CTLA-4 gene expression is influenced by promoter and exon 1 polymorphisms

Cytotoxic T lymphocyte antigen-4 +49A/G polymorphism does not affect susceptibility to autoimmune hepatitis

BACKGROUND & AIMS

Single nucleotide polymorphisms (SNP) in the Cytotoxic T lymphocyte antigen-4 gene (CTLA-4) have been associated with several autoimmune diseases including autoimmune Hepatitis (AIH). In this chronic idiopathic inflammatory liver disease, conflicting results have been reported on the association with a SNP at position +49 in the CTLA-4 gene in small patient cohorts. Here, we established the role of this SNP in a sufficiently large cohort of AIH patients.

METHODS

The study population consisted of 672 AIH patients derived from academic and regional hospitals in the Netherlands and was compared with 500 controls selected from the 'Genome of the Netherlands' project cohort. Genotype frequencies were assessed by PCR for patients and by whole genome sequencing for controls.

RESULTS

No significant differences in allele frequencies were found between patients and controls (G Allele: 40% vs 39%, P = 0.7). Similarly, no significant differences in genotype frequencies between patients and controls were found. Finally, there was no relation between disease activity and the G allele or AG and GG genotypes.

CONCLUSION

The Cytotoxic T Lymphocyte Antigen-4 +49 A/G polymorphism does not represent a major susceptibility risk allele for AIH in Caucasians and is not associated with disease severity at presentation.

Ctla-4 expression and polymorphisms in lung tissue of patients with diagnosed non-small-cell lung cancer

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is a potent immunoregulatory molecule that downregulates T-cell activation and thus influences the antitumor immune response. CTLA-4 polymorphisms are associated with various cancers, and CTLA-4 mRNA/protein increased expression is found in several tumor types. However, most of the studies are based on peripheral blood mononuclear cells, and much less is known about the relationship between CTLA-4 expression, especially gene expression, and its polymorphic variants in cancer tissue. In our study we assessed the distribution of CTLA-4 two polymorphisms (+49A/G and −318C/T), using TaqMan probes (rs231775 and rs5742909, resp.), and CTLA-4 gene expression in real-time PCR assay in non-small-cell lung cancer (NSCLC) tissue samples. The increased CTLA-4 expression was observed in the majority of NSCLC patients, and it was significantly correlated with TT genotype (−318C/T) and with tumor size (T2 versus T3 + T4). The presence of G allele and GG genotype in cancer tissue (+49A/G) was significantly associated with the increased NSCLC risk. Additionally, we compared genotype distributions in the corresponding tumor and blood samples and found statistically significant differences. The shift from one genotype in the blood to another in the tumor may confirm the complexity of gene functionality in cancer tissue.

Lack of association between cytotoxic T-lymphocyte antigen-4 -318C/T polymorphism and cancer risk: a meta-analysis of case-control studies

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is important for the down regulation of T-cell activation. Number of studies assessed the association between CTLA-4 -318C/T polymorphisms and cancer in different populations. However, the studies have provided conflicting results. We performed a meta-analysis to examine the association between CTLA-4 -318C/T polymorphisms and cancer susceptibility. Eligible studies were identified by searching several databases for relevant reports published up to September 30, 2012. Sixteen eligible studies with a total of 6190 patients and 6560 controls were included to summarize the association between CTLA-4 -318C/T polymorphisms and the risk of cancer. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Overall, no significant associations were found in all genetic models when all studies were pooled into the meta-analysis (for -318C/T polymorphisms as estimated using a fixed effect model: TT vs. (CC + CT), OR = 1.02, 95% CI = 0.83-1.24; (TT + CT) vs. CC, OR = 1.20, 95% CI = 1.00-1.44; TT vs. CC, OR = 1.09, 95% CI = 0.74-1.59; CT vs. CC, OR = 1.21, 95% CI = 1.00-1.46). In further subgroup analyses for the -318C/T polymorphisms, stratified by design of ethnicity, cancer types, solid tumors to non-solid tumors, epithelial tumors to non-epithelial tumors, no significant associations were found in any subgroup of the population. This meta-analysis strongly suggests that -318C/T polymorphisms in CTLA-4 are not associated with an increased risk of cancer.

Association of Hashimoto's thyroiditis with cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and inducible co-stimulator (ICOS) genes in a Kuwaiti population

Analysing two CTLA-4 markers [exon 1 A49G single nucleotide polymorphism (SNP) and exon 4 3'UTR (AT)n repeat] and the ICOS intron 4 (GT)n marker for their potential association with HT, and exploring the effect of the tested SNPs on the CTLA-4 isoform expression at the mRNA and protein levels. Total of 270 age-gender-ethnically matched subjects were genotyped by fluorescent-labelled restriction fragment length polymorphism, multiplex PCR, and fragment analysis. Sequencing was used to confirm the genotyping results. Expression of the full-length and soluble CTLA-4 mRNAs analysed using real-time PCR. Sera from subjects were screened for sCTLA-4 using ELISA. Tested subjects revealed ten alleles and sixteen genotypes of CTLA-4 3'UTR(AT)n. The 3'UTR(AT)n was significantly associated with HT: allele (AT)15 and genotype 15/15 were found to cause susceptibility to HT (P = 0.004, OR = 2.13, 95 % CI = 1.26-3.58 and P = 0.029, OR = 2.77, 95 % CI = 1.1-6.94, respectively), whereas allele (AT)6 and genotype 6/6 were found to be protective of HT (P = 0.00002, OR = 0.36, 95 % CI = 0.227-0.57 and P = 0.001, OR = 0.357, 95 % CI = 0.1980.64, respectively). SNP A49G and ICOS(GT)n revealed no significant association with HT (P > 0.05). The expression of sCTLA-4 was inversely proportional to the number of 3'UTR(AT)n repeats, with heterozygous and longer (AT)n repeats showing lower levels of sCTLA-4 mRNA than those with shorter alleles in HC and HT (P = 0.001 and P = 0.04, respectively). Significant increase in the serum level of sCTLA-4 was observed in HT patients compared with the HC (P = 0.0007). The novel finding in our study is that the CTLA-4 3'UTR(AT)n proven to be a key player in the pathogenesis of HT.

Evaluation of polymorphism, hypermethylation and expression pattern of CTLA4 gene in a sample of Iranian patients with schizophrenia

The cytotoxic T lymphocyte-associated antigen 4 gene (CTLA4) has a crucial role in regulation of T cell proliferation and mediates T cell apoptosis by encoding the T cell receptor. Schizophrenia (SCZ) patients often have abnormalities in terms of the function and development of the immune system. The aim of the present study was to investigate promoter variation and expression profile of the CTLA4 gene in patients with SCZ. We isolated genomic DNA from peripheral blood of 94 individuals with SCZ and 99 healthy control subjects. Genotypic analysis of CTLA4 (-318) was done by Tetra-ARMS-PCR. Methylation-specific polymerase chain reaction (MS-PCR) was used to estimate promoter hypermethylation of the CTLA4 gene. In addition, we investigated CTLA4 mRNA levels in 34 blood samples from cases and healthy controls using real-time reverse transcription PCR. The CT genotype of CTLA4 has a significantly protective effect on the risk to SCZ (OR=0.44; 95% CI 0.18-1.06, P=0.007) in comparison with the wild CC genotype. Promoter methylation of the CTLA4 gene increased the risk of disease statistically (OR=3.82, 95% CI 1.34-10.9, P=0.015) in cases when compared to healthy controls in blood samples. The mRNA expression level results showed statistically significant differences (P<0.0001) between cases (n=17) and healthy controls (n=17). To the best of our knowledge, this is the first evidence showing that promoter methylation of the CTLA4 gene along with transition of C to T was linked to a significantly higher expression of CTLA4 mRNA levels in patients with SCZ.

