CTLA-4基因微卫星多态性与粤西汉族人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(cytotoxie T lymphocyte associated antigen-4,CTLA-4)基因微卫星多态性[CTLA-4(AT)n]与湛江沿海地区汉族人Graves病(GD)的相关性.方法:收取2006年门诊及住院患者中确诊为Graves病(Craves' disease,GD)102例和正常对照组100例,应用聚合酶链式反应-单链长度多态性分析法(PCR-SSLP)确定CTLA-4基因第4外显子3'末端AT重复序列的基因型.结果:CTLA-4基因3'末端微卫星位点有20个等位基因,GD组与正常对照组之间之间的基因频率差异无统计学意义(P>0.05).结论:CTLA-4(AT)n多态性可能与GD无相关性.     

TLR4 基因启动子单核苷酸多态性与结直肠癌临床预后的关系

目的:探讨Toll样受体(TLR)基因启动子单核苷酸多态性(SNP)与结直肠癌临床预后的关系。方法:收集我院2006年1月到2010年1月收治的结直肠癌患者200例,通过PCR扩增外周血DNA,经过查找数据库发现TLR4基因启动子区域有rs137853920、ss77136219多态位点,对所有患者随访5年,比较不同手术方式、美国癌症联合委员会(AJCC)分期、分化程度患者的总生存时间(OS)率和疾病无进展时间(PFT)率,分析基因型频率以及单倍体频率对患者生存影响。结果:200例患者生存时间在4~60个月,中位生存时间为54个月,OS率和PFT率在不同手术方式、癌症AJCC分期、分化程度患者间差异均具有统计学意义(P0.05);对生存资料进行多因素的Cox回归分析,结果显示rs137853920基因多态位点基因型AA、AG、GG具有较好的预后(P0.05),而ss77136219基因多态位点基因型GG、GA、AA具有较差预后(P0.05)。rs137853920、ss77136219多态位点共有四个单倍体型分别为AA、AG、GA、GG,频率分别为26.3%、21.7%、38.5%、21.6%,经过Cox多因素分析AG型患者具有较好预后(P0.05),而GG型患者具有较差预后(P0.05)。结论:TLR4基因启动子SNP可以作为结直肠癌临床预后的特异指标。     

巨噬细胞迁移抑制因子基因多态性与结直肠癌风险研究

目的研究巨噬细胞迁移抑制因子(macrophage migration inhibitory factor,MIF)基因单核苷酸多态性(SNPs;rs755662,rs11548059,rs1049829,rs1803976)与结直肠癌发生风险的关系。方法收集共计192例结直肠癌患者(CRC)和256名正常对照者外周血样本,以聚合酶链反应和Taqman探针分析方法,检测MIF基因单核苷酸多态性;以Logistic回归模型计算不同基因型与结直肠癌发生风险的关系。结果 rs755662基因型的出现频率在CRC组和正常对照组之间差异有统计学意义(P=0.011),而在rs11548059、rs1049829和rs1803976位点则差异无统计学意义(P=0.660、P=0.700和P=0.959)。此外,rs755662还分别与早期发病(年龄≤50岁,P=0.026)、分期(Ⅳ期,P=0.038)以及分化(P=0.040)有关。与正常对照组比,rs755662与Ⅲ期和Ⅳ期显著相关(P值分别为0.034和0.003)。结论 MIF基因5′-UTR区域rs755662(G/C)单核苷酸多态性与结直肠癌的易感性、患者发病年龄和分期有关。     

IL-23 受体基因多态性和克罗恩病的相关性研究

目的:探讨白介素23受体(IL-23R)基因rs11465779位点多态性与克罗恩病(Crohn’s Disease,CD)的关系。方法:从98例上海本地汉族CD患者和90例正常对照者外周血标本中提取基因IBD组DNA,用聚合酶链式反应-限制性片段长度多态(PCR-RFLP)技术检测IL-23R基因rs11465779位点变异情况,分析其基因表型、基因频率与IBD的关系。结果:IL-23R基因rs11465779位点基因型和等位基因频率在CD组和对照组中分布差异无显著性(P>0.05),且该位点多态性和CD发病年龄及性别均无相关。结论:IL-23R基因rs11465779位点多态性变异,可能不是中国南方汉族人群CD发病的危险因素。     

