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The development and progression of systemic lupus erythematosus is mediated by the complex interaction of genetic and environmental factors. To decipher the genetics that contribute to pathogenesis and the production of pathogenic autoantibodies, our lab has focused on the generation of congenic lupus-prone mice derived from the New Zealand Black (NZB) strain. Previous work has shown that an NZB-derived chromosome 4 interval spanning 32 to 151 Mb led to expansion of CD5+ B and Natural Killer T (NKT) cells, and could suppress autoimmunity when crossed with a lupus-prone mouse strain. Subsequently, it was shown that CD5+ B cells but not NKT cells derived from these mice could suppress the development of pro-inflammatory T cells. In this paper, we aimed to further resolve the genetics that leads to expansion of these two innate-like populations through the creation of additional sub-congenic mice and to characterize the role of IL-10 in the suppression of autoimmunity through the generation of IL-10 knockout mice. We show that expansion of CD5+ B cells and NKT cells localizes to a chromosome 4 interval spanning 91 to 123 Mb, which is distinct from the region that mediates the majority of the suppressive phenotype. We also demonstrate that IL-10 is critical to restraining autoantibody production and surprisingly plays a vital role in supporting the expansion of innate-like populations. [ABSTRACT FROM AUTHOR]

Previous studies have suggested that murine peritoneal cavity-derived B-1a cells possess similarities with described regulatory B cell subsets. The aim of the current study was to examine the potential immunoregulatory function of peritoneal cavity-derived B(-1a) cells. In vitro activation of peritoneal cavity-derived B- and B-1a cells shows that activation of these B cells with anti-CD40 and LPS induces these cells to secrete more IL-10, IL-6 and IgM as compared to splenic B cells. In a suppression assay, CD40/TLR4-activated peritoneal cavity B cells possess regulatory B cell functions as they inhibit the capacity of CD4+ T cells to produce both tumor necrosis factor-α and interferon-γ. Splenic B cells did not show this, whereas non-activated peritoneal cavity B cells augmented the capacity of CD4+ T cells to produce tumor necrosis factor-α, while the ability to produce interferon-γ was not altered. The current paper compares splenic B cells to peritoneal cavity B(-1a) cells in an in vitro activation- and an suppression-assay and concludes that peritoneal cavity B(-1a) cells possess properties that appear similar to splenic autoimmune-suppressive regulatory B cell subsets described in the literature. [ABSTRACT FROM AUTHOR]

The identification of phenotype descriptions in the scientific literature, case reports and patient records is a rewarding task for bio-medical text mining. Any progress will support knowledge discovery and linkage to other resources. However because of their wide variation a number of challenges still remain in terms of their identification and semantic normalisation before they can be fully exploited for research purposes. This paper presents novel techniques for identifying potential complex phenotype mentions by exploiting a hybrid model based on machine learning, rules and dictionary matching. A systematic study is made of how to combine sequence labels from these modules as well as the merits of various ontological resources. We evaluated our approach on a subset of Medline abstracts cited by the Online Mendelian Inheritance of Man database related to auto-immune diseases. Using partial matching the best micro-averaged F-score for phenotypes and five other entity classes was 79.9%. A best performance of 75.3% was achieved for phenotype candidates using all semantics resources. We observed the advantage of using SVM-based learn-to-rank for sequence label combination over maximum entropy and a priority list approach. The results indicate that the identification of simple entity types such as chemicals and genes are robustly supported by single semantic resources, whereas phenotypes require combinations. Altogether we conclude that our approach coped well with the compositional structure of phenotypes in the auto-immune domain. [ABSTRACT FROM AUTHOR]

c-Rel plays important roles in many inflammatory diseases. Revealing the dynamic expression of c-Rel in disease processes in vivo is critical for understanding c-Rel functions and for developing anti-inflammatory drugs. In this paper, a transgenic mouse line, B6-Tg(c-Rel-luc)Mlit, which incorporated the transgene firefly luciferase driven by a 14.5-kb fragment containing mouse c-Rel gene Rel promoter, was generated to monitor Rel expression in vivo. Luciferase expression could be tracked in living mice by the method of bioluminescence imaging in a variety of inflammatory processes, including LPS induced sepsis and EAE disease model. The luciferase expression in transgenic mice was comparable to the endogenous Rel expression and could be suppressed by administration of anti-inflammatory drug dexamethasone or aspirin. These results indicate that the B6-Tg(c-Rel-luc)Mlit mouse is a valuable animal model to study Rel expression in physiological and pathological processes, and the effects of various drug treatments in vivo. [ABSTRACT FROM AUTHOR]

Objective: Based on US National Health and Nutrition Examination Survey (NHANES) data, we attempted to provide an unbiased, population-based estimate of autoantibody prevalence overall and by age and sex. Methods: US autoantibody prevalence estimates for detectable rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, anti-transglutaminase, anti-endomysial, anti-GAD65, antinuclear autoantibodies, and autoantibodies to extractable nuclear antigens were estimated from the 1960–1962 National Health Examination Survey, NHANES III (1988–1994), and the NHANES 1999–2014 cross-sectional surveys. Survey design variables and sample weights were used to account for differential probabilities of selection within the complex survey design. Data analysis used SASTM and SUDAAN™ software. US Census Bureau data were used to estimate the absolute numbers of persons with autoantibodies. Results: NHANES III data show that the overall US prevalence of having a detectable serum autoantibody is substantial in adults, in both women and men. Thyroid autoantibodies were present in 18% of US adults (31 million persons) including 10% of younger adults and 25% of older persons. Overall autoantibody prevalences increased significantly with age: 32% of US adults 60+ years of age (12.8 million persons) had at least one of the four autoantibodies rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, or anti-tissue transglutaminase. Older women had higher levels of autoantibodies, but this was a relative difference. Autoantibody prevalence in both sexes was substantial (women 39%; men 22%). Fourteen percent of adults 60+ years of age have multiple autoantibodies. Conclusions: Autoantibodies are present in a significant fraction of the general population, especially in older adults and women relative to men. Although all known clinically significant autoantibodies were not analyzed, these data provide an important population perspective on the scope and magnitude of humoral autoimmunity in the US. This is vital for prevention efforts to reduce autoimmune disease and helps clarify the potential impact of autoimmunity on the general population. [ABSTRACT FROM AUTHOR]

The risk factors for preeclampsia, extremes of maternal age, changing paternity, concomitant maternal autoimmunity, and/or birth intervals greater than 5 years, suggest an underlying immunopathology. We used peripheral blood and lymphocytes from the UteroPlacental Interface (UPI) of 3rd trimester healthy pregnant women in multicolor flow cytometry—and in vitro suppression assays. The major end-point was the characterization of activation markers, and potential effector functions of different CD4—and CD8 subsets as well as T regulatory cells (Treg). We observed a significant shift of peripheral CD4 –and CD8- T cells from naïve to memory phenotype in preeclamptic women compared to healthy pregnant women consistent with long-standing immune activation. While the proportions of the highly suppressive Cytokine and Activated Treg were increased in preeclampsia, Treg tolerance toward fetal antigens was dysfunctional. Thus, our observations indicate a long-standing inflammatory derangement driving immune activation in preeclampsia; in how far the Treg dysfunction is caused by/causes this immune activation in preeclampsia will be the object of future studies. [ABSTRACT FROM AUTHOR]

A phenome-wide association study of variants in genes in the Th17 and IL-17 pathway was performed using self-reported phenotypes and genetic data from 521,000 research participants of 23andMe. Results replicated known associations with similar effect sizes for autoimmune traits illustrating self-reported traits can be a surrogate for clinically assessed conditions. Novel associations controlling for a false discovery rate of 5% included the association of the variant encoding p.Ile684Ser in TYK2 with increased risk of tonsillectomy, strep throat occurrences and teen acne, the variant encoding p.Arg381Gln in IL23R with a decrease in dandruff frequency, the variant encoding p.Asp10Asn in TRAF3IP2 with risk of male-pattern balding, and the RORC regulatory variant (rs4845604) with protection from allergies. This approach enabled rapid assessment of association with a wide variety of traits and investigation of traits with limited reported associations to overlay meaningful phenotypic context on the range of conditions being considered for drugs targeting this pathway. [ABSTRACT FROM AUTHOR]

The “hygiene hypothesis” postulates that reduced exposure to infections favours the development of autoimmunity and childhood type 1 diabetes (T1D). But on the other side, viruses, notably enteroviruses, are suspected to trigger T1D. The assessment of the possible relationships between infections and T1D still defies the classical tools of epidemiology. We report the methods and results of a geographical approach that maps the addresses of patients to a communicable diseases surveillance database. We mapped the addresses of patients at birth, infancy and T1D diagnosis to the weekly estimates of the regional incidences of 5 frequent communicable diseases routinely collected since 1984 by the French Sentinel network. The pre-diagnostic infectious environment of 3548 patients with T1D diagnosed between 0.5 and 15 years was compared to those of 100 series of age-matched “virtual controls” drawn randomly on the map. Associations were classified as “suggestive” (summer diarrhea, SD, and varicella, V) when p< 0.05, or “significant” (influenza-like infections, ILI) when they passed the Bonferroni correction for FDR. Exposure to ILI and SD were associated with T1D risk, while V seemed protective. In the subset of 2521 patients for which we had genome wide data, we used a case-only approach to search for interactions between SNPs and the infectious environment as defined by the Sentinel database. Two SNPs, rs116624278 and rs77232854, showed significant interaction with exposure to V between 1 and 3 years of life. The infectious associations found should be taken as possible markers of patients’ environment, not as direct causative factors of T1D. They require replication in other populations. The increasing public availability of geographical environmental databases will expand the present approach to map thousands of environmental factors to the lifeline of patients affected by various diseases. [ABSTRACT FROM AUTHOR]

