Tregs. Interestingly, expression of canonical Treg markers, such as FOXP3, TIGIT, and IKZF2, were... more Tregs. Interestingly, expression of canonical Treg markers, such as FOXP3, TIGIT, and IKZF2, were increased in CB CD4 + CD127 + conventional T cells (Tconv) compared to APB Tconv, post-expansion, implying perinatal T cells may adopt a default regulatory program. Collectively, these data identify surface markers (namely CXCR3) that could be depleted to improve purity and stability of APB Tregs, and support the use of expanded CB Tregs as a potentially optimal ACT modality for the treatment of autoimmune and inflammatory diseases.
We have examined the development of self-peptide-specific CD4 ؉ CD25 ؉ regulatory T cells in line... more We have examined the development of self-peptide-specific CD4 ؉ CD25 ؉ regulatory T cells in lineages of transgenic mice that express the influenza virus PR8 hemagglutinin (HA) under the control of several different promoters (HA transgenic mice). By mating these lineages with TS1-transgenic mice expressing a TCR that recognizes the major I-E d-restricted determinant from HA (site 1 (S1)), we show that S1-specific T cells undergo selection to become CD4 ؉ CD25 ؉ regulatory T cells in each of the lineages, although in varying numbers. In some lineages, S1-specific CD4 ؉ CD25 ؉ regulatory T cells are highly abundant; indeed, TS1xHAtransgenic mice can contain as many S1-specific CD4 ؉ T cells as are present in TS1 mice, which do not express the neo-self HA. In another lineage, however, S1-specific thymocytes are subjected to more extensive deletion and far fewer S1-specific CD4 ؉ CD25 ؉ regulatory T cells accumulate in the periphery. We show that radioresistant stromal cells can direct both deletion and CD4 ؉ CD25 ؉ regulatory T cell selection of S1-specific thymocytes. Interestingly, even though their numbers can vary, the S1-specific CD4 ؉ CD25 ؉ regulatory T cells in all cases coexist with clonally related CD4 ؉ CD25 ؊ T cells that lack regulatory function. These findings show that the formation of the CD4 ؉ CD25 ؉ regulatory T cell repertoire is sensitive to variations in the expression of self-peptides.
Objective Assess the presence, durability, and neutralization capacity of SARS-CoV-2-specific ant... more Objective Assess the presence, durability, and neutralization capacity of SARS-CoV-2-specific antibodies in breastfeeding infants’ stools, mother’s plasma, and human milk following maternal vaccination.DesignThirty-seven mothers and 25 infants were enrolled between December 2020 and November 2021 for this prospective observational study. Human milk, maternal plasma, and infants' stools were collected pre-vaccination and at periods up to 6 months following COVID-19 vaccine series initiation/completion. SARS-CoV-2 antibody levels and their neutralization capacities were assessed in collected samples. Results SARS-CoV-2-specific IgA and IgG levels were higher in infant stool post-maternal vaccination amongst milk-fed compared to pre-COVID controls. Human milk and plasma SARS-CoV-2-specific IgA and IgG concentrations decreased over 6 months post-vaccination but remained higher than pre-vaccination levels. We observed improved neutralization capacity in milk antibodies over time.Conc...
Uveitis is a potentially sight-threatening disease characterized by repeated cycles of remission ... more Uveitis is a potentially sight-threatening disease characterized by repeated cycles of remission and recurrent inflammation. The JAK/STAT pathway regulates the differentiation of pathogenic Th1 and Th17 cells that mediate uveitis. A SOCS1 mimetic peptide (SOCS1-KIR) that inhibits JAK2/STAT1 pathways has recently been shown to suppress experimental autoimmune uveitis (EAU). However, it is not clear whether SOCS1-KIR ameliorated uveitis by targeting JAK/STAT pathways of pathogenic lymphocytes or via inhibition of macrophages and antigen-presenting cells that also enter the retina during EAU. To further investigate mechanisms that mediate SOCS1-KIR effects and evaluate the efficacy of SOCS1-KIR as an investigational drug for chronic uveitis, we induced EAU in rats by adoptive transfer of uveitogenic T-cells and monitored disease progression and severity by slit-lamp microscopy, histology, and optical coherence tomography. Topical administration of SOCS1-KIR ameliorated acute and chroni...
