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.     

稳定表达细胞毒性T淋巴细胞相关抗原CTLA-4的293T细胞株的建立

目的：构建稳定表达细胞毒性 T 淋巴细胞相关抗原-4（cytotoxic T lymphocyte antigen-4, CTLA-4）的293T 细胞株。方法首先从人外周血获取 PBMC 加以 T 细胞活化; PCR 扩增 CTLA-4转录本,连接pUCm-T 质粒引入 HindⅢ和 EcoRⅠ双酶切位点后转入真核细胞表达质粒 pcDNA3．1;重组质粒 pcDNA3．1-CTLA-4经脂质体转染293T 细胞,以抗生素 G418筛选表达 CTLA-4的293T 细胞;定量 PCR、免疫荧光分别检测293T 细胞 CTLA-4表达与细胞定位。结果血样来源 T 细胞经活化后表达 CTLA-4转录本。 HindⅢ和EcoRⅠ双酶切证实重组质粒内 CTLA-4插入序列正确; RT-PCR 及免疫荧光检测证实293T 细胞能够稳定表达目的蛋白 CTLA-4,并定位于细胞膜表面。结论成功构建的 pcDNA3．1-CTLA-4重组真核表达载体,在293T 细胞膜表面实现了稳定表达,为进行相关生物学理论与应用研究打下基础。     

细胞毒性T淋巴细胞相关抗原-4Ig和anti-CD154单抗在移植中的研究进展

细胞毒性T淋巴细胞相关抗原(CTLA)-4Ig和anti-CD154单抗是目前器官移植的新型生物免疫抑制剂.两者均通过阻断协同刺激信号来抑制T淋巴细胞的活化,从而起到免疫耐受作用,在器官移植中有很好的应用前景.CTLA-4 Ig和anti-CD154单抗在动物模型实验中研究发现单用或联用有长久强效的免疫耐受作用能延长移植物的存活期.在临床中的应用尚处于初期,其临床副作用、安全性及长期的疗效有待进一步观察.     

肾移植排斥反应中细胞毒性T淋巴细胞相关抗原4的作用

背景：细胞毒性T淋巴细胞相关抗原4是新近发现的共刺激分子,在肿瘤及自身免疫性疾病中研究较多,在肾移植领域缺少研究。目的：探讨细胞毒性T淋巴细胞相关抗原4在肾移植排斥反应中的作用。方法：纳入肾移植患者50例,根据移植后肾功能分为2组,急性排斥组20例,移植肾功能稳定组30例。同时选择30例健康查体者作为健康对照组。分别抽取外周静脉血,采用ELISA法及流式细胞术检测观察对象血清及外周血淋巴细胞中的细胞毒性T淋巴细胞相关抗原4水平。结果与结论：细胞毒性T淋巴细胞相关抗原4在肾移植后急性排斥组、肾功能稳定组及健康对照组血清中的表达水平差异有显著性意义(F=70.008 1,P=0.000 0)。肾功能稳定组显著低于健康对照组(P=0.000 0),急性排斥组显著低于健康对照组(P=0.000 0),急性排斥组显著低于肾功能稳定组(P=0.000 0)。细胞毒性T淋巴细胞相关抗原4在肾移植后急性排斥组、肾功能稳定组及健康对照组淋巴细胞中的表达水平差异无显著性意义(F=1.865 6,P=0.161 7)。提示细胞毒性T淋巴细胞相关抗原4在肾移植患者发生排斥反应时血清中表达减低,具有一定的相关性,可能参与了排斥反应的发生。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

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。     

细胞毒性T淋巴细胞相关抗原4（CTLA—4）的研究进展

ＣＴＬＡ－４是Ｔ细胞上的一种跨膜受体，与ＣＤ２８共同享有Ｂ７分子配体，而ＣＴＬＡ－４与Ｂ７分子结合后诱导Ｔ细胞无反应性，参与免疫反应的负调节。基因重组的ＣＴＬＡ－４Ｉｇ可在体内外有效、特异地抑制细胞和体液免疫反应，对移植排斥反应及各种自身免疫性疾病有显著的治疗作用，毒副作用极低，是目前被认为较有希望的新的免疫抑制药物。     