Immune mediated nephropathy is one of the most serious manifestations of lupus and is characterized by severe inflammation and necrosis that, if untreated, eventually leads to renal failure. Although lupus has a higher incidence in women, both sexes can develop lupus glomerulonephritis; nephritis in men develops earlier and is more severe than in women. It is therefore important to understand the cellular and molecular mechanisms mediating nephritis in each sex. Previous work by our lab found that the absence or pharmacological inhibition of Poly [ADP-ribose] polymerase 1 (PARP-1), an enzyme involved in DNA repair and necrotic cell death, affects only male mice and results in milder nephritis, with less in situ inflammation, and diminished incidence of necrotic lesions, allowing for higher survival rates. A second pathway mediating necrosis involves Receptor-Interacting Serine-Threonine Kinase 3 (RIPK3); in this study we sought to investigate the impact of RIPK3 on the development of lupus and nephritis in both sexes. To this end, we used two inducible murine models of lupus: chronic graft versus host disease (cGvHD) and pristane-induced lupus; and nephrotoxic serum (NTS)-induced nephritis as a model of immune mediated nephropathy. We found that the absence of RIPK3 has neither positive nor negative impact on the disease development or progression of lupus and nephritis in all three models, and in both male and female mice. We conclude that RIPK3 is dispensable for the pathogenesis of lupus and immune mediated nephropathy as to accelerate, worsen or ameliorate the disease. [ABSTRACT FROM AUTHOR]

Wnt/β-catenin signaling is relatively understudied in immunity and autoimmunity. β-catenin blocks inflammatory mediators and favors tolerogenic dendritic cell (DC) phenotypes. We show here that leukocytes from lupus-prone mice and SLE patients express diminished β-catenin transcriptional activity, particularly in myeloid cells, although other leukocytes revealed similar trends. Serum levels of DKK-1, an inhibitor under transcriptional control of Wnt/β-catenin, were also decreased in lupus-prone mice. Surprisingly, however, preemptive deletion of β-catenin from macrophages appears to have no effect on lupus development, even in mice with varying genetic loads for lupus. Although myeloid-specific loss of β-catenin does not seem to be important for lupus development, the potential role of this transcription factor in other leukocytes and renal cells remain to be elucidated. [ABSTRACT FROM AUTHOR]

Occupational exposure to respirable crystalline silica (cSiO2, quartz) is etiologically linked to systemic lupus erythematosus (lupus) and other human autoimmune diseases (ADs). In the female NZBWF1 mouse, a widely used animal model that is genetically prone to lupus, short-term repeated intranasal exposure to cSiO2 triggers premature initiation of autoimmune responses in the lungs and kidneys. In contrast to cSiO2’s triggering action, consumption of the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) prevents spontaneous onset of autoimmunity in this mouse strain. The aim of this study was to test the hypothesis that consumption of DHA will prevent cSiO2-triggered autoimmunity in the female NZBWF1 mouse. Mice (6 wk old) were fed isocaloric AIN-93G diets containing 0.0, 0.4, 1.2 or 2.4% DHA. Two wk after initiating feeding, mice were intranasally instilled with 1 mg cSiO2 once per wk for 4 wk and maintained on experimental diets for an additional 12 wk. Mice were then sacrificed and the lung, blood and kidney assessed for markers of inflammation and autoimmunity. DHA was incorporated into lung, red blood cells and kidney from diet in a concentration-dependent fashion. Dietary DHA dose-dependently suppressed cSiO2-triggered perivascular leukocyte infiltration and ectopic lymphoid tissue neogenesis in the lung. DHA consumption concurrently inhibited cSiO2–driven elevation of proinflammatory cytokines, B-cell proliferation factors, IgG and anti-dsDNA Ig in both bronchoalveolar lavage fluid and plasma. DHA’s prophylactic effects were further mirrored in reduced proteinuria and glomerulonephritis in cSiO2-treated mice. Taken together, these results reveal that DHA consumption suppresses cSiO2 triggering of autoimmunity in female NZBWF1 mice as manifested in the lung, blood and kidney. Our findings provide novel insight into how dietary modulation of the lipidome might be used to prevent or delay triggering of AD by cSiO2. Such knowledge opens the possibility of developing practical, low-cost preventative strategies to reduce the risk of initiating AD and subsequent flaring in cSiO2-exposed individuals. Additional research in this model is required to establish the mechanisms by which DHA suppresses cSiO2-induced autoimmunity and to ascertain unique lipidome signatures predictive of susceptibility to cSiO2-triggered AD. [ABSTRACT FROM AUTHOR]

We performed a Phenome-Wide Association Study (PheWAS) to identify interrelationships between the immune system genetic architecture and a wide array of phenotypes from two de-identified electronic health record (EHR) biorepositories. We selected variants within genes encoding critical factors in the immune system and variants with known associations with autoimmunity. To define case/control status for EHR diagnoses, we used International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes from 3,024 Geisinger Clinic MyCode® subjects (470 diagnoses) and 2,899 Vanderbilt University Medical Center BioVU biorepository subjects (380 diagnoses). A pooled-analysis was also carried out for the replicating results of the two data sets. We identified new associations with potential biological relevance including SNPs in tumor necrosis factor (TNF) and ankyrin-related genes associated with acute and chronic sinusitis and acute respiratory tract infection. The two most significant associations identified were for the C6orf10 SNP rs6910071 and “rheumatoid arthritis” (ICD-9 code category 714) (pMETAL = 2.58 x 10−9) and the ATN1 SNP rs2239167 and “diabetes mellitus, type 2” (ICD-9 code category 250) (pMETAL = 6.39 x 10−9). This study highlights the utility of using PheWAS in conjunction with EHRs to discover new genotypic-phenotypic associations for immune-system related genetic loci. [ABSTRACT FROM AUTHOR]

The prevalence of celiac disease autoimmunity or tissue transglutaminase autoantibodies (TGA) amongst patients with type 1 diabetes (T1D) and autoimmune thyroid disease (AITD) in the Chinese population remains unknown. This study examined the rate of celiac disease autoimmunity amongst patients with T1D and AITD in the Chinese population. The study included 178 patients with type 1 diabetes and 119 with AITD where 36 had both T1D and AITD, classified as autoimmune polyglandular syndrome type 3 variant (APS3v). The study also included 145 patients with type 2 diabetes (T2D), 97 patients with non-autoimmune thyroid disease (NAITD), and 102 healthy controls. Serum islet autoantibodies, thyroid autoantibodies and TGA were measured by radioimmunoassay. TGA positivity was found in 22% of patients with either type 1 diabetes or AITD, much higher than that in patients with T2D (3.4%; p< 0.0001) or NAITD (3.1%; P < 0.0001) or healthy controls (1%; p<0.0001). The patients with APS3v having both T1D and AITD were 36% positive for TGA, significantly higher than patients with T1D alone (p = 0.040) or with AITD alone (p = 0.017). T1D and AITD were found to have a 20% and 30% frequency of overlap respectively at diagnosis. In conclusion, TGA positivity was high in the Chinese population having existing T1D and/or AITD, and even higher when both diseases were present. Routine TGA screening in patients with T1D or AITD will be important to early identify celiac disease autoimmunity for better clinical care of patients. [ABSTRACT FROM AUTHOR]

Background: Autoimmune diseases, including rheumatoid arthritis (RA) and systemic sclerosis (SSc) are characterized by a strong genetic susceptibility from the Human Leucocyte Antigen (HLA) locus. Additionally, disorders of epigenetic processes, in particular non-random X chromosome inactivation (XCI), have been reported in many female-predominant autoimmune diseases. Here we test the hypothesis that women with RA or SSc who are strongly genetically predisposed are less susceptible to XCI bias. Methods: Using methylation sensitive genotyping of the androgen receptor (AR) gene, XCI profiles were performed in peripheral blood mononuclear cells from 161 women with RA, 96 women with SSc and 100 healthy women. HLA-DRB1 and DQB1 were genotyped. Presence of specific autoantibodies was documented for patients. XCI skewing was defined as having a ratio ≥ 80:20 of cells inactivating the same X chromosome. Results: 110 women with RA, 68 women with SSc, and 69 controls were informative for the AR polymorphism. Among them 40.9% of RA patients and 36.8% of SSc patients had skewed XCI compared to 17.4% of healthy women (P = 0.002 and 0.018, respectively). Presence of RA-susceptibility alleles coding for the “shared epitope” correlated with higher skewing among RA patients (P = 0.002) and such correlation was not observed in other women, healthy or with SSc. Presence of SSc-susceptibility alleles did not correlate with XCI patterns among SSc patients. Conclusion: Data demonstrate XCI skewing in both RA and SSc compared to healthy women. Unexpectedly, skewed XCI occurs more often in women with RA carrying the shared epitope, which usually reflects severe disease. This reinforces the view that loss of mosaicism in peripheral blood may be a consequence of chronic autoimmunity. [ABSTRACT FROM AUTHOR]