Background Lupus is an autoimmune disease characterized by antibodies directed against nuclear co... more Background Lupus is an autoimmune disease characterized by antibodies directed against nuclear components that induce immune complex-mediated injury to multiple organs. Underlying lupus is the induction of T-cell-dependent activation and clonal expansion of autoreactive B cells in germinal centers resulting in their differentiation into plasma cells that secrete pathogenic autoantibodies. Heightened glucose metabolism is inherent to immune/inflammatory disorders, but little is known of its role in lupus etiology. Present treatments for lupus rely heavily on broad-spectrum immunosuppressive agents, and there is a need for targeted therapies that effectively counteract this systemic autoimmune disorder. Methods Here we examined the metabolic and gene expression profiles of key autoimmune populations in mouse models of spontaneous lupus and their responses to treatment with the glycolysis inhibitor 2-deoxyglucose (2DG) in drinking water. Therapeutic efficacy in terms of survival after long-vs. short-term 2DG-exposed times was assessed on BXSB.Yaa and NZBWF1 lupus-prone mice. Furthermore, a chimeric antigen receptor (CAR)-T immunotherapy was used to determine whether a targeted removal of an identified B cell subset can improve disease outcomes. Results We found greater glucose uptake and glycolysis rate in spontaneous germinal center B cells (GCB) compared to that in follicular helper T cells (Tfh). The differential dependency on glucose oxidation between GCB and Tfh was determined, rendering GCB highly susceptible to oxidative stress-induced apoptosis triggered by glycolysis inhibition via 2DG. Short-term glycolytic inhibition selectively targeted GCB, sparing other autoreactive populations, including Tfh. This reduction of GCB is, in turn, responsible for improving kidney function and lifespan of treated mice. Moreover, we identified a subset of GCB, which express TNFSF17 and exhibit a higher reliance on glucose metabolism than TNFSF17-GCB. Their depletion through its ligand TNFSF13-based CART treatment significantly decreased mortality from lupus. Conclusions Differential metabolic requirement for glucose between autoreactive GCB and Tfh dictates different sensitivity to apoptosis via glycolytic inhibition, and this provides a metabolic niche for targeted lupus treatment. Combining therapies that selectively dampen GCB metabolism for survival with T cell-based immunotherapy could provide new effective treatments for lupus.
Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents th... more Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents the only spontaneous model of human recurrent uveitis (RU). Despite the efficacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the inflammatory processes in ERU that promote blindness. Notably, suppressor of cytokine signaling 1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often deficient in autoimmune disease patients. Significantly, we previously showed that topical administration of a SOCS1 peptide mimic (SOCS1-KIR) mitigated induced rodent uveitis. In this pilot study, we test the potential to translate the therapeutic efficacy observed in experimental rodent uveitis to equine patient disease. Through bioinformatics and peptide binding assays we demonstrate putative binding of the SOCS1-KIR peptide to equine Jak2. We also show that...
Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a l... more Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a lack of a clinically approved vaccine in humans. As an intracellular pathogen, Salmonella impacts many cellular pathways. However, the intercellular communication mechanism facilitated by host-derived small extracellular vesicles (EVs), such as exosomes, is an overlooked aspect of the host responses to this infection. We used a comprehensive proteome-based network analysis of exosomes derived from Salmonella-infected macrophages to identify host molecules that are trafficked via these EVs. This analysis predicted that the host-derived small EVs generated during macrophage infection stimulate macrophages and promote activation of T helper 1 (Th1) cells. We identified that exosomes generated during infection contain Salmonella proteins, including unique antigens previously shown to stimulate protective immune responses against Salmonella in murine studies. Furthermore, we showed that host E...
Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a l... more Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a lack of a clinically approved vaccine in humans. As an intracellular pathogen, Salmonella impacts many cellular pathways. However, the intercellular communication mechanism facilitated by host-derived small extracellular vesicles (EVs), such as exosomes, is an overlooked aspect of the host responses to this infection. We used a comprehensive proteome-based network analysis of exosomes derived from Salmonella-infected macrophages to identify host molecules that are trafficked via these EVs. This analysis predicted that the host-derived small EVs generated during macrophage infection stimulate macrophages and promote activation of T helper 1 (Th1) cells. We identified that exosomes generated during infection contain Salmonella proteins, including unique antigens previously shown to stimulate protective immune responses against Salmonella in murine studies. Furthermore, we showed that host E...