艾灸干预免疫抑制兔细胞毒性T淋巴细胞抗原-4的作用效应分析

目的：比较不同艾灸干预下免疫抑制兔细胞毒性T淋巴细胞相关抗原4(CTLA-4)及程序性死亡受体1(PD-1表达变化的异同。方法：20只大耳白兔随机分为空白组、模型组、艾条灸（MSM）组与隔药饼灸（HPM）组,每组5只,连续7 d腹腔注射环磷酰胺（CTX）诱导免疫抑制模型。造模成功后分别进行MSM与HPM干预,均为隔日灸,共治疗10次。治疗结束后麻醉白兔,取血清、肝脏与脾脏,ELISA检测血清中PD-1、PD-L1含量,免疫组化法检测肝组织PD-1含量,RT-qPCR检测肝、脾组织CTLA-4 mRNA含量。结果：HPM和MSM均可降低免疫抑制下PD-1及PD-L1水平,并可有效抑制脾脏CTLA-4和肝脏PD-1、CTLA-4水平升高,与免疫抑制模型组相比差异均存在统计学意义（P<0.05）,且Pearson相关性检验表明肝组织中CTLA-4与PD-1呈显著正相关（r=0.780 7,P<0.001）。结论：HPM可通过调控多个免疫抑制位点改善机体免疫功能。     

细胞毒性T细胞在白血病中的研究进展

T细胞免疫在急性白血病的抗肿瘤免疫中起重要作用，细胞毒性T细胞(CTL)被活化至少需要两个信号，T辅助细胞的活化必须由抗原提呈细胞提呈MHC—Ⅱ类抗原，而后者还必须有表面的B7分子与T辅助细胞上的CD28分子相结合才能完成；急性白血病人体内可能存在可被IL—2诱导的CTL的前体细胞；CTL对白血病细胞的作用途径以MHC限制性途径为主。     

转基因表达HBV抗原特异性细胞毒性T淋巴细胞受体

目的 通过逆转录病毒介导HBV抗原特异性细胞毒性T细胞(CTL)的T细胞受体(TCR)转基因表达,初步观察其结合活性.方法 从HLA-A2阳性急性乙肝患者外周血中诱导、分选、克隆和扩增HBV抗原特异性CTL;提取细胞RNA,用RT-PCR、5'-RACE和OVER-LAP PCR等方法获取TCR的α和β链编码基因;构建TCR重组逆转录病毒,介导特异性TCR分别在人Jurkat T细胞和HLA-A2阳性健康人CD8 T淋巴细胞上表达.结果 从1例HLA-A2阳性急性乙肝患者样本中分别获得了2组TCR Vα、Vβ配对,分别命名为α21β13、α15β13,包装的重组逆转录病毒滴度为(1.5 ～5.0)×105 IU/mL,用针对目标TCR的特异性Vβ链抗体(抗Vβ13 TCR-PE)和HLA-A2限制性表位特异性五聚体(pentamer)进行免疫荧光染色,重组TCR在T细胞表面获得表达:其中在Jurkat细胞上转入的Vβ13链表达细胞占1.06％ ～2.25％,在HLA-A2阳性健康人T细胞上Vβ13阳性细胞和pentamer阳性细胞分别占到1.03％ ～2.06％和1.05％ ～1.12％,在HLA-A2阴性健康人T细胞上Vβ13阳性细胞和pentamer 阳性细胞均低于0.05％.结论 通过逆转录病毒介导可以使HBV特异性CTL TCR获得转基因表达,具有结合HLA-A2限制性表位的活性.     

抗原特异性细胞毒性T细胞体外扩增方法的研究近展

抗原特异性细胞毒性T细胞(cytoxicTlymphocytes,CTLs)在细胞免疫应答中起着重要的效应功能,从而在抗肿瘤和抗感染免疫中发挥着重要作用。由于受到各种因素的限制和影响,抗原特异性CTLs无法在体内有效地诱导和扩增,因此,通过体外诱导和扩增CTLs后再将此CTLs回输到体内是一个比较理想的方法,且具有重要的应用价值,如何高效激活和扩增抗原特异性CTLs是此法能否成功应用的关键。     

CTLA4基因多态性与炎症性肠病遗传易感性相关性研究

目的：系统评价细胞毒性T淋巴细胞相关抗原4（ CTLA-4）基因多态性与炎症性肠病发病风险的相关性。方法计算机检索PubMed、 EMbase、 WanFang Data、 CNKI、 CBM和VIP,查找关于CTLA4基因多态性与炎症性肠病发病风险的病例-对照研究,检索时限均从建库至今。2名评价员按照纳入与排除标准独立筛选文献、提取资料并评价纳入研究的方法学质量后,采用RevMan5．2和Stata12．0软件进行Meta分析。结果纳入2个CTLA?4基因位点： rs231775,及非转录区（ AT） n重复序列微卫星片段,共10个研究。 Meta分析结果显示： CTLA?4?rs231775基因非转录区（ AT） n重复序列多态性与炎症性肠病发病风险有相关性： rs231775多态性增加人群克罗恩病易感性[AG＋GG vs． AA： OR＝1．29,95％CI （1．05～1．59）, P＝0．02。 GG vs． AA： OR＝2．14,95％CI （1．14～4．04）, P＝0．02]; CTLA?4基因非转录区（AT）n重复序列≥118 bp片段人群组发生溃疡性结肠炎的可能性是非≥118 bp片段组的4．85倍（ P＜0．05）,前者发生克罗恩病的可能性是后者的3．82倍（P＜0．05）, CTLA?4基因非转录区（AT）n重复序列122 bp片段人群发生溃疡性结肠炎的可能性是非122 bp片段的15．5倍（ P＜0．05）。结论 CTLA?4?rs231775基因非转录区（ AT） n重复序列多态性会增加炎症性肠病发病风险。但鉴于纳入研究数量有限,尚需开展更多研究予以验证。     

