A novel gain-of-function phosphorylation site modulates PTPN22 inhibition of TCR signaling.

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is encoded by a major autoimmunity gene and is a known inhibitor of T cell receptor (TCR) signaling and drug target for cancer immunotherapy. However, little is known about PTPN22 posttranslational regulation. Here, we characterize a phosphorylation site at Ser325 situated C terminal to the catalytic domain of PTPN22 and its roles in altering protein function. In human T cells, Ser325 is phosphorylated by glycogen synthase kinase-3 (GSK3) following TCR stimulation, which promotes its TCR-inhibitory activity. Signaling through the major TCR-dependent pathway under PTPN22 control was enhanced by CRISPR/Cas9-mediated suppression of Ser325 phosphorylation and inhibited by mimicking it via glutamic acid substitution. Global phospho-mass spectrometry showed Ser325 phosphorylation state alters downstream transcriptional activity through enrichment of Swi3p, Rsc8p, and Moira domain binding proteins, and next-generation sequencing revealed it differentially regulates the expression of chemokines and T cell activation pathways. Moreover, in vitro kinetic data suggest the modulation of activity depends on a cellular context. Finally, we begin to address the structural and mechanistic basis for the influence of Ser325 phosphorylation on the protein's properties by deuterium exchange mass spectrometry and NMR spectroscopy. In conclusion, this study explores the function of a novel phosphorylation site of PTPN22 that is involved in complex regulation of TCR signaling and provides details that might inform the future development of allosteric modulators of PTPN22.

OT-I TCR Transgenic Mice to Study the Role of PTPN22 in Anti-cancer Immunity.

Phosphotyrosine phosphatase non-receptor type 22 (PTPN22) is a key regulator of immune cell activation and responses. Genetic polymorphisms of PTPN22 have been strongly linked with an increased risk of developing autoimmune diseases, while analysis of PTPN22-deficient mouse strains has determined that PTPN22 serves as a negative regulator of T cell antigen receptor signaling. As well as these key roles in maintaining immune tolerance, PTPN22 acts as an intracellular checkpoint for T cell responses to cancer, suggesting that PTPN22 might be a useful target to improve T cell immunotherapies. To assess the potential for targeting PTPN22, we have crossed Ptpn22-deficient mice to an OT-I TCR transgenic background and used adoptive T cell transfer approaches in mouse cancer models. We provide basic methods for the in vitro expansion of effector OT-I cytotoxic T lymphocytes, in vitro phenotypic analysis, and in vivo adoptive T cell transfer models to assess the role of PTPN22 in anti-cancer immunity.

TiO2 nanoparticles abrogate the protective effect of the Crohn's disease-associated variation within the PTPN22 gene locus.

OBJECTIVE: Inflammatory bowel disease (IBD) is a multifactorial condition driven by genetic and environmental risk factors. A genetic variation in the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene has been associated with autoimmune disorders while protecting from the IBD subtype Crohn's disease. Mice expressing the murine orthologous PTPN22-R619W variant are protected from intestinal inflammation in the model of acute dextran sodium sulfate (DSS)-induced colitis. We previously identified food-grade titanium dioxide (TiO2, E171) as a neglected IBD risk factor. Here, we investigate the interplay of the PTPN22 variant and TiO2-mediated effects during IBD pathogenesis. DESIGN: Acute DSS colitis was induced in wild-type and PTPN22 variant mice (PTPN22-R619W) and animals were treated with TiO2 nanoparticles during colitis induction. Disease-triggering mechanisms were investigated using bulk and single-cell RNA sequencing. RESULTS: In mice, administration of TiO2 nanoparticles abrogated the protective effect of the variant, rendering PTPN22-R619W mice susceptible to DSS colitis. In early disease, cytotoxic CD8+ T-cells were found to be reduced in the lamina propria of PTPN22-R619W mice, an effect reversed by TiO2 administration. Normalisation of T-cell populations correlated with increased Ifng expression and, at a later stage of disease, the promoted prevalence of proinflammatory macrophages that triggered severe intestinal inflammation. CONCLUSION: Our findings indicate that the consumption of TiO2 nanoparticles might have adverse effects on the gastrointestinal health of individuals carrying the PTPN22 variant. This demonstrates that environmental factors interact with genetic risk variants and can reverse a protective mechanism into a disease-promoting effect.

