Autoimmune Symptoms Research Articles

Cell-penetrable mouse forkhead box protein 3 alleviates experimental arthritis in mice by up-regulating regulatory T cells.

Regulatory T cells (T(regs)) have potential applications in clinical disease therapy, such as autoimmune diseases and transplant rejection. However, their numbers are limited. Forkhead box protein 3 (FoxP3) is a key transcription factor that controls T(reg) development and function. Here, we generated a cell-permeable fusion protein, protein transduction domain (PTD)-conjugated mouse FoxP3 protein (PTD-mFoxP3), and evaluated whether PTD-mFoxp3 can alleviate rheumatoid arthritis (RA) in the collagen-induced arthritis (CIA) mouse model. As expected, PTD-mFoxP3 was transduced into cells effectively, and inhibited T cell activation and attenuated the cell proliferation. It decreased interleukin (IL) 2 and interferon (IFN)-γ expression, and increased IL-10 expression in activated CD4(+)CD25(-) T cells. PTD-mFoxP3-transduced CD4(+)CD25(-) T cells attenuated proliferation of activated CD4(+)CD25(-) T cells. In addition, PTD-mFoxP3 blocked the Th17 differentiation programme in vitro and down-regulated IL-17 production from T cells by modulating induction and levels of retinoid-related orphan receptor gamma t (RORγt). Intra-articular delivery of PTD-mFoxP3 delayed disease incidence remarkably and alleviated autoimmune symptoms of CIA mice. Moreover, protective effects of PTD-mFoxP3 were associated with regulating the balance of T helper type 17 (Th17) and T(regs). These results suggest that PTD-mFoxP3 may be a candidate for RA therapy.

The tumor suppressor PTEN enforces Treg stability in control of TH1 and TFH cell responses (IRC7P.427)

Abstract Regulatory T cells (Tregs) suppress CD4+ T cell responses during homeostasis and inflammation to prevent autoimmunity and other immune disorders. Although the transcriptional and epigenetic programs regulating Treg function have been extensively studied, the signaling and metabolic pathways underlying Treg stability and function are not fully understood. In this study, we determined the role of the phosphatase PTEN in Tregs. We found that specific depletion of Pten in Tregs results in excessive TH1 and T follicular helper cells (TFH) responses, associated with elevated germinal center (GC) B cells and spontaneous development of autoimmune and lymphoproliferative disease in vivo. Interestingly, the exaggerated TFH and GC responses and autoimmune symptoms are reduced when IFNγ expression is abrogated in mice containing Pten-deficient Tregs. Thus, the uncontrolled TH1-mediated inflammation in these mice drives aberrant TFH responses and autoimmune and lymphoproliferative disease. Mechanistically, we linked PTEN to mTORC2-mediated control of transcriptional and metabolic programs that enforce Treg stability and function. Consistent with this notion, deletion of Rictor, the obligate component for mTORC2, restores Treg function and stability in the absence of Pten. Together, these results establish that Tregs rely on the PTEN-mTORC2 axis to maintain their stability and suppressive activity in controlling TH1 and TFH cell responses.

Fatal autoimmunity results from the conditional deletion of Snai2 and Snai3 (BA4P.121)

Abstract Transcriptional regulation of gene expression is a key component of orchestrating proper immune cell development and function. One strategy for maintaining these transcriptional programs has been the evolution of transcription factor families with members possessing overlapping functions. Using the germ line deletion of Snai2 combined with the hematopoietic specific deletion of Snai3, we report that these factors function redundantly to preserve the development of B and T cells. Such animals display severe lymphopenia, alopecia and dermatitis as well as profound autoimmunity manifested by the production of high levels of autoantibodies as early as three weeks of age followed by death within 30 days of birth. Autoantibodies included both IgM and IgG isotypes and were reactive against cytoplasmic and membranous components. A regulatory T cell defect contributed to the autoimmune response in that adoptive transfer of wild type regulatory T cells alleviated symptoms of autoimmunity. The results demonstrated that appropriate expression of Snai2 and Snai3 in cells of hematopoietic derivation plays an important role in development and maintenance of immune tolerance.

