CTLA-4在重症肌无力患者中的表达及其多态性导致的无效转录研究

目的 探讨重症肌无力(MG)患者细胞毒性T淋巴细胞相关抗原-4(CTLA-4)的表达状况及由CTLA-4基因启动区多态性导致的不同遗传易感性机制。方法 ELISA法测定MG患者血清中sCTLA-4的水平；限制性片段长度多态性分析用于检测启动区-1772、-1661位点的多态性；转录因子NF-1和c／EBPβ结合位点通过染色质免疫沉淀实验(CHIP)得以验证。结果 MG患者血清sCTLA-4的表达水平与等位基因的突变相关，携带T→C^1772突变基因的患者可表达高水平的sCTLA-4。TC^1772基因型的频率在MG患者尤其是胸腺瘤亚组明显高于对照组，而G^-1661等位基因和GG^-1661基因型的频率在MG患者则显著降低。当-1772位点的等位基因是T而非C时，存在转录因子NF-1结合位点；同样，当-1661位点的等位基因是G而非A时，存在转录因子c／EBPβ结合位点，刀豆蛋白A(Con A)、植物血凝素(PHA)能促进NF-1和c／EBPβ的这种位点特异性转录活性。结论 MG患者CTLA-4表达异常，启动区C／T^1772和A／G^-1661多态性可导致无效转录，T→C^1772的突变能影响基因的剪接，干扰蛋白的表达和功能，阻止了负性调节信号的传递而致发病。     

CTLA-4基因启动子区单核苷酸多态性与特发性扩张型心肌病的关联研究

目的探讨特发性扩张型心肌病（idiopathic dilated cardiomyopathy，IDC）患者细胞毒性T淋巴细胞相关抗原-4（cytotoxic T lymphocyte assoccated antigen 4，CTLA-4）表达状况及由CTLA-4基因启动子区单核苷酸多态性（single nucleotide polymorphism，SNP）导致的不同遗传易感性机制。方法采用限制性片段长度多态性分析151例IDC患者，120名正常健康人CTLA-4基因启动区-1772、-1661及-318位点SNP；免疫酶联吸附测定法检测血清sCTLA-4、干扰素-7及白介素-4水平；综合分析CTLA-4启动区基因型、等位基因频率及与sCTLA-4、干扰素-γ／白介素一4的相关性。结果IDC患者sCTLA-4水平与CTLA一4基因启动区SNP相关，携带-1772T／C变异者sCTLA-4表达增高。-1772TC基因型频率在IDC组尤其低射血分数亚组显著高于对照组，IDC组-1661G和-1661GG频率显著降低，具有-1772TC-1661AA及-1772TC-1661AG单倍型IDC患者sCTLA-4显著升高。结论IDC患者CTLA-4表达异常，CTLA-4基因启动区-1772C／T和-1661A／GSNP与IDC遗传易感性相关。-1772T／C变异可能影响CTLA-4基因剪接，干扰蛋白表达和功能，阻止负性调节信号传递而导致对IDC的易感。     

CTLA-4基因多态性与粤西汉族人Graves病遗传易感性的关系

应用限制性片段长度多态性方法检测102例Graves病(Graves'disease,GD)及伴Graves眼病(Graves'ophthalmopathy,GO)亚组患者与100例正常组细胞毒性T淋巴细胞相关抗原-4(cytotoxic T lymphocyte associated antigen-4,CTLA-4)基因外显子1+49位点A/G及启动子-318位点C/T多态性。以探讨CTLA-4基因外显子1+49位点和启动子-318位点多态性与粤西汉族人GD及GO发病的关联性。结果显示GD组外显子1+49位点的GG基因型及G等位基因频率显著高于正常组(P=0.0142、0.0017),GD组AA基因型及A等位基因频率显著低于正常组(P=0.0079、P=0.006);启动子-318位点的各基因型及等位基因频率与正常组相比无统计学意义;外显子1+49位点和启动子-318位点基因型、等位基因频率在GO、无眼病GD亚组及正常组中任两组比较均无统计学意义。研究提示CTLA-4基因外显子1+49位点GG基因型及G等位基因可能是粤西汉族人GD的易感因素,但与GO无相关,AA基因型及A等位基因则是保护因素;启动子-318位点多态性与粤西汉族人GD及GO均不相关。     