Meta-analysis confirmed genetic susceptibility conferred by multiple risk variants from CTLA4 and SERPINA1 in granulomatosis with polyangiitis.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease. Smaller sample size and complex nature of the disease pathogenesis has made it challenging to perform well-powered genetic investigations. We performed a systematic review based meta-analysis in GPA to investigate the genetic susceptibility conferred by non-human leukocyte antigen (non-HLA) candidate genes. METHODS: A systematic review was performed using web-based literature search and eligible studies were included following inclusion-exclusion criteria. Studies were evaluated for their quality of evidence and study outcome was assessed using the Newcastle-Ottawa Scale and Grades of Research, Assessment, Development and Evaluation tools. Reviewer's agreement was accessed through Cohen's κ value. Meta-analyses were performed using RevMan 5 tool. Meta-odds ratio (meta-OR) and Z test P value were evaluated to estimate the genetic susceptibility for each of the variants. RESULTS: Eighteen studies were found eligible and 7 genetic variants from only 4 genes, namely CTLA4, PRTN3, SERPINA1 and PTPN22 could be studied for meta-analysis. rs231775-G (49-G) (Meta-OR = 1.42 [1.14-1.76]; P = .001) of CTLA4 and rs7151526-A (Meta-OR = 2.70 [1.51-4.85]; P = .0008) of SERPINA1 were confirmed to be predisposing alleles, and rs5742909-C (318-C) (Meta-OR = 0.65 [0.44-0.97]; P =.03) of CTLA4 was found to be protective for GPA. In concordance with the genetic association of rs7151526-A, serological marker for the same variant "Z" allele of SERPINA1 was found to be predisposing (Meta-OR = 12.60 [5.01-31.68]; P < .00001) for GPA. CONCLUSION: Genetic variants confirmed in this study play critical roles in T-cell mediated immune function and could be significantly implicated in GPA. Molecular pathology studies are warranted to confirm their role. These markers could be used for efficient patient classification and disease management.

Clinical value of the expression levels of protein tyrosine phosphatase non-receptor type 22.6 mRNA in peripheral blood mononuclear cells in Crohn's disease.

OBJECTIVE: To explore the relationship between the expression levels of protein tyrosine phosphatase non-receptor type (PTPN) 22.6 mRNA in peripheral blood mononuclear cells (PBMCs) and the disease activity as well as clinical characteristics in Crohn's disease (CD) patients. METHODS: A total of 480 subjects were enrolled. Data were collected including baseline information, expression levels of PTPN22.6 mRNA in PBMCs for all subjects, C-reactive protein (CRP) levels in serum, clinical characteristics, and disease activity for all patients. Expression levels of PTPN22.6 mRNA in PBMCs, CRP levels in serum, clinical characteristics according to Montreal Classification [8], and Crohn's disease activity index (CDAI) were the primary observation outcomes. RESULTS: The expression levels of PTPN22.6 mRNA (P = 0.032) in PBMCs and serum CRP levels (P < 0.001) were significantly higher in active CD patients than in inactive CD patients (P = 0.032). Correlation analysis showed that there was a positive correlation between expression levels of PTPN22.6 mRNA and CDAI value (r = 0.512, P = 0.003), as well as expression levels of PTPN22.6 mRNA and CRP levels in the CD group (r = 0.456, P = 0.006). There were significantly higher expression levels of PTPN22.6 mRNA in PBMCs in patients with structuring behavior than that in patients with non-stricturing and non-penetrating (NSNP) behaviors (P = 0.018) and penetrating behaviors (P = 0.024). CONCLUSIONS: The expression levels of PTPN22.6 mRNA can be used as an indicator to help predict CD diagnosis, disease activity, serum CRP level, and behavior type of CD disease.

PTPN22: structure, function, and developments in inhibitor discovery with applications for immunotherapy.