Suppressors of cytokine signaling (SOCS) are inducible intracellular proteins that play essential... more Suppressors of cytokine signaling (SOCS) are inducible intracellular proteins that play essential regulatory roles in both immune and non-immune function. Of the eight known members, SOCS1 and SOCS3 in conjunction with regulatory T cells play key roles in regulation of the immune system. Molecular tools such as gene transfections and siRNA have played a major role in our functional understanding of the SOCS proteins where a key functional domain of 12-amino acid residues called the kinase inhibitory region (KIR) has been identified on SOCS1 and SOCS3. KIR plays a key role in inhibition of the JAK2 tyrosine kinase, which in turn plays a key role in cytokine signaling. A peptide corresponding to KIR (SOCS1-KIR) bound to the activation loop of JAK2 and inhibited tyrosine phosphorylation of STAT1α transcription factor by JAK2. Cell internalized SOCS1-KIR is a potent therapeutic in the experimental allergic encephalomyelitis (EAE) mouse model of multiple sclerosis and showed promise in a psoriasis model and a model of diabetes-associated cardiovascular disease. By contrast, a peptide, pJAK2(1001-1013), that corresponds to the activation loop of JAK2 is a SOCS1 antagonist. The antagonist enhanced innate and adaptive immune response against a broad range of viruses including herpes simplex virus, vaccinia virus, and an EMC picornavirus. SOCS mimetics and antagonists are thus potential therapeutics for negative and positive regulation of the immune system.
Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease, and represents t... more Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease, and represents the only spontaneous model of human recurrent uveitis (RU). Despite the e cacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the in ammatory processes in ERU that promote blindness. Notably, suppressor of signaling-1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often de cient in autoimmune disease patients. Signi cantly, we previously showed that topical administration of a SOCS1 peptide mimic (SOCS1-KIR) mitigated induced rodent uveitis. In this pilot study, we test the potential to translate the therapeutic e cacy observed in experimental rodent uveitis to equine patient disease. Through bioinformatics and peptide binding assays we demonstrate putative binding of the SOCS1-KIR peptide to equine Jak2. We also show that topical, or intravitreal injection of SOCS1-KIR was well tolerated within the equine eye through physical and ophthalmic examinations. Finally, we show that topical SOCS1-KIR administration was associated with signi cant clinical ERU improvement. Together, these results provide a scienti c rationale, and supporting experimental evidence for the therapeutic use of a SOCS1 mimetic peptide in RU.
Background: The intestinal epithelium is a barrier that composes one of the most immunologically ... more Background: The intestinal epithelium is a barrier that composes one of the most immunologically active surfaces of the body due to constant exposure to microorganisms as well as an infinite diversity of food antigens. Disruption of intestinal barrier function and aberrant mucosal immune activation have been implicated in a variety of diseases within and outside of the gastrointestinal tract. With this model in mind, recent studies have shown a link between diet, composition of intestinal microbiota, and type 1 diabetes pathogenesis. In the BioBreeding rat model of type 1 diabetes, comparison of the intestinal microbial composition of diabetes prone and diabetes resistant animals found Lactobacillus species were negatively correlated with type 1 diabetes development. Two species, Lactobacillus johnsonii and L. reuteri, were isolated from diabetes resistant rats. In this study diabetes prone rats were administered pure cultures of L. johnsonii or L. reuteri isolated from diabetes res...
Autoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly act... more Autoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly activated lymphocytes. Many cytokines, including interferon gamma (IFN-γ), utilize the JAK/STAT pathway for signal propagation. Suppressor of Cytokine Signaling-1 (SOCS1) is an inducible, intracellular protein that regulates IFN-γ signaling by dampening JAK/STAT signaling. Using Fas deficient, MRL/MpJ-Faslpr/J (MRL/lpr) mice, which develop lupus-like disease spontaneously, we tested the hypothesis that a peptide mimic of the SOCS1 kinase inhibitory region (SOCS1-KIR) would inhibit lymphocyte activation and modulate lupus-associated pathologies. Consistent with in vitro studies, SOCS1-KIR intraperitoneal administration reduced the frequency, activation, and cytokine production of memory CD8+ and CD4+ T lymphocytes within the peripheral blood, spleen, and lymph nodes. In addition, SOCS1-KIR administration reduced lymphadenopathy, severity of skin lesions, autoantibody production, and modestly...
ABSTRACTImportanceIn 2019, a deadly virus known as severe acute respiratory syndrome coronavirus ... more ABSTRACTImportanceIn 2019, a deadly virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, emerged. In December 2020, two mRNA-based COVID-19 vaccines were approved for use in the United States (US) which provide immunity to those receiving the vaccine. Maternally derived antibodies are a key element of infants’ immunity. Certain vaccines given to pregnant and lactating mothers provide immunity to infants through transmission across the placenta, umbilical cord (IgG) and human milk (IgA). Human milk produced by mothers with a history of COVID-19 infection contains SARS-CoV-2 IgA and IgG.ObjectiveTo determine whether SARS-CoV-2 specific immunoglobulins are found in human milk after the COVID-19 vaccination, and to characterize the types of immunoglobulins present.Design, setting, and participantsThis is a prospective observational study conducted at Shands Hospital, University of Florida from December 2020 to March 2021. Twenty-two lact...