Pemphigus vulgaris (PV) is characterized by IgG1 and IgG4 autoantibodies to desmoglein (Dsg) 3, causing suprabasal blistering of skin and mucous membranes. IgG4 is the dominant autoantibody subclass in PV and correlates with disease activity, whereas IgG1 can be associated with remittent disease. It is unknown if switching the same variable region between IgG4 and IgG1 directly impacts pathogenicity. Here, we tested whether three pathogenic PV monoclonal antibodies (mAbs) from three different patients demonstrate differences in antigen affinity, epitope specificity, or pathogenicity when expressed as IgG1 or IgG4. F706 anti-Dsg3 IgG4 and F779 anti-Dsg3 IgG1, previously isolated as heterohybridomas, and Px43, a monovalent anti-Dsg3/Dsg1 IgG antibody isolated by phage display, were subcloned to obtain paired sets of IgG1 and IgG4 mAbs. Using ELISA and cell surface staining assays, F706 and F779 demonstrated similar antigen binding affinities of IgG1 and IgG4, whereas Px43 showed 3- to 8-fold higher affinity of IgG4 versus IgG1 by ELISA, but identical binding affinities to human skin, perhaps due to targeting of a quaternary epitope best displayed in tissues. All 3 mAb pairs targeted the same extracellular cadherin (EC) domain on Dsg3, caused Dsg3 internalization in primary human keratinocytes, and caused suprabasal blisters in human skin at comparable doses. We conclude that switching IgG1 and IgG4 subclasses of pathogenic PV mAbs does not directly affect their antigen binding or pathogenic properties. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is an autoimmune disease that attacks myelinated axons in the central nervous system. Induction of oral tolerance is a potent mechanism to prevent autoimmunity. The food yeast Candida utilis was used to test the therapeutic potential of oral tolerance induction in an animal model of human multiple sclerosis (MS). We constructed a C. utilis strain, which displays a fusion peptide composed of the encephalitogenic MOG35-55 peptide and the C. utilis Gas1 cell wall protein on its surface.By immunizing mice with MOG35-55 peptide experimental autoimmune encephalomyelitis (EAE) was induced in a mouse model. Feeding of mice with C. utilis that expresses MOG35-55 peptide on its surface was started seven days prior to immunization and was continued for ten days. Control animals were treated with wild-type fungus or left untreated. Untreated mice developed first clinical symptoms ten days post immunization (p. i.) with an ascending paralysis reaching maximal clinical disability at day 18 to 20 p. i.. Treatment with the wild-type strain demonstrated comparable clinical symptoms. In contrast, oral gavage of MOG35-55-presenting fungus ameliorated the development of EAE. In addition, incidence as well as maximal clinical disease severity were significantly reduced. Interestingly, reduction of disease severity also occurred in animals treated with heat-inactivated C. utilis cells indicating that tolerance induction was independent of fungal viability. Better disease outcome correlated with reduced demyelination and cellular inflammation in the spinal cord, lower T cell proliferation against rechallenge with MOG35-55 and more regulatory T cells in the lymph nodes. Our data demonstrate successful that using the food approved fungus C. utilis presenting the immunogenic MOG35-55 peptide on its surface induced an oral tolerance against this epitope in EAE. Further studies will reveal the nature and extent of an anti-inflammatory environment established by the treatment that prevents the development of an autoimmune disorder affecting the CNS. [ABSTRACT FROM AUTHOR]

Background: Subjects at risk for major mood disorders have a higher risk to develop autoimmune thyroid disease (AITD) and vice-versa, implying a shared pathogenesis. In mood disorder patients, an abnormal profile of hematopoietic/neuronal growth factors is observed, suggesting that growth/differentiation abnormalities of these cell lineages may predispose to mood disorders. The first objective of our study was to investigate whether an aberrant profile of these hematopoietic/neuronal growth factors is also detectable in subjects at risk for AITD. A second objective was to study the inter relationship of these factors with previously determined and published growth factors/cytokines in the same subjects. Methods: We studied 64 TPO-Ab-negative females with at least 1 first- or second-degree relative with AITD, 32 of whom did and 32 who did not seroconvert to TPO-Ab positivity in 5-year follow-up. Subjects were compared with 32 healthy controls (HCs). We measured serum levels of brain-derived neurotrophic factor (BDNF), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF) and IL-7 at baseline. Results: BDNF was significantly lower (8.2 vs 18.9 ng/ml, P<0.001), while EGF (506.9 vs 307.6 pg/ml, P = 0.003) and IGFBP-2 (388.3 vs 188.5 ng/ml, P = 0.028) were significantly higher in relatives than in HCs. Relatives who seroconverted in the next 5 years had significantly higher levels of SCF than non-seroconverters (26.5 vs 16.7 pg/ml, P = 0.017). In a cluster analysis with the previously published growth factors/cytokines SCF clustered together with IL-1β, IL-6 and CCL-3, of which high levels also preceded seroconversion. Conclusion: Relatives of AITD patients show aberrant serum levels of 4 hematopoietic/neuronal growth factors similar to the aberrancies found in mood disorder patients, suggesting that shared growth and differentiation defects in both the hematopoietic and neuronal system may underlie thyroid autoimmunity and mood disorders. A distinct pattern of four inter correlating immune factors in the relatives preceded TPO-Ab seroconversion in the next 5 years. [ABSTRACT FROM AUTHOR]

Background: The association between type 1 diabetes and thyroid autoimmunity has been studied in various populations, but seldom on Taiwanese children and adolescents. Therefore, the aim of this study was to examine the incidence of autoimmune thyroid disorders in Taiwanese children and adolescent patients with type 1 diabetes, based on data from a nationwide, population-based, health claims database. Methods: Using Taiwan’s National Health Insurance Research Database, we identified 3,652 patients with type 1 diabetes between 2000 and 2012. A comparison cohort was assembled, which consisted of five patients without type 1 diabetes, based on frequency matching for sex and 3-year age interval, for each patient with type 1 diabetes. Both groups were followed until diagnosis of thyroid disorders or the end of the follow-up period. Poisson regression models were used to calculate incidence rate ratios for the thyroid disorders between the type 1 diabetes cohort and the comparison cohort. Results: Simple and unspecified goiter (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 240), thyrotoxicosis (ICD-9-CM code 242), unspecified hypothyroidism (ICD-9-CM code 244.9), and thyroiditis (ICD-9-CM code 245) showed significantly higher incidences in the type 1 diabetes cohort compared with the control cohort, with incidence rate ratios of 2.74, 6.95, 6.54, 16.07, respectively. Conclusions: Findings from this nationwide, population-based cohort study showed that the incidences of autoimmune thyroid disorders were significantly higher in Taiwanese children and adolescents with type 1 diabetes compared with those without the disease. [ABSTRACT FROM AUTHOR]

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in adults. CVID patients often present changes in the frequency and function of B lymphocytes, reduced number of Treg cells, chronic immune activation, recurrent infections, high incidence of autoimmunity and increased risk for malignancies. We hypothesized that the frequency of B10 cells would be diminished in CVID patients because these cells play an important role in the development of Treg cells and in the control of T cell activation and autoimmunity. Therefore, we evaluated the frequency of B10 cells in CVID patients and correlated it with different clinical and immunological characteristics of this disease. Forty-two CVID patients and 17 healthy controls were recruited for this study. Cryopreserved PBMCs were used for analysis of T cell activation, frequency of Treg cells and characterization of B10 cells by flow cytometry. IL-10 production by sorted B cells culture and plasma sCD14 were determined by ELISA. We found that CVID patients presented decreased frequency of IL-10-producing CD24hiCD38hi B cells in different cell culture conditions and decreased frequency of IL-10-producing CD24hiCD27+ B cells stimulated with CpG+PIB. Moreover, we found that CVID patients presented lower secretion of IL-10 by sorting-purified B cells when compared to healthy controls. The frequency of B10 cells had no correlation with autoimmunity, immune activation and Treg cells in CVID patients. This work suggests that CVID patients have a compromised regulatory B cell compartment which is not correlated with clinical and immunological characteristics presented by these individuals. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and function of Treg is still limited and based on single kinase cascades so far. To gain a more comprehensive insight into the pathways determining Treg function we performed kinome profiling using a phosphorylation-based kinome array in human Treg at different activation stages compared to Teff. Here we have determined intriguing quantitative differences in both populations. Resting and activated Treg showed an altered pattern of CD28-dependent kinases as well as of those involved in cell cycle progression. Additionally, significant up-regulation of distinct kinases such as EGFR or CK2 in activated Treg but not in Teff not only resemble data we obtained in previous studies in the murine system but also suggest that those specific molecular activation patterns can be used for definition of the activation and functional state of human Treg. Taken together, detailed investigation of kinome profiles opens the possibility to identify novel molecular mechanisms for a better understanding of Treg biology but also for development of effective immunotherapies against unwanted T cell responses in allergy, autoimmunity and cancer. [ABSTRACT FROM AUTHOR]

