Toll样受体4基因多态性与消化性溃疡和幽门螺杆菌感染的相关性研究

背景：幽门螺杆菌（H．pylori）感染是消化性溃疡的主要病因。脂多糖（LPS）通过TOU样受体（TLR）4激活核因子（NF）-KB，在抗感染免疫应答中起启动和调节作用。TLR4基因发生Asp299Gly突变可中断TLR4介导LPS信号传导。目的：研究我国湖北省汉族人群TLR4基因Asp299Gly多态性与消化性溃疡和肌pylori感染的关系。方法：采用病例对照研究和聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法．检测126例消化性溃疡患者和264名正常对照者的TLR4等位基因Asp299Gly基因型分布。结果：消化性溃疡者肌pylori阳性率（90．5％）显著高于正常对照组（61．7％）（P〈0．0001，OR=5．889，95％CI：3．089-11．216）。在H．pylori感染相关性消化性溃疡组和正常对照组中均未发现TLR4基因Asp299Gly的突变型，其基因型、等位基因以及携带者频率总体分布无显著性差异。结论：本研究未能显示TLR4基因Asp299Gly基因多态性与H.pylori感染、H．pylori相关性消化性溃疡形成有相关性。     

TLR4基因多态性与慢性胃炎幽门螺杆菌感染无相关性

目的:研究我国湖北汉族人群TLR4基因 Asp299Gly多态性与慢性浅表性胃炎及幽门螺杆(H pylori)感染的关系．方法:采用病例-对照研究和多聚酶链反应-限制性片段长度多态性(PCR-RFLP)方法,检测 115例慢性浅表性胃炎患者115例和正常对照者2644例的TLR4等位基因Asp299Gly基因型分布．结果:慢性浅表性胃炎患者的H pylori阳性率 89．6％,显著高于正常对照组61．7％(P<0．000 1, OR=5．319．95％CI:2．784-10．162)．在H pylori 感染相关性的慢性胃炎组和正常对照组中 TLR4基因Asp299Gly基因型所有个体均为 AA纯合子,未发现的突变型,其基因型、等位基因以及携带者频率总体分布无显著性差异．结论:TLR4基因Asp299Gly基因多态性与H pylori相性慢性胃炎无明显相关性．     

TLR4基因Asp299Gly及TLR2基因Arg753Glu、Arg677Trp多态性与中国湖北汉族炎症性肠病无相关性

目的:研究TLR4基因Asp299Gly及LTLR2基因 Arg753Glu及Arg677Trp多态性在中国汉族人群中的分布,探讨其与炎症性肠病的相关性．方法:采用聚合酶链反应-限制性片段长度多态性方法,检测120例中国湖北汉族炎症性肠病患者与110例正常对照者TLR4 基因ASp299Gly及TLR2基因Arg753Glu及 Arg677Trp基因型,分析该基因多态性与炎症性肠病以及临床亚型的相关性．结果:炎症性肠病患者和健康对照者均未检测出TLR4基因ASp299Gly及TLR2基因 Arg753Glu及Arg677Trp突变型．结论:TLR4基因Asp299Gly及TLR2基因 Arg753Glu及Arg677Trp基因多态性与中国湖北汉族人群炎症性肠病的易感性无相关性．     

类风湿关节炎与TLR4单核苷酸多态性关联研究的Meta分析

目的探讨类风湿关节炎(RA)与TLR4基因Asp299Gly多态性的关联情况。方法检索已发表的有关RA和TLR4基因Asp299Gly多态性的文献．进行Meta分析。结果3项研究共纳入718例RA患者和1392名正常对照，综合分析显示TLR4基因Asp299Gly多态性不是RA的关联基因，OR=1．23(0．67，2．25)，P=0．5；TLR4基因Asp299Gly多态性分布在男女性RA患者分布差异无统计学意义，OR=0．48(0．22．1．03)，P=0．06：在共同表位基因阳性和阴性患者组差异无统计学意义，OR=0．67(0．40，1．13)，P=0．13；在类风湿因子(RF)阳性和阴性患者组差异无统计学意义，OR=I．02(0．51，2．02)，P=-I；RA患者中，Asp299Asp基因型患者发病早于Asp299Gly基因型者，OR=-4．35(-7．45，-1．25)，P=0．006。结论Meta分析显示，TLR4基因Asp299Gly多态性与RA易感性无关联．但Asp299Asp基因型者起病早于Asp299Gly基因型者。应在东方人群进一步开展随机对照和前瞻的队列研究揭示其在RA发病中的作用。     

