both BBdp and BBdr rats, the incidence of TUNEL positive -cells increased until 10 days of age before declining. The number of apoptotic -cells was significantly higher in BBdp as compared to BBdr neonates from birth until 20 days of age (P < 0.05). Using a mathematical model applied to the time course of -cell mass and replication rate, a wave of net -cell loss was detected between 10 and 20 days of age in both strains. In contrast to the observed difference in the incidence of TUNEL positive cells, with the model-based approach we found no difference in the rate of -cell apoptosis between BBdp and BBdr rats prior to weaning. As the number of apoptotic cells present in a tissue depends on the rate at which cells die and the rate at which the apoptotic cell debris is cleared, we compared in vitro phagocytosis of apoptotic thymocytes by peritoneal macrophages from 2-week-old BBdp and BBdr rats. Macrophages from BBdp neonates engulfed significantly less apoptotic cells as compared to BBdr neonates (P < 0.0005). Taken together, these findings suggest that there is impaired clearance of apoptotic -cells in diabetes-prone BB rats during the neonatal period
Zhang, Y, O'Brien, B, Trudeau, J, Tan, R, Santamaria, P & Dutz, JP 2002, 'In situ beta cell death promotes priming of diabetogenic CD8 T lymphocytes', Journal of Immunology, vol. 168, no. 3, pp. 1466-1472.View/Download from: UTS OPUS or Publisher's site
This paper was the first to report that increased beta cell death can lead to the priming of diabetogenic T cells, and hence, the initiation of autoimmunity in Type 1 diabetes. The Journal of Immunology is the top-ranked immunology journal.
Heczko, U., Carthy, C.M., O'Brien, B. & Finlay, B.B. 2001, 'Decreased apoptosis in the ileum and ileal Peyer's patches after infection with rabbit enteropathogenic Escherichia coli O103', Infection And Immunity, vol. 69, no. 7, pp. 4580-4589.View/Download from: UTS OPUS or Publisher's site
Significant changes occur in intestinal epithelial cells after infection with enteropathogenic Escherichia coli (EPEC), However, it is unclear whether this pathogen alters rates of apoptosis, By using: a naturally occurring weaned rabbit infection model, we determined physiological levels of apoptosis in rabbit ileum and ileal Peyer's patches (PP) and compared them to those found after infection with adherent rabbit EPEC (REPEC O103), Various REPEC O103 strains were first tested in vitro for characteristic virulence features. Rabbits were then inoculated with the REPEC O103 strains that infected cultured cells the most efficiently. After experimental infection, intestinal samples were examined by light and electron microscopy, Simultaneously, ileal apoptosis was assessed by using terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and caspase 3 assays and by apoptotic cell counts based on morphology (hematoxylin-and-eosin staining). The highest physiological apoptotic indices were measured in PP germinal centers (median = 14.7%), followed by PP domed villi (8.1%), tips of absorptive villi (3.8%), and ileal crypt regions (0.5%), Severe infection with REPEC O103 resulted in a significant decrease in apoptosis in PP germinal centers (determined by TUNEL assay; P = 0.01), in the tips of ileal absorptive villi (determined by H&E staining; P = 0.04), and in whole ileal cell lysates (determined by caspase 3 assay; P = 0.001). We concluded that REPEC O103 does not promote apoptosis, Furthermore, we cannot rule out the possibility that REPEC O103, in fact, decreases apoptotic levels in the rabbit ileum.
O'Brien, B, Harmon, BV, Cameron, DP & Allan, DJ 2000, 'Nicotinamide prevents the development of diabetes in the cyclophosphamide-induced NOD mouse model by blocking beta cell apoptosis', Journal of Pathology, vol. 191, no. 1, pp. 86-92.View/Download from: UTS OPUS
The development of diabetes in non-obese diabetic (NOD) mice, which normally takes between 3 and 7 months, can be accelerated by cyclophosphamide (CY) injections, with rapid progression to diabetes within only 2±3 weeks. This insulin-dependent diabetes mellitus (IDDM) can be prevented or delayed in CY-treated NOD mice by nicotinamide (NA). The present study was undertaken to determine the mode of cell death responsible for the development of IDDM in CYtreated male NOD mice and to investigate the effect of NA on beta-cell death. Apoptotic beta cells were present within the islets of Langerhans in haematoxylin and eosin-stained sections of the pancreata harvested from 3- and 12-week-old male NOD mice, from 8 h until 14 days after a single intraperitoneal injection of CY (150 mg/kg body weight). The maximum amount of betacell apoptosis in 3-week-old animals occurred 1±2 days after CY treatment (20 apoptotic cells per 100 islets), after which time levels of apoptosis declined steadily throughout the 14-day period studied. The incidence of beta-cell apoptosis in 12-week-old male NOD mice occurred in two peaks; the ®rst was recorded 8±24 h after CY treatment (30 apoptotic cells/100 islets), while the second, at 7 days (36 apoptotic cells per 100 islets), coincided with increased insulitis. Administration of NA 15 min before CY treatment, and thereafter daily, substantially reduced the amount of apoptosis and effectively eliminated (4 apoptotic cells per 100 islets) the second wave of beta-cell apoptosis seen at day 7 in 12-week-old animals given CY alone. These results show that apoptosis is the mode of beta-cell death responsible for the development of CY-induced IDDM and that prevention of IDDM by NA is associated with a reduction in beta-cell apoptosis.