Ovarian cancer G protein-coupled receptor 1 (OGR1) is a proton-sensing molecule that can detect decreases in extracellular pH that occur during inflammation. Although OGR1 has been shown to have pro-inflammatory functions in various diseases, its role in autoimmunity has not been examined. We therefore sought to determine whether OGR1 has a role in the development of T cell autoimmunity by contrasting the development of experimental autoimmune encephalomyelitis between wild type and OGR1-knockout mice. OGR1-knockout mice showed a drastically attenuated clinical course of disease that was associated with a profound reduction in the expansion of myelin oligodendrocyte glycoprotein 35-55-reactive T helper 1 (Th1) and Th17 cells in the periphery and a reduced accumulation of Th1 and Th17 effectors in the central nervous system. We determined that these impaired T cell responses in OGR1-knockout mice associated with a reduced frequency and number of dendritic cells in draining lymph nodes during EAE and a higher production of nitric oxide by macrophages. Our studies suggest that OGR1 plays a key role in regulating T cell responses during autoimmunity. [ABSTRACT FROM AUTHOR]

Type 1 diabetes (T1D) results from autoimmune destruction of insulin producing β cells of the pancreatic islets. Curbing autoimmunity at the initiation of T1D can result in recovery of residual β cells and consequently remission of diabetes. Here we report a cell-based therapy for autoimmune diabetes in non-obese diabetic (NOD) mice using dermal fibroblasts. This was achieved by a single injection of fibroblasts, expressing the immunoregulatory molecule indoleamine 2,3 dioxygenase (IDO), into peritoneal cavity of NOD mice shortly after the onset of overt hyperglycemia. Mice were then monitored for reversal of hyperglycemia and changes in inflammatory / regulatory T cell profiles. Blood glucose levels dropped into the normal range in 82% of NOD mice after receiving IDO-expressing fibroblasts while all control mice remained diabetic. We found significantly reduced islet inflammation, increased regulatory T cells, and decreased T helper 17 cells and β cell specific autoreactive CD8+ T cells following IDO cell therapy. We further showed that some of intraperitoneal injected fibroblasts migrated to local lymph nodes and expressed co-inhibitory molecules. These findings suggest that IDO fibroblasts therapy can reinstate self-tolerance and alleviate β cell autoreactivity in NOD mice, resulting in remission of autoimmune diabetes. [ABSTRACT FROM AUTHOR]

Cytokines secreted from dendritic cells (DCs) play an important role in the regulation of T helper (Th) cell differentiation and activation into effector cells. Therefore, controlling cytokine secretion from DCs may potentially regulate Th differentiation/activation. DCs also induce de-novo generation of regulatory T cells (Treg) that modulate the immune response. In the current study we used the mixed leukocyte reaction (MLR) to investigate the effect of allospecific Treg on IL-12, TNFα and IL-6 secretion by DCs. Treg cells were found to markedly down-regulate IL-12 secretion from DCs following stimulation with TLR7/8 agonist. This down-regulation of IL-12 was neither due to a direct suppression of its production by the DCs nor a result of marked DC death. We found that IL-12 was rather actively consumed by Treg cells. IL-12 consumption was mediated by a subpopulation of IL-12Rβ2-expressing Treg cells and was dependent on MHC class-II expressed on dendritic cells. Furthermore, IL-12 consumption by Tregs increased their suppressive effect on T cell proliferation and Th1 activation. These results provide a new pathway of Th1 response regulation where IL-12 secreted by DCs is consumed by a sub-population of IL-12Rβ2-expressing Treg cells. Consumption of IL-12 by Tregs not only reduces the availability of IL-12 to Th effector cells but also enhances the Treg immunosuppressive effect. This DC-induced IL-12Rβ2-expressing Treg subpopulation may have a therapeutic advantage in suppressing Th1 mediated autoimmunity. [ABSTRACT FROM AUTHOR]

Adaptive immune responses are complex dynamic processes whereby B and T cells undergo division and differentiation triggered by pathogenic stimuli. Deregulation of the response can lead to severe consequences for the host organism ranging from immune deficiencies to autoimmunity. Tracking cell division and differentiation by flow cytometry using fluorescent probes is a major method for measuring progression of lymphocyte responses, both in vitro and in vivo. In turn, mathematical modeling of cell numbers derived from such measurements has led to significant biological discoveries, and plays an increasingly important role in lymphocyte research. Fitting an appropriate parameterized model to such data is the goal of these studies but significant challenges are presented by the variability in measurements. This variation results from the sum of experimental noise and intrinsic probabilistic differences in cells and is difficult to characterize analytically. Current model fitting methods adopt different simplifying assumptions to describe the distribution of such measurements and these assumptions have not been tested directly. To help inform the choice and application of appropriate methods of model fitting to such data we studied the errors associated with flow cytometry measurements from a wide variety of experiments. We found that the mean and variance of the noise were related by a power law with an exponent between 1.3 and 1.8 for different datasets. This violated the assumptions inherent to commonly used least squares, linear variance scaling and log-transformation based methods. As a result of these findings we propose a new measurement model that we justify both theoretically, from the maximum entropy standpoint, and empirically using collected data. Our evaluation suggests that the new model can be reliably used for model fitting across a variety of conditions. Our work provides a foundation for modeling measurements in flow cytometry experiments thus facilitating progress in quantitative studies of lymphocyte responses. [ABSTRACT FROM AUTHOR]

Background: Fatigue is a debilitating condition with a significant impact on patients’ quality of life. Fatigue is frequently reported by patients suffering from primary Sjögren’s Syndrome (pSS), a chronic autoimmune condition characterised by dryness of the eyes and the mouth. However, although fatigue is common in pSS, it does not manifest in all sufferers, providing an excellent model with which to explore the potential underpinning biological mechanisms. Methods: Whole blood samples from 133 fully-phenotyped pSS patients stratified for the presence of fatigue, collected by the UK primary Sjögren’s Syndrome Registry, were used for whole genome microarray. The resulting data were analysed both on a gene by gene basis and using pre-defined groups of genes. Finally, gene set enrichment analysis (GSEA) was used as a feature selection technique for input into a support vector machine (SVM) classifier. Classification was assessed using area under curve (AUC) of receiver operator characteristic and standard error of Wilcoxon statistic, SE(W). Results: Although no genes were individually found to be associated with fatigue, 19 metabolic pathways were enriched in the high fatigue patient group using GSEA. Analysis revealed that these enrichments arose from the presence of a subset of 55 genes. A radial kernel SVM classifier with this subset of genes as input displayed significantly improved performance over classifiers using all pathway genes as input. The classifiers had AUCs of 0.866 (SE(W) 0.002) and 0.525 (SE(W) 0.006), respectively. Conclusions: Systematic analysis of gene expression data from pSS patients discordant for fatigue identified 55 genes which are predictive of fatigue level using SVM classification. This list represents the first step in understanding the underlying pathophysiological mechanisms of fatigue in patients with pSS. [ABSTRACT FROM AUTHOR]

Dual TCRα-expressing T cells outnumber dual TCRβ-expressing cells by ~10:1. As a result, efforts to understand how dual TCR T cells impact immunity have focused on dual TCRα expression; dual TCRβ expression remains understudied. We recently demonstrated, however, that dual TCRβ expression accelerated disease in a TCR transgenic model of autoimmune arthritis through enhanced positive selection efficiency, indicating that dual TCRβ expression, though rare, can impact thymic selection. Here we generated mice hemizygous for TCRα, TCRβ, or both on the C57BL/6 background to investigate the impact bi-allelic TCR chain recombination has on T cell development, repertoire diversity, and autoimmunity. Lack of bi-allelic TCRα or TCRβ recombination reduced αβ thymocyte development efficiency, and the absence of bi-allelic TCRβ recombination promoted γδ T cell development. However, we observed no differences in the numbers of naïve and expanded antigen-specific T cells between TCRα+/-β+/- and wildtype mice, and TCR repertoire analysis revealed only subtle differences in Vβ gene usage. Finally, the absence of dual TCR T cells did not impact induced experimental autoimmune encephalomyelitis pathogenesis. Thus, despite more stringent allelic exclusion of TCRβ relative to TCRα, bi-allelic TCRβ expression can measurably impact thymocyte development and is necessary for maintaining normal αβ/γδ T cell proportions. [ABSTRACT FROM AUTHOR]

