CTLA4CT60 gene polymorphism is not associated with differential susceptibility to pemphigus foliaceus

Pemphigus foliaceus is an organ-specific autoimmune disease characterized by autoantibodies against the extracellular region of desmoglein 1, a protein that mediates intercellular adhesion in desmosomes. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a key negative regulator of the T cell immune response, playing an important role in T cell homeostasis and maintenance of peripheral tolerance. Polymorphisms in the CTLA4 gene have been associated with autoimmune diseases and the functional CT60 single nucleotide polymorphism (rs3087243, also named 6230G > A) has been proposed to be a casual variant in several of these diseases. The aim of this study was to ascertain whether this polymorphism is associated with inter-individual variation in susceptibility to pemphigus foliaceus. The population sample in this case-control association study comprised 248 patient and 367 controls. We did not found a significant association of pemphigus foliaceus with the CT60 variants. We conclude that the CTLA4CT60 polymorphism is not an important factor for pemphigus foliaceus pathogenesis in the population analyzed

Evaluation of the association between the common E469K polymorphism in the ICAM-1 gene and diabetic nephropathy among type 1 diabetic patients in GoKinD population

<p>Abstract</p> <p>Background</p> <p>The ICAM-1 gene is a strong positional and biological candidate for susceptibility to the development of T1D and DN. We have recently demonstrated that SNP rs5498(E469K) confers susceptibility to the development of T1D and might be associated with DN in Swedish Caucasians. The present study aimed to further evaluate the association between the ICAM-1 genetic polymorphisms and DN.</p> <p>Methods</p> <p>Two common non-synonymous SNPs, including rs5498(E469K) and rs1799969(R241G), in the ICAM-1 gene were genotyped in 662 (312 female/350 male) T1D patients with DN and 620 (369/251) without DN. All patients were selected from the GoKinD study.</p> <p>Results</p> <p>Genotype distributions of both SNPs were in Hardy-Weinberg equilibrium but SNP rs5498(E469K) had high heterozygous index. In this SNP, the heterozygosity and positivity for the allele G were found to be significantly associated with DN in female T1D patients (P = 0.010, OR = 0.633, CI 95% 0.447–0.895 and P = 0.026, OR = 0.692, CI 95% 0.500–0.958). Furthermore, the female patients without DN carrying three genotypes A/A, A/G and G/G had different cystatin levels (0.79 ± 0.17, 0.81 ± 0.14 and 0.75 ± 0.12 mg/L, P = 0.021). No significant association of SNP rs1799969 (R241G) with DN was found.</p> <p>Conclusion</p> <p>The present study provides further evidence that SNP rs5498(E469K) in the ICAM-1 gene presents a high heterozygous index and the allele G of this polymorphism may confers the decreased risk susceptibility to the development of DN in female T1D patients among the GoKinD population.</p

SNP Analysis of Genes Implicated in T Cell Proliferation in Primary Biliary Cirrhosis

Previous studies on primary biliary cirrhosis (PBC) have focused on the role of T lymphocytes as potential effectors of tissue injury. We hypothesized that single nucleotide polymorphisms (SNPs) of genes involved in lymphocyte proliferation would be responsible for uncontrolled expansion of T cells and autoreactivity. To address this, we genotyped DNA from 154 patients with PBC and 166 ethnically matched healthy controls for SNPs of five candidate genes (60G/A CTLA-4, 1858 C/T LYP, -IVS9 C/T foxp3, p1323 C/G ICOS and -9606 T/C CD25) using a TaqMan assay