CTLA-4启动子区基因多态性与系统性红斑狼疮关系的meta分析

目的:评价CTLA-4基因多态性与系统性红斑狼疮(SLE)易感性之间的相关性.方法:检索PubMed、Web of Knowledge、Embase、万方学术期刊全文数据库、中国期刊全文数据库和中国生物医学数据库,检索CTLA-4多态性与SLE易感性相关的文献,末次检索时间为2012-05-20.使用Meta分析方法对数据进行分析.结果:共纳入12篇文献,共涉及CTLA-4启动子区域3个多态位点:-1722、-166及-318位点,全人群研究结果显示在CTLA-4基因-1722T/C多态性(显性模型下:OR=2.570,95％CI=1.845-3.581,P＜0.01)及-318T/C多态性(隐性模型:OR =0.044,95％CI=0.020-0.094,P＜0.01)与SLE存在统计学上的相关性,人群分层后亚裔人群中-1722T/C及-318T/C多态性与SLE的此种相关性仍存在,但欧裔及非裔人群的CTLA-4启动区所有研究位点均未发现与SLE有关.结论:CTLA-4基因1722T/C及-318T/C多态性可能与SLE人群易感性有关,特别是亚裔人群.     

细胞毒T淋巴细胞相关抗原4基因多态性与吸毒并HIV感染相关

目的研究细胞毒T淋巴细胞相关抗原4(CTLA-4)基因外显子1的49位点A/G和启动子-318位点C/T多态性与吸毒并HIV感染的相关性。方法 采用序列特异性引物聚合酶链反应(PCR-SSP)方法,检测24例单纯吸毒者、41例吸毒合并HIV感染患者以及204例正常对照者CTLA-4基因外显子1的49位点A/G和启动子-318位点C/T的基因型。结果 与正常对照组比较,吸毒组C/C(12.50%vs51.47%)(P<0.01)型频率明显下降;在吸毒合并HIV感染患者组,CTLA-4A+49G基因型差异无统计学意义(P>0.05);CTLA-4C-318T基因型差异有统计学意义(P<0.01),C/T(68.3%vs45.6%)、T/T(21.95%vs2.94%)型频率明显上升,C/C(9.76%vs51.47%)型频率显著下降。与吸毒组比较,吸毒合并HIV感染组中CTLA-4A+49G及CTLA-4C-318T各基因型频率变化无统计学差异(P>0.05)。结论 吸毒合并HIV感染与CTLA-4基因动态密切相关,C-318T基因型C/T、T/T型与吸毒合并HIV感染呈正相关,C/C行呈负相关。     