Defective clearance of apoptotic cells can result in sustained inflammation and subsequent autoimmunity. Macrophages, the “professional phagocyte” of the body, are responsible for efficient, non-phlogistic, apoptotic cell clearance. Controlling phagocytosis of apoptotic cells by macrophages is an attractive therapeutic opportunity to ameliorate inflammation. Using high content imaging, we have developed a system for evaluating the effects of antibody treatment on apoptotic cell uptake in primary human macrophages by comparing the Phagocytic Index (PI) for each antibody. Herein we demonstrate the feasibility of evaluating a panel of antibodies of unknown specificities obtained by immunization of mice with primary human macrophages and show that they can be distinguished based on individual PI measurements. In this study ~50% of antibodies obtained enhance phagocytosis of apoptotic cells while approximately 5% of the antibodies in the panel exhibit some inhibition. Though the specificities of the majority of antibodies are unknown, two of the antibodies that improved apoptotic cell uptake recognize recombinant MerTK; a receptor known to function in this capacity in vivo. The agonistic impact of these antibodies on efferocytosis could be demonstrated without addition of either of the MerTK ligands, Gas6 or ProS. These results validate applying the mechanism of this fundamental biological process as a means for identification of modulators that could potentially serve as therapeutics. This strategy for interrogating macrophages to discover molecules regulating apoptotic cell uptake is not limited by access to purified protein thereby increasing the possibility of finding novel apoptotic cell uptake pathways. [ABSTRACT FROM AUTHOR]

CD44 is a multi-functional receptor with multiple of isoforms engaged in modulation of cell trafficking and transmission of apoptotic signals. We have previously shown that injection of anti-CD44 antibody into NOD mice induced resistance to type 1 diabetes (T1D). In this communication we describe our efforts to understand the mechanism underlying this effect. We found that CD44-deficient NOD mice develop stronger resistance to T1D than wild-type littermates. This effect is not explained by the involvement of CD44 in cell migration, because CD44-deficient inflammatory cells surprisingly had greater invasive potential than the corresponding wild type cells, probably owing to molecular redundancy. We have previously reported and we show here again that CD44 expression and hyaluronic acid (HA, the principal ligand for CD44) accumulation are detected in pancreatic islets of diabetic NOD mice, but not of non-diabetic DBA/1 mice. Expression of CD44 on insulin-secreting β cells renders them susceptible to the autoimmune attack, and is associated with a diminution in β-cells function (e.g., less insulin production and/or insulin secretion) and possibly also with an enhanced apoptosis rate. The diabetes-supportive effect of CD44 expression on β cells was assessed by the TUNEL assay and further strengthened by functional assays exhibiting increased nitric oxide release, reduced insulin secretion after glucose stimulation and decreased insulin content in β cells. All these parameters could not be detected in CD44-deficient islets. We further suggest that HA-binding to CD44-expressing β cells is implicated in β-cell demise. Altogether, these data agree with the concept that CD44 is a receptor capable of modulating cell fate. This finding is important for other pathologies (e.g., cancer, neurodegenerative diseases) in which CD44 and HA appear to be implicated. [ABSTRACT FROM AUTHOR]

Viral agents are of interest as possible autoimmune triggers due to prior reported associations and widely studied molecular mechanisms of antiviral immune responses in autoimmunity. Here we examined new viral candidates for the initiation and/or promotion of systemic autoimmune diseases (SAID), as well as possible related signaling pathways shared in the pathogenesis of those disorders. RNA isolated from peripheral blood samples from 33 twins discordant for SAID and 33 matched, unrelated healthy controls was analyzed using a custom viral-human gene microarray. Paired comparisons were made among three study groups—probands with SAID, their unaffected twins, and matched, unrelated healthy controls—using statistical and molecular pathway analyses. Probands and unaffected twins differed significantly in the expression of 537 human genes, and 107 of those were associated with viral infections. These 537 differentially expressed human genes participate in overlapping networks of several canonical, biologic pathways relating to antiviral responses and inflammation. Moreover, certain viral genes were expressed at higher levels in probands compared to either unaffected twins or unrelated, healthy controls. Interestingly, viral gene expression levels in unaffected twins appeared intermediate between those of probands and the matched, unrelated healthy controls. Of the viruses with overexpressed viral genes, herpes simplex virus-2 (HSV-2) was the only human viral pathogen identified using four distinct oligonucleotide probes corresponding to three HSV-2 genes associated with different stages of viral infection. Although the effects from immunosuppressive therapy on viral gene expression remain unclear, this exploratory study suggests a new approach to evaluate shared viral agents and antiviral immune responses that may be involved in the development of SAID. [ABSTRACT FROM AUTHOR]

Interferon Regulatory Factors (IRFs) play fundamental roles in dendritic cell (DC) differentiation and function. In particular, IRFs are critical transducers of TLR signaling and dysregulation in this family of factors is associated with the development of autoimmune disorders such as Systemic Lupus Erythematosus (SLE). While several IRFs are expressed in DCs their relative contribution to the aberrant phenotypic and functional characteristics that DCs acquire in autoimmune disease has not been fully delineated. Mice deficient in both DEF6 and SWAP-70 (= Double-knock-out or DKO mice), two members of a unique family of molecules that restrain IRF4 function, spontaneously develop a lupus-like disease. Although autoimmunity in DKO mice is accompanied by dysregulated IRF4 activity in both T and B cells, SWAP-70 is also known to regulate multiple aspects of DC biology leading us to directly evaluate DC development and function in these mice. By monitoring Blimp1 expression and IL-10 competency in DKO mice we demonstrate that DCs in these mice exhibit dysregulated IL-10 production, which is accompanied by aberrant Blimp1 expression in the spleen but not in the peripheral lymph nodes. We furthermore show that DCs from these mice are hyper-responsive to multiple TLR ligands and that IRF4 plays a differential role in in these responses by being required for the TLR4-mediated but not the TLR9-mediated upregulation of IL-10 expression. Thus, DC dysfunction in lupus-prone mice relies on both IRF4-dependent and IRF4-independent pathways. [ABSTRACT FROM AUTHOR]

Object: Studies have suggested that depression was accompanied by oxidative stress dysregulation, including abnormal total antioxidant capacity (TAC), antioxidants, free radicals, oxidative damage and autoimmune response products. This meta-analysis aims to analyse the clinical data quantitatively by comparing the oxidative stress markers between depressed patients and healthy controls. Methods: A search was conducted to collect the studies that measured the oxidative stress markers in depressed patients. Studies were searched in Embase, Medline, PsychINFO, Science direct, CBMDisc, CNKI and VIP from 1990 to May 2015. Data were subjected to meta-analysis by using a random effects model for examining the effect sizes of the results. Bias assessments, heterogeneity assessments and sensitivity analyses were also conducted. Results: 115 articles met the inclusion criteria. Lower TAC was noted in acute episodes (AEs) of depressed patients (p<0.05). Antioxidants, including serum paraoxonase, uric acid, albumin, high-density lipoprotein cholesterol and zinc levels were lower than controls (p<0.05); the serum uric acid, albumin and vitamin C levels were increased after antidepressant therapy (p<0.05). Oxidative damage products, including red blood cell (RBC) malondialdehyde (MDA), serum MDA and 8-F2-isoprostanes levels were higher than controls (p<0.05). After antidepressant medication, RBC and serum MDA levels were decreased (p<0.05). Moreover, serum peroxide in free radicals levels were higher than controls (p<0.05). There were no differences between the depressed patients and controls for other oxidative stress markers. Conclusion: This meta-analysis supports the facts that the serum TAC, paraoxonase and antioxidant levels are lower, and the serum free radical and oxidative damage product levels are higher than controls in depressed patients. Meanwhile, the antioxidant levels are increased and the oxidative damage product levels are decreased after antidepressant medication. The pathophysiological relationships between oxidative stress and depression, and the potential benefits of antioxidant supplementation deserve further research. [ABSTRACT FROM AUTHOR]

Neutrophils release fibrous traps of DNA, histones, and granule proteins known as neutrophil extracellular traps (NETs), which contribute to microbicidal killing and have been implicated in autoimmunity. The role of NET formation in the host response to nonbacterial pathogens is not well-understood. In this study, we investigated the release of NETs by human neutrophils upon their interaction with Trypanosoma cruzi (Y strain) parasites. Our results showed that human neutrophils stimulated by T. cruzi generate NETs composed of DNA, histones, and elastase. The release occurred in a dose-, time-, and reactive oxygen species-dependent manner to decrease trypomastigote and increase amastigote numbers of the parasites without affecting their viability. NET release was decreased upon blocking with antibodies against Toll-like receptors 2 and 4. In addition, living parasites were not mandatory in the release of NETs induced by T. cruzi, as the same results were obtained when molecules from its soluble extract were tested. Our results increase the understanding of the stimulation of NETs by parasites, particularly T. cruzi. We suggest that contact of T. cruzi with NETs during Chagas’s disease can limit infection by affecting the infectivity/pathogenicity of the parasite. [ABSTRACT FROM AUTHOR]