Immunoregulatory gene polymorphisms in women with preeclampsia

The costimulatory molecules CD28, cytotoxic T-lymphocyte antigen-4 (CTLA-4) (cytotoxic T-lymphocyte-associated antigen-4) and inducible costimulator (ICOS) are believed to have a critical modulatory role in the immune response. However, few studies have been performed on the role of these immune regulatory molecules and their polymorphisms in women with preeclampsia (PE). the aim of our study was to evaluate the CTLA4 (+49 A/G) (rs 231775), CD28 (+17 T/C) (rs 3116496) and ICOS (-1564 T/C) (rs 4675378) gene polymorphisms in Brazilian women with PE. This case-control study included 130 patients with PE and 261 control women without any obstetric or systemic disorders. Genomic DNA was extracted from peripheral blood, and the polymorphism genotyping was performed by digesting the PCR products with the restriction endonucleases BbvI (CTLA-4), Afel (CD28) and AluI (ICOS). Data were analyzed by X(2) or Fisher's exact test; a P-value of < 0.05 was considered as significant. There were significant differences in the ICOS genotype and allelic frequencies between the PE and control groups (P=0.01 and P=0.01, respectively). We found a significantly lower frequency of the ICOS (-1564) T allele in women with mild PE compared with the controls. There were no differences in the CTLA-4 (+49 A/G) and CD28 (+17 T/C) genotypes and allelic frequencies between the PE patients and controls. Our data suggest that PE is associated with ICOS, but is not associated with the CTLA-4 or CD28 gene polymorphisms. Hypertension Research (2011) 34, 384-388; doi:10.1038/hr.2010.247; published online 16 December 2010Fundacao de Amparo a PesquisaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, Dept Obstet, BR-01415002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Obstet, BR-01415002 São Paulo, BrazilFundacao de Amparo a Pesquisa: 07/57446-0Web of Scienc

Excessive Food Intake, Obesity and Inflammation Process in Zucker fa/fa Rat Pancreatic Islets

Inappropriate food intake-related obesity and more importantly, visceral adiposity, are major risk factors for the onset of type 2 diabetes. Evidence is emerging that nutriment-induced β-cell dysfunction could be related to indirect induction of a state of low grade inflammation. Our aim was to study whether hyperphagia associated obesity could promote an inflammatory response in pancreatic islets leading to ß-cell dysfunction. In the hyperphagic obese insulin resistant male Zucker rat, we measured the level of circulating pro-inflammatory cytokines and estimated their production as well as the expression of their receptors in pancreatic tissue and β-cells. Our main findings concern intra-islet pro-inflammatory cytokines from fa/fa rats: IL-1β, IL-6 and TNFα expressions were increased; IL-1R1 was also over-expressed with a cellular redistribution also observed for IL-6R. To get insight into the mechanisms involved in phenotypic alterations, abArrays were used to determine the expression profile of proteins implicated in different membrane receptors signaling, apoptosis and cell cycle pathways. Despite JNK overexpression, cell viability was unaffected probably because of decreases in cleaved caspase3 as well as in SMAC/DIABLO and APP, involved in the induction and amplification of apoptosis. Concerning β-cell proliferation, decreases in important cell cycle regulators (Cyclin D1, p35) and increased expression of SMAD4 probably contribute to counteract and restrain hyperplasia in fa/fa rat islets. Finally and probably as a result of IL-1β and IL-1R1 increased expressions with sub-cellular redistribution of the receptor, islets from fa/fa rats were found more sensitive to both stimulating and inhibitory concentrations of the cytokine; this confers some physiopathological relevance to a possible autocrine regulation of β-cell function by IL-1β. These results support the hypothesis that pancreatic islets from prediabetic fa/fa rats undergo an inflammatory process. That the latter could contribute to β-cell hyperactivity/proliferation and possibly lead to progressive β-cell failure in these animals, deserves further investigations

Effects of Inhibition of Interleukin-6 Signalling on Insulin Sensitivity and Lipoprotein (A) Levels in Human Subjects with Rheumatoid Diseases

Interleukin-6 (IL-6) is a pro-inflammatory cytokine that has been found to be increased in type 2 diabetic subjects. However, it still remains unclear if these elevated IL-6 levels are co-incidental or if this cytokine is causally related to the development of insulin resistance and type 2 diabetes in humans. Therefore, in the present study we examined insulin sensitivity, serum adipokine levels and lipid parameters in human subjects before and after treatment with the IL-6 receptor antibody Tocilizumab.11 non-diabetic patients with rheumatoid disease were included in the study. HOMA-IR was calculated and serum levels for leptin, adiponectin, triglycerides, LDL-cholesterol, HDL-cholesterol and lipoprotein (a) (Lp (a)) were measured before as well as one and three months after Tocilizumab treatment. The HOMA index for insulin resistance decreased significantly. While leptin concentrations were not altered by inhibition of IL-6 signalling, adiponectin concentrations significantly increased. Thus the leptin to adiponectin ratio, a novel marker for insulin resistance, exhibited a significant decrease. Serum triglycerides, LDL-cholesterol and HDL-cholesterol tended to be increased whereas Lp (a) levels significantly decreased.Inhibition of IL-6 signalling improves insulin sensitivity in humans with immunological disease suggesting that elevated IL-6 levels in type 2 diabetic subjects might be causally involved in the pathogenesis of insulin resistance. Furthermore, our data indicate that inhibition of IL-6 signalling decreases Lp (a) serum levels, which might reduce the cardiovascular risk of human subjects