The suppressor of cytokine signaling (SOCS) family of intracellular proteins has a vital role in ... more The suppressor of cytokine signaling (SOCS) family of intracellular proteins has a vital role in the regulation of the immune system and resolution of inflammatory cascades. SOCS1, also called STAT-induced STAT inhibitor (SSI) or JAK-binding protein (JAB), is a member of the SOCS family with actions ranging from immune modulation to cell cycle regulation. Knockout of SOCS1 leads to perinatal lethality in mice and increased vulnerability to cancer, while several SNPs associated with the SOCS1 gene have been implicated in human inflammation-mediated diseases. In this review, we describe the mechanism of action of SOCS1 and its potential therapeutic role in the prevention and treatment of autoimmunity and cancer. We also provide a brief outline of the other JAK inhibitors, both FDA-approved and under investigation.
Conflict of Interest Statement: HJ and JL declare a patent pending for the use of SOCS mimetic pe... more Conflict of Interest Statement: HJ and JL declare a patent pending for the use of SOCS mimetic peptides for the treatment of disease.
IL-17-producing T lymphocytes (T17s) play important roles in the clearance of extracellular bacte... more IL-17-producing T lymphocytes (T17s) play important roles in the clearance of extracellular bacterial and fungal infections. T17s consist of several subsets of lymphocytes possessing both innate and adaptive immune phenotypes. The production of IL-17 by innate and adaptive immune cells allows the presence of this important cytokine at distinct parts of the immune response. Notably, T lymphocytes can acquire the IL-17 effector function in either the thymus or the periphery. Although CD4+IL17+ T lymphocytes are generally considered to be reciprocal in effector functions compared to Foxp3+ regulatory T cells, the presence of IL-17+Foxp3+ cells requires additional characterisation. Notably, strong evidence also implicates IL-17-producing T lymphocytes in several autoimmune disorders including multiple sclerosis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus and asthma. It has been suggested that T lymphocytes such as IL17+Foxp3+ T lymphocytes, bearing aberrant effector functions, may be contributors to autoimmunity. Key Concepts Transcription factors are critical in the skewing of T lymphocyte effector functions. Interleukin 17 (IL-17) is a cytokine which is critical in the regulation of bacterial communities and fungi within mammalian host organisms; however, it is also associated with autoimmunity. Interleukin 17 can be produced by several T cell populations including αβ CD4+ cells, αβ CD8+ and γδ T lymphocytes. IL-17-producing T lymphocytes are a heterogeneous population that elicits a spectrum of effector functions. The IL-17 effector function can be acquired in the thymus or periphery. Although evidence suggests that IL-17 production can drive immune events associated with autoimmunity, it is possible IL-17 production may serve as a biomarker for T lymphocytes possessing varied autoimmune disease-promoting effector functions. Regulation of T lymphocyte stability may have efficacy in the prevention of autoimmune disease. Keywords: cytokine; plasticity; effector function; homeostasis; transcription factor; autoimmunity; interleukin 17; T lymphocyte
We have developed an antagonist to suppressor of cytokine signaling 1 (SOCS1), pJAK2(1001-1013), ... more We have developed an antagonist to suppressor of cytokine signaling 1 (SOCS1), pJAK2(1001-1013), which corresponds to the activation loop of the Janus kinase JAK2, which is the binding site for the kinase inhibitory region (KIR) of SOCS1. Internalized pJAK2(1001-1013) inhibits SOCS1 and SOCS3. SOCS1 has been shown to be an influenza virus-induced virulence factor that enhances infection of cells. The antagonist was protective in cell culture and in influenza virus PR8 lethally infected C57BL/6 mice. The SOCS antagonist also prevented adverse morbidity as assessed by parameters, such as weight loss and drop in body temperature, and showed potent induction of both the cellular and humoral immune responses to the influenza virus candidate universal antigen matrix protein 2 (M2e). The SOCS antagonist, thus, protected mice against lethal influenza virus infection and possessed potent adjuvancy against the M2e candidate influenza virus universal vaccine antigen.