Cytotoxic T-lymphocyte antigen-4 genetic variants and risk of Ewing's sarcoma

Despite the knowledge of many genetic alterations present in Ewing's sarcoma (ES), the complexity of this disease precludes placing its biology into a simple conceptual framework. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) can decrease T-cell activation and attenuate antitumor responses. Polymorphisms in the CTLA-4 gene have been shown to be associated with different diseases. Here, we investigated the association of four CTLA-4 gene polymorphisms, -1661A/G (rs4553808), -318C/T (rs5742909), +49G/A (rs231775), and CT60A/G (rs3087243), with ES in the Chinese population. A total of 308 ES cases and 362 healthy controls were recruited and CTLA-4 polymorphisms were tested by polymerase chain reaction-restriction fragment length polymorphism. Results showed that frequencies of the CTLA-4 gene +49AA genotype, +49A allele, and GTAG haplotype were significantly increased in ES patients compared to healthy controls (odds ratio [OR]=2.42, 95% confidence interval [CI] 1.43-4.09, p<0.001; OR 1.38, 95% CI 1.11-1.73, p=0.005, and OR=1.46, 95% CI 1.06-2.02, p=0.020, respectively). We further compared CTLA-4 polymorphisms in ES patients based on different clinical parameters and data revealed that ES patients with metastasis had higher numbers of the +49AA genotype than those without metastasis (p=0.004). These results indicated that the CTLA-4 polymorphism could be a risk factor for ES and suggested a potential role of CTLA-4 in the metastasis of this malignancy.

Recipient cytotoxic T lymphocyte antigen 4 +49 single-nucleotide polymorphism is not associated with acute rejection after liver transplantation in Chinese population

OBJECTIVE

Single-nucleotide polymorphisms (SNPs) in Cytotoxic T lymphocyte antigen 4 (CTLA-4) gene have been detected and proved to associate with the incidence of rejection after transplantation. However, previous studies gained inconsistent results about the association between CTLA-4 +49 single-nucleotide polymorphism and susceptibility of allograft rejection. Therefore we sought to clarify whether CTLA-4 +49 SNP influences the incidence of acute rejection after liver transplantation in Chinese population.

METHODS

Genomic DNA from 335 liver transplant recipients was genotyped for CTLA-4 +49 SNP by DNA sequencing. Acute rejection was confirmed by pathologic evidences. The association between CTLA-4 +49 SNP and incidence of acute rejection was then analyzed by dominant, recessive, codominant and overdominant models.

RESULTS

The incidence of acute rejection within the first 3 months was 11.9%. In acute rejectors, the frequency was 45% for G/G, 10% for A/A and 45% for A/G respectively, compared with 47.5% for G/G, 10.8% for A/A and 41.7% for A/G in non-acute rejectors. And no significant difference of allele distribution between these 2 groups was detected.

CONCLUSIONS

This study suggests that CTLA-4 +49 SNP is not associated with acute rejection after liver transplantation in Chinese population.

A new method for post Genome-Wide Association Study (GWAS) analysis of colorectal cancer in Taiwan

Recently, single nucleotide polymorphisms (SNPs) located in specific loci or genes have been identified associated with susceptibility to colorectal cancer (CRC) in Genome-Wide Association Studies (GWAS). However, in different ethnicities and regions, the genetic variations and the environmental factors can widely vary. Therefore, here we propose a post-GWAS analysis method to investigate the CRC susceptibility SNPs in Taiwan by conducting a replication analysis and bioinformatics analysis. One hundred and forty-four significant SNPs from published GWAS results were collected by a literature survey, and two hundred and eighteen CRC samples and 385 normal samples were collected for post-GWAS analysis. Finally, twenty-six significant SNPs were identified and reported as associated with susceptibility to colorectal cancer, other cancers, obesity, and celiac disease in a previous GWAS study. Functional analysis results of 26 SNPs indicate that most biological processes identified are involved in regulating immune responses and apoptosis. In addition, an efficient prediction model was constructed by applying Jackknife feature selection and ANOVA testing. As compared to another risk prediction model of CRC for European Caucasians population, which performs 0.616 of AUC by using 54 SNPs, the proposed model shows good performance in predicting CRC risk within the Taiwanese population, i.e., 0.724 AUC by using 16 SNPs. We believe that the proposed risk prediction model is highly promising for predicting CRC risk within the Taiwanese population. In addition, the functional analysis results could be helpful to explore the potential associated regulatory mechanisms that may be involved in CRC development.

CTLA-4 exon 1 +49A/G polymorphism is associated with renal involvement in pediatric Henoch-Schönlein purpura

BACKGROUND

Henoch-Schönlein purpura (HSP) is a multisystemic vasculitis of unknown etiology. Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and CD28 have been reported to be important candidate genes for conferring susceptibility to autoimmunity. In this study, we investigated the correlation of CTLA-4 and CD28 gene polymorphisms with HSP in children with and without renal involvement.

METHODS

The CTLA-4 exon 1 +49A/G, promoter -318C/T and CD28 IVS3 +17T/C single nucleotide polymorphisms (SNPs) were genotyped in 110 children with HSP and 90 ethnically matched healthy controls through restriction fragment-length polymorphism (RFLP).

RESULTS

The CTLA-4 (+49) GG genotype and G allele (GG + AG genotype) were more common in HSP patients with renal involvement (n = 52) than in HSP patients without renal involvement (n = 58) (P = 0.019 and 0.001, respectively). There were no significant differences in the prevalence of CTLA-4 (+49 A/G), (-318C/T) and CD28 IVS3 (+17 /T/C) polymorphisms between HSP patients and controls.

CONCLUSIONS

Our findings suggest that the CTLA-4 +49 GG genotype and G allele may contribute to increased risk for the development of renal damage in HSP patients.

Allelic combinations of immune-response genes as possible composite markers of IFN-β efficacy in multiple sclerosis patients

Background: IFN-β is widely used as the first-line disease-modifying treatment for multiple sclerosis. However, 30–50% of multiple sclerosis patients do not respond to this therapy. Identification of genetic variants and their combinations that predict responsiveness to IFN-β could be useful for treatment prognosis. Materials & methods: The combinations of alleles of nine polymorphic loci in immune-response genes were analyzed in 253 Russian multiple sclerosis patients as possible determinants of clinically optimal IFN-β treatment response using APSampler software. Results: Carriage of TGFB1*-509C and CCR5*d was associated with favorable IFN-β response by itself. CCR5*d, IFNAR1*16725G, IFNG*874T and IFNB1*153T/T were the components of the combinations, associated with clinically optimal response to IFN-β. Carriage of composite markers (CCR5*d + IFNAR1*G + IFNB1*T/T) or (CCR5*d + IFNAR1*G + IFNG*T) is beneficial for IFN-β treatment efficacy. Discussion: The data obtained provides evidence of the cumulative effect of immune-response genes on IFN-β treatment efficacy. This joint contribution may reflect the additive effect of independent allelic variants and epistatic interactions between some of them.