重庆市汉族健康人群白细胞介素-1基因多态性的研究

为了了解白细胞介素-I基因在中国重庆市汉族健康人群中的分布及其与不同种族比较的特点,采用了聚合酶链反应-限制性片段长度多态（PCR—RFLP）的方法,对140名重庆市汉族健康者的IL-1B-511基因多态性和IL-1RN第2内含子可变数目串联重复序列多态性进行检测,并结合相关文献进行了不同种族间的分析比较。结果表明重庆市汉族健康人群中1L-1B-511的各基因型频率为C/T型0．58、形,型0．50、C/C型0,32,与西班牙白种人相比,重庆地区汉族人IL-1B,B-511等位基因频率存在明显差异（P〈0．05）。1L-1RN的各基因型频率为1／1型0．93、1／2型0．05、1／4型0．01、4／4型0．01,与西班牙白种人及南非黑种人相比,重庆地区汉族人,IL-IRN等位基因频率存在明显差异（P〈0．05）。由此可以得出重庆地区汉族人群IL-1B-511位点存在C／T多态性和IL-1RN基因的第2号内含子存在可变数目串联重复序列多态性．其在不同种族间的分布存在着差异．     

PD-L1基因多态性与结直肠癌患者奥沙利铂化疗疗效和安全性的相关性研究

目的:研究PD-L1/3'-UTR上单核苷酸多态性rs4143815与结直肠癌患者奥沙利铂化疗疗效及安全性的相关性。方法:首先,测定262例接受奥沙利铂化疗的结直肠癌患者rs4143815的基因型;然后,统计分析基因型与奥沙利铂化疗疗效、不良反应发生情况及临床病理参数的相关性。结果:PD-L1/3'-UTR上单核苷酸多态性rs4143815与奥沙利铂治疗的疗效显著相关(P=0.028);与C/C型相比,C/G型患者的化疗疗效更好(OR=2.10),而G/G型患者的疗效却更差(OR=0.49)。然而,G/G型患者的不良反应发生率更低(OR=0.46)。此外,PD-L1/3'-UTR上单核苷酸多态性rs4143815与结直肠癌的肿瘤大小显著相关,G/G型患者的肿瘤体积比C/C型患者更小(R=0.08)。结论:rs4143815与奥沙利铂治疗结直肠癌患者的疗效、安全性和肿瘤大小显著相关,可能成为预测结直肠癌患者奥沙利铂治疗的疗效和安全性的参考分子标志物。     

CTLA4在T调节细胞诱导异种抗原免疫耐受中的机制研究

目的:通过靶向CTLA4 siRNA探讨CTLA4在T调节细胞诱导异种抗原免疫耐受中是否发挥功能及其作用机制。方法:体外扩增培养利用磁珠分选出的T调节细胞,AO/PI染色计算活率并通过细胞计数作出生长曲线,流式细胞仪检测扩增后细胞表型;采用Alex488染料标记siRNA,通过流式细胞仪检测siRNA的转染效率;实时定量PCR检测靶向CTLA4 siRNA的沉默效率;流式细胞术检测CTLA4在蛋白水平的变化;混合淋巴实验检测CTLA4表达下调后,T调节细胞的功能变化。结果:经过4周体外扩增,T调节细胞能够增长约1 200倍,并具有高活率和高纯度;siRNA的转染效率为61.8%±4.5%;Realtime PCR和流式细胞术检测CTLA4在mRNA水平和蛋白水平均有不同程度下降,其结果与对照组相比差异显著(P0.05);混合淋巴实验结果显示T效应细胞在受到异种抗原刺激时会发生增殖,Treg细胞能够抑制这种增殖,但是CTLA4表达下调后明显减弱了T调节细胞的抑制能力。进一步,在DC细胞参与的混合淋巴实验中发现Treg能够通过DC抑制T效应细胞对异种抗原的应答,而si CTLA4-Treg不能通过DC抑制T效应细胞增殖。结论:CTLA4在Treg介导的异种免疫应答中发挥着重要作用,这种作用方式可能是通过直接作用于T效应细胞或者间接通过DC细胞作用于T效应细胞发挥作用。靶向CTLA4 siRNA能够下调Treg细胞CTLA4的表达,影响Treg细胞抑制异种抗原引起T效应细胞应答的能力。     

