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。     

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     

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。     

细胞毒T淋巴细胞相关抗原4基因C-658T多态性与溃疡性结肠炎相关性研究

,与UC患者的病变范围有显著相关(P=0.037;P=0.0067);UC组C61T基因型频率与对照组相比,差异无统计学意义(P=0.192).结论 CTLA-4基因启动子区C-658T位点T等位基因与中国汉族UC存在显著相关性.     

CTLA-4基因多态性与Graves病

细胞毒性T淋巴细胞相关抗原4（cytotoxie Tlymphocyte associated antigen4，CTLA-4）是激活的T细胞表达的一种膜蛋白，属免疫球蛋白超家族成员，对T细胞增生起负性调节作用。与抗原呈递细胞（APC）表面的B7分子结合，作为协同刺激信号抑制T细胞增生、活化，诱导T细胞耐受。CTLA-4功能和（或）表达缺陷参与了T细胞介导的自身免疫性疾病的发生发展。Graves病（GD）是一种由于抑制性T淋巴细胞（TS）功能缺陷所导致的器官特异性自身免疫病。近年来研究结果认为，CTLA4基因的多态性与GD有关，CTLA4基因作为GD的易感候选基因已成为研究的热点。     

血清可溶性 CTLA-4表达与重症肌无力的相关性研究

目的探讨血清可溶性细胞毒性T淋巴细胞相关抗原-4（CTLA-4）表达与福建地区重症肌无力（ myasthenia gravis ,MG）患者的相关性。方法 ELISA法检测福建地区80例MG患者（ MG患者分为激素未治疗组及激素治疗组,且激素治疗组进一步分为免疫抑制剂治疗组和胸腺切除组）和80例正常对照组血清可溶性CTLA-4（ sCTLA-4）水平。结果 MG激素未治疗组、激素治疗组的sCTLA-4均高于正常对照组[（6．03±3．58） ng/ml、（3．44±2．36） ng/ml vs （0．49±0．95） ng/ml],它们之间的差别具有统计学意义（χ2＝100．67,P＜0．001）;其中激素治疗组sCTLA-4表达水平高于正常对照组（Z＝-9．03,P＜0．001）,而 MG激素未治疗组sCTLA-4表达高于激素治疗组（Z＝-3．37,P＝0．001）;并且激素未治疗组激素治疗前后血清sCTLA-4水平差异有统计学意义（t＝3．10,P＝0．005）;胸腺切除术后sCTLA-4低于手术前（Z＝-2．21,P＝0．04）,而免疫抑制剂治疗前后差异却没有统计学意义（Z＝-1．26,P＝0．21）。结论 sCTLA-4参与MG的发病机制,激素治疗、胸腺切除治疗减少sCT-LA-4表达。     

CTLA-4基因外显子4区AT重复序列多态性及碘摄入量与Graves病的相关性研究

目的 探讨细胞毒性T淋巴细胞相关抗原-4(cytotoxic T lymphocyte associated antigen-4,CTLA-4)基因第4外显子区AT重复序列多态性多态性[CTLA-4(AT)n]及碘摄入状况与粤西汉族人Graves病(Graves disease,GD)发病的相关性.方法 收取2006年...     

Toll样受体与自身免疫性肝病

Toll样受体(Toll like receptors,TLRs)是近些年来发现的一类新的细胞表面信号传导跨膜受体,能够识别作为配体的病原相关的分子模式(Pathogen-associated molecular patterns,PAMPs),是人体固有免疫和适应性免疫的桥梁[1].     

广西地区壮族Graves病与CTLA4基因多态性相关性研究

目的分析CTLA4基因微卫星多态性与广西地区壮族Graves病（Graves’disease，GD）相关性。方法提取48例广西地区壮族GD患者和44名正常对照组的外周血白细胞基因组DNA，应用聚合酶链反应检测CTLA4第4外显子的3’非翻译区包含（AT）n[CTLA4（AT）n]重复序列的特异性等位基因。结果广西地区壮族人CTLA4微卫星多态性检出19种等位基因。壮族GD组106bp等位基因频率与正常对照组比较显著增高，差异有统计学意义（P〈0．05）。结论广西壮族GD患者与CTLA4基因多态性明显相关,CTA4（AT）n 106bp可能是广西壮族GD的易感等位基因。     