INTRODUCTION: While immunotherapy strategies such as immune checkpoint inhibition and adoptive T cell therapy have become commonplace in cancer therapy, they suffer from limitations, including lack of patient response and toxicity. To wield the maximum potential of the immune system, cancer immunotherapy must integrate novel targets and therapeutic strategies with potential to augment clinical efficacy of currently utilized immunotherapies. PTPN22, a member of the protein tyrosine phosphatase (PTP) superfamily that downregulates T cell signaling and proliferation, has recently emerged as a systemically druggable and novel immunotherapy target. AREAS COVERED: This review describes the basics of PTPN22 structure and function and provides comprehensive insight into recent advances in small molecule PTPN22 inhibitor development and the immense potential of PTPN22 inhibition to synergize with current immunotherapies. EXPERT OPINION: It is apparent that small molecule PTPN22 inhibitors have enormous potential to augment efficacy of current immunotherapy strategies such as checkpoint inhibition and adoptive cell transfer. Nevertheless, several constraints must be overcome before these inhibitors can be applied as useful therapeutics, namely selectivity, potency, and in vivo efficacy.

Redox regulation of PTPN22 affects the severity of T-cell-dependent autoimmune inflammation.

Chronic autoimmune diseases are associated with mutations in PTPN22, a modifier of T cell receptor (TCR) signaling. As with all protein tyrosine phosphatases, the activity of PTPN22 is redox regulated, but if or how such regulation can modulate inflammatory pathways in vivo is not known. To determine this, we created a mouse with a cysteine-to-serine mutation at position 129 in PTPN22 (C129S), a residue proposed to alter the redox regulatory properties of PTPN22 by forming a disulfide with the catalytic C227 residue. The C129S mutant mouse showed a stronger T-cell-dependent inflammatory response and development of T-cell-dependent autoimmune arthritis due to enhanced TCR signaling and activation of T cells, an effect neutralized by a mutation in Ncf1, a component of the NOX2 complex. Activity assays with purified proteins suggest that the functional results can be explained by an increased sensitivity to oxidation of the C129S mutated PTPN22 protein. We also observed that the disulfide of native PTPN22 can be directly reduced by the thioredoxin system, while the C129S mutant lacking this disulfide was less amenable to reductive reactivation. In conclusion, we show that PTPN22 functionally interacts with Ncf1 and is regulated by oxidation via the noncatalytic C129 residue and oxidation-prone PTPN22 leads to increased severity in the development of T-cell-dependent autoimmunity.

Redoxing PTPN22 activity.

The oxidative state of a critical cysteine residue determines the enzymatic activity of a phosphatase involved in T-cell immune responses.

SH3-domain mutations selectively disrupt Csk homodimerization or PTPN22 binding.

The kinase Csk is the primary negative regulator of the Src-family kinases (SFKs, e.g., Lck, Fyn, Lyn, Hck, Fgr, Blk, Yes), phosphorylating a tyrosine on the SFK C-terminal tail that mediates autoinhibition. Csk also binds phosphatases, including PTPN12 (PTP-PEST) and immune-cell PTPN22 (LYP/Pep), which dephosphorylate the SFK activation loop to promote autoinhibition. Csk-binding proteins (e.g., CBP/PAG1) oligomerize within membrane microdomains, and high local concentration promotes Csk function. Purified Csk homodimerizes in solution through an interface that overlaps the phosphatase binding footprint. Here we demonstrate that Csk can homodimerize in Jurkat T cells, in competition with PTPN22 binding. We designed SH3-domain mutations in Csk that selectively impair homodimerization (H21I) or PTPN22 binding (K43D) and verified their kinase activity in solution. Disruption of either interaction in cells, however, decreased the negative-regulatory function of Csk. Csk W47A, a substitution previously reported to block PTPN22 binding, had a secondary effect of impairing homodimerization. Csk H21I and K43D will be useful tools for dissecting the protein-specific drivers of autoimmunity mediated by the human polymorphism PTPN22 R620W, which impairs interaction with Csk and with the E3 ubiquitin ligase TRAF3. Future investigations of Csk homodimer activity and phosphatase interactions may reveal new facets of SFK regulation in hematopoietic and non-hematopoietic cells.