TLR4和TNF-α基因多态性与支气管哮喘的相关性研究

目的探讨Toll样受体4和肿瘤坏死因子-α基因多态性与支气管哮喘的关系。方法采用病例对照研究和PCR-DNA测序的方法,检测50例支气管哮喘患者和30例对照组的TLR4的Asp299Gly和TNF-308的基因多态性。结果 （1）在支气管哮喘和健康对照组间,未发现TLR4Asp299Gly突变型。（2）支气管哮喘和正常对照组间未发现存在TNF-308G-A替换多态性。结论 （1）TLR4Asp299Gly基因多态性与支气管哮喘的易感性不相关,TNF-α基因多态性与支气管哮喘的易感性无相关性。     

白细胞介素-1基因多态性与消化性溃疡的关系

背景：大量临床流行病学证据表明消化性溃疡发病率的地域差异与宿主免疫遗传因素密切相关,目前宿主炎症因子基因多态性与消化性溃疡的关系正受到广泛关注。目的：探讨白细胞介素（IL）-1B-511、IL-1RN基因多态性与消化性溃疡的关系。方法：选取2008年9月～2009年5月昆明医学院第一附属医院确诊的57例十二指肠溃疡（DU）、38例胃溃疡（GU）以及40例非萎缩性胃炎（NAG）患者。以快速尿素酶试验和Giemsa染色检测幽门螺杆菌（H.pylori）感染,采用PCR-RFLP检测IL-1B-511、IL-1RN基因多态性。分析IL-1基因多态性、H.pylori感染、年龄与不同疾病之间的关系。结果：NAG、DU和GU组之间H.pylori感染率、IL-1B-511、IL-1RN基因型频率的差异无统计学意义。与NAG和DU相比,年龄≥60岁是GU的危险因素（OR=5.650,95%CI：1.811～17.624;OR=3.159,95%CI：1.254～7.955）。IL-1B-511、IL-1RN基因型和H.pylori感染与消化性溃疡类型无关（P〉0.05）。结论：在昆明市,年龄≥60岁是GU的危险因素,IL-1基因多态性与消化性溃疡无关。     

CD14及Toll样受体4基因多态性与大肠癌的相关性研究

目的探讨我国湖北汉族人Toll样受体（TLR）4基因Asp299Gly和CD14 C-260T基因多态性分布与大肠癌的相关性。方法采用聚合酶链反应限制性片段长度多态性（PCR—RFLP）方法，检测110例大肠癌患者及160例正常对照者TLR4基因Asp299Gly及CD14 C-260T基因型及等位基因频率的分布。结果大肠癌组CD14 C-260T基因型与正常对照组比较，差异有统计学意义（P〈0．05）。正常对照组CC基因型的频率为15．6%，明显低于大肠癌组的31．8％（P=0．0027，OR=0．3968，95％CI=0．2209～0．7129）；正常对照组中CT基因型的频率为48．1％，明显高于大肠癌组的30．9％（P=0．0056，OR=2．074，95%CI=1．246～3．452）。所有样本中均未发现TLR4基因Asp299Gly的突变型。结论CD14 C-260T基因多态性与中国湖北汉族大肠癌显著相关，而TLR4基因Asp299Gly多态性与大肠癌无关。     