CTLA-4基因多态性调节溃疡性结肠炎患者CTLA-4 mRNA稳定性和蛋白水平

目的 研究细胞毒T淋巴细胞相关抗原4(cytotoxic T-lymphocyte associated antigen 4,CTLA-4)基因3'非转录区(AT)n重复序列多态性对溃疡性结肠炎(ulcerative colitis,UC)患者CTLA-4mRNA稳定性和基因表达的影响.方法 采用实时定量PCR方法检测膜型CTLA-4(full length CTLA-4,flCTLA-4)和可溶性CTLA-4(soluble CTLA-4,sCTLA-4)mRNA表达,半衰期法分析其mRNA稳定性.免疫组化检测flCTLA-4蛋白表达.酶联免疫吸附实验测定sCTLA-4蛋白水平.荧光PCR-毛细管电泳技术检测300例UC患者和700名健康对照者CTLA-4基因(AT)n重复序列多态性.结果 活动期UC患者肠黏膜sCTLA-4 mRNA的表达显著低于缓解期UC患者(P=0.004).在UC患者中,(AT)n重复序列长等位基因携带者表达低水平的flCTLA-4和sCTLA-4 mRNA以及sCTLA-4蛋白(均P＜0.01).携带长等位基因的UC患者CTLA-4 mRNA的稳定性明显降低.UC患者CTLA-4基因(AT)n重复序列长等位基因携带者(≥116 bp)频率显著高于正常对照组(P＜0.01),且与广泛型结肠炎相关(P=0.008).结论 UC患者CTLA-4基因(AT)n重复序列多态性与CTLA-4基因表达水平相关,携带(AT)n重复序列长等位基因的UC患者CTLA-4 mRNA及蛋白的表达降低,提示CTLA-4基因在UC遗传免疫发病机制中起重要作用.     

Correlation of CTLA-4 polymorphism and the risk of gastric cancer in a Chinese Bai population

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is involved in the regulation of immune responses mediated by T cells. This study aimed to explore the correlation between CTLA-4 gene polymorphisms and the risk of gastric cancer (GC) in the Bai minority population of southwestern China. A total of 422 GC patients and 397 healthy controls (HC) were included in this case–control study. Four single nucleotide polymorphism sites of CTLA-4 gene (rs231775, rs733618, rs16840252 and rs3087243) were selected and analysed. The results showed a significant difference in the rs733618 loci between GC and HC groups. The frequency of the rs733618 polymorphism ‘TC’ genotype was significantly lower in GC group compared to the HC group [odds ratio (OR), 95% confidence interval (CI): .47 (.35–.63), p < .001]. GC cases with dominant genetic model ‘TC + CC’ had a 47% reduced risk of GC [OR, 95%CI: .53 (.40–.71), p < .001]. Subgroup analyses revealed that the rs733618 ‘TC + CC’ genotype was associated with a lower risk of GC in male patients [OR, 95%CI: .42 (.31–.58), p < .001], those aged ≤60 years old [OR, 95%CI: .27 (.18–.42), p < .001], non-drinkers [OR, 95%CI: .21 (.13–.33), p < .001], non-smokers [OR, 95%CI: .38 (.25–.57), p < .001] and individuals without Helicobacter pylori infection [OR, 95%CI: .16 (.10–.26), p < .001]. Further multivariated analyses indicated that individuals with the ‘TC + CC’ rs733618 genotype who were aged ≤60 years old [OR, 95%CI: .42 (.29–.83), p = .032] and had no H. pylori infection [OR, 95%CI: .35 (.28–.76), p = .018] were found to have a protective effect against GC. Additionally, soluble CTLA-4 were significantly lower in GC patients with ‘TC’ and ‘TC + CC’ genotypes (all p < .05). Our findings suggest that the rs733618 polymorphism of CTLA-4 gene may play a critical role in the prevention of GC.     

Meta-Analysis: The Relationship Between CTLA-4 +49 A/G Polymorphism and Primary Biliary Cirrhosis and Type I Autoimmune Hepatitis

Objectives: CTLA-4 exon-1 +49A?>?G (rs231775) polymorphism has been reported to influence the risk for primary biliary cirrhosis (PBC) as well as type I autoimmune hepatitis (AIH-1) in many studies; however, the results still remain controversial and ambiguous. This study aimed to determine more precise estimations for the relationship between CTLA-4 +49 A?>?G polymorphism and the risk for PBC and AIH-1 by using a meta-analysis.

Design and Methods: PubMed, EMBASE and MEDLINE were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association.