Targeting Protein Tyrosine Phosphatase 22 Does Not Enhance the Efficacy of Chimeric Antigen Receptor T Cells in Solid Tumors.

Adoptive cell therapy with chimeric antigen receptor (CAR) T cells has revolutionized the treatment of certain B cell malignancies but has been in ineffective against solid tumors. Recent studies have highlighted the potential of targeting negative regulators of T cell signaling to enhance the efficacy and extend the utility of CAR T cells to solid tumors. Autoimmunity-linked protein tyrosine phosphatase N22 (PTPN22) has been proposed as a target for cancer immunotherapy. Here, we have used CRISPR/Cas9 gene editing to generate PTPN22-deficient (Ptpn22Δ/Δ) mice (C57BL/6) and assessed the impact of PTPN22 deficiency on the cytotoxicity and efficacy of CAR T cells in vitro and in vivo. As reported previously, PTPN22 deficiency was accompanied by the promotion of effector T cell responses ex vivo and the repression of syngeneic tumor growth in vivo. However, PTPN22 deficiency did not enhance the cytotoxic activity of murine CAR T cells targeting the extracellular domain of the human oncoprotein HER2 in vitro. Moreover, PTPN22-deficient α-HER2 CAR T cells or ovalbumin-specific OT-I CD8+ T cells adoptively transferred into mice bearing HER2+ mammary tumors or ovalbumin-expressing mammary or colorectal tumors, respectively, were no more effective than their wild-type counterparts in suppressing tumor growth. The deletion of PTPN22 using CRISPR/Cas9 gene editing also did not affect the cytotoxic activity of human CAR T cells targeting the Lewis Y antigen that is expressed by many human solid tumors. Therefore, PTPN22 deficiency does not enhance the antitumor activity of CAR T cells in solid organ malignancies.

Effect of PTPN22, FAS/FASL, IL2RA and CTLA4 genetic polymorphisms on the risk of developing alopecia areata: A systematic review of the literature and meta-analysis.

OBJECTIVES: Genetic association studies on alopecia areata (AA) performed in various populations have shown heterogeneous results. The aim of the current review was to synthesize the results of said studies to estimate the impact of FAS, FASL, PTPN22, CTLA4 and IL2RA gene polymorphisms on AA susceptibility. DESIGN: A systematic literature search was conducted in the Medline, Web of Science, Scopus, EMBASE and LILACS databases. Studies published up to June 2020 were included. The results available in the grey literature including the Open Grey and Google Scholar databases were also used. The texts of potentially related studies were screened by individual reviewers. Evidence of publication bias was assessed using the Newcastle-Ottawa scale and the quality of evidence was assessed using the GRADE system. The quantitative synthesis was performed using the fixed effect model. RESULTS: Out of 1784 articles, we identified 18 relevant articles for the qualitative synthesis and 16 for the quantitative synthesis. In a study of rs2476601 polymorphism of PTPN22 gene, including 1292 cases and 1832 controls, a correlation was found with the risk of developing AA in the allelic model (OR1.49 [95% C:1.13-1.95]), the heterozygous codominant (OR1.44 [95% CI:1:19-1.76]) and dominant model (OR1.43 [95% CI:1.18-1.73]). No association was found between the presence of FASL, PTPN22, CTLA and IL2RA gene polymorphisms with AA susceptibility. CONCLUSIONS: The results suggest that the T allele of the single nucleoid polymorphism (SNP) rs2476601 in PTPN22 gene is a risk factor for developing alopecia areata. However, more robust studies defining the ethnic background of the population of origin are required, so that the risk identified in the present study can be validated. Additionally, a greater number of studies is necessary to evaluate the role of the FAS, FASL, PTPN22, CTLA4 and IL2RA genetic variants, given the heterogenous results found in the literature.

Proautoimmune Allele of Tyrosine Phosphatase, PTPN22, Enhances Tumor Immunity.