Evaluation of six CTLA-4 polymorphisms in high-risk melanoma patients receiving adjuvant interferon therapy in the He13A/98 multicenter trial

<p>ABSTRACT</p> <p>Purpose</p> <p>Interferon is approved for adjuvant treatment of patients with stage IIb/III melanoma. The toxicity and uncertainty regarding survival benefits of interferon have qualified its acceptance, despite significant durable relapse prevention in a fraction of patients. Predictive biomarkers that would enable selection of patients for therapy would have a large impact upon clinical practice. Specific CTLA-4 polymorphisms have previously shown an association with response to CTLA-4 blockade in patients with metastatic melanoma and the development of autoimmunity.</p> <p>Experimental design</p> <p>286 melanoma patients and 288 healthy controls were genotyped for six CTLA-4 polymorphisms previously suggested to be important (AG 49, CT 318, CT 60, JO 27, JO30 and JO 31). Specific allele frequencies were compared between the healthy and patient populations, as well as presence or absence of these in relation to recurrence. Alleles related to autoimmune disease were also investigated.</p> <p>Results</p> <p>No significant differences were found between the distributions of CTLA-4 polymorphisms in the melanoma population compared with healthy controls. Relapse free survival (RFS) and overall survival (OS) did not differ significantly between patients with the alleles represented by these polymorphisms. No correlation between autoimmunity and specific alleles was shown. The six polymorphisms evaluated where strongly associated (Fisher's exact p-values < 0.001 for all associations) and significant linkage disequilibrium among these was indicated.</p> <p>Conclusion</p> <p>No polymorphisms of CTLA-4 defined by the SNPs studied were correlated with improved RFS, OS, or autoimmunity in this high-risk group of melanoma patients.</p

Polymorphism analysis of the CTLA-4 gene in paracoccidioidomycosis patients

The CTLA-4 protein is expressed in activated T cells and plays an essential role in the immune response through its regulatory effect on T cell activation. Polymorphisms of the CTLA-4 gene have been correlated with autoimmune, neoplastic and infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) in CTLA-4, -318C/T in the promoter and +49A/G in exon 1 and paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients and 76 healthy controls had their allele, genotype and haplotype frequencies determined. The genetic admixture structure of the patients and controls was evaluated to eliminate ancestral bias. The comparison of frequencies indicated no significant differences between patients and controls that could link the SNPs to PCM. Groups were admixture matched with no difference observed in population ancestry inference, indicating that the absence of association between CTLA-4 polymorphisms and PCM could not be attributed to ancestral bias. This study showed that there was no association between the CTLA-4 SNPs -318 and +49 and the resistance or susceptibility to PCM

Association between the Interleukin-6 Promoter Polymorphism −174G/C and Serum Lipoprotein(a) Concentrations in Humans

Background: Lipoprotein(a) [Lp(a)] is an independent risk factor for cardiovascular disease. The interleukin-6 (IL-6) receptor antagonist tocilizumab has been shown to lower serum Lp(a) concentrations. We investigated whether the IL-6 single nucleotide polymorphism 2174G/C is associated with baseline serum Lp(a) concentrations. Methodology/Principal Findings: We divided 2321 subjects from the Lipid Analytic Cologne (LIANCO) cohort into 2 groups, the ones with substantially elevated Lp(a), defined as concentrations $60 mg/dl (n = 510), and the ones with Lp(a),60 mg/ dl (n = 1811). The association with the genotypes GG (33.7%), GC (50.75%) and CC (15.55%) was investigated. The GC and the CC genotype were associated with a significantly increased odds ratio of having substantially elevated Lp(a) concentrations (OR = 1.3, 95 % CI 1.04 to 1.63, P = 0.02 and OR = 1.44, 95 % CI 1.06 to 1.93, P = 0.018). These associations remained significant after adjusting for age, sex, smoking behavior, body mass index, serum lipoproteins, hypertension and diabetes. Of these covariates, only LDL cholesterol was significantly and independently associated with elevated Lp(a) concentrations. Conclusions/Significance: The IL-6 single nucleotide polymorphism 2174G/C is associated with increased odds of having elevated Lp(a). Whether this association plays a role in the Lp(a)-lowering effects of IL-6 receptor antagonists remains to b