CTLA-4基因多态性与特发性扩张型心肌病的相关性

目的包括细胞和体液免疫在内的自身免疫机制至少参与了部分特发性扩张型心肌病(Idiopathicdilatedcar-diomyopathy,IDC)患者的发病,且前者介导的心肌损害在IDC中更重要。CTLA-4是特异性细胞免疫的负性调节因子。本研究旨在探讨CTLA-4基因启动子-318C/T、外显子A/G多态性及3′非翻译区(AT)n微卫星多态性与IDC及血清可溶性CT-LA-4(sCTLA-4)水平的相关性。方法采用聚合酶链反应-限制性片段长度多态性(Polymerasechainreaction-restrictionfragmentlengthpolymorphisms,PCR-RFLP)方法分析黑龙江省无血缘关系汉族人群(包括72例IDC患者,100例正常健康人)CTLA-4基因-318C/T、49位点A/G多态性及3′微卫星多态性;ELISA法检测血清sCTLA-4水平。综合分析CTLA-4基因型频率、等位基因频率与IDC及sCTLA-4水平的相关性。结果IDC组外显子1GG基因型和G等位基因频率显著高于正常对照组(P=0.012,P=0.008);3′非翻译区共发现18种等位基因,106bp等位基因频率在IDC患者中显著增高(22.22%vs1%,P=0.0002,OR=23.56,95%CI9.65~83.74);两组间-318C/T多态性分布无统计学差异。与对照组相比,IDC组sCTLA-4水平显著升高[(1.87±1.06)μg/L比(0.54±0.19)μg/L,P<0.05];直线回归分析显示,IDC组GG基因型及G等位基因频率与血清sCTLA-4水平(r=0.57,P=0.021)显著相关,而AA、A/G基因型及A等位基因频率与sCTLA-4水平无相关性。启动子-318C/T多态性及3′非翻译区(AT)n微卫星多态性与sCTLA-4水平的亦无相关性。结论CTLA-4基因外显子1A49→G变异与IDC相关,携带G等位基因者易患IDC,其机制可能为该多态性造成CTLA-4信号肽中编码苏氨酸和甘氨酸的替换,从而影响蛋白翻译后加工、修饰,使sCTLA-4功能发生变化。提示3′末端非翻译区(AT)n重复序列中106bp等位基因可能是IDC的易感基因。     

亚洲人群CTLA-4基因（-318T/C）多态性与宫颈癌易感关系的Meta分析

目的 评估细胞毒性T淋巴细胞抗原基因-318T/C位点多态性与亚洲人群宫颈癌之间的相关性。方法 检索中英文数据库2023年3月前发表有关CTLA-4基因-318T/C位点多态性与亚洲人群宫颈癌之间关系的研究，OR值和95%CI作为评价指标，采用State11.0软件统计分析。结果 共纳入8项病例对照研究，病例组1497例和对照组1872例，Meta分析结果显示：CTLA-4基因-318T/C位点多态性与亚洲人群宫颈癌之间存在明显相关性（T vs C OR=1.59,95%CI:1.37～1.83;TC vs CC OR=1.57,95%CI:1.33～1.86;TT vs CC OR=3.53,95%CI:1.86～6.69;TT vs TC+CC OR=3.13,95%CI:1.65～5.93;TT+TC vs CC OR=1.64,95%CI:1.39～1.93），根据研究人群来源地区不同进行亚组分析发现CTLA-4基因-318T/C位点多态性与中国人群宫颈癌之间存在明显相关性，与印度和伊朗妇女不存在显著关联。结论 CTLA-4基因-318T/C位点多态性与亚洲人群宫颈癌之间存在明...     

自身免疫性甲状腺病CTLA—4基因外显子1A／G^49多态性研究

目的　探讨细胞毒性T淋巴细胞相关抗原4（CTLA-4）基因外显子1的49位点A／G多态性与自身免疫性甲状腺病（AITDs）的相关性。方法　采用多聚酶链反应限制性片段长度多态性（PCR-RFLP）技术分析122例自身免疫甲状腺病患者,其中Graves’病（GD）87例,桥本甲状腺炎（HT）35例,84例健康对照的CTLA-4基因外显子1的49位点基因型。采用ELISA技术检测AITDs患者甲状腺功能,间接免疫荧光法检测甲状腺球蛋白抗体（TGAb）和甲状腺抗过氧化物酶抗体（TPOAb）。结果　AITDs患者CTLA-4／G     

人CCAAT/增强子-结合蛋白ε研究进展

人核内转录因子C/EBP ε属于CCAAT/增强子-结合蛋白(CCAAT/enhancer-binding protein,C/EBP)家族成员,特异性表达于造血系统,对髓系细胞增殖与分化具有重要作用,参与了一系列髓系特异性基因的转录调控.本文就C/EBP ε基因的结构、调控机制以及产物的生物学功能进行综述.     