AIDS与肝病患者胃镜活检组织幽门螺杆菌感染和消化性溃疡发现率的临床比较研究

目的探讨艾滋病、肝病和普通人群上中腹不适的患者胃幽门螺旋杆菌（H.pylori）感染发生率的异同,以发现H.pylori感染在诱发艾滋病患者和肝病患者消化性溃疡过程中作用的异同。方法艾滋病组患者46例,肝病组患者668例,非艾滋病非肝病普通人群对照组226例,均有上腹不适,行胃镜检查,活检组织分别进行快速尿素酶和Warthin-Starry银染检测H.pylori感染,同时记录内镜下发现的病变。结果肝病患者H.pylori感染率（36.08%）低于艾滋病患者（43.48%）和普通人群对照组（59.73%）（P〈0.05）,艾滋病患者H.pylori感染低于普通人群对照组患者（P〈0.05）;肝病伴发消化性溃疡患者的H.pylori感染率（45.22%）低于普通人群消化性溃疡患者的H.pylori感染率（80.49%）（P〈0.05）,艾滋病伴发消化性溃疡的H.pylori感染率（50.00%）与普通人群无差异（P〉0.05）。结论 H.pylori肝病患者消化性溃疡的发生与H.pylori感染的关系,不像普通人群消化性溃疡的发生与H.pylori感染的关系密切;而艾滋病患者中H.pylori感染率即使低于普通人群,H.pylori感染仍是促进艾滋病患者发生消化性溃疡的重要因素。     

中国汉族人群Toll样受体2基因多态性与肺结核易感性之间关系

目的 检测中国汉族人群特异TLR2基因多态性,并分析与结核病易感性之间关系。 方法 在小样本中测序检测TLR2基因中可能存在的基因多态性,再用连接酶特异检测技术在大样本进行SNP分型,并通过统计学方法分析基因多态性与结核病易感性之间相关性。 结果 共检测到6个基因多态性,它们在结核病患者与健康人之间等位基因、基因型以及单配体型上差异无统计学意义（P>0.05）。 结论 TLR2基因多态性并不是中国汉族人群结核病发病的重要危险因素。     

髓过氧化物酶基因多态性与胃癌易感性的关系

流行病学研究表明髓过氧化物酶（MPO）-463G→A多态性与多种疾病相关.目的：探讨MPO基因多态性与胃癌易感性之间的关系.方法：应用PCR-RFLP检测117例胃癌患者和105例对照者的MPO-463G→A多态性,比较两组MPO基因型频率和等位基因频率,分析MPO基因多态性与胃癌危险性的关系,并行分层分析探讨性别、年龄、吸烟状况、幽门螺杆菌（H.pylori）感染和胃癌家族史对胃癌的影响.结果：胃癌组GA和 AA基因型频率显著低于对照组（GA：25.6%对37.1%,AA：3.4%对11.4%,P〈0.05）,A等位基因频率亦明显降低（16.2%对30.0%,P〈0.05）.与GG基因型患者相比,携带MPO-463GA/AA基因型者罹患胃癌的危险性明显降低（OR=0.43,95% CI：0.25-0.75）.分层分析示男性、年龄≤60岁、不吸烟、H.pylori感染阴性和无胃癌家族史人群携带GA/AA基因型较携带GG基因型者罹患胃癌的危险性降低.结论：MPO基因多态性与胃癌易感性相关,A等位基因对胃癌易感性具有保护作用.     

TLR4 Asp299Gly polymorphism is not associated with coronary artery stenosis

Inflammation and innate immunity may play a role in the pathogenesis of atherosclerosis. The Asp299Gly polymorphism in the toll-like receptor 4 (TLR4) gene reduces responsiveness to lipopolysaccharide and has been associated with reduced incidence and slower progression of carotid atherosclerosis. We analyzed this polymorphism in relation to susceptibility to and severity of coronary artery disease. METHODS: 1400 participants (mean age: 63 years, 31% female) in the Southampton Atherosclerosis Study were genotyped for the TLR4 Asp299Gly polymorphism using the tetra-primer PCR method. RESULTS: There was no significant difference between the frequencies of the Asp/Gly or Gly/Gly genotypes combined, compared to the Asp/Asp genotype, in patients with 0, 1, 2 or 3 coronary arteries with >50% stenosis (chi2(3 d.f.)2=0.4, P=0.94). No associations were observed between genotype groups and cardiac risk factors (P>0.05). CONCLUSION: The findings of this study do not support the hypothesis that the TLR4 Asp299Gly polymorphism influences predisposition to and progression of coronary artery disease.     