Results: Fifteen studies including 3661 patients with PBC and 4427 controls as well as seven studies including 1270 patients with AIH-1 and 1614 controls were identified. Our pooled analysis revealed that G allele of CTLA-4 gene +49A/G polymorphism may confer an increased risk of PBC in overall (p?=?0.001, OR?=?1.29; 95% CI?=?1.13–1.47) and Caucasians (p?=?0.001, OR?=?1.32; 95% CI?=?1.21–1.44). At genotypic level, the codominant, dominant and recessive models showed no significant association with PBC. With respect to AIH-1, the AG genotype demonstrated a trend for association with increased risk of AIH-1 (p?=?0.04, AG vs. AA, OR?=?1.20; 95% CI?=?1.01–1.43). However, the CTLA-4 alleles as well as genotypes in dominant and recessive models were not associated with a risk for AIH-1 in both Caucasians and Asians.

Conclusions: This meta-analysis concluded that the CTLA-4 G allele and the AG genotype were associated with an increased risk for PBC and AIH-1, respectively, suggesting the CTLA-4 +49 A/G polymorphism as a candidate of susceptibility locus to PBC and AIH-1.     

CTLA-4 +49A/G polymorphism is associated with Behçet's disease in a Tunisian population

The involvement of excessive T-helper cell functions in the pathogenesis of Behçet's disease (BD) has been reported. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) plays a role in T-cell downregulation. In this report, we investigated the possible association between BD patients and the CTLA-4 +49A/G polymorphism in Tunisian population. A total of 135 Tunisian BD patients and 151 healthy blood donors from the same geographic area were genotyped by polymerase chain reaction for the CTLA-4 +49 A/G polymorphism. A highly significant difference between Tunisian BD patients and healthy controls was found regarding the distribution of CTLA-4 +49 A allele [ P  < 10⁻⁷; χ² = 75.63; odds ratio (OR) = 4.63; 95% confidence interval (CI) = 3.20–6.72] and genotype frequencies ( P  < 10⁻⁷; χ² = 71.02). Furthermore, in the BD group, the A allele was predominant in males (76.3%) when compared with females (62%), ( P  = 0.014; χ² = 5.97; OR = 1.99; 95% CI = 1.10–3.59). No relationship was found between the studied genotype and clinical manifestations. Our results show a gene dose effect of the A allele on the BD. The A allele exerts a stronger effect on disease susceptibility in males compared with females.     

Association of the A/G polymorphism at position 49 in exon 1 of CTLA-4 with the susceptibility to unexplained recurrent spontaneous abortion in the Chinese population

PROBLEM: To investigate whether the A/G polymorphism at position 49 in exon 1 of cytotoxic T lymphocyte antigen-4 (CTLA-4) gene, which delivers a negative signal to T-cell activation, confers the susceptibility to unexplained recurrent spontaneous abortion in the Chinese population. METHOD OF STUDY: A total of 168 patients with unexplained recurrent spontaneous abortion (RSA), who were treated in the Renji Hospital affiliated to the Shanghai Second Medical University, were matched against 117 women with normal pregnancy history. Case-control study to compare the frequency of G/A alleles, AA/AG/GG genotypes and A + (AA + AG) /G+ (GG + AG) phenotypes of CTLA-4 between RSA patients and controls were performed. After amplification of CTLA-4 exon-1 region by polymerase chain reaction (PCR), restriction fragment-length polymorphism (RFLP) was used to detect the polymorphism at position 49 in exon-1 of CTLA-4 gene. Statistical significance was tested by SPSS software. RESULTS: There were dissimilar distributions of G/A alleles, AA/AG/GG genotypes and A+/G+ phenotypes of CTLA-4 between RSA patients and controls. The frequencies of G allele (P = 0.032) and GG genotype (P = 0.011) in RSA patients were significantly higher than those in controls, while the frequencies of AG genotype (P = 0.039) and A + (AA + AG) phenotype in RSA patients were decreased significantly (P = 0.011). CONCLUSIONS: Our findings suggest that A/G polymorphism in exon-1 of CTLA-4 is associated with the immunopathogenesis of RSA, and it confers susceptibility to RSA in Chinese population.     

Immunoglobulin-containing cells in liver biopsies of patients with chronic hepatitis and primary biliary cirrhosis

The numbers of IgA, IgM and IgG-containing cells were studied by means of an indirect immunoperoxidase technique and morphometry in liver biopsies of patients with primary biliary cirrhosis and chronic hepatitis, in whom serum immunoglobulin concentrations were also determined. In patients with primary biliary cirrhosis the absolute and relative number of IgM-containing cells in the liver was significantly higher, whereas the absolute and relative number of IgG-containing cells in the liver was significantly lower compared to patients with chronic hepatitis. IgM-containing cells in liver biopsies of patients with primary biliary cirrhosis correlated strongly with their serum IgM levels. It is concluded that determination of the pattern of immunoglobulin containing cells in liver biopsies may help in the differentiation of primary biliary cirrhosis from chronic hepatitis and that local production of IgM in the liver may contribute significantly to the high serum IgM levels in patients with primary biliary cirrhosis.     