Tregs. Interestingly, expression of canonical Treg markers, such as FOXP3, TIGIT, and IKZF2, were... more Tregs. Interestingly, expression of canonical Treg markers, such as FOXP3, TIGIT, and IKZF2, were increased in CB CD4 + CD127 + conventional T cells (Tconv) compared to APB Tconv, post-expansion, implying perinatal T cells may adopt a default regulatory program. Collectively, these data identify surface markers (namely CXCR3) that could be depleted to improve purity and stability of APB Tregs, and support the use of expanded CB Tregs as a potentially optimal ACT modality for the treatment of autoimmune and inflammatory diseases.
We have examined the development of self-peptide-specific CD4 ؉ CD25 ؉ regulatory T cells in line... more We have examined the development of self-peptide-specific CD4 ؉ CD25 ؉ regulatory T cells in lineages of transgenic mice that express the influenza virus PR8 hemagglutinin (HA) under the control of several different promoters (HA transgenic mice). By mating these lineages with TS1-transgenic mice expressing a TCR that recognizes the major I-E d-restricted determinant from HA (site 1 (S1)), we show that S1-specific T cells undergo selection to become CD4 ؉ CD25 ؉ regulatory T cells in each of the lineages, although in varying numbers. In some lineages, S1-specific CD4 ؉ CD25 ؉ regulatory T cells are highly abundant; indeed, TS1xHAtransgenic mice can contain as many S1-specific CD4 ؉ T cells as are present in TS1 mice, which do not express the neo-self HA. In another lineage, however, S1-specific thymocytes are subjected to more extensive deletion and far fewer S1-specific CD4 ؉ CD25 ؉ regulatory T cells accumulate in the periphery. We show that radioresistant stromal cells can direct both deletion and CD4 ؉ CD25 ؉ regulatory T cell selection of S1-specific thymocytes. Interestingly, even though their numbers can vary, the S1-specific CD4 ؉ CD25 ؉ regulatory T cells in all cases coexist with clonally related CD4 ؉ CD25 ؊ T cells that lack regulatory function. These findings show that the formation of the CD4 ؉ CD25 ؉ regulatory T cell repertoire is sensitive to variations in the expression of self-peptides.
Objective Assess the presence, durability, and neutralization capacity of SARS-CoV-2-specific ant... more Objective Assess the presence, durability, and neutralization capacity of SARS-CoV-2-specific antibodies in breastfeeding infants’ stools, mother’s plasma, and human milk following maternal vaccination.DesignThirty-seven mothers and 25 infants were enrolled between December 2020 and November 2021 for this prospective observational study. Human milk, maternal plasma, and infants' stools were collected pre-vaccination and at periods up to 6 months following COVID-19 vaccine series initiation/completion. SARS-CoV-2 antibody levels and their neutralization capacities were assessed in collected samples. Results SARS-CoV-2-specific IgA and IgG levels were higher in infant stool post-maternal vaccination amongst milk-fed compared to pre-COVID controls. Human milk and plasma SARS-CoV-2-specific IgA and IgG concentrations decreased over 6 months post-vaccination but remained higher than pre-vaccination levels. We observed improved neutralization capacity in milk antibodies over time.Conc...
Uveitis is a potentially sight-threatening disease characterized by repeated cycles of remission ... more Uveitis is a potentially sight-threatening disease characterized by repeated cycles of remission and recurrent inflammation. The JAK/STAT pathway regulates the differentiation of pathogenic Th1 and Th17 cells that mediate uveitis. A SOCS1 mimetic peptide (SOCS1-KIR) that inhibits JAK2/STAT1 pathways has recently been shown to suppress experimental autoimmune uveitis (EAU). However, it is not clear whether SOCS1-KIR ameliorated uveitis by targeting JAK/STAT pathways of pathogenic lymphocytes or via inhibition of macrophages and antigen-presenting cells that also enter the retina during EAU. To further investigate mechanisms that mediate SOCS1-KIR effects and evaluate the efficacy of SOCS1-KIR as an investigational drug for chronic uveitis, we induced EAU in rats by adoptive transfer of uveitogenic T-cells and monitored disease progression and severity by slit-lamp microscopy, histology, and optical coherence tomography. Topical administration of SOCS1-KIR ameliorated acute and chroni...