Increased oxidative stress under hyperglycemic conditions, through the interaction of AGEs with RAGE receptors and via activation of interleukin mediated transcription signalling, has been reported in cancer. Proteins modifications are being explored for their roles in the development and progression of cancer and autoantibody response against them is gaining interest as a probe for early detection of the disease. This study has analysed the changes in histone H1 upon modification by methylglyoxal (MG) and its implications in auto-immunopathogenesis of cancer. Modified histone showed modifications in the aromatic residues, changed tyrosine microenvironment, intermolecular cross linking and generation of AGEs. It showed masking of hydrophobic patches and a hypsochromic shift in the in ANS specific fluorescence. MG aggressively oxidized histone H1 leading to the accumulation of reactive carbonyls. Far UV CD measurements showed di-carbonyl induced enhancement of the alpha structure and the induction of beta sheet conformation; and thermal denaturation (Tm) studies confirmed the thermal stability of the modified histone. FTIR analysis showed amide I band shift, generation of a carboxyethyl group and N-Cα vibrations in the modified histone. LCMS analysis confirmed the formation of Nε-(carboxyethyl)lysine and electron microscopic studies revealed the amorphous aggregate formation. The modified histone showed altered cooperative binding with DNA. Modified H1 induced high titre antibodies in rabbits and the IgG isolated form sera of rabbits immunized with modified H1 exhibited specific binding with its immunogen in Western Blot analysis. IgG isolated from the sera of patients with lung cancer, prostate cancer, breast cancer and cancer of head and neck region showed better recognition for neo-epitopes on the modified histone, reflecting the presence of circulating autoantibodies in cancer. Since reports suggest a link between AGE-RAGE axis and carcinogenesis, glycoxidation of histone H1 and its immunogenicity paves ways for understanding role of glycoxidatively damaged nuclear proteins in cancer. [ABSTRACT FROM AUTHOR]

We have recently reported that, although adenosine receptor (AR) agonists have a suppressive effect on Th1 autoreactive T cells, their effect on Th17 autoreactive T cells and γδ T cells is stimulatory and this effect is mainly mediated via A2A adenosine receptors (A2ARs). In this study, we further demonstrate that treatment of C57BL/6 (B6) mice with a selective A2B adenosine receptor (A2BR) agonist greatly enhanced the development of experimental autoimmune uveitis (EAU), whereas treatment with an A2BR antagonist significantly ameliorated severity of EAU. The A2BR agonist-treated mice showed augmented Th17, but not Th1, responses. Mechanistic studies showed that the A2BR agonist-induced enhancement of the Th17 response was significantly lower when TCR-δ-/- mice received the same treatment and that transfer of γδ T cells into TCR-δ-/- mice partially restored this effect. We also showed that dendritic cells (DCs) from A2BR agonist-treated mice showed a significantly increased ability to activate γδ T cells and Th17 autoreactive T cells. Thus, our previous studies have shown that, in EAU, activated γδ T cells possess greatly increased ability to enhance Th17 autoimmune responses. In the present study, we showed that exposure of DCs to A2BR agonist facilitated γδ T cell activation, leading to augmented Th17 responses and progressive EAU development. Our results further support our previous finding that AR agonists have distinct effects on Th1 and Th17 autoimmune responses. [ABSTRACT FROM AUTHOR]

Restoration of endogenous insulin production by islet transplantation is considered a curative option for patients with type 1 diabetes. However, recurrent autoimmunity and alloreactivity cause graft rejection hindering successful transplantation. Here we tested whether transplant tolerance to allogeneic islets could be achieved in non-obese diabetic (NOD) mice by simultaneously tackling autoimmunity via antigen-specific immunization, and alloreactivity via granulocyte colony stimulating factor (G-CSF) and rapamycin (RAPA) treatment. Immunization with insB9-23 peptide alone or in combination with two islet peptides (IGRP206-214and GAD524-543) in incomplete Freund’s adjuvant (IFA) were tested for promoting syngeneic pancreatic islet engraftment in spontaneously diabetic NOD mice. Treatment with G-CSF/RAPA alone or in combination with insB9-23/IFA was examined for promoting allogeneic islet engraftment in the same mouse model. InsB9-23/IFA immunization significantly prolonged syngeneic pancreatic islet survival in NOD mice by a mechanism that necessitated the presence of CD4+CD25+ T regulatory (Treg) cells, while combination of three islet epitopes was less efficacious in controlling recurrent autoimmunity. G-CSF/RAPA treatment was unable to reverse T1D or control recurrent autoimmunity but significantly prolonged islet allograft survival in NOD mice. Blockade of interleukin-10 (IL-10) during G-CSF/RAPA treatment resulted in allograft rejection suggesting that IL-10-producing cells were fundamental to achieve transplant tolerance. G-CSF/RAPA treatment combined with insB9-23/IFA did not further increase the survival of allogeneic islets. Thus, insB9-23/IFA immunization controls recurrent autoimmunity and G-CSF/RAPA treatment limits alloreactivity, however their combination does not further promote allogeneic pancreatic islet engraftment in NOD mice. [ABSTRACT FROM AUTHOR]

Autoimmunity is associated with defective phagocytic clearance of apoptotic cells. IgM deficient mice exhibit an autoimmune phenotype consistent with a role for circulating IgM antibodies in apoptotic cell clearance. We have extensively characterised IgM binding to non-apoptotic and apoptotic mouse thymocytes and human Jurkat cells using flow cytometry, confocal imaging and electron microscopy. We demonstrate strong specific IgM binding to a subset of Annexin-V (AnnV)+PI (Propidium Iodide)+ apoptotic cells with disrupted cell membranes. Electron microscopy studies indicated that IgM+AnnV+PI+ apoptotic cells exhibited morphologically advanced apoptosis with marked plasma membrane disruption compared to IgM-AnnV+PI+ apoptotic cells, suggesting that access to intracellular epitopes is required for IgM to bind. Strong and comparable binding of IgM to permeabilised non-apoptotic and apoptotic cells suggests that IgM bound epitopes are 'apoptosis independent' such that IgM may bind any cell with profound disruption of cell plasma membrane integrity. In addition, permeabilised erythrocytes exhibited significant IgM binding thus supporting the importance of cell membrane epitopes. These data suggest that IgM may recognize and tag damaged nucleated cells or erythrocytes that exhibit significant cell membrane disruption. The role of IgM in vivo in conditions characterized by severe cell damage such as ischemic injury, sepsis and thrombotic microangiopathies merits further exploration. [ABSTRACT FROM AUTHOR]

Drak2 is a serine/threonine kinase expressed highest in T cells and B cells. Drak2-/- mice are resistant to autoimmunity in mouse models of type 1 diabetes and multiple sclerosis. Resistance to these diseases occurs, in part, because Drak2 is required for the survival of autoreactive T cells that induce disease. However, the molecular mechanisms by which Drak2 affects T cell survival and autoimmunity are not known. A recent report demonstrated that Drak2 negatively regulated transforming growth factor-β (TGF-β) signaling in tumor cell lines. Thus, increased TGF-β signaling in the absence of Drak2 may contribute to the resistance to autoimmunity in Drak2-/- mice. Therefore, we examined if Drak2 functioned as a negative regulator of TGF-β signaling in T cells, and whether the enhanced susceptibility to death of Drak2-/- T cells was due to augmented TGF-β signaling. Using several in vitro assays to test TGF-β signaling and T cell function, we found that activation of Smad2 and Smad3, which are downstream of the TGF-β receptor, was similar between wildtype and Drak2-/- T cells. Furthermore, TGF-β-mediated effects on naïve T cell proliferation, activated CD8+ T cell survival, and regulatory T cell induction was similar between wildtype and Drak2-/- T cells. Finally, the increased susceptibility to death in the absence of Drak2 was not due to enhanced TGF-β signaling. Together, these data suggest that Drak2 does not function as a negative regulator of TGF-β signaling in primary T cells stimulated in vitro. It is important to investigate and discern potential molecular mechanisms by which Drak2 functions in order to better understand the etiology of autoimmune diseases, as well as to validate the use of Drak2 as a target for therapeutic treatment of these diseases. [ABSTRACT FROM AUTHOR]

Background: The autoimmune regulator (AIRE) is expressed in the thymus, particularly in thymic medullary epithelial cells (mTECs), and is required for the ectopic expression of a diverse range of peripheral tissue antigens by mTECs, facilitating their ability to perform negative selection of auto-reactive immature T-cells. The expression profile of peripheral tissue antigens is affected not only by AIRE deficiency but also with variation of AIRE activity in the thymus. Method and Results: Therefore we screened 591bp upstream of the AIRE transcription start site including AIRE minimal promoter for single nucleotide polymorphism (SNPs) and identified two SNPs -655R (rs117557896) and -230Y (rs751032) respectively. To study the effect of these variations on AIRE promoter activity we generated a Flp-In host cell line which was stably transfected with a single copy of the reporter vector. Relative promoter activity was estimated by comparing the luciferase specific activity for lysates of the different reporter AIRE promoter-reporter gene constructs including AIRE-655G AIRE-230C, AIRE-655G AIRE-230T and AIRE-655A AIRE-230C. The analysis showed that the commonest haplotype AIRE-655G AIRE-230C has the highest luciferase specific activity (p<0.001). Whereas AIRE-655G AIRE-230T has a luciferase specific activity value that approaches null. Both AIRE promoter polymorphic sites have one allele that forms a CpG methylation site which we determined can be methylated in methylation assays using the M.SssI CpG methyltransferase. Conclusion: AIRE-230Y is in a conserved region of the promoter and is adjacent to a predicted WT1 transcription factor binding site, suggesting that AIRE-230Y affects AIRE expression by influencing the binding of biochemical factors to this region. Our findings show that AIRE-655GAIRE-230T haplotype could dramatically alter AIRE transcription and so have an effect on the process of negative selection and affect susceptibility to autoimmune conditions. [ABSTRACT FROM AUTHOR]