广东人汉族群CTLA-4基因外显子1多态性与Graves病的相关性

目的探讨CTLA-4基因外显子1多态性与广东地区汉族人群Graves病的关系。方法以PCR-RFLP技术观察100名健康人与100例Graves病(GD)患者细胞毒性T淋巴细胞相关抗原4(CTLA-4)基因外显子1的多态性。结果提示GD患者的CTLA-4外显子1的G49等位基因频率较正常对照组显著增高(P<0.01)。结论CTLA-4基因可能是广东地区汉族人群中GD的易感候选基因。     

Genetic analysis and functional evaluation of the C/T(-318) and A/G(-1661) polymorphisms of the CTLA-4 gene in patients affected with Graves' disease

In this study, we evaluated the A/G(-1661), C/T(-318), A/G49 and A/G6230 single nucleotide polymorphisms (SNPs) of the cytotoxic T lymphocyte antigen 4 (CTLA-4) gene for association with Graves' disease (GD) in 126 Russian simplex families. The conditional TDT analysis revealed significant overtransmission of the A(-1661)G(-318) haplotype (P = 0.033) and undertransmission of the GT haplotype (P = 0.0043) from parents homozygous for both +49 and +6230 polymorphisms. Parents homozygous for both (-1661) and (-318) markers significantly overtransmitted the G49G6230 haplotype (P = 0.0013) and undertransmitted the AG haplotype (P = 0.035) to affected offspring. This suggests in favor of the independent genetic effects of the 3' and 5'ends of CTLA-4 in conferring the susceptibility to GD. Both SNPs located at the 5' untranslated region of CTLA-4 were functionally analyzed using the luciferase reporter assay. We observed differential activation of the C/T(-318) promoter variant when Jurkat T cells and HeLa cells were cotransfected with a plasmid expressing lymphoid enhancing factor 1 (LEF1) and various CTLA-4 promoter constructs. The (-318) SNP modifies a putative binding site for LEF1 so that it alters the stimulating effect of LEF1 on the expression ability of the CTLA-4 promoter. The (-1661) dimorphism modifies a potential binding site for myocyte enhancer factor 2 (MEF2). No significant correlation between the (-1661) SNP and MEF2 activity in cotransfection experiments was found. Observed data help for further understanding a functional role of CTLA-4 promoter polymorphisms in the pathogenic mechanism of GD.     

CDS1 and promoter single nucleotide polymorphisms of the CTLA-4 gene in human myasthenia gravis

The cytotoxic T lymphocyte associated protein 4 (CTLA-4) gene (Ctla-4) is a candidate gene for autoimmune disease. We here report results of two single nucleotide polymorphisms (SNPs) in the Ctla-4, a +49 A/G SNP in CDS1 and a C/T promoter SNP at position -318. There were no differences in these two SNPs between patients and healthy individuals. The frequency of allele G and genotype G/G at position +49 in CDS1 was increased in patients with thymoma when compared with patients with normal and hyperplastic thymic histopathology. Patients with the G/G genotype had signs of immune activation manifested as higher levels of serum IL-1beta and higher percentage of CD28(+) T lymphocytes. There was a strong linkage between the 86bp allele in the 3'-UTR and the A(+49) allele in CDS1. Our results suggest that the SNP at position +49 in CDS1 might be associated with the manifestations of MG.     