Original submitted 2 July 2012; Revision submitted 21 September 2012

Analysis of cytotoxic T lymphocyte antigen-4 (CTLA-4) promoter -318C/T and +49A/G gene polymorphisms in Turkish patients with familial Mediterranean fever

Either the role of the adaptive immune system or the interaction between innate and adaptive immune systems in familial Mediterranean fever (FMF) is not clear so far. So, we planned to search for the interaction between the innate and adaptive immune systems in the pathogenesis of FMF by investigating polymorphism for CTLA-4 gene, which plays a role in controlling antigen presentation to T cells. We also aimed to investigate whether there is an association between -318C/T and +49A/G polymorphisms in the CTLA-4 gene and the main clinical features of the disease. 75 FMF patients and 179 controls were studied. Polymorphism was detected by the PCR-RFLP technique. The CT genotype and T allele frequencies of the -318C/T polymorphism and the haplotype frequency for the -318T/+49A in the CTLA-4 gene were higher in the FMF (21.3, 21.3, and 10.7 %) when compared with the controls (10.6, 10.6, and 5.3 %; P = 0.029, 0.044, and 0.029). However, these differences did not reach a statistically significant level after the Bonferroni correction. A significant linkage disequilibrium was found between the -318C/T and +49A/G polymorphisms in the CTLA-4 gene (D' = 0.997, r(2) = 0.027, P = 0.0002). Genotype and carrier frequencies of the CTLA-4 gene +49A/G polymorphism were not significantly different between FMF patients and healthy controls. No association was found between the studied polymorphisms and the main clinical features of the disease. Our findings suggest that although not statistically significant, higher frequencies of CTLA-4 gene -318CT genotype, T allele, and -318T/+49A haplotype in FMF patients may be related to the non-autoimmune pathogenesis of FMF.

Genetic associations in acquired immune-mediated bone marrow failure syndromes: insights in aplastic anemia and chronic idiopathic neutropenia

Increasing interest on the field of autoimmune diseases has unveiled a plethora of genetic factors that predispose to these diseases. However, in immune-mediated bone marrow failure syndromes, such as acquired aplastic anemia and chronic idiopathic neutropenia, in which the pathophysiology results from a myelosuppressive bone marrow microenvironment mainly due to the presence of activated T lymphocytes, leading to the accelerated apoptotic death of the hematopoietic stem and progenitor cells, such genetic associations have been very limited. Various alleles and haplotypes of human leucocyte antigen (HLA) molecules have been implicated in the predisposition of developing the above diseases, as well as polymorphisms of inhibitory cytokines such as interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 along with polymorphisms on molecules of the immune system including the T-bet transcription factor and signal transducers and activators of transcription. In some cases, specific polymorphisms have been implicated in the outcome of treatment on those patients.

Autoimmunity-mediated antitumor immunity: tumor as an immunoprivileged self

The association of autoimmunity with antitumor immunity challenges a paradigm of selective surveillance against tumors. Aided with well-characterized models of robust autoimmunity, we show that self-antigen-specific effector T (Teff) cell clones could eradicate tumor cells. However, a tumor microenvironment reinforced by Treg cells and myeloid-derived suppressor cells (MDSCs) presented a barrier to the autoimmune effectors, more so in tumors than in healthy tissues. This barrier required optimal CTLA4 expression in Teff cells. In a spontaneous model of breast cancer, subtle reductions in CTLA4 expression impeded tumor onset and progression, providing the first direct evidence that CTLA4 inhibits spontaneous tumor development. In an adoptive therapy model of lymphoma, self-antigen-specific Teff cells were potentiated by even a modest reduction of CTLA4. A subtle reduction of CTLA4 did not curtail Treg-cell suppression. Thus, Teff cells had an exquisite sensitivity to physiological levels of CTLA4 variations. However, both Treg and Teff cells were impacted by anti-CTLA4 antibody blockade. Therefore, whether CTLA4 impacts through Treg cells or Teff cells depends on its expression level. Overall, the results suggest that the tumor microenvironment represents an "immunoprivileged self" that could be overcome practically and at least partially by RNAi silencing of CTLA4 in Teff cells.

Genetic variants of TNFα, IL10, IL1β, CTLA4 and TGFβ1 modulate the indices of alcohol-induced liver injury in East Indian population

Alcohol induced liver disease or alcoholic liver disease (ALD), a complex trait, encompasses a gamut of pathophysiological alterations in the liver due to continuous exposure to a toxic amount of alcohol (more than 80 g per day). Of all chronic heavy drinkers, only 15-20% develops hepatitis or cirrhosis concomitantly or in succession. Several studies revealed that inter-individual as well as inter-ethnic genetic variation is one of the major factors that predispose to ALD. The role of genetic factors in ALD has long been sought for in ethnically distinct population groups. ALD is fast emerging as an important cause of chronic liver disease in India; even in populations such as "Bengalis" who were "culturally immune" earlier. While the genetic involvement in the pathogenesis of ALD is being sought for in different races, the complex pathophysiology of ALD as well as the knowledge of population level diversity of the relevant alcohol metabolizing and inflammatory pathways mandates the need for well designed studies of genetic factors in ethnically distinct population groups. An array of cytokines plays a critical role as mediators of injury, inflammation, fibrosis and cirrhosis in ALD. We, therefore, studied the association of polymorphisms in five relevant cytokine genes with "clinically significant" ALD in an ethnic "Bengali" population in Eastern India. Compared with "alcoholic" controls without liver disease (n=110), TNFα -238AA genotype, IL1β -511CC genotype, TGFβ1 -509CC genotype and IL10 -592AA genotype were significantly overrepresented in ALD patients (n=181; OR=2.4 and 95% CI 1.2-5.5, P(genotype)=0.042, P(allelic)=0.008; OR=2.7 and 95% CI 1.2-5.9, P(genotype)=0.018, P(allelic)=0.023; OR=4.7 and 95% CI 1.7-13.1, P(genotype)=0.003, P(allelic)=0.014; and OR=2.2 and 95% CI 1.1-4.8, P(genotype)=0.04, P(allelic)=0.039 respectively). Moreover a cumulative genetic risk analysis revealed a significant trend for developing ALD with an increase in the number of risk alleles on IL10 and TGFβ1 loci among alcoholics. The risk genotype of IL1β and TGFβ1 also influences the total bilirubin, albumin and alanine aminotransferase levels among alcoholic "Bengalis". The present study is the first case-control study from Eastern India that comprehensively identified polymorphic markers in TNFα, IL10, IL1β and TGFβ1 genes to be associated with ALD in the Bengali population, accentuating the significance of genetic factors in clinical expressions of ALD.

Cytotoxic T-lymphocyte associated antigen 4 polymorphisms and asthma risk: a meta-analysis

Background

A number of studies assessed the association of cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) gene polymorphisms with asthma in different populations. However, the results were contradictory. We performed a meta-analysis to examine the association between CTLA-4 polymorphisms and asthma susceptibility.