Background Lupus is an autoimmune disease characterized by antibodies directed against nuclear co... more Background Lupus is an autoimmune disease characterized by antibodies directed against nuclear components that induce immune complex-mediated injury to multiple organs. Underlying lupus is the induction of T-cell-dependent activation and clonal expansion of autoreactive B cells in germinal centers resulting in their differentiation into plasma cells that secrete pathogenic autoantibodies. Heightened glucose metabolism is inherent to immune/inflammatory disorders, but little is known of its role in lupus etiology. Present treatments for lupus rely heavily on broad-spectrum immunosuppressive agents, and there is a need for targeted therapies that effectively counteract this systemic autoimmune disorder. Methods Here we examined the metabolic and gene expression profiles of key autoimmune populations in mouse models of spontaneous lupus and their responses to treatment with the glycolysis inhibitor 2-deoxyglucose (2DG) in drinking water. Therapeutic efficacy in terms of survival after long-vs. short-term 2DG-exposed times was assessed on BXSB.Yaa and NZBWF1 lupus-prone mice. Furthermore, a chimeric antigen receptor (CAR)-T immunotherapy was used to determine whether a targeted removal of an identified B cell subset can improve disease outcomes. Results We found greater glucose uptake and glycolysis rate in spontaneous germinal center B cells (GCB) compared to that in follicular helper T cells (Tfh). The differential dependency on glucose oxidation between GCB and Tfh was determined, rendering GCB highly susceptible to oxidative stress-induced apoptosis triggered by glycolysis inhibition via 2DG. Short-term glycolytic inhibition selectively targeted GCB, sparing other autoreactive populations, including Tfh. This reduction of GCB is, in turn, responsible for improving kidney function and lifespan of treated mice. Moreover, we identified a subset of GCB, which express TNFSF17 and exhibit a higher reliance on glucose metabolism than TNFSF17-GCB. Their depletion through its ligand TNFSF13-based CART treatment significantly decreased mortality from lupus. Conclusions Differential metabolic requirement for glucose between autoreactive GCB and Tfh dictates different sensitivity to apoptosis via glycolytic inhibition, and this provides a metabolic niche for targeted lupus treatment. Combining therapies that selectively dampen GCB metabolism for survival with T cell-based immunotherapy could provide new effective treatments for lupus.
Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents th... more Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents the only spontaneous model of human recurrent uveitis (RU). Despite the efficacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the inflammatory processes in ERU that promote blindness. Notably, suppressor of cytokine signaling 1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often deficient in autoimmune disease patients. Significantly, we previously showed that topical administration of a SOCS1 peptide mimic (SOCS1-KIR) mitigated induced rodent uveitis. In this pilot study, we test the potential to translate the therapeutic efficacy observed in experimental rodent uveitis to equine patient disease. Through bioinformatics and peptide binding assays we demonstrate putative binding of the SOCS1-KIR peptide to equine Jak2. We also show that...
Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a l... more Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a lack of a clinically approved vaccine in humans. As an intracellular pathogen, Salmonella impacts many cellular pathways. However, the intercellular communication mechanism facilitated by host-derived small extracellular vesicles (EVs), such as exosomes, is an overlooked aspect of the host responses to this infection. We used a comprehensive proteome-based network analysis of exosomes derived from Salmonella-infected macrophages to identify host molecules that are trafficked via these EVs. This analysis predicted that the host-derived small EVs generated during macrophage infection stimulate macrophages and promote activation of T helper 1 (Th1) cells. We identified that exosomes generated during infection contain Salmonella proteins, including unique antigens previously shown to stimulate protective immune responses against Salmonella in murine studies. Furthermore, we showed that host E...
Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a l... more Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a lack of a clinically approved vaccine in humans. As an intracellular pathogen, Salmonella impacts many cellular pathways. However, the intercellular communication mechanism facilitated by host-derived small extracellular vesicles (EVs), such as exosomes, is an overlooked aspect of the host responses to this infection. We used a comprehensive proteome-based network analysis of exosomes derived from Salmonella-infected macrophages to identify host molecules that are trafficked via these EVs. This analysis predicted that the host-derived small EVs generated during macrophage infection stimulate macrophages and promote activation of T helper 1 (Th1) cells. We identified that exosomes generated during infection contain Salmonella proteins, including unique antigens previously shown to stimulate protective immune responses against Salmonella in murine studies. Furthermore, we showed that host E...