Promoter region -318 C/ T and -1661 A/G CTLA-4 single nucleotide polymorphisms and type 1 diabetes in North Indians

Single nucleotide polymorphisms (SNPs) of the CTLA-4 gene have been associated with manifestation of type 1 diabetes in several populations. We assessed the association of five SNPs present in the CTLA-4 gene [-318C/T, -1661A/G and -1722C/T in the promoter region, +49A/G in exon 1 and CT60 in the 3' untranslated region (UTR) region] with type 1 diabetes in North Indian subjects. Genotyping was performed in the patients (n = 130) and the healthy control (n = 180) subjects by polymerase chain reaction-fragment length polymorphism analysis using MseI, BbvI, BstEII and NcoI restriction endonucleases for the -318, -1661, -1722, +49 and CT60 SNPs, respectively. The frequency of G alleles at -1661 locus was significantly higher in the patient group compared with the control subjects. Although the frequency of T alleles at -318 SNP was significantly higher in patients with type 1 diabetes compared with the controls, it did not remain significant after Bonferroni correction for the number of alleles tested. The frequencies of C/T alleles and genotypes at -1722C/T and G allele at +49A/G and CT60 SNPs were not significantly different between the patient and the control groups. Of the various possible haplotypes constructed using the five genetic loci tested (-318, -1661, -1722, +49, CT60), the frequency of 'TGTAG' haplotype was significantly higher in the patients when compared with the controls. The results of the present study indicate that the presence of G allele at -1661 locus at the CTLA-4 gene (IDDM12 locus) is associated with increased susceptibility to type 1 diabetes in North Indians, whereas A allele is protective.     

Association of the CTLA-4 gene with Vogt-Koyanagi-Harada syndrome

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a critical negative regulator of the T cell response, has been shown to be associated with a variety of autoimmune diseases. In this study, we investigated the association of CTLA-4 gene polymorphisms (- 1661A/G; - 318C/T; + 49G/A, and CT60) with Vogt-Koyanagi-Harada (VKH) syndrome in Chinese Han patients and normal controls. The results showed that the frequency of the G allele at the + 49 site was significantly higher in VKH patients than that observed in healthy controls (71.6% versus 62.8%, P = 0.0046, Pc = 0.037). Three haplotypes were identified from the four SNPs. The frequency of haplotype - 1661A:- 318C:+ 49G:CT60G, the most prevalent haplotype both in patients and controls, was significantly higher in patients than that in controls (70.1% versus 60.0%, P= 0.0013, n= 16, Pc = 0.021). These results suggest that CTLA-4 genetic polymorphisms are associated with the susceptibility to VKH syndrome.     

Distribution of CTLA-4 polymorphisms in allergic asthma

BACKGROUND: The CTLA-4 molecule is an important negative regulator of T cell activation. It is encoded on chromosome 2q33 and found to be associated with several allergic phenotypes including asthma. However, the association of CTLA-4 gene polymorphisms with allergic asthma is still controversial and therefore was the subject of this study. METHODS: By PCR-RFLP, the distribution of three single nucleotide polymorphisms (SNPs), -1147 C/T, -318 C/T, and +49 A/G, was examined in 219 Polish Caucasoid patients diagnosed with allergic asthma and in 102 ethnically matched healthy control individuals. (AT)(n) microsatellite polymorphism was also tested in the same individuals. RESULTS: No statistically significant differences in SNPs or microsatellite allele, genotype or haplotype frequencies between patients and controls were found. CONCLUSION: CTLA-4 polymorphisms do not seem to be a risk factor for allergic asthma in Poles.     

Polymorphisms in Cytotoxic T-lymphocyte Associated Antigen 4 Gene Does Not Affect sCytotoxic T-lymphocyte Associated Antigen 4 Levels in Human Papillomavirus-Infected Women with or without Cervical Cancer