Allan, DJ, Cameron, DP, Harmon, BV & O'Brien, B 1997, 'Apoptosis is the mode of beta-cell death responsible for the development of IDDM in the nonobese diabetic (NOD) mouse', Diabetes, vol. 46, no. 5, pp. 750-757.View/Download from: UTS OPUS or Publisher's site
The NOD/Lt mouse, a widely used model of human autoimmune IDDM, was used to establish the mode of beta-cell death responsible for the development of IDDM. Apoptotic cells were present within the islets of Langerhans in hematoxylin and eosin-stained sections of pancreases harvested from 3- to 18-week-old female NOD/Lt mice (a range of 11-50 apoptotic cells per 100 islets). Immunohistochemical localization of insulin to the dying cells confirmed the beta-cell origin of the apoptosis. Although some islets from age-matched control female NOD/scid mice contained apoptotic cells, virtually all of these cells were insulin negative as determined by immunohistochemistry. The small number of apoptotic insulin-positive cells identified in islets from NOD/scid mice (a range of 0-1 apoptotic cells per 100 islets) was not statistically significant, compared with the numbers recorded in NOD/Lt mice. All dying cells showed the morphological changes characteristic of cell death by apoptosis and stained positively with the TUNEL method for end-labeling DNA strand breaks. The maximum mean amount of beta-cell apoptosis occurring in NOD/Lt mice was at week 15 (50 apoptotic cells per 100 islets), which coincided with the earliest onset of diabetes as determined by blood glucose, urine glucose, and pancreatic immunoreactive insulin measurements. While there was no peak incidence of beta-cell apoptosis throughout the time period studied (weeks 3-18), the incidence of apoptosis decreased at week 18, by which time 50% of the animals had overt diabetes. The low levels of beta-cell apoptosis observed is indicative of a gradual deletion of the beta-cell population throughout the extensive preclinical period seen in this model and would be sufficient to account for the beta-cell loss resulting in IDDM. Apoptosis of beta-cells preceded the appearance of T-cells (CD3-positive by immunohistochemistry) in islets.
O'Brien, B, Harmon, BV, Cameron, DP & Allan, DJ 1996, 'Beta cell apoptosis is responsible for the development of IDDM in the multiple low-dose streptozotocin model', Journal Of Pathology, vol. 178, pp. 176-181.View/Download from: UTS OPUS
Although insulin-dependent diabetes mellitus (IDDM) results from irreversible loss of beta cells, the mode of cell death responsible for this loss has not previously been categorized. In this study, the multiple low-dose streptozotocin (stz) model (intraperitoneal injection of stz at a concentration of 40 mglkg body weight per day for five consecutive days) was used to investigate beta-cell death during the development of IDDM in male C57B116 mice. Apoptotic cells were evident by light microscopy within the islets of Langerhans of treated animals from day 2 (the day of the second stz injection) until day 17. Immunohistochemical localization of insulin to the dying cells confirmed the beta-cell origin of the apoptosis. Two peaks in the incidence of beta-cell apoptosis occurred: the first at day 5, which corresponded to an increase in blood glucose concentration, and the second at day 11, when lymphocytic infiltration of the islets (insulitis) was maximal. Insulitis did not begin until day 9, by which time treated animals had developed overt diabetes as revealed by blood glucose and pancreatic immunoreactive insulin (IRI) measurements. Beta-cell apoptosis preceded the appearance of T-cells in the islets and continued throughout the period of insulitis. Thus, whether induced by stz or a subsequent immune response, apoptosis is the mode of cell death responsible for beta-cell loss in the multiple low-dose stz model of IDDM.
Kane, E., McCabe, B. & O'Brien, B. 1987, 'Professional affiliations.', Nursing administration quarterly, vol. 11, no. 4, pp. 33-34.