Methods

Pubmed, EMBASE, HuGE Navigator, and Wanfang Database were searched. Data were extracted independently by two reviewers. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

Seventeen studies involving 6378 cases and 8674 controls were included. Significant association between +49 A/G polymorphism and asthma was observed for AA vs. AG+GG (OR = 1.18, 95% CI 1.01–1.37, P = 0.04). There were no significant associations between −318 C/T, −1147 C/T, CT60 A/G, −1722 C/T, or rs926169 polymorphisms and asthma risk.

Conclusions

This meta-analysis suggested that the +49 A/G polymorphism in CTLA-4 was a risk factor for asthma.

Association of CTLA4 gene polymorphisms with susceptibility and pathology correlation to pulmonary tuberculosis in Southern Han Chinese

The cytotoxic T lymphocyte antigen-4 (CTLA4) gene is a key negative regulator of the T lymphocyte immune response. It has been found that CTLA4 +49A>G (rs231775), +6230G>A (rs3087243), and 11430G>A (rs11571319) polymorphisms are associated with susceptibility to many autoimmune diseases, and can down-regulate the inhibition of cellular immune response of CTLA4. Three SNPs in CTLA4 were genotyped by using the PCR and DNA sequencing methods in order to reveal the susceptibility and pathology correlation to pulmonary tuberculosis in Southern Han Chinese. We found that the frequency of CTLA4 +49AG genotype in the pulmonary tuberculosis patients (38.42%) was significantly lower than that of the healthy controls (49.77%), (P(cor)=0.038, OR 0.653, 95% CI 0.436-0.978). But, no associations were found between the other 2 SNPs (+6230G>A, 11430G>A) and tuberculosis (P>0.05). Haplotype analysis showed that the frequency of haplotype AGG in the healthy controls group (6.9%) was significantly higher than the pulmonary tuberculosis patients group (1.4%), (global P=0.005, P(cor)=0.0002, OR 0.183, 95% CI 0.072-0.468). In addition, haplotype GGA was found to be significantly related to tuberculosis with double lung lesion rather than single lung lesion (P(cor)=0.042). This study is the first to report that genetic variants in the CTLA4 gene can be associated with pulmonary tuberculosis in Southern Han Chinese, and CTLA4 +49AG genotype as well as haplotype AGG may reduce the risk of being infected with pulmonary tuberculosis. The GGA haplotype was related to tuberculosis with double lung lesion, which provides a new experimental basis to clarify the pathogenesis of pulmonary tuberculosis.

Cytotoxic T-lymphocyte associated antigen-4 gene polymorphisms and primary biliary cirrhosis: a systematic review

BACKGROUND AND AIM

The cytotoxic T-lymphocyte antigen 4 (CTLA4) is an inhibitory receptor expressed on activated and regulatory T lymphocytes. Polymorphisms could have remarkable effects on susceptibility to autoimmunity. However, the associations between CTLA-4 polymorphisms and primary biliary cirrhosis (PBC) remain ambiguous. The aim of this meta-analysis is to determine more precise estimations of the relationship.

METHODS

From literature retrieval from PubMed, Web of Science, Science Direct, and the Chinese National Knowledge Infrastructure (CNKI) Database, the publications on the associations between rs231775, rs3087243, rs5742909, rs231725 and rs11571317 polymorphisms of CTLA4 and PBC through June 2011 were collected. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated in fixed or random model, I(2) was calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects with Revman 5.1 and Stata 11.

RESULTS

Overall, a significantly increased risk was found for G versus A allele for rs231775 (OR = 1.28, 95% CI = 1.17-1.41). For rs3087243, a significant association was found for AA versus GG genotype (OR = 0.66; 95% CI = 0.55-0.80). When subgroup analysis by ethnicity was performed, the same association was only found in Caucasians. For rs231725, the OR values (95% CI) for GG versus AA, GA versus AA and G versus A allele were 0.52 (0.40-0.68), 0.74 (0.60-0.92) and 0.73 (0.61-0.88). No significant associations were found for other polymorphisms.

CONCLUSION

The G allele of rs231775 is a risk factor for PBC, while AA genotype of rs3087243 and GG, GA and G allele of rs231725 show negative associations with PBC.

Polymorphisms in the cytotoxic T-lymphocyte antigen 4 gene and acute rejection risk in transplant recipients

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene polymorphisms have been reported to influence the risk for acute rejection (AR) in transplant recipients. However, the results still remain controversial and ambiguous. The objective of the current study was to conduct a meta-analysis investigating the association between polymorphisms in the CTLA-4 gene and the risk of AR in transplant recipients. Electronic searches for all publications were conducted on associations between this variant and acute rejection in Medline and Embase databases through November 2011. Crude odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated to estimate the strength of the association. Three polymorphisms (+49 adenine/guanine [+49A/G], -318 cytosine/thymine [-318C/T], and the +6230G/A polymorphism [CT60]) in 18 case-control studies from ten articles were analyzed. This meta-analysis included 2,081 cases of transplant recipients in which 813 cases developed AR and 1,268 cases did not develop AR. The results indicated that there was no statistically significant association between the risk of AR and the +49A/G polymorphism or the -318C/T polymorphism (+49A/G: OR = 0.876, 95 % CI = 0.650-1.180 for GG vs. AA; OR = 1.121, 95 % CI = 0.911-1.379 for AG + GG vs. AA; -318C/T: OR = 0.397, 95 % CI = 0.138-1.143 for TT vs. CC; OR = 0.987, 95 %CI = 0.553-1.760 for CT + TT vs. CC). However, individuals who carried CT60 A allele might have a decreased risk of AR (AA vs. GG OR = 0.535, 95 % CI = 0.340-0.841, A vs. G OR = 0.759, 95 % CI = 0.612-0.914) in liver transplant recipients among Europeans, but because only two studies were included, so the result should be caution. In further stratified analyses for the +49A/G and the -318C/T polymorphisms, no obvious significant associations were found in subgroups of renal transplant recipients and Europeans, a reduced incidence of acute rejection was observed in liver transplant recipients that are homogenous for +49G (OR = 0.638, 95 % CI = 0.427-0.954 for GG vs. AA/AG), while this has not been observed in renal transplant recipients. Overall this meta-analysis suggests that +49A/G and the -318C/T polymorphisms in CTLA-4 may be not associated with the risk of rejection after organ transplantation, but CTLA +49A/G and +6230G/A polymorphisms may be associated with acute rejection after liver transplantation, not after renal transplantation. In future, more studies should be included to evaluate the association between +6230G/A polymorphism and AR risk.