血清CA72-4、CA199对结直肠癌的诊断价值及与肿瘤进展的关系研究

摘要 目的：探讨血清糖类抗原72-4（CA72-4）、糖类抗原199（CA199）对结直肠癌的诊断价值及与肿瘤进展的关系。方法：选取2016年7月到2018年7月期间在我院接受治疗的结直肠癌患者60例作为结直肠癌组,另选取同期在我院接受治疗的结直肠良性病变患者40例作为良性病变组,比较结直肠癌组、良性病变组血清CA72-4、CA199的水平,比较不同TNM分期、不同分化程度的结直肠癌患者血清CA72-4、CA199的水平,以病理诊断为金标准,分析血清CA72-4、CA199对结直肠癌的诊断价值。结果：结直肠癌组的血清CA72-4、CA199水平高于良性病变组（P<0.05）。TNM分期为III-IV期的结直肠癌患者的血清CA72-4、CA199水平高于I-II期的患者（P<0.05）,分化程度为低分化的结直肠癌患者的血清CA72-4、CA199水平高于中高分化的患者（P<0.05）。CA72-4联合CA199检测对结直肠癌的灵敏度高于CA72-4、CA199单独检测。结论：CA72-4与CA199联合检测对结直肠癌具有较高的诊断价值,且两指标的水平与结直肠癌的分化程度和TNM分期有关,可在一定程度上反映肿瘤进展情况。     

唾液酸免疫球蛋白型凝集素-15促进结直肠癌细胞增殖和迁移并抑制肿瘤组织中CD4+与CD8+T细胞浸润

唾液酸免疫球蛋白型凝集素-15(sialic acid-binding immunoglobulin-type lectin-15,Siglec-15)属于Siglecs家族的一员,是一种新型免疫抑制分子。Siglec-15在多种人类肿瘤细胞和肿瘤相关巨噬细胞中高表达,但Siglec-15在结直肠癌(colorectal cancer,CRC)中的生物学功能及其对免疫微环境的影响尚不明确。本文旨在分析Siglec-15异常表达对CRC细胞功能及CD4⁺T细胞、CD8⁺T细胞浸润的影响。首先,分析TCGA数据库中结直肠癌与正常组织中Siglec-15 mRNA表达水平,并对52例人CRC与配对癌旁组织进行免疫组织化学染色(IHC),发现Siglec-15在CRC中的表达水平高于癌旁组织(P<0.01)。CCK8和划痕愈合结果显示,敲低Siglec-15能抑制人CRC细胞SW480增殖(P<0.01)和迁移(P<0.05)。磁珠分选小鼠脾的CD8⁺T细胞并与小鼠CRC细胞MC38共培养,发现MC38细胞过表达Siglec-15能抑制CD8⁺T细胞对其的杀伤以及IFN-γ和TNF-α的分泌(P<0.01)。小鼠荷瘤结果表明,过表达Siglec-15可以促进小鼠肿瘤生长(P<0.05)。单样本基因集富集分析、荷瘤小鼠肿瘤组织及人结直肠癌组织IHC分析均表明,Siglec-15高表达时,肿瘤微环境中CD4⁺T细胞、CD8⁺T细胞浸润减少(P<0.05)。综上所述,Siglec-15可能通过促进CRC细胞增殖迁移以及抑制CD4⁺T细胞、CD8⁺T细胞浸润促进结直肠癌进展。本文为探究Siglec-15在CRC中的免疫抑制作用提供了一些新的实验依据。     

结直肠癌远处转移相关miRNA的基因多态性研究

为了探讨miRNA-499、miRNA-146、miRNA-149基因多态性与结直肠癌远处转移的相关性,本研究收集了376例结直肠癌患者,分为无远处转移组(n=167)和有远处转移组(n=180),同时搜集健康对照组患者(n=193)。采用PCR-限制性内切酶片段长度多态性技术对患者外周血miR-146a rs2910164 GC、miR-149rs2292832 CT和miR-499 rs3746444 TC进行基因型分析。结果证实携带miR-146a rs2910164 CC基因型的结直肠癌患者在远处转移组和健康对照组(CC vs CG, p=0.006; CC vs GG, p=0.047)以及无远处转移组和远处转移组(CC vs CG, p=0.02; CC vs GG, p=0.012)之间的差异均具有统计学意义。病理分期分析显示携带miR-146a rs2910164 CC基因型的结直肠癌患者在病理低分化组和高分化组(CC vs CG, p=0.03; CC vs GG,p=0.047)之间差异具有统计学意义。因此本研究推测携带miR-146a rs2910164 CC基因型的结直肠癌患者分化程度更低,更容易发生远处转移。     

A DNA vaccine against cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) prevents tumor growth