Genetic predisposition and environmental factors influence the development of human autoimmune disease. Occupational exposure to crystalline silica (cSiO2) has been etiologically linked to increased incidence of autoimmunity, including systemic lupus erythematosus (SLE), but the underlying mechanisms are poorly understood. The purpose of this study was to test the hypothesis that early repeated short-term cSiO2 exposure will modulate both latency and severity of autoimmunity in the lupus-prone female NZBWF1 mouse. Weekly intranasal exposure to cSiO2 (0.25 and 1.0 mg) for 4 wk beginning at 9 wk of age both reduced latency and increased intensity of glomerulonephritis. cSiO2 elicited robust inflammatory responses in the lungs as evidenced by extensive perivascular and peribronchial lymphoplasmacytic infiltration consisting of IgG-producing plasma cells, and CD45R+ and CD3+ lymphocytes that were highly suggestive of ectopic lymphoid tissue (ELT). In addition, there were elevated concentrations of immunoglobulins and the cytokines MCP-1, TNF-α and IL-6 in bronchoalveolar lavage fluid. cSiO2-associated kidney and lung effects paralleled dose-dependent elevations of autoantibodies and proinflammatory cytokines in plasma. Taken together, cSiO2-induced pulmonary inflammation and ectopic lymphoid neogenesis in the NZBWF1 mouse corresponded closely to systemic inflammatory and autoimmune responses as well as the early initiation of pathological outcomes in the kidney. These findings suggest that following airway exposure to crystalline silica, in mice genetically prone to SLE, the lung serves as a platform for triggering systemic autoimmunity and glomerulonephritis. [ABSTRACT FROM AUTHOR]

Background and Aim: Mesenchymal precursor cells (MPC) are reported to possess immunomodulatory properties that may prove beneficial in autoimmune and other inflammatory conditions. However, their mechanism of action is poorly understood. A collagen-induced arthritis model has been previously developed which demonstrates local joint inflammation and systemic inflammatory changes. These include not only increased levels of inflammatory markers, but also vascular endothelial cell dysfunction, characterised by reduced endothelium-dependent vasodilation. This study aimed to characterise the changes in systemic inflammatory markers and endothelial function following the intravenous administration of MPC, in the ovine model. Methods: Arthritis was induced in sixteen adult sheep by administration of bovine type II collagen into the hock joint following initial sensitisation. After 24h, sheep were administered either 150 million allogeneic ovine MPCs intravenously, or saline only. Fibrinogen and serum amyloid-A were measured in plasma to assess systemic inflammation, along with pro-inflammatory and anti-inflammatory cytokines. Animals were necropsied two weeks following arthritis induction. Coronary and digital arterial segments were mounted in a Mulvaney-Halpern wire myograph. The relaxant response to endothelium-dependent and endothelium-independent vasodilators was used to assess endothelial dysfunction. Results and Conclusion: Arthritic sheep treated with MPC demonstrated a marked spike in plasma IL-10, 24h following MPC administration. They also showed significantly reduced plasma levels of the inflammatory markers, fibrinogen and serum amyloid A, and increased HDL. Coronary arteries from RA sheep treated with MPCs demonstrated a significantly greater maximal relaxation to bradykinin when compared to untreated RA sheep (253.6 ± 17.1% of pre-contracted tone vs. 182.3 ± 27.3% in controls), and digital arteries also demonstrated greater endothelium-dependent vasodilation. This study demonstrated that MPCs given intravenously are able to attenuate systemic inflammatory changes associated with a monoarthritis, including the development of endothelial dysfunction. [ABSTRACT FROM AUTHOR]

Despite the success of genome-wide association studies (GWAS) in detecting a large number of loci for complex phenotypes such as rheumatoid arthritis (RA) susceptibility, the lack of information on the causal genes leaves important challenges to interpret GWAS results in the context of the disease biology. Here, we genetically fine-map the RA risk locus at 19p13 to define causal variants, and explore the pleiotropic effects of these same variants in other complex traits. First, we combined Immunochip dense genotyping (n = 23,092 case/control samples), Exomechip genotyping (n = 18,409 case/control samples) and targeted exon-sequencing (n = 2,236 case/controls samples) to demonstrate that three protein-coding variants in TYK2 (tyrosine kinase 2) independently protect against RA: P1104A (rs34536443, OR = 0.66, P = 2.3x10-21), A928V (rs35018800, OR = 0.53, P = 1.2x10-9), and I684S (rs12720356, OR = 0.86, P = 4.6x10-7). Second, we show that the same three TYK2 variants protect against systemic lupus erythematosus (SLE, Pomnibus = 6x10-18), and provide suggestive evidence that two of the TYK2 variants (P1104A and A928V) may also protect against inflammatory bowel disease (IBD; Pomnibus = 0.005). Finally, in a phenome-wide association study (PheWAS) assessing >500 phenotypes using electronic medical records (EMR) in >29,000 subjects, we found no convincing evidence for association of P1104A and A928V with complex phenotypes other than autoimmune diseases such as RA, SLE and IBD. Together, our results demonstrate the role of TYK2 in the pathogenesis of RA, SLE and IBD, and provide supporting evidence for TYK2 as a promising drug target for the treatment of autoimmune diseases. [ABSTRACT FROM AUTHOR]

Background: Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disorder with typical onset in the 5th- 6th decade of life. The hypothesis of an autoimmune origin of ALS receives less attention today, but immunological phenomena still seem to be involved and mechanisms such as protective autoimmunity may be important. Detection of antibodies against a variety of gangliosides has been repeatedly described in ALS-patients by several authors, but widely differing frequencies and titres have been reported. Therefore, we investigated the presence of six common antibodies with a commercially available test panel for GA1, GM1, GM2, GD1a, GD1b and GQ1b in a large group of clinically well-characterized ALS patients and compared them to a collective of 200 healthy blood donors. Methods: IgG and IgM antibodies to the six gangliosides asialoGM1 (GA1), GM1, GM2, GD1a, GD1b, GQ1b were determined by GanglioCombi ELISA in sera of 84 ALS patients. Results were expressed as a %-ratio of a highly positive control and categorized as negative (<30%), borderline (30–50%), moderately (50–100%) and strongly positive (>100%). The values obtained from 200 Swiss blood donors served as a reference group. Results: In twenty-two (26.2%) ALS-patients elevated anti-ganglioside antibodies could be detected: Taking all subspecific antibodies together, IgG antibodies were found in 9/84 (10.7%) and IgM in 15/84 (17.9%) patients. There was no correlation between age, gender, site of onset or survival and anti-ganglioside-positive/-negative titres in ALS-patients. No statistically significant difference in the frequency of anti-ganglioside antibodies compared to the group of healthy blood donors was found. Conclusion: Even with this more comprehensive approach, anti-ganglioside antibody frequencies and patterns in our ALS cohort closely resembled the values measured in healthy controls. In accordance with other studies, we did not observe any association of a distinct ALS phenotype with elevated anti-ganglioside antibodies or an impact on survival. [ABSTRACT FROM AUTHOR]

BXD2 mice spontaneously develop autoantibodies and subsequent glomerulonephritis, offering a useful animal model to study autoimmune lupus. Although initial studies showed a critical contribution of IL-17 and Th17 cells in mediating autoimmune B cell responses in BXD2 mice, the role of follicular helper T (Tfh) cells remains incompletely understood. We found that both the frequency of Th17 cells and the levels of IL-17 in circulation in BXD2 mice were comparable to those of wild-type. By contrast, the frequency of PD-1+CXCR5+ Tfh cells was significantly increased in BXD2 mice compared with wild-type mice, while the frequency of PD-1+CXCR5+Foxp3+ follicular regulatory T (Tfr) cells was reduced in the former group. The frequency of Tfh cells rather than that of Th17 cells was positively correlated with the frequency of germinal center B cells as well as the levels of autoantibodies to dsDNA. More importantly, CXCR5+ CD4+ T cells isolated from BXD2 mice induced the production of IgG from naïve B cells in an IL-21-dependent manner, while CCR6+ CD4+ T cells failed to do so. These results together demonstrate that Tfh cells rather than Th17 cells contribute to the autoimmune germinal center reactions in BXD2 mice. [ABSTRACT FROM AUTHOR]