PDCD1 polymorphism amplifies the predisposing effect conferred by CTLA4 polymorphism in chronic hepatitis B virus infection

Programmed cell death 1 (PDCD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) both negatively regulate the T-cell response in chronic hepatitis B virus (HBV) infection. This study determined genotypes of PDCD1 -606 G/A and +8669 G/A and CTLA4 -318 C/T and +49 A/G polymorphisms in 172 chronic HBV patients and 145 healthy controls and analyzed the interaction between these polymorphisms of the 2 genes. The results indicated that carriage of the PDCD1 +8669 A allele was increased in HBV patients carrying the CTLA4 -318 CC genotype and carrying the CTLA4 +49 AA genotype compared with controls carrying the CTLA4 -318 CC genotype (80.2% vs 64.8%, p = 0.002, odds ratio [OR] = 2.202, 95% confidence interval [95% CI] = 1.326-3.656) and carrying the CTLA4 +49 AA genotype (18.6% vs 9.7%, p = 0.024, OR = 2.139, 95% CI = 1.093-4.187), respectively. More obviously, carriage of the PDCD1 +8669 AA genotype was significantly increased in HBV patients carrying the CTLA4 +49 AA genotype compared with controls carrying the same CTLA4 +49 genotype (14.0% vs 3.4%, p = 0.001, OR = 4.541, 95% CI = 1.686-12.230). These results suggest that the PDCD1 +8669 A allele and AA genotype may amplify the predisposing effect conferred by the CTLA4 polymorphism through PDCD1 and CTLA4 gene interaction in chronic HBV infection.

A pilot study on cytotoxic T lymphocyte-4 gene polymorphisms in urinary schistosomiasis

Urinary schistosomiasis is caused by the digenetic trematode Schistosoma haematobium, characterized by accumulation of eggs in the genitourinary tract. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) can play an important role in parasitic infection due to its major role as a negative regulator of T-cell activation and proliferation. This study was performed in patients with schistosomiasis and healthy controls to analyze the allele and genotype frequencies of four CTLA-4 gene polymorphisms. The CTLA-4 gene was amplified using Taqman real-time polymerase chain reaction, and allele and genotypes of 49 patients with schistosomiasis were analyzed using allelic discrimination analysis followed by subsequent direct sequencing. The results were compared with healthy control subjects. The frequencies of CTLA-4 rs733618 A allele at position -1722 (p=0.001), rs11571316 C allele at position -1577 (p<0.001), and rs231775 A allele at position +49 (p=0.002) in the patient group were significantly higher than the control group. The rs733618 AA genotype (p=0.001), rs11571316 CC genotype (p<0.001), and rs231775 AA genotype (p=0.007) were also significantly overrepresented. Meanwhile, rs733618 AG genotype (p=0.001), rs11571316 CT genotype (p=0.02), and rs231775 GG genotype (p=0.029) were significantly decreased in the patients with schistosomiasis, as compared with the controls. No significant difference was observed in both allele and genotype of rs16841252. The results of this study suggest that the rs733618, rs11571316, and rs231775 polymorphisms in the CTLA-4 gene may influence susceptibility to schistosomiasis infection in the Gabonese children.

Genetic polymorphisms and surface expression of CTLA-4 and PD-1 on T cells of silica-exposed workers

Exposure to silica dust has been examined as a possible risk factor for autoimmune diseases, including scleroderma, rheumatoid arthritis and systemic lupus erythematosus. Since CTLA-4 [CD152] and PD-1 [CD279] are important for the maintenance of peripheral tolerance by regulating T cell responsiveness, we evaluated the expression of these molecules on the surface of CD4 and CD8 T cells, as well as single nucleotide polymorphisms (SNP) in CTLA-4 and PDCD1 genes, of 70 silica-exposed workers and 30 non-exposed, age-, ethnically- and sex-matched controls. Expression of CTLA-4 was significantly (P<0.05) reduced in CD4 T cells of exposed individuals [median=0.1% and interquartile range, IQR 0.0-0.1% (exposed), median=0.20%, IQR 0.0-0.4% (control)]. Also the expression of PD-1 was significantly (P<0.0001) reduced in both CD4 [median=0.9%, IQR 0.4-2.3% (exposed), median=5.7%, IQR 1.4-13.3% (control)] and CD8 T cells [median=0.9%, IQR 0.3-1.9% (exposed), median=5.0%, IQR 3.4-8.9% (control)]. The study of polymorphisms demonstrated a lower frequency of the A allele in the analysis of the PD1.3 SNP in the exposed group, which might be associated with the lower expression of PD-1 on the surface of CD4 T cells. Our findings provide evidence for the association of silica exposure and the maintenance of self-tolerance, i.e., the susceptibility to autoimmune disorders.

Allelic combinations of immune-response genes associated with glatiramer acetate treatment response in Russian multiple sclerosis patients

BACKGROUND

Glatiramer acetate (GA) is widely used as a first-line disease-modifying treatment for multiple sclerosis (MS). However, a significant proportion of MS patient appears to experience modest benefit from GA-treatment. Genetic variants affecting the clinical response to GA are believed to be relevant as biomarkers of GA-treatment efficiency.

PATIENTS & METHODS

Nine polymorphisms in candidate genes were analyzed as possible determinants of GA response in 285 Russian MS patients. Special attention was given to identification of response-associated allelic combinations by means of the APSampler algorithm.

RESULTS

No significant associations were found for individual polymorphisms. Alleles DRB1*15, TGFB1*T, CCR5*d and IFNAR1*G were the components of the combinations, of which carriage was significantly higher in nonresponders than in responders. Carriers of the most significant combinations: DRB1*15 + TGFB1*T + CCR5*d + IFNAR1*G and DRB1*15 + TGFB1*T + CCR5*d (permutation p-values: 0.0056 and 0.013, respectively) had a 14 to 15-times increased risk of ineffective response to GA therapy.

DISCUSSION

The results suggest that the influence of immune-response genes on GA-induced response has a polygenic nature. The data are interpreted as evidence of additive and epistatic influences of the genes on GA efficiency for MS treatment.

Dysregulated expression of both the costimulatory CD28 and inhibitory CTLA-4 molecules in PB T cells of advanced cervical cancer patients suggests systemic immunosuppression related to disease progression

Cervical cancer (CC) occurs more frequently in women who are immunosuppressed, suggesting that both local and systemic immune abnormalities may be involved in the evolution of the disease. Costimulatory CD28 and inhibitory CTLA-4 molecules expressed in T cells play a key role in the balanced immune responses. There has been demonstrated a relation between CD28, CTLA-4, and IFN genes in susceptibility to CC, suggesting their importance in CC development. Therefore, we assessed the pattern of CD28 and CTLA-4 expression in T cells from PB of CC patients with advanced CC (stages III and IV according to FIGO) compared to controls. We also examined the ability of PBMCs to secrete IFN-gamma. We found lower frequencies of freshly isolated and ex vivo stimulated CD4 + CD28+ and CD8 + CD28+ T cells in CC patients than in controls. Loss of CD28 expression was more pronounced in the CD8+ T subset. Markedly increased proportions of CTLA-4+ T cells in CC patients before and after culture compared to controls were also observed. In addition, patients’ T cells exhibited abnormal kinetics of surface CTLA-4 expression, with the peak at 24 h of stimulation, which was in contrast to corresponding normal T cells, revealing maximum CTLA-4 expression at 72 h of stimulation. Of note, markedly higher IFN-gamma concentrations were shown in supernatants of stimulated PBMCs from CC patients. Conclusions: Our report shows the dysregulated CD28 and CTLA-4 expression in PB T cells of CC patients, which may lead to impaired function of these lymphocytes and systemic immunosuppression related to disease progression.