Co-stimulatory signaling pathway triggered by the binding of B7.1/B7.2 (CD80/86) of antigen-presenting cells (APCs) to CD28 of T cells is required for optimal T-cell activation. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T cell activation, which competes with CD28 for B7.1/B7.2 binding with a greater affinity. Ipilimumab, a monoclonal antibody against CTLA-4, has shown positive efficacy in a pivotal clinical trial for the treatment of metastatic melanoma and was approved by FDA. However, the cost of monoclonal antibody-based therapeutics might limit the number of patients treated. To develop a novel therapeutics specifically targeting CTLA-4, we constructed a DNA vaccine by cloning the sequence of CTLA-4 fused with a transmembrane domain sequence of placental alkaline phosphatase (PLAP) into a mammalian expression plasmid, pVAC-1. Immunization with the resulting construct, pVAC-1-hCTLA-4, elicited antibody specific to human CTLA-4 with cross reactivity to murine CTLA-4, which was sufficient for inhibiting B16F10 tumor growth in c57BL/6 mice in the absence of measurable toxicity. Coupling liposome with pVAC-1-mCTLA-4 could break tolerance to self-antigen in BALB/c mice and induce potent immunity against murine CTLA-4, and suppress growth of subcutaneous renal cell carcinoma (Renca).     

Therapeutic efficacy of ipilimumab,an anti-CTLA-4 monoclonal antibody,in patients with metastatic melanoma unresponsive to prior systemic treatments: clinical and immunological evidence from three patient cases

The management of unresectable metastatic melanoma is a major clinical challenge because of the lack of reliably effective systemic therapies. Blocking cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has recently been proposed as a strategy to enhance cell-mediated immune responses to cancer, and clinical trials have demonstrated that anti-CTLA-4 therapy can produce durable outcomes with different response patterns than cytotoxic chemotherapy. We enrolled eight out of 155 patients with advanced melanoma in a multicentre phase II trial that evaluated the activity and tolerability of ipilimumab, a fully human, anti-CTLA-4 monoclonal antibody (; NCT00289627; CA184-008). Here we report our experience with three of these patients, who experienced progressive disease after a variety of previous therapies, including prior immunotherapies, and who achieved good outcomes with ipilimumab. One patient had a partial response ongoing at 17+ months on ipilimumab despite failure with four prior therapies, and the other two patients showed durable stable disease, both still ongoing at 17+ and 20+ months, respectively. The patient achieving a partial response experienced no side effects while receiving ipilimumab. The other two patients developed immune-related adverse events (irAEs) including rash (one case; grade 2) and diarrhoea (both cases; grades 1 and 2, respectively); the histopathology of colon biopsy samples from both was suggestive of colitis, with an abundant CD8+ T-cell infiltrate. Nausea, vomiting and acute pancreatitis were also observed in one patient. In addition, immunohistochemical findings of a dense CD8+, TIA1+ and granzyme B+ lymphoid infiltrate within a biopsied lesion provide indirect evidence of functional T-cell activation induced by treatment. These case reports highlight the potential for anti-CTLA-4-based therapy in previously treated patients with advanced melanoma. Moreover, because the patterns of response to ipilimumab differ from chemotherapy, we need to understand how and when patients may respond to treatment so that appropriate clinical decisions can be made.     

Current Understanding of Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) Signaling in T-Cell Biology and Disease Therapy

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an immune checkpoint molecule that is mainly expressed on activated T cells and regulatory T (Treg) cells that inhibits T-cell activation and regulates immune homeostasis. Due to the crucial functions of CTLA-4 in T-cell biology, CTLA-4-targeted immunotherapies have been developed for autoimmune disease as well as cancers. CTLA-4 is known to compete with CD28 to interact with B7, but some studies have revealed that its downstream signaling is independent of its ligand interaction. As a signaling domain of CTLA-4, the tyrosine motif plays a role in inhibiting T-cell activation. Recently, the lysine motif has been shown to be required for the function of Treg cells, emphasizing the importance of CTLA-4 signaling. In this review, we summarize the current understanding of CTLA-4 biology and molecular signaling events and discuss strategies to target CTLA-4 signaling for immune modulation and disease therapy.     

Molecular Characterization of Human Rotavirus VP4 Genes by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism Assay

A restriction fragment length polymorphism (RFLP) assay was developed to examine the genetic variability and similarity of the VP4 genes of human rotaviruses. The VP4 genes of 14 human rotavirus strains, including VP4 serotype P1A strains (Wa, P, VA70), serotype P1B strain (DS-1), serotype P2 strains (M37, 1076, McN, ST3) and serotype P3 strains (AU-1, AU228, K8, PA151, PCP5, MZ58), and those of 2 feline strains (FRV-1 and Cat2) were reverse-transcribed and amplified by the polymerase chain reaction (PCR). The amplified VP4 cDNAs were then digested with a panel of restriction endonucleases (HindIII, NruI, HaeIII, and EcoRI), resulting in the identification of at least one enzyme with which digestion produced an RFLP profile specific for a particular P serotype. Of interest was the presence of two distinct RFLP patterns within the serotype P3 VP4 genes: one corresponding to the VP4 gene carried by the members of the AU-1 genogroup and the other corresponding to the VP4 genes carried by naturally-occurring reassortants between members of the AU-1 and other genogroups.     