Regulation of Foxo1 in T cell homeostasis (LYM2P.733)

Abstract The Foxo (forkhead box O) family of transcription factors has been shown to be important for maintaining homeostasis of both effector and regulatory T cells. Interesting Foxo1 is necessary for proper development and function of regulatory T cells (TR) and absence of Foxo1 results in fatal inflammation due to TR dysfunction. During normal conditions phosphorylation of Foxo1 by Akt results in inactivation of the transcription factor and translocation from the nucleus. We have bred mice that contain a floxed non-phosphorylatable Foxo1 allele under control of CD4-cre (CD4cre-Foxo1CA), resulting in constitutive activation of Foxo1 in both CD4 and CD8 T cells. Mice which are unable to properly regulate Foxo1 have reduced body weight, chronic inflammation and develop spontaneous autoimmunity. CD4cre-Foxo1CA displaying symptoms of autoimmunity have tissue damage in the lung along with increases in eosinophils, alveolar macrophages and mucus production. In the periphery CD4cre-Foxo1CA mice have reduced TR, increased activated effector T cells and an altered B cell compartment. Together this data demonstrates that proper regulation of Foxo1 is essential for T cell homeostasis and prevention of autoimmunity.

Survival and maintenance of regulatory T cells require the kinase TAK1.

Regulatory T (Treg) cells play a central role in regulating peripheral immune tolerance and preventing autoimmunity. Despite the extensive studies on the development of Treg cells, the molecular mechanisms that maintain the population of committed Treg cells remain poorly understood. We show here that Treg-conditional ablation of the kinase TAK1 reduced the number of Treg cells in the peripheral lymphoid organs, causing abnormal activation of conventional T cells and autoimmune symptoms. Using an inducible gene knockout approach, we further demonstrate that TAK1 is crucial for the survival of Treg cells. Expression of a constitutively active IκB kinase partially restored the level of Treg cells in the TAK1Treg-KO mice. These results suggest a crucial role for TAK1 for maintaining the survival of committed Treg cells under physiological conditions.

Fatal autoimmunity results from the conditional deletion of Snai2 and Snai3

Transcriptional regulation of gene expression is a key component of orchestrating proper immune cell development and function. One strategy for maintaining these transcriptional programs has been the evolution of transcription factor families with members possessing overlapping functions. Using the germ line deletion of Snai2 combined with the hematopoietic specific deletion of Snai3, we report that these factors function redundantly to preserve the development of B and T cells. Such animals display severe lymphopenia, alopecia and dermatitis as well as profound autoimmunity manifested by the production of high levels of autoantibodies as early as 3weeks of age and die by 30days after birth. Autoantibodies included both IgM and IgG isotypes and were reactive against cytoplasmic and membranous components. A regulatory T cell defect contributed to the autoimmune response in that adoptive transfer of wild type regulatory T cells alleviated symptoms of autoimmunity. Additionally, transplantation of Snai2/Snai3 double deficient bone marrow into Snai2 sufficient Rag2−/− recipients resulted in autoantibody generation. The results demonstrated that appropriate expression of Snai2 and Snai3 in cells of hematopoietic derivation plays an important role in development and maintenance of immune tolerance.

Ophthalmoparesis Mimicking Myasthenia Gravis as Acute Manifestation of HashimotoÂ’s Encephalopathy

Hashimoto’s encephalopathy is a rare steroid-responsive disorder in which neuropsychological and neurological symptoms are associated with Hashimoto’s thyroiditis. Recently, it has gained attention in the differential diagnosis of encephalopathy of unknown origin, although its pathogenesis is poorly understood. The diagnosis of Hashimoto’s encephalopathy rests upon the association of autoimmune thyroiditis and neurological symptoms after excluding more common diseases, but is a serious challenge in atypical cases. We here present a patient with isolated ocular disorder as presenting and unic feature of Hashimoto’s encephalopathy that resolved with steroids therapy. Brain MRI showed non-specific white matter abnormalities; EEG and an extensive neurophysiological investigation were normal. The diagnosis in this euthyroid patient was supported by the presence of serum anti-thyroid antibodies and the identification in the CSF of anti-dimethylargininase-I and aldehyde reductase-I autoantibodies. The description of atypical cases of this rare but certainly underestimated condition is clinically important and adds relevant information for the clinical practice.