Validation of genetic sequence variants as prognostic factors in early-stage head and neck squamous cell cancer survival

PURPOSE

From the published literature, we identified 23 germ line sequence variants in 17 genes from hypothesis-generating studies that were associated with prognosis of head and neck cancer, including sequence variants of DNA repair (ERCC1, ERCC4, ERCC5, MSH2, XPA, ERCC2, XRCC1, XRCC3), DNA methylation (DNMT3B), cell cycle and proliferation (CCND1, TP53), xenobiotic metabolism (GSTM1, GSTT1, CYP2D6), metastatic -potential (MMP3), immunologic (CTLA4), and growth factor pathways (FGFR4). The purpose of this study was to validate the role of these 23 sequence variants for overall (OS) and disease-free survival (DFS) in a large, comprehensive, well-annotated data set of patients with head and neck cancer.

EXPERIMENTAL DESIGN

We genotyped these sequence variants in 531 patients with stage I and II radiation-treated head and neck cancer (originally recruited for an alpha-tocopherol/beta-carotene placebo-controlled secondary prevention study), and analyzed using Cox proportional hazards models, stratified by treatment arm, adjusting for clinical prognostic factors.

RESULTS

Two OS associations were statistically significant for each variant allele when compared with the wild-type: CTLA4: A49G [rs231775; adjusted HR (aHR), 1.32 (1.1-1.6); P = 0.01] and XRCC1: Arg339Gln [rs25487; aHR, 1.28 (1.05-1.57); P = 0.02]. Both of these sequence variants had significant results in the opposite direction as prior published literature. Two DFS associations were of borderline significance in the same direction as prior literature: ERCC2: Lys751Gln [rs13181; aHR, 0.80 (0.6-1.0); P = 0.05] and TP53: Arg72Pro [rs1042522; aHR, 1.28 (1.0-1.6); P = 0.03], comparing number of variant alleles with reference of zero variants.

CONCLUSIONS

None of the prognostic sequence variants previously published was validated for OS in our patients with early-stage radiation-treated head and neck cancer, though rs1381and rs1042522 had borderline significant association with DFS.

CTLA-4 exon 1 +49 polymorphism alone and in a haplotype with -318 promoter polymorphism may confer susceptibility to chronic HBV infection in Chinese Han patients

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) plays a pivotal role in regulating T cell activation, which is believably critical for the outcome of hepatitis B virus (HBV) infection. The expression and function of CTLA-4 may be affected by gene polymorphisms. This study investigated the influence of CTLA-4 polymorphisms on disease susceptibility in Chinese Han patients with chronic HBV infection. CTLA-4 +49A/G and -318C/T polymorphisms were evaluated by DNA amplification with polymerase chain reaction followed by the restriction fragment length polymorphism analysis. The patients with chronic HBV infection had higher frequencies of genotype AA and allele A of CTLA-4 +49A/G polymorphism. The haplotype +49A-318C was significantly over-represented (P < 0.001) and haplotype +49G-318C under-represented (P = 0.006) in the patients. The +49GG genotype was more frequent (P = 0.009) and +49A allele was less frequent in patients with lower ALT levels (P = 0.012) in HBeAg positive chronic hepatitis B. It is indicated that CTLA-4 +49A/G polymorphism alone and in a haplotype with -318C allele may confer susceptibility to chronic HBV infection in Chinese Han patients.

Associations between cytotoxic T lymphocyte-associated antigen-4 polymorphisms and serum tumor necrosis factor-α and interferon-γ levels in patients with chronic hepatitis B virus infection

BACKGROUND

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) polymorphism, which may affect host immune response including cytokines production, is thought to be associated with hepatitis B virus (HBV) infection. This study investigated the associations between CTLA4 polymorphism and serum tumor necrosis factor (TNF)-α and interferon (IFN)-γ levels in patients with chronic HBV infection.

METHODS

CTLA4 promoter -318C/T and exon 1 +49A/G polymorphisms and serum TNF-α and IFN-γ levels were determined in 172 patients with chronic HBV infection and 145 healthy controls.

RESULTS

The genotype of CTLA4 -318C/T polymorphism had no association to TNF-α and IFN-γ levels. Serum levels of TNF-α and IFN-γ in chronic HBV patients with +49GG genotype were lower than those with +49AG genotype (p = 0.030 and p = 0.042, respectively), and haplotypes -318C + 49A and -318C + 49G seemed to have no significant effects on TNF-α and IFN-γ levels.

CONCLUSIONS

CTLA4 +49GG genotype was associated to lower TNF-α and IFN-γ levels in patients with chronic HBV infection but this association was diminished by haplotype formation with -318C/T alleles, indicating that the influence of CTLA4 -318C/T and +49A/G polymorphisms on the susceptibility and disease progress of chronic HBV infection may not be effectuated by affecting TNF-α and IFN-γ secretion.

Do proteolytic antibodies complete the panoply of the autoimmune response in acquired haemophilia A?

Acquired haemophilia A (AHA) is a rare bleeding disorder characterized by the sudden generation of autoantibodies against factor VIII (FVIII) in individuals with no previous history of abnormal haemostasis. Understanding the pathogenesis of this disease has been hampered by the rarity of the patients and the difficulty in obtaining biological material from untreated patients. Still, progress has been made recently in understanding the pathogenesis of AHA. In particular, the importance of CD4(+) T cells in AHA development has been documented and the epitopes targeted by T cells on FVIII have been delineated. Accordingly, a polymorphism in the cytotoxic T-lymphocyte-associated protein 4 gene (CTLA4), known to participate in the regulation of CD4(+) T-cell responses, and a preferential usage of certain human leukocyte antigen class II haplotypes, have been associated with the disease. Recent findings have documented the presence of immunoglobulin G (IgG) with proteolytic activity against FVIII and factor IX (FIX) in patients with AHA. While FVIII-hydrolysing IgG has been shown to inactivate FVIII, FIX-hydrolysing IgG from AHA patients activate FIX in vitro. Here, we describe the latest findings on the immuno-pathogenesis of AHA, with a special focus on the potential role played by antibodies endowed with proteolytic properties.

CTLA-4 +49A>G polymorphism is associated with advanced non-small cell lung cancer prognosis

BACKGROUND

Cytotoxic T lymphocyte antigen 4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by downregulating T cell activation. The most studied +49A>G polymorphism of the CTLA-4 gene has been associated with several autoimmune diseases. However, little is known about the association between this functional polymorphism of CTLA-4 and cancer prognosis.

OBJECTIVE

To investigate the association between CTLA-4 +49A>G polymorphism and prognosis of advanced non-small cell lung cancer (NSCLC) patients in a Chinese population.

METHODS

The CTLA-4 +49A>G polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism in 338 advanced NSCLC patients.

RESULTS

The frequencies of CTLA-4 +49 GG, GA and AA in advanced NSCLC patients were 44.4%, 42.0% and 13.6%, respectively. No significant association was observed between CTLA-4 +49A>G polymorphism and clinicopathologic features of advanced NSCLC including gender, histopathological type, clinical stage and tumor markers. Patients with the AA genotype had a survival time of 9.8 months, significantly shorter than those with the GG genotype (12.5 months) or the GA genotype (12.0 months) (p < 0.001; log-rank test). Multivariate Cox analysis further revealed that the CTLA-4 +49AA genotype is an independent adverse prognostic indicator for NSCLC patients.

