Cytotoxic T lymphocyte antigen-4 gene (CTLA4) polymorphisms in Japanese patients with psoriasis vulgaris

The Role of Co-Signaling Molecules in Psoriasis and Their Implications for Targeted Treatment

Psoriasis is a chronic, systemic immune-mediated inflammatory disease manifesting in the skin, joint or both. Co-signaling molecules are essential for determining the magnitude of the T cell response to the antigen. According to the function of co-signaling molecules, they can be divided into co-stimulatory molecules and co-inhibitory molecules. The role of co-signaling molecules in psoriasis is recognized, mainly including the co-stimulatory molecules CD28, CD40, OX40, CD27, DR3, LFA-1, and LFA-3 and the co-inhibitory molecules CTLA-4, PD-1, and TIM-3. They impact the pathological process of psoriasis by modulating the immune strength of T cells, regulating the production of cytokines or the differentiation of Tregs. In recent years, immunotherapies targeting co-signaling molecules have made significant progress and shown broad application prospects in psoriasis. This review aims to outline the possible role of co-signaling molecules in the pathogenesis of psoriasis and their potential application for the treatment of psoriasis.

Association of Cytotoxic T Lymphocyte Antigen-4 Gene Polymorphisms with Psoriasis Vulgaris: A Case-Control Study in Turkish Population

Psoriasis is a common, chronic, and autoimmune skin disease in which dysregulation of immune cells, particularly T cells, is thought to play an important role in the pathogenesis. Cytotoxic T lymphocyte antigen-4 (CTLA-4) expressed only on activated T cells is an immunoregulatory molecule and plays a role in the pathogenesis of autoimmune disorders. We aimed to determine whether CTLA-4 gene polymorphisms are associated with development and/or clinical features of psoriasis vulgaris (Pv). Genotyping of SNPs (−318C>T, +49A>G, and CT60A>G) in CTLA-4 gene was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 103 Pv patients and 102 controls. No statistically significant associations were detected in any of the investigated genetic models for the −318C>T polymorphism. The genotype distributions of +49A>G and CT60A>G were associated with Pv development. In haplotype analysis, while frequency of CAA haplotype was significantly higher in the control group, frequencies of CGG and CAG haplotype were significantly higher among the patients. However, all of CTLA-4 polymorphisms and haplotypes do not have an effect on severity and onset age of Pv. In conclusion, the +49A>G and CT60A>G polymorphisms may be risk factors for Pv development. Furthermore, CGG and CAG haplotypes may contribute to Pv development, while CAA haplotype may be protective against Pv.

The role of regulatory T cells and genes involved in their differentiation in pathogenesis of selected inflammatory and neoplastic skin diseases. Part III: Polymorphisms of genes involved in Tregs' activation and function

Regulatory T cells (Tregs) represent a cell type that promotes immune tolerance to autologous components and maintains immune system homeostasis. The abnormal function of Tregs is relevant to the pathogenesis of several skin diseases like psoriasis, atopic dermatitis, systemic lupus erythematosus, cutaneous T-cell lymphomas, and skin cancer and is also important in rheumatoid arthritis, diabetes and other autoimmune diseases. In this review, we will summarize the role of mutations and/or polymorphisms of genes involved in Tregs development, and functions in the pathogenesis of selected skin diseases.

Lack of association between cytotoxic T-lymphocyte antigen-4+49A/G polymorphism and psoriasis and vitiligo: A meta-analysis of case-control studies

BACKGROUND

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a critical negative regulator of T-cell activation and proliferation. Several studies have assessed the association between CTLA-4+49A/G polymorphism and psoriasis and vitiligo, but the results are inconsistent.

AIMS

This study was conducted to examine the association between CTLA-4+49A/G polymorphism and psoriasis and vitiligo susceptibility.

METHODS

The PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched according to predefined criteria for all relevant studies published prior to July 3, 2014. Odds ratios (ORs) with 95% confidence intervals (CIs), and heterogeneity and publication bias tests were performed to estimate the strength of the association.

RESULTS

Fourteen studies comprising six on psoriasis (700 cases, 781 controls) and eight on vitiligo (1514 cases, 2049 controls) were included. Overall, no significant association was detected between CTLA-4+49A/G polymorphism and psoriasis. There was still no significant relationship when the studies were limited to ethnicity (Asian and Caucasian), HWE or heterogeneity, except the limitation to heterogeneity in the dominant (OR=0.69, 95% CI=0.51-0.93, I(2)=0.0%) and additive (OR=0.69, 95% CI=0.48-0.98, I(2)=0.0%) models, and the limitation to both heterogeneity and HWE in the dominant model (OR=0.68, 95% CI=0.48-0.98, I(2)=0.0%). Both overall and subgroup analyses based on ethnicity, genotype frequencies, and heterogeneity also failed to demonstrate an association between CTLA-4+49A/G polymorphism and vitiligo.

CONCLUSION

CTLA-4+49A/G polymorphism may not contribute to psoriasis and vitiligo susceptibility, but further well-designed studies with large sample size are warranted to confirm this conclusion.