Simpson, A.M., Swan, M.A., Liu, G.J., Tao, C.Z., O'Brien, B., Ch'ng, E., Castro, L.M., Ting, H.J., Elgundi, Z., An, T., Lutherborrow, M., Torpy, F.R., Martin, D.K., Tuch, B.E. & Nicholson, G.M. 2013, 'Insulin trafficking in a glucose responsive engineered human liver cell line is regulated by the interaction of ATP-sensitive potassium channels and voltage- gated calcium channels' in Molina, F.M. (ed), Gene Therapy - Tools and Potential Applications, In-Tech, Rijeka, Croatia, pp. 703-726.View/Download from: UTS OPUS or Publisher's site
Type I diabetes is caused by the autoimmune destruction of pancreatic beta (â) cells . Current treatment requires multiple daily injections of insulin to control blood glucose levels. Tight glucose control lowers, but does not eliminate, the onset of diabetic complications, which greatly reduce the quality and longevity of life for patients. Transplantation of pancreatic tissue as a treatment is restricted by the scarcity of donors and the requirement for lifelong immunosuppression to preserve the graft, which carries adverse side-effects. This is of particular concern as Type 1 diabetes predominantly affects children. Lack of glucose control could be overcome by genetically engineering "an artificial â-cell" that is capable of synthesising, storing and secreting insulin in response to metabolic signals. The donor cell type must be readily accessible and capable of being engineered to synthesise, process, store and secrete insulin under physiological conditions.
O'Brien, B. 1998, 'Morphological criteria for identifying apoptosis.' in Celis, J.E. (ed), CELL BIOLOGY - A LABORATORY HANDBOOK, 2ND EDITION, VOL 1, Academic Press, USA, pp. 327-340.
Lawandi, J., Tao, C., Ren, B., Williams, P., Ling, D., Swan, M.A., Nassif, N.T., Torpy, F.R., O'Brien, B.A. & Simpson, A.M. 2015, 'MELLIGEN CELSS: AN INSULIN-SECRETING HUMAN LIVER CELL LINE WHICH IS RESISTANT TO CYTOKINE-INDUCED IMMUNE ATTACK', JOURNAL OF GENE MEDICINE, pp. 189-189.View/Download from: UTS OPUS
Ren, B., O'Brien, B.A., Alexander, I.E., Nassif, N.T., Tan, Y., Martiniello-Wilks, R. & Simpson, A.M. 2015, 'Pancreatic Transdiffereniation of Human Hepatocytes in the Livers of a Humanized Mouse Model', MOLECULAR THERAPY, pp. S110-S110.View/Download from: UTS OPUS
Simpson, A., Ren, B., O'Brien, B.A., Alexander, I.E., Nassif, N.T., Tan, Y. & Martiniello-Wilks, R. 2015, 'GENE THERAPY FOR DIABETES: REVERSAL OF DIABETES IN THE HUMANISED FRG MOUSE MODEL.', TRANSPLANTATION, pp. S67-S67.View/Download from: UTS OPUS
Gerace, D., Ren, B., Hawthorne, W.J., Byrne, M.R., Phillips, P., O'Brien, B.A., Nassif, N., Alexander, I.E. & Simpson, A.M. 2013, 'REVERSAL OF DIABETES IN A PORCINE MODEL FOLLOWING LIVER-DIRECTED GENE THERAPY', JOURNAL OF GENE MEDICINE, pp. 326-326.View/Download from: UTS OPUS
Biady, J., O'Brien, B. & Simpson, A.M. 2007, 'An insulin secreting liver cell line, TAO, is resistant to the cytotoxic effects of pro-inflammatory cytokines via NF-KB-dependent pathways', Journal of Gene Medicine, Wiley, Canberra, pp. 527-527.
Ren, B., O'Brien, B., Swan, M.A., Koina, M.E., Nassif, N. & Wei, M.Q. 2007, 'Delivery of furin-cleavable insulin to diabetic rat livers resulted in long-term correction of diabetes and partial pancreatic transdifferentiation of the liver', Journal of Gene Medicine, Wiley, Canberra, pp. 532-532.
Biady, J., Tao, C.Z., O'Brien, B. & Simpson, A.M. 2005, 'Susceptibility of an insulin-secreting liver cell line to the toxic effects of cytokines involved in the autoimmune destruction of pancreatic beta cells', Journal of Medicine, Wiley, Melbourne, pp. 1124-1124.
Lawandi, J., Tao, C.Z., O'Brien, B. & Simpson, A.M. 2005, 'Susceptibility of an insulin-secreting liver cell line to the toxic effects of cytokines involved in the autoimmune destruction of pancreatic beta cells', Journal Of Gene Medicine, 4th Meeting of the Australasian-Gene-Therapy-Society, Unknown, Melbourne, Australia, pp. 1124-1124.
O'Brien, B. 2002, 'In vivo phagocytosis of apoptotic cells by macrophages from NOD mice is reduced', Diabetes, Amer Diabetes Assoc, USA, pp. 1167-1167.
O'Brien, B. 2000, 'Beta-cell apoptosis in the neonatal BioBreeding rat.', Diabetes, Amer Diabetes Assoc, USA, pp. 1083-1083.