CONCLUSION

Our data suggest that the polymorphism of CTLA-4 +49A>G is a prognostic predictor for advanced NSCLC.

Variations in suppressor molecule ctla-4 gene are related to susceptibility to multiple myeloma in a polish population

Various phenotype and functional T-cell abnormalities are observed in multiple myeloma (MM) patients. The aim of this study was to investigate the association between polymorphisms in the gene encoding cytotoxic T-lymphocyte antigen-4 (CTLA-4), a negative regulator of the T-lymphocyte immune response and susceptibility to multiple myeloma in a Polish population. Two hundred MM patients and 380 healthy subjects were genotyped for the following polymorphisms: CTLA-4c.49A>G, CTLA-4g.319C>T, CTLA-4g.*642AT(8_33), CT60 (CTLA-4g.*6230G>A), Jo31 (CTLA-4g.*10223G>T). Our study is the largest and most comprehensive evaluation to date of the association between genetic polymorphisms in the CTLA-4 molecule and multiple myeloma. It was found that CTLA-4c.49A>G[G], CT60[G], and Jo31[G] alleles were more frequently observed in MM patients than in controls (0.50 vs. 0.44, p = 0.03, 0.65 vs. 0.58, p = 0.04, and 0.63 vs. 0.57, p = 0.03, respectively). Moreover, the haplotype CTLA-4c.49A>G[G], CTLA-4g.319C>T[C], CTLA-4g.*642AT(8_33) [8], CT60[G], Jo31[G] including all susceptibility alleles increases the risk of MM about fourfold (OR: 3.79, 95%CI: 2.08–6.89, p = 0.00001). These findings indicate that genetic variations in the CTLA-4 gene play role in susceptibility to multiple myeloma and warrant further investigation through replication studies.

Association of CTLA-4 (+49A/G) gene polymorphism with type 1 diabetes mellitus in Egyptian children

OBJECTIVE

To investigate the distribution of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) (+49 A/G) gene variants and the association of these variants with the clinical and laboratory findings in Egyptian children with Type-1 Diabetes (T1D).

METHODS

A case control study was done for 104 Egyptian children with T1D and 78 age and sex matched healthy control. CTLA-4 (+49 A/G) gene polymorphism typing was done by PCR amplification followed by restriction fragment length polymorphism (RFLP) method.

RESULTS

CTLA-4 G allele and GG homozygous genotype were significantly increased in T1D patients than in control group (P = 0.047, P = 0.048 respectively). There is no statistical difference between patient with optimal diabetic control (HbA1c < 8.5) and poor control (HbA1c ≥ 8.5) as regarding the CTLA-4 gene variant. The CTLA-4 GG genotype was statistically associated with younger age of patients (P = 0.027) and younger age of presentation (P = 0.036). Insignificant association was found between CTLA-4 alleles / genotypes and diabetic complications.

CONCLUSION

The CTLA-4 +49 GG homozygous genotype is associated with T1D in Egyptian children especially with younger age of onset and in younger patients, and not associated with grades of diabetic control or diabetic complication.

Cytotoxic T-lymphocyte antigen-4 polymorphisms and susceptibility to osteosarcoma

Despite the knowledge of many genetic alterations present in osteosarcoma, the complexity of this disease precludes placing its biology into a simple conceptual framework. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) plays important roles in downregulating T-cell activation, thereby attenuating anti-tumor responses and increasing cancer susceptibility. Polymorphisms in the CTLA-4 gene are associated with different autoimmune diseases and cancers. The current study evaluated the association of four CTLA-4 gene mutations, -1661A/G (rs4553808), -318C/T (rs5742909), +49G/A (rs231775), and CT60A/G (rs3087243), with osteosarcoma in the Chinese population. CTLA-4 polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism in 267 osteosarcoma patients and 282 age-matched healthy controls. Results showed that the CTLA-4 gene +49 AA genotype, +49 A allele, and GTAG haplotype were significantly more frequent in osteosarcoma patients than in controls (odds ratio [OR] 2.20, 95% confidence interval [CI] 1.23-2.95, p = 0.007; OR 1.32, 95% CI 1.03-1.69, p = 0.029, and OR = 1.47, 95% CI 1.03-2.09, p = 0.033, respectively). The CTLA-4 +49G/A polymorphism and GTAG haplotype are associated with increased risk of osteosarcoma.

CTLA-4, CD28, and ICOS gene polymorphism associations with non-small-cell lung cancer

Polymorphisms in genes encoding CD28, ICOS, and CTLA-4 were demonstrated to be associated with susceptibility to malignancies. To the best of our knowledge, no study on this association has been performed in a Caucasian population for non-small-cell lung cancer (NSCLC). In the present work, we investigated the polymorphisms CTLA-4c.49A>G (rs231775), CTLA-4g.319C>T (rs5742909), CTLA-4g.*642AT(8_33), CTLA-4g.*6230G>A (CT60) (rs3087243), CTLA-4g.*10223G>T (Jo31) (rs11571302), CD28c.17+3T>C (rs3116496), and ICOSc.1554+4GT(8_15) in 208 NSCLC patients and 326 controls. The distributions of the allele and genotype were similar in both groups for CTLA-4, CD28, and ICOS gene polymorphisms. However, we noted a tendency toward overrepresentation of individuals possessing the CTLA-4c.49A>G[A] allele in NSCLC patients compared with controls (0.84 vs 0.79, p = 0.09). The association became significant compared with controls in women for the CTLA-4c.49A>G[A] allele and CTLA-4c.49A>G[AA] genotype (0.67 vs 0.54, p = 0.01, and 0.47 vs 0.30, p = 0.02; respectively). Moreover, the constellation of alleles CTLA-4c.49A>G[A]/CT60[G]/CD28c.17+3T>C[T]/ICOSc.1554+4GT(8_15)[>10] increased the risk of NSCLC about 2-fold (p = 0.002). The same constellation of alleles combined with smoking, CTLA-4g.319C>T[T], and ICOSc.1554+4GT(8_15)[>10] was associated with a decreased overall survival rate. In conclusion, the constellation of specific alleles in CTLA-4, CD28, and ICOS genes contributes to the susceptibility and clinical course of NSCLC.

CD86 + 1057G/A polymorphism and susceptibility to osteosarcoma

CD86 (B7-2), one of the costimulatory molecules on antigen-presenting cells, plays essential roles not only in autoimmunity and transplantation but also in tumor immunity. CD86 + 1057G/A polymorphism (rs1129055) is associated with various diseases. The objective of this study was to investigate the association between CD86  + 1057G/A polymorphism and susceptibility to osteosarcoma in a Chinese population. The CD86 + 1057G/A mutation was detected by polymerase chain reaction-restriction fragment length polymorphism in 205 osteosarcoma cases and 216 age-matched healthy controls. Frequencies of CD86 + 1057 AA genotype and +1057 A allele were significantly increased in osteosarcoma patients than in healthy controls (odds ratio = 2.18, 95% confidence interval, 1.21-3.93, p = 0.008; and odds ratio = 1.43, 95% confidence interval, 1.08-1.88, p = 0.011). Our data suggest that the +1057G/A polymorphism of the CD86 gene is associated with increased susceptibility to osteosarcoma.