Roles of all-trans-retinoic acid (tRA), a metabolite of vitamin A (VA), in both tolerogenic and immunogenic responses are documented. However, how tRA affects the development of systemic autoimmunity is poorly understood. Here we demonstrate that tRA have paradoxical effects on the development of autoimmune lupus in the MRL/lpr mouse model. We administered, orally, tRA or VA mixed with 10% of tRA (referred to as VARA) to female mice starting from 6 weeks of age. At this age, the mice do not exhibit overt clinical signs of lupus. However, the immunogenic environment preceding disease onset has been established as evidenced by an increase of total IgM/IgG in the plasma and expansion of lymphocytes and dendritic cells in secondary lymphoid organs. After 8 weeks of tRA, but not VARA treatment, significantly higher pathological scores in the skin, brain and lung were observed. These were accompanied by a marked increase in B-cell responses that included autoantibody production and enhanced expression of plasma cell-promoting cytokines. Paradoxically, the number of lymphocytes in the mesenteric lymph node decreased with tRA that led to significantly reduced lymphadenopathy. In addition, tRA differentially affected renal pathology, increasing leukocyte infiltration of renal tubulointerstitium while restoring the size of glomeruli in the kidney cortex. In contrast, minimal induction of inflammation with tRA in the absence of an immunogenic environment in the control mice was observed. Altogether, our results suggest that under a predisposed immunogenic environment in autoimmune lupus, tRA may decrease inflammation in some organs while generating more severe disease in others. [ABSTRACT FROM AUTHOR]

Perfluoropentane (PFP)-based oxygen-loaded nanobubbles (OLNBs) were previously proposed as adjuvant therapeutic tools for pathologies of different etiology sharing hypoxia as a common feature, including cancer, infection, and autoimmunity. Here we introduce a new platform of oxygen nanocarriers, based on 2H,3H-decafluoropentane (DFP) as core fluorocarbon. These new nanocarriers have been named oxygen-loaded nanodroplets (OLNDs) since DFP is liquid at body temperature, unlike gaseous PFP. Dextran-shelled OLNDs, available either in liquid or gel formulations, display spherical morphology, ~600 nm diameters, anionic charge, good oxygen carrying capacity, and no toxic effects on human keratinocytes after cell internalization. In vitro OLNDs result more effective in releasing oxygen to hypoxic environments than former OLNBs, as demonstrated by analysis through oxymetry. In vivo, OLNDs effectively enhance oxy-hemoglobin levels, as emerged from investigation by photoacoustic imaging. Interestingly, ultrasound (US) treatment further improves transdermal oxygen release from OLNDs. Taken together, these data suggest that US-activated, DFP-based OLNDs might be innovative, suitable and cost-effective devices to topically treat hypoxia-associated pathologies of the cutaneous tissues. [ABSTRACT FROM AUTHOR]

Antibodies to glutamic acid decarboxylase (GAD-ab) associate to different neurological syndromes. It is unknown if the diversity in syndrome association represents epitopes in different immunodominant domains or co-existence of antibodies to other proteins of the inhibitory synapsis. We examined the serum and CSF of 106 patients with anti-GAD related syndromes (39 cerebellar ataxia, 32 stiff-person syndrome [SPS], 18 epilepsy, and 17 limbic encephalitis [LE]). GAD65-ab titres were quantified by ELISA. Immunoblot was used to determine if the antibody-targeted epitopes of GAD65 and GAD67 were linear. A cell-based assay (CBA) with HEK293 cells expressing the GAD65 N-terminal, central catalytic domain, or C-terminal was used to investigate the immunodominant domains. Antibodies to GAD67, gamma-aminobutyric acid A receptor (GABAaR), glycine receptor (GlyR), GABAaR-associated protein (GABARAP), and gephyrin were determined with CBA. GAD-ab internalization was investigated using cultured rat hippocampal neurons. CSF GAD65-ab titres were higher in patients with cerebellar ataxia and LE compared to those with SPS (p = 0.02). GAD67-ab were identified in 81% of sera and 100% of CSF. GAD65-ab recognized linear epitopes in 98% of the patients and GAD67-ab in 42% (p<0.001). The GAD65 catalytic domain was recognized by 93% of sera, and the three domains by 22% of sera and 74% of CSF (p<0.001). Six patients had GABAaR-ab and another 6 had GlyR-ab without association to distinctive symptoms. None of the patients had gephyrin- or GABARAP-ab. GAD65-ab were not internalized by live neurons. Overall, these findings show that regardless of the neurological syndrome, the CSF immune response against GAD is more widespread than that of the serum and that there is no specific association between clinical phenotype and the presence of antibodies against other proteins of the inhibitory synapsis. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a debilitating chronic inflammatory disease of the nervous system that affects approximately 2.3 million individuals worldwide, with higher prevalence in females, and a strong genetic component. While over 200 MS susceptibility loci have been identified in GWAS, the underlying mechanisms whereby they contribute to disease susceptibility remains ill-defined. Forward genetics approaches using conventional laboratory mouse strains are useful in identifying and functionally dissecting genes controlling disease-relevant phenotypes, but are hindered by the limited genetic diversity represented in such strains. To address this, we have combined the powerful chromosome substitution (consomic) strain approach with the genetic diversity of a wild-derived inbred mouse strain. Using experimental allergic encephalomyelitis (EAE), a mouse model of MS, we evaluated genetic control of disease course among a panel of 26 consomic strains of mice inheriting chromosomes from the wild-derived PWD strain on the C57BL/6J background, which models the genetic diversity seen in human populations. Nineteen linkages on 18 chromosomes were found to harbor loci controlling EAE. Of these 19 linkages, six were male-specific, four were female-specific, and nine were non-sex-specific, consistent with a differential genetic control of disease course between males and females. An MS-GWAS candidate-driven bioinformatic analysis using orthologous genes linked to EAE course identified sex-specific and non-sex-specific gene networks underlying disease pathogenesis. An analysis of sex hormone regulation of genes within these networks identified several key molecules, prominently including the MAP kinase family, known hormone-dependent regulators of sex differences in EAE course. Importantly, our results provide the framework by which consomic mouse strains with overall genome-wide genetic diversity, approximating that seen in humans, can be used as a rapid and powerful tool for modeling the genetic architecture of MS. Moreover, our data represent the first step towards mechanistic dissection of genetic control of sexual dimorphism in CNS autoimmunity. [ABSTRACT FROM AUTHOR]

Background: Heredity and environmental exposures may contribute to a predisposition to allergic rhinitis (AR). Autoimmunity may also involve into this pathologic process. FCRL3 (Fc receptor-like 3 gene), a novel immunoregulatory gene, has recently been reported to play a role in autoimmune diseases. Objective: This study was performed to evaluate the potential association of FCRL3 polymorphisms with AR in a Chinese Han population. Methods: Five single-nucleotide polymorphisms of FCRL3, rs945635, rs3761959, rs7522061, rs10489678 and rs7528684 were genotyped in 540 AR patients and 600 healthy controls using a PCR-restriction fragment length polymorphism assay. Allele, genotype and haplotype frequencies were compared between patients and controls using the χ2 test. The online software platform SHEsis was used to analyze their haplotypes. Results: This study identified three strong risk SNPs rs7528684, rs10489678, rs7522061 and one weak risk SNP rs945635 of FCRL3 in Chinese Han AR patients. For rs7528684, a significantly increased prevalence of the AA genotype and A allele in AR patients was recorded. The frequency of the GG genotype and G allele of rs10489678 was markedly higher in AR patients than those in controls. For rs7522061, a higher frequency of the TT genotype, and a lower frequency of the CT genotype were found in AR patients. Concerning rs945635, a lower frequency of the CC genotype, and a higher frequency of G allele were observed in AR patients. According to the analysis of the three strong positive SNPs, the haplotype of AGT increased significantly in AR cases (AR = 38.8%, Controls = 24.3%, P = 8.29×10-14, OR [95% CI] 1.978 [1.652~2.368]). Conclusions: This study found a significant association between the SNPs in FCRL3 gene and AR in Chinese Han patients. The results suggest these gene polymorphisms might be the autoimmunity risk for AR. [ABSTRACT FROM AUTHOR]

Introduction: Increased expression of IL-33 and its receptor ST2, encoded by the IL1RL1 gene, has been detected in the inflamed arteries of giant cell arteritis (GCA) patients. The aim of the present study was to investigate for the first time the potential influence of the IL33 and IL1RL1 loci on GCA predisposition. Methods: A total of 1,363 biopsy-proven GCA patients and 3,908 healthy controls from four European cohorts (Spain, Italy, Germany and Norway) were combined in a meta-analysis. Six genetic variants: rs3939286, rs7025417 and rs7044343, within the IL33 gene, and rs2058660, rs2310173 and rs13015714, within the IL1RL1 gene, previously associated with immune-related diseases, were genotyped using predesigned TaqMan assays. Results: A consistent association between the rs7025417 polymorphism and GCA was evident in the overall meta-analysis, under both allele (PMH = 0.041, OR = 0.88, CI 95% 0.78–0.99) and recessive (PMH = 3.40E-03, OR = 0.53, CI 95% 0.35–0.80) models. No statistically significant differences between allele or genotype frequencies for the other IL33 and IL1RL1 genetic variants were detected in this pooled analysis. Conclusions: Our results clearly evidenced the implication of the IL33 rs7025417 polymorphism in the genetic network underlying GCA. [ABSTRACT FROM AUTHOR]