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。     

CTLA-4 promoter variants in patients with Graves' disease and Hashimoto's thyroiditis

Abstract: Graves' disease (GD) and Hashimoto's thyroiditis (HT) are T-cell mediated organ-specific autoimmune disorders with a genetic predisposition. The cytotoxic T-lymphocyte antigen 4 (CTLA-4) molecule is the predominant receptor for B7 on activated T cells and represents a negative regulator for T-cell function. Since the CTLA-4-guanine at position 49 of exon 1 is associated with susceptibility to GD as well as to HT and IDDM, we investigated a recently detected cytosine/thymine substitution at position -318 within the CTLA-4 promoter region in patients with GD and HT. 125 patients with GD were significantly more often homozygous for cytosine (86% vs. 73% in controls, P=0.006) and less frequently heterozygous for cytosine and thymine (14% vs. 27%, P=0.008). In 64 patients with HT, the distribution was similar but not significant (81% homozygous for cytosine and 16% heterozygous). When correlating the promoter and the exon 1 polymorphism we found the strongest linkage between thymine (promoter) and adenine (exon 1). In conclusion, a promoter variant of the CTLA-4 gene represents an additional risk marker for GD and HT, but their predisposition is linked to the exon 1 alleles.     

4p14区段和CTLA-4基因多态性与Graves病相关

目的探讨中国安徽蚌埠地区汉族人群4p14区段位点rs6832151和CTLA-4基因4个SNPs(单核苷酸多态性)位点基因多态性与Graves病相关性,和基因-基因交互作用对Graves病的影响。方法提取611例诊断明确的GD患者和644名健康对照者的全基因组DNA,用Taq Man探针技术进行基因分型,使用Plink和Haploview等统计软件分析这些位点与蚌埠地区汉族人群Graves病的相关性。结果 4p14区段位点rs6832151的等位基因、基因型频率在GD组和对照组之间有差异(P0.05),CTLA-4基因区域内rs231804和rs231726两个SNP位点基因型在显性模型下差异显著(P0.05);GMDR模型显示CTLA-4基因内rs10197319、rs231726、rs231804、rs1024161位点和4p14区段内rs6832151位点组成的五阶模型(P=0.001)为最佳模型,CTLA-4基因内rs1024161和rs10197319位点之间上位效应分析结果有差异(P0.05)结论 4p14区段rs6832151,CTLA-4基因区域内rs231804和rs231726位点基因多态性与蚌埠地区汉族人群Graves病的遗传易感性相关;rs6832151(4p14区段)和rs10197319、rs231726、rs231804、rs1024161(CTLA-4基因)5个SNP位点间的基因-基因交互作用与Graves病相关,CTLA-4基因内rs1024161和rs10197319位点之间存在上位效应。     

Study of the CTLA-4 gene polymorphisms in systemic lupus erythematosus (SLE) samples from Malaysia

Abstract

In this study, we investigated the polymorphisms of the exon 1 (+49A/G), promoter sites (–1722T/C, –1661A/G, –318C/T), and 3′-untranslated region (3′-UTR) (+6230 A/G) of the CTLA-4 gene in systemic lupus erythematosus (SLE) affected patients. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of these five markers in 130 SLE patients and 130 healthy controls. Of the five tested polymorphisms, there was no statistical significant difference between the genotypic and allelic frequencies of patients with SLE and controls. Hence, we propose that the CTLA-4 gene does not play a major role in the genetic susceptibility to the development of SLE in the Malaysian population.     