Integrated map of AFLP, SSLP and RFLP markers using a recombinant inbred population of rice (Oryza sativa L.)

 A molecular map of rice consisting of 231 amplified fragment length polymorphisms (AFLPs), 212 restriction fragment length polymorphisms (RFLPs), 86 simple-sequence length polymorphisms (SSLPs), five isozyme loci, and two morphological mutant loci [phenol staining of grain (Ph), semi-dwarf habit (sd-1)] has been constructed using an F₁₁ recombinant inbred (RI) population. The mapping population consisted of 164 RI lines and was developed via single-seed descent from an intercross between the genetically divergent parents Milyang 23 (M) (tongil type) and Gihobyeo (G) ( japonica type). A subset of previously mapped RFLP and SSLP markers were used to construct the map framework. The AFLP markers were derived from ten EcoRI(+2) and MseI(+3) primer combinations. All marker types were well distributed throughout the 12 chromosomes. The integrated map covered 1814 cM, with an average interval size of 3.4 cM. The MG map is a cornerstone of the Korean Rice Genome Research Program (KRGRP) and is being continuously refined through the addition of partially sequenced cDNA markers derived from an immature-seed cDNA library developed in Korea, and microsatellite markers developed at Cornell. The population is also being used for quantitative trait locus (QTL) analysis and as the basis for marker-assisted variety development. Received: 24 June 1997 / Accepted: 25 November 1997     

错配修复系统hMSH2基因IVS12(-6)T>C多态及饮食习惯 与结直肠癌的易感性

目的:研究江苏省结直肠癌发病与hMSH2基因IVS12(-6)T>C多态及饮食习惯的相关性。方法:对江苏省金坛、泰兴和淮安地区近2年来新发结直肠癌患者共计108例以及配对180例健康体检者的饮食等生活习惯因素进行调查,提取外周血DNA,应用PCR-DHPLC和DNA序列分析的方法,采用病例对照研究结合现场收集的流行病学资料统计分hMSH2基因IVS12(-6)T>C与结直肠癌发病的关系。结果:hMSH2基因IVS12(-6)T>C在家族性结直肠癌患者中检出率较高,且与散发性结直肠癌病例之间差异有统计学意义(P<0.05),在喜食油炸和腌渍食物组,hMSH2基因IVS12(-6)T>CC突变与正常人群之间也存在明显的统计学差异(P<0.05)。结论:hMSH2基因IVS12(-6)T>C突变,通过遗传性和后天获得性等多重因素影响,使得该突变的携带者有更高的结直肠癌发病风险。     

Abdominal Visceral Fat is Associated with a BclI Restriction Fragment Length Polymorphism at the Glucocorticoid Receptor Gene Locus

Several investigations have suggested that body fat distribution is influenced by nonpathologic variations in the responsiveness to Cortisol. Genetic variations in the glucocorticoid receptor (GRL) could therefore potentially have an impact on the level of abdominal fat. A restriction fragment length polymorphism (RFLP) has previously been detected with the BelI restriction enzyme in the GRL gene identifying two alleles with fragment lengths of 4.5 and 2.3 kb. This study investigates whether abdominal fat areas measured by computerized tomography (CT) are associated with this polymorphism in 152 middle-aged men and women. The less frequent 4.5-kb allele was found to be associated with a higher abdominal visceral fat (A VF) area independently of total body fat mass (4.5/4.5 vs. 2.3/2.3 kb genotype; men: 190.7 ± 30.1 vs. 150.7 ± 33.3 cm², p=0.04; women: 132.7 ± 37.3 vs. 101.3 ± 34.5 cm², p=0.06). However, the association with AVF was seen only in subjects of the lower tertile of the percent body fat level. In these subjects, the polymorphism was found to account for 41% (p=0.003) and 35% (p=0.007), in men and women, respectively, of the total variance in AVF area. The consistent association between the GRL polymorphism detected with BelI and AVF area suggests that this gene or a locus in linkage disequilibrium with the BelI restriction site may contribute to the accumulation of AVF.