TGF-β2 mediated secretion of sCTLA-4 from regulatory T cells

Cytotoxic T lymphocyte antigen-4 (CTLA-4), a membrane bound inhibitory receptor whose expression is induced on activated T cells, has been established as an important regulator of T cell responses and serves to maintain peripheral tolerance. Additionally, recent characterization of a novel mechanism of extrinsic suppression mediated by the soluble isoform of CTLA-4 (sCTLA-4) has served to further establish the importance of CTLA-4 in maintaining homeostasis of the immune system. Previously, we have shown that selective blockade of sCTLA-4 in patients with metastatic melanoma enhances immune responses including increased antigen-specific proliferation of both CD4+ and CD8+ T cells, compared with an isotype antibody control or pan CTLA-4 blockade. Selective blockade also enhanced T cell effector cytokine responses, notably IFN-γ and IL-17. In this study, we demonstrate a protocol for generating a regulatory T cell population, which is characterised by the production of high levels of sCTLA-4. Treatment of naive human T cells with TGF-β2 together with an anti-CD3 mAb/IL-2 T cell stimulus increased their capacity to produce high levels of sCTLA-4, while decreasing production of effector cytokines - IFN-γ, IL-17 and IL-10. Furthermore, analysis of these sCTLA-4 producing T cells has shown that they express the T regulatory cell transcription factor – FoxP3. Taken together, our data show that TGF-β2 could serve as an attractive therapeutic tool to alleviate symptoms of autoimmunity through the induction of regulatory T cell populations that secrete immunosuppressive sCTLA-4; while on the other hand, neutralizing the effects of TGF-β2 could also prove beneficial to patients with cancer.

Long-term remission after allogeneic hematopoietic stem cell transplantation in LPS-responsive beige-like anchor (LRBA) deficiency

Long-term remission after allogeneic hematopoietic stem cell transplantation in LPS-responsive beige-like anchor (LRBA) deficiency

Autoimmune symptoms in idiopathic pulmonary fibrosis: clinical significance.

Information regarding autoimmune symptoms that do not meet the diagnostic criteria for connective tissue disease in patients with idiopathic pulmonary fibrosis (IPF) is limited. The aim of the present study was to investigate differences in the clinical characteristics and prognosis of IPF patients with and without autoimmune symptoms. Consecutive patients diagnosed with IPF (N = 96) from January 2008 to December 2012 were included. We compared the clinical characteristics of patients with and without autoimmune symptoms. Survival was compared by log-rank and Cox proportional hazard analyses. Thirty-six (38%) patients reported autoimmune symptoms. There were no significant differences in clinical characteristics between those with and without autoimmune symptoms. Patients with autoimmune symptoms had a better survival rate than those without symptoms [hazard ratio (HR) 0.27; 95% confidence interval (CI) 0.09-0.82; P = 0.020]. After adjusting for age, gender and smoking status, the presence of autoimmune symptoms was associated with improved survival (HR 0.29, 95% CI 0.09-0.89; P = 0.032). However, after adjusting for other covariates, including per cent predicted forced vital capacity and high-resolution computed tomography total extent score, the presence of autoimmune symptoms did not influence survival (HR 0.49, 95% CI 0.15-1.61; P = 0.240). The median follow-up period for the studied cohort was 31.5 months. It appears that autoimmune symptoms are associated with better prognosis among IPF patients. However, future studies are needed to validate our findings.

P023 - Investigation of Oncostatin M protein expression in Iranian relapsing remitting multiple sclerosis patients

Background Oncostatin M (OSM) is an interlukin-6 (IL-6) cytokine secreted by diverse immune cells in-order to moderate cell proliferation, survival, differentiation, and inflammation by effecting gp-130 cell surface receptors. Relapsing remitting multiple sclerosis (RRMS) is the common type of MS influencing 85% of MS patients. It seems that up-regulation of cytokines has an undeniable role in arising autoimmune mechanisms and symptoms. Isfahan province, Iran, is an area with an alarming increase in incidence and prevalence of MS in recent years. Thus, we focused on the investigation of OSM as an immune-dependent risk factor in disease patho-physiology in Isfahan RRMS patients. Objectives To measure the association between OSM plasma level in MS patients and the healthy subjects. To evaluate the correlation between the demographic info such as age, sex, EDSS, drugs, and OSM concentration in cases. Methods Blood sample from 60 RRMS patients and 30 healthy subjects between 15 and 40 years was gathered on EDTA and the evaluation on OSM in their plasma was achieved by EASTBIOPHARMA enzyme-linked immunosorbent assay (ELISA) kit. The statistical analysis was performed utilizing SPSS software. Results Data showed a significant higher OSM plasma level in the cases than the healthy donors (P value<0.05). Conclusions As the first step of studying IL-6 cytokine family in autoimmune diseases in Iranian population, we accomplished to approve the OSM active role in RRMS patients of Isfahan province. Further future investigation of IL-6 family such as “studying IL-6 in central nervous system (CNS) plaques”, “genetic polymorphisms in association with MS”, and “revealing newer aspects of their implications in cellular pathways” might result in development of immunotherapy and diagnosis in chronic autoimmune diseases of the CNS. Oncostatin M (OSM) is an interlukin-6 (IL-6) cytokine secreted by diverse immune cells in-order to moderate cell proliferation, survival, differentiation, and inflammation by effecting gp-130 cell surface receptors. Relapsing remitting multiple sclerosis (RRMS) is the common type of MS influencing 85% of MS patients. It seems that up-regulation of cytokines has an undeniable role in arising autoimmune mechanisms and symptoms. Isfahan province, Iran, is an area with an alarming increase in incidence and prevalence of MS in recent years. Thus, we focused on the investigation of OSM as an immune-dependent risk factor in disease patho-physiology in Isfahan RRMS patients. To measure the association between OSM plasma level in MS patients and the healthy subjects. To evaluate the correlation between the demographic info such as age, sex, EDSS, drugs, and OSM concentration in cases. Blood sample from 60 RRMS patients and 30 healthy subjects between 15 and 40 years was gathered on EDTA and the evaluation on OSM in their plasma was achieved by EASTBIOPHARMA enzyme-linked immunosorbent assay (ELISA) kit. The statistical analysis was performed utilizing SPSS software. Data showed a significant higher OSM plasma level in the cases than the healthy donors (P value<0.05). As the first step of studying IL-6 cytokine family in autoimmune diseases in Iranian population, we accomplished to approve the OSM active role in RRMS patients of Isfahan province. Further future investigation of IL-6 family such as “studying IL-6 in central nervous system (CNS) plaques”, “genetic polymorphisms in association with MS”, and “revealing newer aspects of their implications in cellular pathways” might result in development of immunotherapy and diagnosis in chronic autoimmune diseases of the CNS.