Cytotoxic T lymphocyte antigen-4 promoter -658CT gene polymorphism is associated with ulcerative colitis in Chinese patients

BACKGROUND AND AIM

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a role in the downregulation of T cell activation. The present study aimed to examine an association between the CTLA-4 gene polymorphisms and ulcerative colitis (UC) in the Han Chinese in central China.

MATERIALS AND METHODS

One hundred seventeen patients with UC and 246 healthy controls were genotyped for CTLA-4 gene -658CT in the promoter and CT61 at the 3' untranslated region using a method of polymerase chain reaction-based restriction fragment length polymorphism and single-strand conformation polymorphism, respectively. The distributions of the genotypes and the allele frequencies of the CTLA-4 gene in UC patients and healthy controls were compared by chi-square test.

RESULTS

The frequency of the T/T+C/T genotype at the CTLA-4 gene -658CT in the promoter was significantly higher in UC patients than in healthy controls (26.5% vs 15.4%, chi (2) = 6.287, P = 0.015, OR = 1.973, 95%CI = 1.153-3.375). The frequency of the T allele at the CTLA-4 -658CT was also significantly higher in UC patients than in the controls (13.2% vs 8.1%, chi (2) = 4.707, P = 0.033, OR = 1.726, 95%CI = 1.049-2.838). The frequency of the T/T genotype at the -658 locus was highly associated with extensive colitis in UC patients (P = 0.037, OR = 3.955, 95%CI = 1.068-14.647). The frequency of the T allele at the -658 locus was highly associated with extensive colitis in UC patients (P = 0.0067, OR = 3.05, 95%CI = 1.320-7.048).

CONCLUSION

The T allele of CTLA-4 -658 polymorphism in the promoter of CTLA-4 gene was highly associated with UC in the Han Chinese in central China.

Distribution of the CTLA-4 single nucleotide polymorphisms CT60G>A and +49A>G in psoriasis vulgaris patients and control individuals from a Polish Caucasian population

Psoriasis vulgaris is a multifactorial disease with an autoimmune component, and T lymphocytes seem to be involved in its aetiology. CTLA-4 molecule is an important down-regulator of T-lymphocyte activation, and several polymorphisms of the CTLA-4 gene were found to be associated with some autoimmune diseases. We examined whether single nucleotide polymorphisms (SNPs) in the CTLA-4 gene, CT60A>G and +49A>G, are associated with psoriasis vulgaris. Alleles of these two SNPs were determined by the polymerase chain reaction-restriction fragment length polymorphism method. Both the CT60G>A and the +49A>G alleles and genotypes were distributed similarly in patients and controls. Although the two SNPs studied here in Poles were in linkage disequilibrium, all four possible two-locus haplotypes were found, one of them rare; of the remaining three, the haplotype +49G, CT60G was significantly (P = 0.019, OR = 0.58, 95%CI = 0.37-0.91) less frequent in the patient group with disease onset between the ages of 21 and 40 years than in controls and the other patient groups, whereas the frequencies of the other haplotypes were similar in patients and controls. To the authors' knowledge, this is the first study on CTLA-4 CT60 allele frequencies in psoriasis.

CTLA-4 gene polymorphisms and natural soluble CTLA-4 protein in psoriasis vulgaris

CTLA-4 molecule is an important inhibitor of T-lymphocyte activation. Several single nucleotide polymorphisms (SNPs) in the CTLA-4 gene were found, and their associations with many human diseases were described. So far, however, such studies have not been performed in psoriasis vulgaris in Caucasoids. Therefore, we examined the distribution of three CTLA-4 SNPs: -1147C/T, -318C/T and +49 A/G in 116 patients with psoriasis vulgaris and 123 healthy blood donors using the polymerase chain reaction-restriction fragment length polymorphism method. For all three SNPs, the frequencies of alleles, genotypes and three-point haplotypes were very similar in patients and controls, suggesting no contribution of these genetic variants to psoriasis.

Analysis of cytotoxic T lymphocyte associated antigen 4 gene polymorphisms in patients with ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is a multifactorial disease associated with dysregulated immunity. Recently, cytotoxic T lymphocyte associated antigen 4 (CTLA-4) gene polymorphisms have been reported in association with several autoimmune diseases in several populations. In the present study, the possible implication of the CTLA-4 gene as a risk factor for UC in the Iranian population was investigated.

METHODS

One hundred UC patients and 100 healthy subjects were studied. CTLA-4 exon 1 position 49 (A/G: codon 17: Thr/Ala) polymorphisms were investigated by polymerase chain reaction single strand confirmation polymorphism method. Four of the patients and one of the healthy controls were excluded from the study because of incomplete DNA extraction.

RESULTS

The allele frequencies of A and G in 96 patients (A: 66.1%; G: 33.9%) were not significantly different from the 99 control subjects (A: 63.1%; G: 36.9%, P > 0.05). No significant differences in the distribution of genotype frequencies were observed between A + 49G gene polymorphisms and UC in the Iranian population (P > 0.05).

CONCLUSION

CTLA-4 polymorphism is not associated with UC in the Iranian population.