Background: Cervical cancer (CaCx) is the second most common cancer in Indian women. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) + 49 AA polymorphism is known to be associated with CaCx. Current attempt is to use immunotherapy for the treatment of metastatic melanoma and metastatic castration-resistant prostate cancer, i.e., blocking of CTLA-4 using a fully human monoclonal CTLA-4 antibody to disrupt its inhibitory signal. This allows the CTLs to destroy the cancer cells. There is no information available on the soluble level of CTLA-4 on which the immunotherapy is targeted. This is specifically in Indian population including cases with CaCx. Objective: The aim of this study is to evaluate the levels of soluble CTLA-4 (sCTLA-4) in human papillomavirus (HPV)-infected women with or without CaCx and their association with the polymorphism at CTLA-4 + 49 A/G and CTLA-4 −318 C/T genotypes. Materials and Methods: This is an exploratory case–control study involving two groups of HPV-infected women, the cases were with invasive CaCx and the control group was women with the healthy cervix. sCTLA-4 levels were measured using ELISA in 92 CaCx cases and 57 HPV-positive women with the healthy cervix. Results: Both cases and controls have similar sCTLA-4 levels. Comparison of CTLA-4 + 49A/G and −318 C/T genotypes with sCTLA-4 levels among cases and control also did not show any statistically significant difference. Conclusion: The present study suggests sCTLA-4 levels are not affected by a polymorphism at + 49 A>G CTLA-4. Hence, levels of CTLA-4 are similar in both CaCx cases and control group.     

Functional genetic variants of CTLA-4 and risk of tobacco-related oral carcinoma in high-risk North Indian population

Single nucleotide polymorphisms (SNPs) of the CTLA-4 gene have been implicated in susceptibility to different cancer in different ethnic populations. We assessed the association of five SNPs [−1722C/T, −1661A/G and −318C/T in the promoter region49A/G in exon 1 and CT60A/G in the 3′untranslated region (UTR)] with tobacco-related oral squamous cell carcinoma (OSCC) in North Indian subjects. We genotyped 130 OSCC patients and 180 normal subjects by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) using BbvI, MseI, NcoI and BstEII restriction endonucleases. Among these SNPs, −1722CC, −1661AG and CT60AA genotypes were more prevalent in OSCC patients as compared to controls and in the logistic regression analysis with odd ratio (OR) 2.85, 95% CI (0.69–11.68); OR 2.48, 95% CI (1.29–4.78) and OR 3.0, 95% CI (1.43–6.28) respectively, these genotypes showed strong association with OSCC risk. With higher prevalence in controls 49GG genotype and G allele (OR 0.57, 95% CI 0.40–0.81) appeared to be protective. Moreover, TACAG, TACGA and TATAG appeared as susceptible while TACGG and CACGG appeared as protective haplotypes. These results suggest significant risk modifying effects of CTLA-4 −1722C/T, −1661A/G, −318T/C, CT60 A/G and 49A/G SNPs in tobacco-related OSCC in North Indian population.     

Association between CTLA-4 gene polymorphism and ankylosing spondylitis: a case-control study

Aims: The aim of our study was to evaluate the association between CTLA-4 polymorphisms (+49A/G, -318C/T and CT60A/G) and ankylosing spondylitis (AS) susceptibility. Methods: A total of 120 AS cases and healthy controls, matched on the age and gender, were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) were used to determine the gentypes of +49A/G, -318C/T and CT60A/G polymorphisms. Genotype distribution in control group was assessed by Hardy Weinberg Equilibrium (HWE) test. Odds ratio (OR) with 95% confidence interval (95% CI) were adopted to evaluate the relationship of CTLA-4 polymorphisms and AS susceptibility. Results: In our study, genotype distribution of the three polymorphisms in control group was consistent with the HWE (P > 0.05). The genotype analysis showed that AA genotype of + 49A/G polymorphism could increase the risk for AS (OR=2.357, 95% CI=1.127-4.930). Moreover, the frequency of A allele was also presented as a risk factor for AS. Additionally, AA genotype and A allele of CT60A/G appeared to be related with AS susceptibility (OR=2.610, 95% CI=1.047-6.510; OR=1.751, 95% CI=1.160-2.641). However, the T allele of -318C/T appeared to be a protective factor for AS (OR=0.383, 95% CI=0.228-0.643). Conclusion: In summary, there existed significant association between CTLA-4 gene polymorphisms and increased or decreased risk for AS.     

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.