94: A viral sensor MDA5 and autoimmune diseases

MDA5 is an essential intracellular sensor for several viruses, including picornaviruses, and elicits antiviral interferon (IFN) responses by recognizing viral dsRNAs. MDA5 has been implicated in autoimmunity. However, the mechanisms of how MDA5 contributes to autoimmunity remain unclear. Here we provide direct evidence that dysregulation of MDA5 caused autoimmune disorders. We established a mutant mouse line bearing MDA5 mutation by ENU mutagenesis, which spontaneously developed lupus-like autoimmune symptoms and also progressive encephalopathy without viral infection. Inflammation was dependent on an adaptor molecule, MAVS indicating the importance of MDA5-signaling. In addition, intercrossing the mutant mice with type I IFN receptor-deficient mice ameliorated clinical manifestations. This MDA5 mutant could activate signaling in the absence of its ligand but was paradoxically defective for ligand- and virus-induced signaling, suggesting that the mutation induces a conformational change in MDA5.These findings provide insight into the association between disorders of the innate immune system and autoimmunity.

Food-derived opioid peptides inhibit cysteine uptake with redox and epigenetic consequences

Dietary interventions like gluten-free and casein-free diets have been reported to improve intestinal, autoimmune and neurological symptoms in patients with a variety of conditions; however, the underlying mechanism of benefit for such diets remains unclear. Epigenetic programming, including CpG methylation and histone modifications, occurring during early postnatal development can influence the risk of disease in later life, and such programming may be modulated by nutritional factors such as milk and wheat, especially during the transition from a solely milk-based diet to one that includes other forms of nutrition. The hydrolytic digestion of casein (a major milk protein) and gliadin (a wheat-derived protein) releases peptides with opioid activity, and in the present study, we demonstrate that these food-derived proline-rich opioid peptides modulate cysteine uptake in cultured human neuronal and gastrointestinal (GI) epithelial cells via activation of opioid receptors. Decreases in cysteine uptake were associated with changes in the intracellular antioxidant glutathione and the methyl donor S-adenosylmethionine. Bovine and human casein-derived opioid peptides increased genome-wide DNA methylation in the transcription start site region with a potency order similar to their inhibition of cysteine uptake. Altered expression of genes involved in redox and methylation homeostasis was also observed. These results illustrate the potential of milk- and wheat-derived peptides to exert antioxidant and epigenetic changes that may be particularly important during the postnatal transition from placental to GI nutrition. Differences between peptides derived from human and bovine milk may contribute to developmental differences between breastfed and formula-fed infants. Restricted antioxidant capacity, caused by wheat- and milk-derived opioid peptides, may predispose susceptible individuals to inflammation and systemic oxidation, partly explaining the benefits of gluten-free or casein-free diets.

SP0040 The Immune/Inflammatory Response Follows Circadian Rhythms

Alternating sunlight and darkness regulate the cyclical 24-hour period of human biological activity, generally reported as “circadian rhythms” or referred as “chronobiology”, and biological signaling occur in a complex network...