The 1858C>T allele of the tyrosine phosphatase PTPN22 (causing amino acid substitution R620W in encoded protein lymphoid tyrosine phosphatase) is present in 5-10% of the North American population and is strongly associated with numerous autoimmune diseases. Although much research has been done to define how this allele potentiates autoimmunity, the influence PTPN22 and its proautoimmune allele have in tumor immunity is poorly defined. To interrogate the role this allele may have in the antitumor immune response, we used CRISPR/Cas9 to generate mice in which the ortholog of lymphoid tyrosine phosphatase, PEST domain-enriched protein (PEP), is mutated at position 619 to produce the relevant proautoimmune mutation (R619W). Results of this study show that mice homozygous for this alteration (PEP-619WW) resist tumor growth as compared with wild-type mice. Consistent with these results, tumors from PEP-619WW mice have more CD45 infiltrates containing more activated CD8 T cells and CD4 T cells. In addition, there are more conventional dendritic cell type 1 (cDC1) cells and fewer myeloid-derived suppressor cells in tumors from PEP-619WW mice. Interestingly, the tumor-infiltrating PEP-619WW cDC1 cells have decreased PD-L1 expression compared with cDC1 cells from PEP-wild-type mice. Taken together, our data show that the proautoimmune allele of Ptpn22 drives a strong antitumor response in innate and adaptive immune cells resulting in superior control of tumors.

Modulation of PTPN2/22 Function by Spermidine in CRISPR-Cas9-Edited T-Cells Associated with Crohn's Disease and Rheumatoid Arthritis.

Crohn's Disease (CD) and Rheumatoid Arthritis (RA) share some single nucleotide polymorphisms (SNPs) in protein tyrosine phosphatase non-receptor types 2 and 22 (PTPN2/22). Recently, we reported that clinical samples from CD and RA patients associated with PTPN2:rs478582 or PTPN22:rs2476601 genotypes were linked to overactive immune response and exacerbation of inflammation. Here, we investigated in vitro the effects of these SNPs in Jurkat T-cells using CRISPR-Cas9. All cells were evaluated for PTPN22/22 loss of function and effects on cell response. We measured gene expression via RT-qPCR and cytokines by ELISA. We also measured cell proliferation using a BrdU labeling proliferation ELISA, and T-cell activation using CD-25 fluorescent immunostaining. In PTPN2 SNP-edited cells, PTPN2 expression decreased by 3.2-fold, and proliferation increased by 10.2-fold compared to control. Likewise, expression of PTPN22 decreased by 2.4-fold and proliferation increased by 8.4-fold in PTPN22 SNP-edited cells. IFN-γ and TNF-α secretions increased in both edited cell lines. CD25 expression (cell activation) was 80.32% in PTPN2 SNP-edited cells and 85.82% in PTPN22 SNP-edited cells compared to 70.48% in unedited Jurkat T-cells. Treatment of PTPN2 and PTPN22-edited cells with a maximum 20 µM spermidine restored PTPN2/22 expression and cell response including cell proliferation, activation, and cytokines secretion. Most importantly, the effect of spermidine on edited cells restored normal expression and secretion of IFN-γ and TNF-α. The data clearly demonstrated that edited SNPs in PTPN2 or PTPN22 were associated with reduced gene expression, which resulted in an increase in cell proliferation and activation and overactive immune response. The data validated our earlier observations in CD and RA clinical samples. Surprisingly, spermidine restored PTPN2/22 expression in edited Jurkat T-cells and the consequent beneficial effect on cell response and inflammation. The study supports the use of polyamines dietary supplements for management of CD and in RA patients.

Loss of PTPN22 Promotes Intestinal Inflammation by Compromising Granulocyte-mediated Antibacterial Defence.