Suppressors of cytokine signaling (SOCS) are inducible intracellular proteins that play essential... more Suppressors of cytokine signaling (SOCS) are inducible intracellular proteins that play essential regulatory roles in both immune and non-immune function. Of the eight known members, SOCS1 and SOCS3 in conjunction with regulatory T cells play key roles in regulation of the immune system. Molecular tools such as gene transfections and siRNA have played a major role in our functional understanding of the SOCS proteins where a key functional domain of 12-amino acid residues called the kinase inhibitory region (KIR) has been identified on SOCS1 and SOCS3. KIR plays a key role in inhibition of the JAK2 tyrosine kinase, which in turn plays a key role in cytokine signaling. A peptide corresponding to KIR (SOCS1-KIR) bound to the activation loop of JAK2 and inhibited tyrosine phosphorylation of STAT1α transcription factor by JAK2. Cell internalized SOCS1-KIR is a potent therapeutic in the experimental allergic encephalomyelitis (EAE) mouse model of multiple sclerosis and showed promise in a psoriasis model and a model of diabetes-associated cardiovascular disease. By contrast, a peptide, pJAK2(1001-1013), that corresponds to the activation loop of JAK2 is a SOCS1 antagonist. The antagonist enhanced innate and adaptive immune response against a broad range of viruses including herpes simplex virus, vaccinia virus, and an EMC picornavirus. SOCS mimetics and antagonists are thus potential therapeutics for negative and positive regulation of the immune system.
Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease, and represents t... more Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease, and represents the only spontaneous model of human recurrent uveitis (RU). Despite the e cacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the in ammatory processes in ERU that promote blindness. Notably, suppressor of signaling-1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often de cient in autoimmune disease patients. Signi cantly, we previously showed that topical administration of a SOCS1 peptide mimic (SOCS1-KIR) mitigated induced rodent uveitis. In this pilot study, we test the potential to translate the therapeutic e cacy observed in experimental rodent uveitis to equine patient disease. Through bioinformatics and peptide binding assays we demonstrate putative binding of the SOCS1-KIR peptide to equine Jak2. We also show that topical, or intravitreal injection of SOCS1-KIR was well tolerated within the equine eye through physical and ophthalmic examinations. Finally, we show that topical SOCS1-KIR administration was associated with signi cant clinical ERU improvement. Together, these results provide a scienti c rationale, and supporting experimental evidence for the therapeutic use of a SOCS1 mimetic peptide in RU.
Background: The intestinal epithelium is a barrier that composes one of the most immunologically ... more Background: The intestinal epithelium is a barrier that composes one of the most immunologically active surfaces of the body due to constant exposure to microorganisms as well as an infinite diversity of food antigens. Disruption of intestinal barrier function and aberrant mucosal immune activation have been implicated in a variety of diseases within and outside of the gastrointestinal tract. With this model in mind, recent studies have shown a link between diet, composition of intestinal microbiota, and type 1 diabetes pathogenesis. In the BioBreeding rat model of type 1 diabetes, comparison of the intestinal microbial composition of diabetes prone and diabetes resistant animals found Lactobacillus species were negatively correlated with type 1 diabetes development. Two species, Lactobacillus johnsonii and L. reuteri, were isolated from diabetes resistant rats. In this study diabetes prone rats were administered pure cultures of L. johnsonii or L. reuteri isolated from diabetes res...
Autoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly act... more Autoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly activated lymphocytes. Many cytokines, including interferon gamma (IFN-γ), utilize the JAK/STAT pathway for signal propagation. Suppressor of Cytokine Signaling-1 (SOCS1) is an inducible, intracellular protein that regulates IFN-γ signaling by dampening JAK/STAT signaling. Using Fas deficient, MRL/MpJ-Faslpr/J (MRL/lpr) mice, which develop lupus-like disease spontaneously, we tested the hypothesis that a peptide mimic of the SOCS1 kinase inhibitory region (SOCS1-KIR) would inhibit lymphocyte activation and modulate lupus-associated pathologies. Consistent with in vitro studies, SOCS1-KIR intraperitoneal administration reduced the frequency, activation, and cytokine production of memory CD8+ and CD4+ T lymphocytes within the peripheral blood, spleen, and lymph nodes. In addition, SOCS1-KIR administration reduced lymphadenopathy, severity of skin lesions, autoantibody production, and modestly...
ABSTRACTImportanceIn 2019, a deadly virus known as severe acute respiratory syndrome coronavirus ... more ABSTRACTImportanceIn 2019, a deadly virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, emerged. In December 2020, two mRNA-based COVID-19 vaccines were approved for use in the United States (US) which provide immunity to those receiving the vaccine. Maternally derived antibodies are a key element of infants’ immunity. Certain vaccines given to pregnant and lactating mothers provide immunity to infants through transmission across the placenta, umbilical cord (IgG) and human milk (IgA). Human milk produced by mothers with a history of COVID-19 infection contains SARS-CoV-2 IgA and IgG.ObjectiveTo determine whether SARS-CoV-2 specific immunoglobulins are found in human milk after the COVID-19 vaccination, and to characterize the types of immunoglobulins present.Design, setting, and participantsThis is a prospective observational study conducted at Shands Hospital, University of Florida from December 2020 to March 2021. Twenty-two lact...