CTLA-4/CD 28 region polymorphisms in children from families with autoimmune hepatitis

Susceptibility to autoimmune hepatitis is associated with particular human leucocyte antigen class II alleles. However, non-HLA genetic factors are likely to be required for development of the disease. Among the candidate genes, the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and CD28 genes, located on chromosome 2q33 in humans, encode a cell surface molecule playing a dominant role in the regulation of T-cell activation. The CTLA-4 and CD28 polymorphisms were investigated in children from 32 families with autoimmune hepatitis (AIH). The transmission/disequilibrium test revealed increased transmission of the (AT)8 (dinucleotide repeat) and A (exon 1) alleles of CTLA-4 gene from heterozygous parents to affected offspring (87.5% and 83.5%) with type 1 AIH, compared with unaffected offspring (50.0% for both, p = 0.009 and 0.02, respectively). In contrast, no deviation in transmission for CTLA-4 polymorphisms was found between type 2 AIH patients and unaffected offspring. No evidence for association was found between CD28 gene polymorphism or D2S72 genetic marker and both types of AIH. This study identified the CTLA-4 gene polymorphism as a non-HLA determinant that predisposes to AIH type 1 in children. The genetic heterogeneity seen in the present study provides a new argument in favor of pathogenic differences between type 1 and type 2 AIH.     

CD4+CD25+ but not CD4+Foxp3+ T cells as a regulatory subset in primary biliary cirrhosis

Increasing evidence indicates a role for regulatory T cells (Tregs) in the immune response and in autoimmune diseases, but the role of Tregs and cytokines in autoimmune hepatic diseases remains largely unclear and controversial, especially in patients with primary biliary cirrhosis (PBC). This study was undertaken to investigate Tregs and different cytokines in the liver and peripheral blood of PBC patients. We found that these patients demonstrated a reduction of CD4⁺CD25⁺ T cells but elevated CD4⁺Foxp3⁺ T cells in peripheral blood mononuclear cells (PBMCs) and CD4⁺ T cells. The percentage of CD4⁺CD25⁺ T cells in PBMCs was negatively correlated with elevated plasma interferon (IFN)-γ levels. A liver-specific analysis showed that the frequency of Foxp3⁺ Tregs, transforming growth factor (TGF)-β1 and IFN-γ were increased in PBC patients. Our findings suggest that an imbalance between CD4⁺CD25⁺ Tregs and cytotoxic cytokines plays a crucial role in the pathogenesis of PBC while the role of Foxp3 needs further investigation.     

IL-27诱导原发性胆汁性肝硬化患者CD4+T细胞增殖分化作用机制研究

目的 探讨IL-27对原发性胆汁性肝硬化(primary biliary cirrhosis,PBC)患者外周血CD4+T细胞的增殖分化作用及其相关免疫学机制.方法 收集PBC患者、慢性乙肝患者(choronic hepatitis B,CHB)、健康体检者(health controls,HCs)外周血,磁珠分离CD4+T细胞.IL-27体外作用后,CCK-8测定细胞增殖情况,ELISA法检测细胞因子,定量PCR分析T-bet和GATA3基因表达情况,免疫印迹测定p-STAT-1和p-STAT-3的表达.结果 IL-27作用后,PBC组、CHB组和HCs组CD4+T细胞增殖能力均显著增强,PBC组CD4+T细胞增殖能力强于CHB和HCs组,差异有统计学意义(P＜0.001),同时PBC组细胞培养液中IL-2和IFN-γ在IL-27作用后较CHB和正常对照组均显著增高(P＜0.001),IL-10表达无明显变化.未经IL-27诱导情况下,PBC组T-bet表达高于CHB组(P=0.007),IL-27诱导后PBC组CD4+T淋巴细胞T-bet基因表达显著增加,同时对GATA3具有抑制作用,作用前后差异有统计学意义(P＜0.001),CHB组作用前后无显著变化(P=0.3).免疫印迹测定p-STAT-1、p-STAT-3发现,正常情况下各研究组均不表达p-STAT-1、p-STAT-3,IL-27作用后,表达明显升高,其中PBC组升高尤为明显.结论 IL-27可以诱导PBC患者CD4+T细胞增殖,并通过活化p-STAT-1、p-STAT-3信号通路,诱导CD4+T细胞向Th1分化,同时分泌相关细胞因子,可能在PBC早期免疫炎症反应过程中具有重要作用.