BACKGROUND AND AIMS: A single nucleotide polymorphism in protein tyrosine phosphatase non-receptor type 22 [PTPN22] has been associated with the onset of autoimmune disorders, but protects from Crohn's disease. PTPN22 deficiency in mice promotes intestinal inflammation by modulating lymphocyte function. However, the impact of myeloid PTPN22 in colitis development remains unclear. The aim of this study was to investigate the role of PTPN2 in the IL-10 and the T cell transfer colitis models. METHODS: PTPN22-deficient mice were crossed with IL-10-/- and RAG2-/- mice. Naïve T cells were injected in RAG-/- mice to induce T-cell transfer colitis. Spontaneous colitis in IL-10-/- mice was monitored for up to 200 days. RESULTS: Here, we demonstrate that PTPN22 in non-lymphoid immune cells is required to protect against T cell transfer-mediated and IL-10 knock-out colitis. Analysis of the intestinal immune landscape demonstrated a marked reduction of granulocyte influx into the inflamed colon in PTPN22-deficient mice. On a molecular level, granulocytes were not only reduced by numbers, but also revealed a defective function. In particular, granulocyte activation and granulocyte-mediated bacteria killing was impaired upon loss of PTPN22, resulting in elevated bacterial burden and translocation beyond the intestinal epithelial barrier in PTPN22-deficient mice. Consistently, antibiotic-induced depletion of bacteria reverted the increased colitis susceptibility in PTPN22-deficient mice, whereas granulocyte depletion induced acolitis phenotype in wild-type mice similar to that observed in PTPN22-deficient mice. CONCLUSIONS: In conclusion, our data demonstrate that PTPN22 is essential for adequate granulocyte activation and antimicrobial defence to protect the inflamed intestine from bacterial invasion and exacerbated colitis.

Tumor necrosis factor receptor II and PTPN22 genes polymorphisms and the risk of systemic lupus erythematosus in Egyptian children.

BACKGROUND: Many genes have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Tumor necrosis factor (TNF) is a potent cytokine stimulator acting through 2 cell surface receptors (TNFR I and II). TNFRII gene which controls expression of these receptors has been linked to SLE susceptibility through promoting apoptosis. Also; Protein tyrosine phosphatase non receptor 22 (PTPN22) gene enhances intrinsic phosphatase activity of T lymphocytes leading to their dysregulation and stimulates autoimmune process of lupus and its rs2476601 has been linked to susceptibility to thyroiditis in SLE patients in few studies. OBJECTIVES: (i) to investigate the correlation between 2 SNPs of TNFR II and PTPN22 genes and SLE susceptibility in a cohort of Egyptian children compared to controls (ii) and to investigate their possible association with different clinical presentations of the disease in children. SUBJECTS AND METHODS: Typing of TNFR II rs1061622 and PTPN22 rs2476601 SNPs were done using polymerase chain reaction-restriction fragment length polymorphism for 74 children with SLE and 100 matched healthy controls. RESULTS: Children with SLE had more frequent G allele and GG genotype of TNFR II rs1061622 (p < 0.001) and more T allele and TT genotype of PTPN22 rs2476601 (p = 0.012 and <0.001, respectively) compared to controls. Only 6 patients (8%) had thyroiditis (hypothyroidism) with T allele and TT genotype of PTPN22 1858 T more prevalent in those patients versus those without thyroiditis (p ≤ 0.001). Apart from, thyroiditis, no significant association was found between genotypes and alleles frequencies of the 2 studied SNPs and other clinical manifestations of the disease. CONCLUSION: The G allele and GG genotype of TNFR II rs1061622 and T allele and TT genotype of PTPN22 rs2476601 genes polymorphism can be considered as risk factors for the development of SLE. The presence of the T allele of PTPN22 rs2476601 may increase the risk of concomitant thyroiditis in Egyptian children with SLE but further studies are required to confirm this finding as thyroiditis was reported only in few cases in this study.

Altered Antibody Response to Epstein-Barr Virus in Patients With Rheumatoid Arthritis and Healthy Subjects Predisposed to the Disease. A Twin Study.