The toll-like receptor 4 Asp299Gly variant: no influence on LPS responsiveness or susceptibility to pulmonary tuberculosis in The Gambia

SETTING: Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide. Studies in a murine model of pulmonary TB have identified a role for Toll-like receptor 4 (TLR4) in the development of chronic lung infection with Mycobacterium tuberculosis. The Asp299Gly polymorphism in the human TLR4 gene is associated with in vivo hyporesponsiveness to lipopolysaccharide (LPS) in Caucasians. OBJECTIVE: To determine whether TLR4 Asp299Gly influences LPS responses or susceptibility to pulmonary TB in humans in a Gambian population sample. DESIGN: We compared whole blood monokine responses to LPS in 245 healthy blood donors stratified by TLR4 Asp299Gly genotype to assess whether this polymorphism was functional in this population. A case-control study of 640 subjects was conducted to investigate whether TLR4 Asp299Gly was associated with TB. RESULTS: LPS-induced tumour necrosis factor, interleukin-1 beta and interleukin-10 production was not influenced by TLR4 Asp299Gly genotype. There was no association between TLR4 Asp299Gly and TB. CONCLUSION: Our data suggest that TLR4 Asp299Gly has no influence on monocyte LPS responses or susceptibility to TB in Gambians and could be an ancient neutral polymorphism.     

Association of the ASP299GLY TLR4 polymorphism with COPD

Bacterial infection and colonization plays an important role in COPD. The inflammatory response to these bacteria is mediated by Toll-like receptors. The Asp299Gly polymorphism of the Toll-like receptor-4 (TLR4) has been shown to be associated with decreased lipopolysaccharide (LPS) signal transduction resulting in impaired antimicrobial defense. Because altered TLR4 signalling may facilitate bacterial infection, we clinically phenotyped and genotyped 152 patients with COPD (including 24 non-smokers), and 444 healthy controls for the presence of the Asp299Gly polymorphism. Frequencies of the TLR4 Gly allele (4% vs. 8% in controls, odds ratio (OR) 2.24 (95% confidence interval (95%CI) 1.17-4.3)) as well as TLR4 Gly genotype (6% vs. 13% in controls, OR 2.39 (95%CI 1.20-4.79)) were significantly decreased among the patients with COPD. The TLR4 Gly allele was not detected at all in a subgroup of non-smoking patients (n=24). We conclude that the frequency of the Asp299Gly polymorphism is decreased in COPD patients. Unaltered LPS signal transduction by TLR4 may be important for the development of COPD.     

TLR4 polymorphisms, infectious diseases, and evolutionary pressure during migration of modern humans

Infectious diseases exert a constant evolutionary pressure on the genetic makeup of our innate immune system. Polymorphisms in Toll-like receptor 4 (TLR4) have been related to susceptibility to Gram-negative infections and septic shock. Here we show that two polymorphisms of TLR4, Asp299Gly and Thr399Ile, have unique distributions in populations from Africa, Asia, and Europe. Genetic and functional studies are compatible with a model in which the nonsynonymous polymorphism Asp299Gly has evolved as a protective allele against malaria, explaining its high prevalence in subSaharan Africa. However, the same allele could have been disadvantageous after migration of modern humans into Eurasia, putatively because of increased susceptibility to severe bacterial infections. In contrast, the Asp299Gly allele, when present in cosegregation with Thr399Ile to form the Asp299Gly/Thr399Ile haplotype, shows selective neutrality. Polymorphisms in TLR4 exemplify how the interaction between our innate immune system and the infectious pressures in particular environments may have shaped the genetic variations and function of our immune system during the out-of-Africa migration of modern humans.     