The suppressor of cytokine signaling (SOCS) family of intracellular proteins has a vital role in ... more The suppressor of cytokine signaling (SOCS) family of intracellular proteins has a vital role in the regulation of the immune system and resolution of inflammatory cascades. SOCS1, also called STAT-induced STAT inhibitor (SSI) or JAK-binding protein (JAB), is a member of the SOCS family with actions ranging from immune modulation to cell cycle regulation. Knockout of SOCS1 leads to perinatal lethality in mice and increased vulnerability to cancer, while several SNPs associated with the SOCS1 gene have been implicated in human inflammation-mediated diseases. In this review, we describe the mechanism of action of SOCS1 and its potential therapeutic role in the prevention and treatment of autoimmunity and cancer. We also provide a brief outline of the other JAK inhibitors, both FDA-approved and under investigation.
Conflict of Interest Statement: HJ and JL declare a patent pending for the use of SOCS mimetic pe... more Conflict of Interest Statement: HJ and JL declare a patent pending for the use of SOCS mimetic peptides for the treatment of disease.
IL-17-producing T lymphocytes (T17s) play important roles in the clearance of extracellular bacte... more IL-17-producing T lymphocytes (T17s) play important roles in the clearance of extracellular bacterial and fungal infections. T17s consist of several subsets of lymphocytes possessing both innate and adaptive immune phenotypes. The production of IL-17 by innate and adaptive immune cells allows the presence of this important cytokine at distinct parts of the immune response. Notably, T lymphocytes can acquire the IL-17 effector function in either the thymus or the periphery. Although CD4+IL17+ T lymphocytes are generally considered to be reciprocal in effector functions compared to Foxp3+ regulatory T cells, the presence of IL-17+Foxp3+ cells requires additional characterisation. Notably, strong evidence also implicates IL-17-producing T lymphocytes in several autoimmune disorders including multiple sclerosis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus and asthma. It has been suggested that T lymphocytes such as IL17+Foxp3+ T lymphocytes, bearing aberrant effector functions, may be contributors to autoimmunity. Key Concepts Transcription factors are critical in the skewing of T lymphocyte effector functions. Interleukin 17 (IL-17) is a cytokine which is critical in the regulation of bacterial communities and fungi within mammalian host organisms; however, it is also associated with autoimmunity. Interleukin 17 can be produced by several T cell populations including αβ CD4+ cells, αβ CD8+ and γδ T lymphocytes. IL-17-producing T lymphocytes are a heterogeneous population that elicits a spectrum of effector functions. The IL-17 effector function can be acquired in the thymus or periphery. Although evidence suggests that IL-17 production can drive immune events associated with autoimmunity, it is possible IL-17 production may serve as a biomarker for T lymphocytes possessing varied autoimmune disease-promoting effector functions. Regulation of T lymphocyte stability may have efficacy in the prevention of autoimmune disease. Keywords: cytokine; plasticity; effector function; homeostasis; transcription factor; autoimmunity; interleukin 17; T lymphocyte
We have developed an antagonist to suppressor of cytokine signaling 1 (SOCS1), pJAK2(1001-1013), ... more We have developed an antagonist to suppressor of cytokine signaling 1 (SOCS1), pJAK2(1001-1013), which corresponds to the activation loop of the Janus kinase JAK2, which is the binding site for the kinase inhibitory region (KIR) of SOCS1. Internalized pJAK2(1001-1013) inhibits SOCS1 and SOCS3. SOCS1 has been shown to be an influenza virus-induced virulence factor that enhances infection of cells. The antagonist was protective in cell culture and in influenza virus PR8 lethally infected C57BL/6 mice. The SOCS antagonist also prevented adverse morbidity as assessed by parameters, such as weight loss and drop in body temperature, and showed potent induction of both the cellular and humoral immune responses to the influenza virus candidate universal antigen matrix protein 2 (M2e). The SOCS antagonist, thus, protected mice against lethal influenza virus infection and possessed potent adjuvancy against the M2e candidate influenza virus universal vaccine antigen.
Uploads
Papers by Joseph Larkin