Association of T-cell regulatory gene polymorphisms with oral squamous cell carcinoma

Costimulatory molecules have complementary effects on T-cell activation and their balance may control the development of oral cancer. The aim of this study was to determine the relevance of cytotoxic T-lymphocyte antigen 4 (CTLA-4), CD28 and inducible costimulator (ICOS) polymorphisms in oral squamous cell carcinoma (OSCC). Genotyping for CTLA-4 (-1661 A/G and +49 A/G), CD28 (0 C/G and +3160 G/T) and ICOS (+637 A/C and +1599 C/T) was performed in the 83 patients with OSCC, compared to the 40 unrelated healthy volunteers as controls. The genotype CTLA-4 -1661 was significantly different between the patient group and the control group. The allele CTLA-4 -1661 G was significantly found more frequent in patients with OSCC (p=0.001). In bivariate analysis, noticeable differences between OSCC and controls were seen. The combinations CTLA-4 -1661 G/G and CTLA-4 +49 A/G, ICOS +1559 C/T and ICOS +1559 C/C each with CTLA-4 -1661 G/G, ICOS +637 C/C and ICOS +637 A/C each with CTLA-4 -1661, CTLA-4 -1661 A/G and ICOS +637 C/C, CD28 +3160 G/T and CTLA-4 -1661 A/A and CD28 +3160 G/T and CTLA-4 -1661 A/G were seen in the patient group only. Especially the polymorphisms of the CTLA-4 -1661-genotype - alone and in combination with other T cell regulator polymorphisms - seem to be possible predisposing factors for OSCC. Therefore, they might be future targets for a primary prophylaxis or an individualised therapy.

Cytotoxic T-lymphocyte antigen-4 +49G/A polymorphism is associated with increased risk of osteosarcoma

BACKGROUND

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a potent immunoregulatory molecule that suppresses anti-tumor response by down-regulating T-cell activation. CTLA-4 gene +49G/A polymorphism (rs231775) has been reported to be associated with various cancers.

OBJECTIVE

The objective of this study is to investigate the association between CTLA-4 gene +49G/A polymorphism and the susceptibility to osteosarcoma in the Chinese population.

METHODS

The CTLA-4 variant +49G/A was detected by polymerase chain reaction-restriction fragment length polymorphism in 205 osteosarcoma cases and 216 age-matched healthy controls. Data were analyzed using the Chi-square test.

RESULTS

Frequencies of the CTLA-4 +49AA genotype and the +49A allele were significantly increased in patients with osteosarcoma compared to healthy controls (OR 2.27, p=0.010, and OR 1.41, p=0.015).

CONCLUSIONS

Our data suggest that the +49G/A polymorphism of CTLA-4 gene is associated with increased susceptibility to osteosarcoma.

Polymorphisms in the cytotoxic T-lymphocyte antigen 4 gene and cancer risk: a meta-analysis

BACKGROUND

Polymorphisms in the cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene have been implicated in susceptibility to cancer, but the many published studies have reported inconclusive results. The objective of the current study was to conduct a meta-analysis investigating the association between polymorphisms in the CTLA-4 gene and the risk of cancer.

METHODS

The PubMed and EMBASE databases were searched for all articles published up to September 19, 2010 that addressed cancer and polymorphisms, variants, or mutations of CTLA-4. A statistical analysis was performed using proprietary statistical software.

RESULTS

Three polymorphisms (+49 adenine/guanine [+49A/G], -318 cytosine/thymine [-318C/T], and the +6230G/A polymorphism [CT60]) in 48 case-control studies from 27 articles were analyzed. The results indicated that individuals who carried the +49 G allele (AG + GG) had a 16% decreased risk of cancer compared with homozygotes (+49AA; odds ratio [OR], 0.84; 95% confidence interval [CI], 0.74-0.95). However, there was no significant association between the risk of cancer and the -318C/T polymorphism or the CT60 polymorphism (-318C/T: OR, 1.23; 95% CI, 0.99-1.54 for TT + TC vs CC; CT60: OR, 1.02; 95% CI, 0.80-1.29 for AA + AG vs GG). In further stratified analyses for the +49A/G and -318C/T polymorphisms, the decreased risk of cancer remained in subgroups of Europeans, patients with breast cancer, and patients with lung cancer for the +49A/G polymorphism; whereas an increased risk of cancer was observed among Europeans for the -318C/T polymorphism.

CONCLUSIONS

Results from the current meta-analysis suggested that the +49A/G and -318C/T polymorphisms in CTLA-4 are risk factors for cancer. To further evaluate gene-gene and gene-environment interactions between CTLA-4 polymorphisms and the risk of cancer, more studies with larger groups of patients will be required.

Investigation of cytotoxic T-lymphocyte-associated protein 4 gene polymorphisms in symptomatic gallstone disease

Gallstone disease (GSD), which is increasingly prevalent in Taiwan, develops through a complex process involving genetic, environmental, and immune factors. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) limits T-cell proliferation. The present study looked for associations between symptomatic GSD and polymorphisms of the CTLA4 gene. For this case-control cross-sectional study among Taiwanese, 275 patients with symptomatic GSD and 852 controls were enrolled. Genotyping of CTLA4-318 C/T, +49 A/G, and CT60 A/G single nucleotide polymorphisms (SNPs) was performed by polymerase chain reaction-restriction fragment length polymorphism. The genotype, allele, carrier, and haplotype frequencies were calculated by direct counting or with Haploview 4.1 software. Genotype, allele, carrier, and haplotype frequencies of the CTLA4 SNPs studied were equally distributed in symptomatic GSD patients and controls. No significant associations between symptomatic GSD and these 3 SNPs were observed. Our data suggest that CTLA4-318 C/T, +49 A/G, and CT60 A/G SNPs do not confer increased susceptibility to symptomatic GSD.

Cytotoxic T-lymphocyte antigen 4 haplotype correlates with relapse and survival after allogeneic hematopoietic SCT

CTLA-4 is a negative regulator of activated T cells and the association of CTLA-4 polymorphisms with autoimmune diseases and transplant outcome has been reported. We evaluated the effect of donor CTLA-4 polymorphisms on outcome after allogeneic hematopoietic SCT (HSCT). We analyzed 147 Japanese HLA-matched sibling recipients and their donors who had undergone allogeneic HSCT. Genotyping of three single-nucleotide polymorphisms in CTLA-4 (-318, +49, CT60) was performed using TaqMan-PCR. According to the international HapMap database, only these three CTLA-4 haplotypes, classified as C-G-G, C-A-A and T-A-G, are present in the Japanese population. In this study, percentage expression of the C-G-G, C-A-A and T-A-G haplotypes was 59.5, 30.6 and 9.9%, respectively. Recipients of the C-A-A haplotype donor showed a significantly lower risk of relapse (HR: 0.54, 95% CI: 0.30-0.97, P=0.040) and a trend toward higher OS (HR: 0.61, 95% CI: 0.36-1.0, P=0.054) than did recipients of a donor without the C-A-A haplotype. The presence or absence of the C-A-A haplotype did not affect GVHD or non-relapse mortality. As the presence of the C-A-A haplotype reduced relapse risk and improved survival after allogeneic HSCT, this CTLA-4 haplotype may provide useful information for donor selection.