Kidney injuries related to ipilimumab

Monoclonal antibodies directed against the immune checkpoint protein cytotoxic T-lymphocyte antigen-4 (CTLA-4; CD152) have been investigated in metastatic melanoma and other cancers and have shown promising results. Inhibition of CTLA-4 characteristically induces well-known side effects called "immune-related adverse events" (irAEs). IrAEs mainly include colitis, dermatitis, hepatitis, endocrinopathies; uveitis, iridocyclitis, neuropathies, and inflammatory myopathy have occasionally been reported. Kidney involvement is rare. We report 2 cases of acute granulomatous interstitial nephritis and present, based on literature review, renal disorders related to Ipilimumab therapy. Autoimmune symptoms have to be carefully checked for patients treated with CTLA-4 inhibitors. In order to reduce the risk of sequelae, early recognition of irAEs and treatment initiation are crucial.

Towards inhibition of morbidity and mortality in Sjögren’s syndrome: opportunities and challenges

In recent years considerable progress has been made in our understanding of the immunopathology of primary Sjögren’s syndrome. Several genetic and environmental risk factors as well as cellular and molecular pathways have been identified, providing multiple targets for therapeutic strategies. Establishment of disease activity scores allows careful monitoring of therapeutic strategies and has set the stage for definition of clinical response criteria. Early detection of autoimmune symptoms before the onset of primary Sjögren’s syndrome might trigger early intervention strategies to prevent immunopathology. New studies that indicated a strong association between lymphoid neogenesis and development of lymphoma and extra-glandular manifestations indicate that future therapeutic strategies should perhaps be directed at patients at risk for more severe disease. Several challenges remain, such as dissecting the causes and consequences of several types of IFN signatures or elucidating how viral triggering of the immune system is involved and could be targeted. The biggest challenge may be prevention of dryness since the causes of dryness remain elusive and could include non-immunological ones. In the coming years it will become clear to what extent novel drugs can prevent immunopathology and clinical symptoms like dryness and fatigue.

Research in practice: The impact of interferon-α therapy on immune tolerance

Interferon-α (IFN-α) is the only drug approved for adjuvant therapy of malignant melanoma and is also used in the treatment of hematological and solid tumors. Along with its proven clinical efficacy, IFN-α produces several side effects, particularly with regard to autoimmune disorders. Curious about symptoms of autoimmunity during IFN-α therapy, we asked whether IFN-α directly impacts on immune tolerance. We found that IFN-α does alter the function of tolerogenic dendritic cells (DC) as well as of induced and naturally occurring T-regulatory cells (nTregs). IFN-α blocks the tolerogenic phenotype of DC by inducing maturation and thus preventing the induction of inducible Tregs by DC. It also has direct effects on nTregs. IFN-α reduces cAMP in Tregs via ERK/phosphodiesterase-mediated pathways. Since cAMP is essentially involved in suppression by nTregs, the IFN-α-dependent reduction of cAMP levels abolishes the suppressive capacity of nTregs. Therefore, Tregs are incapable of suppressing the activity of effector T cells and natural killer cells, resulting in tumor rejection. Thus, IFN-α overcomes immunological tolerance processes, leading to an improved immunostimulation and efficient tumor rejection, but also increases the risk of autoimmunity.

Idiopathic CD4 Lymphocytopenia

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19–70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14–24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm3 (range, 4–294); mean CD8: 236/mm3 (range, 1–1293); mean CD19: 113/mm3 (range, 3–547); and mean NK cell count: 122/mm3 (range, 5–416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm3 and NK cell count <100/mm3 were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.

Autoimmune Disorders Associated with Gain of Function of the Intracellular Sensor MDA5

MDA5 is an essential intracellular sensor for several viruses, including picornaviruses, and elicits antiviral interferon (IFN) responses by recognizing viral dsRNAs. MDA5 has been implicated in autoimmunity. However, the mechanisms of how MDA5 contributes to autoimmunity remain unclear. Here we provide direct evidence that dysregulation of MDA5 caused autoimmune disorders. We established a mutant mouse line bearing MDA5 mutation by ENU mutagenesis, which spontaneously developed lupus-like autoimmune symptoms without viral infection. Inflammation was dependent on an adaptor molecule, MAVS indicating the importance of MDA5-signaling. In addition, intercrossing the mutant mice with type I IFN receptor-deficient mice ameliorated clinical manifestations. This MDA5 mutant could activate signaling in the absence of its ligand but was paradoxically defective for ligand- and virus-induced signaling, suggesting that the mutation induces a conformational change in MDA5. These findings provide insight into the association between disorders of the innate immune system and autoimmunity.

Environmental triggers and autoimmunity.

Environmental triggers and autoimmunity.