Deficient host-bacteria interactions in inflammatory bowel disease? The toll-like receptor (TLR)-4 Asp299gly polymorphism is associated with Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS: Elicitation of an innate immune response to bacterial products is mediated through pattern recognition receptors (PRRs) such as the toll-like receptors (TLRs) and the NODs. The recently characterised Asp299Gly polymorphism in the lipopolysaccharide (LPS) receptor TLR4 is associated with impaired LPS signalling and increased susceptibility to Gram negative infections. We sought to determine whether this polymorphism was associated with Crohn's disease (CD) and/or ulcerative colitis (UC). METHODS: Allele frequencies of the TLR4 Asp299Gly polymorphism and the three NOD2/CARD15 polymorphisms (Arg702Trp, Gly908Arg, and Leu1007fsinsC) were assessed in two independent cohorts of CD patients (cohort 1, n = 334; cohort 2, n = 114), in 163 UC patients, and in 140 controls. A transmission disequilibrium test (TDT) was then performed on 318 inflammatory bowel disease (IBD) trios. RESULTS: The allele frequency of the TLR4 Asp299Gly polymorphism was significantly higher in CD (cohort 1: 11% v 5%, odds ratio (OR) 2.31 (95% confidence interval (CI) 1.28-4.17), p = 0.004; and cohort 2: 12% v 5%, OR 2.45 (95% CI 1.24-4.81), p = 0.007) and UC patients (10% v 5%, OR 2.05 (95% CI 1.07-3.93), p = 0.027) compared with the control population. A TDT on 318 IBD trios demonstrated preferential transmission of the TLR4 Asp299Gly polymorphism from heterozygous parents to affected children (T/U: 68/34, p = 0.01). Carrying polymorphisms in both TLR4 and NOD2 was associated with a genotype relative risk (RR) of 4.7 compared with a RR of 2.6 and 2.5 for TLR4 and NOD2 variants separately. CONCLUSION: We have reported on a novel association of the TLR4 Asp299Gly polymorphism with both CD and UC. This finding further supports the genetic influence of PRRs in triggering IBD.     

The role of Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms and CARD15/NOD2 mutations in the susceptibility and phenotype of Crohn's disease

BACKGROUND: We investigated the influence of 2 common Toll-like receptor 4 (TLR4) polymorphisms on susceptibility and disease characteristics of Crohn's disease (CD). METHODS: Genomic DNA from 204 patients with CD and 199 unrelated controls was analyzed for the presence of 2 single nucleotide polymorphisms in the TLR4 gene, resulting in the amino acid substitutions Asp299Gly and Thr399Ile. In addition, the carrier status for the 3 common CD-associated CARD15/NOD2 gene mutations, Arg702Trp, Gly908Arg, and 1007fs, was determined. The frequency of the different genotypes was compared, and a detailed genotype-phenotype correlation was performed. RESULTS: An almost 2-fold increase in the frequency of the TLR4 Asp299Gly phenotype was observed in patients with CD (14.2%) compared with healthy controls (7.5%, P = 0.038, odds ratio = 2.03). The prevalence of a stricturing phenotype was increased in patients heterozygous for 1 of the TLR4 polymorphisms studied (Asp299Gly, 34.5%; Thr399Ile, 36.7%) compared with patients with wild-type TLR4 (17.1% and 16.7%; P = 0.04 and 0.02, respectively). The presence of the Asp299Gly polymorphism in the absence of CARD15/NOD2 mutations was a particularly strong predictor of the stricturing disease phenotype that was present in 47.4% of the patients with Asp299Gly+/NOD2- compared with 10.1% of the patients with the Asp299Gly-/NOD2+ status (P = 0.0009; P = 0.0004 for Thr399Ile+/NOD2- versus Thr399Ile-/NOD2+). In contrast, there was a trend toward a higher prevalence of the penetrating phenotype in the TLR4-/NOD2+ group (71.6%) compared with the TLR4+/NOD2- group (47.4%, P = 0.059). CONCLUSIONS: The TLR4 Asp299Gly polymorphism is a risk factor for CD. TLR4 and CARD15/NOD2 mutations may contribute to distinct disease phenotypes.