Objectives: To study Epstein-Barr virus (EBV) antibody patterns in twin individuals with rheumatoid arthritis (RA) and their healthy co-twins, and to determine the heritability of antibody responses against the EBV encoded EBNA1 protein. Methods: Isotypes of EBNA1 antibodies were measured in 137 RA affected- and 150 healthy twin pairs. We estimated the effect of RA and RA predisposition, anti-citrullinated antibodies (ACPA), IgM rheumatoid factor (RF), the shared epitope (SE) and the PTPN22-T allele (PTPN22) on the level of EBNA1 antibodies. We also determined the heritability of EBNA1 antibody levels. Results: IgA-EBNA1 antibody levels were increased in twins from RA discordant twin pairs irrespective of RA, ACPA or IgM-RF status. The IgG-EBNA1 antibody level was elevated in healthy co-twins from RA discordant twin pairs but not in RA affected twins. The IgM-EBNA1 antibody level was elevated in both RA twins and their healthy co-twins. The effect of RA on the IgA-EBNA1 antibody level was reversed when SE was present and with no effect of PTPN22. The heritability of IgA-, IgG- and IgM-EBNA1 antibody level was 40.6, 65.5, and 54.3%, with no effect of environment shared by the twins. Conclusion: EBNA1 antibody levels are distinctively different between patients with RA and healthy subjects but also between relatives of RA strongly predisposed to RA and healthy subjects. The high level of IgA EBNA1 antibodies associated with RA and a family predisposition to RA is attributable to both genetics incl. the shared epitope and environmental variation.

GWAS for autoimmune Addison's disease identifies multiple risk loci and highlights AIRE in disease susceptibility.

Autoimmune Addison's disease (AAD) is characterized by the autoimmune destruction of the adrenal cortex. Low prevalence and complex inheritance have long hindered successful genetic studies. We here report the first genome-wide association study on AAD, which identifies nine independent risk loci (P < 5 × 10-8). In addition to loci implicated in lymphocyte function and development shared with other autoimmune diseases such as HLA, BACH2, PTPN22 and CTLA4, we associate two protein-coding alterations in Autoimmune Regulator (AIRE) with AAD. The strongest, p.R471C (rs74203920, OR = 3.4 (2.7-4.3), P = 9.0 × 10-25) introduces an additional cysteine residue in the zinc-finger motif of the second PHD domain of the AIRE protein. This unbiased elucidation of the genetic contribution to development of AAD points to the importance of central immunological tolerance, and explains 35-41% of heritability (h2).

Polymorphisms of the genes CTLA4, PTPN22, CD40, and PPARG and their roles in Graves' disease: susceptibility and clinical features.

PURPOSE: CTLA4, PTPN22, and CD40 are immune-regulatory genes strongly associated with GD, as well as PPARG, but their clinical significance in different populations is still uncertain. METHODS: We genotyped 282 Brazilian GD patients (234 women and 48 men, 39.80 ± 11.69 years old), including 144 patients with GO, and 308 healthy control individuals (246 women and 62 men, 36.86 ± 12.95 years old). RESULTS: A multivariate analysis demonstrated that the inheritance of the GG genotype rs3087243 of CTLA4 (OR = 2.593; 95% CI = 1.630-4.123; p < 0.0001) and the CC genotype of rs3789607 of PTPN22 (OR = 2.668; 95% CI = 1.399-5.086; p = 0.0029) consisted in factors independent of the susceptibility to GD. The inheritance of polymorphic genotypes of rs5742909 of CTLA4 was associated with older age at the time of diagnosis (42.90 ± 10.83 versus 38.84 ± 11.81 years old; p = 0.0105), with higher TRAb levels (148.17 ± 188.90 U/L versus 112.14 ± 208.54 U/L; p = 0.0229) and the need for higher therapeutic doses of radioiodine (64.23 ± 17.16 versus 50.22 ± 16.86; p = 0.0237). The inheritance of the CC genotype of rs1883832 CD40 gene was more frequent among women (69.65%) than men (52.00%; p = 0.0186). The polymorphic genotype of PPARG gene (rs1801282) was associated with TPOAb positivity (p = 0.0391), and the GG genotype of rs2476601 of PTPN22 gene was associated with positivity for both TgAb (p = 0.0360) and TPOAb (p < 0.0001). Both polymorphic genotypes rs2476601 and rs3789607 of the PTPN22 gene were more frequent among nonsmoking patients (p = 0.0102 and p = 0.0124, respectively). CONCLUSIONS: Our data confirm the important role of CTLA4 polymorphisms in GD susceptibility; demonstrate the role of PTPN22 polymorphisms in patients' clinical features; and suggest these genes may influence the severity of the disease.