共刺激分子CTLA-4的研究进展及在风湿病治疗中的应用

细胞毒T淋巴细胞抗原-4(CTLA-4)是免疫应答反应起始阶段T细胞活化的重要共同活化分子,它与T细胞表面的配体结合后可以抑制T细胞功能,使T细胞不能被激活,从而抑制免疫反应的发生。在多种风湿病中都发现有CTLA-4等位基因异常和蛋白表达异常。CTLA-4免疫球蛋白(CTLA-4 Ig)是针对CTLA-4的融合蛋白,能选择性地抑制免疫反应,改善患者的临床症状,达到控制疾病进展的目的。但目前的临床研究尚仅限于类风湿关节炎。临床研究的初步结果表明CTLA-4 Ig治疗类风湿关节炎是有效而安全的,但由于其临床应用时间短,在风湿病治疗中的作用还有待进一步的长期临床观察来证实。     

CTLA-4 promoter polymorphisms are associated with latent autoimmune diabetes in adults

The cytotoxic T lymphocyte antigen-4 (CTLA-4) molecule is an important regulator of T-cell activation and a susceptibility candidate for autoimmune diseases. To evaluate the impact of CTLA-4 promoter allelic variants of the CTLA-4 gene in latent autoimmune diabetes in adults (LADA), the MH30 (rs231806), -1147 (rs16840252), and -318 (rs5742909) single nucleotide polymorphisms (SNPs) were studied in a population of Estonian origin, including 61 LADA patients and 230 controls. The MH30 GG genotype (p = 0.0051) and the G allele (p = 0.0023) were significantly associated with LADA. The frequency distribution of alleles and genotypes of rs16840252 and rs5742909 SNPs were not significantly different between the patient and control groups. The frequency of the CTLA-4 GCC (p = 0.000073) haplotype was significantly higher in LADA patients, whereas the frequency of the CTLA-4 CCC (p = 0.0019) was significantly lower in LADA patients in comparison with the control group. The current study confirms the involvement of CTLA-4 gene promoter polymorphisms in the susceptibility of LADA and extends our previous findings of associations with other CTLA-4 polymorphisms.     

Interaction of maternal atopy, CTLA-4 gene polymorphism and gender on antenatal immunoglobulin E production

BACKGROUND: Genetic heritability and maternal atopy have been correlated to antenatal IgE production, but very few studies have studied gene-maternal atopy interaction on antenatal IgE production. This study investigated the interaction of CTLA-4 polymorphism with prenatal factors on the elevation of cord blood IgE (CBIgE). METHODS: Pregnant women were antenatally recruited for collection of prenatal environmental factors by a questionnaire. Umbilical cord blood samples were collected for CBIgE detection by fluorescence-linked enzyme assay and CTLA-4 polymorphism measurement by restriction fragment length polymorphism. RESULTS: A total of 1104 pregnant women initially participated in this cohort study, and 898 of them completed cord blood collection. 21.4% of the newborns had elevation of CBIgE (>or=0.5 kU/L). The CTLA-4+49A allele (P=0.021), maternal atopy (P<0.001) and gender (P=0.034), but not the CTLA-4+49G allele, -318C allele, -318T allele, parental smoking or paternal atopy, were significantly correlated with the CBIgE elevation in multivariate analysis. A dichotomous analysis of gene-maternal atopy interactions identified maternal atopy and CTLA-4+49A allele had an additive effect on the CBIgE elevation, especially prominent in male newborns; and in the absence of maternal atopy, CTLA-4+49GG genotype had a protective effect on CBIgE elevation in female newborns. CONCLUSIONS: Maternal but not paternal atopy has significant impacts on CBIgE elevation depending on gender and CTLA-4+49A/G polymorphism of newborns. Control of maternal atopy and modulation of CTLA-4 expression in the prenatal stage may be a target for the early prevention of perinatal allergy sensitization.     

Enhanced expression of CTLA-4 (CD152) on CD4+ T cells in HIV infection

CTLA-4 (CD152) is a surface molecule of activated T cells with sequence homology to CD28. Both molecules bind to the same ligands, B7.1 (CD80) and B7.2 (CD86) but have antagonistic functions. While CD28 is an important costimulator, CTLA-4 has an essential inhibitory function in maintaining the homeostasis of the immune system. Down-regulation of CD28 predominantly on CD8+ T cells has been described in HIV infection, but analysis of CTLA-4 is complicated by its low expression levels. Here we have used potent signal enhancement to study CTLA-4 on peripheral blood mononuclear cells (PBMC) during HIV infection. CTLA-4 was expressed only on T cells. Expression levels were significantly increased selectively on CD4+ T cells during all stages of HIV infection, while CTLA-4 expression on CD8+ T cells was always low. In contrast, after stimulation with the mitogen phytohaemagglutinin (PHA), CTLA-4 levels were strongly increased on T cells from controls but in T cells from HIV patients this response was severely impaired. Our data suggest that in HIV infection CD4+ and CD8+ T cells may be less responsive to B7 costimuli due to two different mechanisms: increase in CTLA-4 expression by CD4+ cells and down-regulation of CD28 by CD8+ cells.