广东汉族人群TLR2基因的多态性研究

目的:人类Toll样受体2(TLR2)是先天免疫系统中一个重要的病原微生物识别受体。本研究将建立广东汉族人群TLR2基因座位的功能性多态性图谱,为下一步疾病相关性研究打下基础。方法:收集200例健康、无亲缘关系的中国广东汉族人外周血液,随机抽取其中24例样品,对TLR2基因的启动子区、3个外显子以及它们周围的部分内含子序列进行聚合酶链式反应(PCR)扩增和直接测序,找出多态性位点,对剩余176例样品分别用序列特异性引物聚合酶链反应(PCR-SSP)及PCR技术对发现的单核苷酸多态性(SNPs)和插入/缺失(INDEL)多态性位点进行基因分型,分型结果进行Hardy-W e inberg平衡分析、中性进化分析以及连锁不平衡分析。结果:发现5个SNPs位点,其中2个位于启动子区的SNPs是首次发现,位于编码区的3个SNPs位点均为同义突变,频率最高的SNP是rs3804099,其次要等位基因频率为26.3%;在第1外显子区发现1个长度为22bp的INDEL多态位点(-196到-174),其缺失等位基因所占的频率为31.8%。所有多态性位点均符合Hardy-W e inberg平衡。中性检验显示广东汉族人群TLR2基因符合中性进化假说。连锁不平衡分析显示位于调控区的-18945 C/T和-18883 C/G 2位点之间完全连锁,而位于编码区的rs3804099和rs3804100两位点之间紧密连锁。结论:本研究首次建立了汉族正常人群TLR2基因座位的功能性多态性图谱,并研究了其分布频率,发现了一些种族特异性的多态性位点,为今后开展汉族人基因多态性与疾病相关性研究以及人群进化研究提供了重要资料。     

广东地区汉族人群TLR1 基因多态性的测序研究

目的: 人类Toll样受体1(TLR1)在先天性免疫中起着重要作用。本文将着重研究广东地区汉族正常人群中TLR1 基因功能区的单核苷酸多态性(SNPs)图谱和频率分布。方法: 随机收集50例健康、无亲缘关系的中国广东地区汉族人外周血液,对TLR1 基因的启动子区、5'和3'非翻译区、4个外显子区的序列进行PCR扩增和直接测序,找出多态性位点及其频率分布规律。在此基础上对多态性位点进行Hardy-Weinberg平衡分析、中性进化分析和连锁不平衡分析。结果: 共发现17个SNPs以及2个插入/缺失多态位点,其中2个是首次发现的新多态性位点。位于编码区的新SNP位点+1 378 A/G为非同义突变位点,能导致460位丝氨酸(Ser)残基替换为甘氨酸(Gly)残基,并且这个氨基酸残基的替换处于TLR1胞外区的LRR结构域中,从而有可能影响蛋白的识别功能。另外,频率最高的SNPs是+743 A/G和+1 518 A/G,其次要等位基因频率均达到48%。所有多态性位点均符合Hardy-Weinberg平衡。中性检验显示广东汉族人群 TLR1 基因不符合中性进化假说,很可能是其调控区受到平衡选择作用的原因。连锁不平衡分析显示多态性位点-6 912 C/TA、-6 876 C/T、-6 399 C/T和-6 375 C/T之间,-6 847 A/G和-6 737 A/T之间,以及-5 984 -/CT、-5 531 A/G和-5 490 C/G之间完全连锁。结论: 本研究首次报道了汉族正常人群TLR1 基因的功能性多态性图谱,发现了一些种族特异性的多态性位点及频率分布规律,为今后开展汉族人基因多态性与疾病相关性研究打下一定的基础。     

TLR4基因多态性在中国人群中的初步研究

目的检测中国人Toll样受体4(Toll—like receptor 4．TLR4)基因调控区和编码区的单核苷酸多态性(single nucleotide polymorphisms，SNPs)．寻找TLR4基因的遗传标记。方法采用直接测序的方法检测基因的5′区、编码区、部分内含子区和3′区，以确定中国人群中TLR4基因SNP的位置和类型，并用聚合酶链反应-限制性片段长度多态性对重庆汉族样本进行了抽样调查。结果在4．98kb的测序范围内，发现5个新的SNP，3个位于5′区．2个位于3′非翻译区。在重庆地区汉族样本中．两个高频分布SNP的等位基因频率分别是0．266和0．404。结论在TLR4基因新发现的两个高频多态性位点在我国人群中比较常见，可以作为关联分析的遗传标记。     

早老素-1基因启动子区-48C/T位点多态性与LOAD的遗传相关性

目的研究早老素-1基因启动子区-48C/T位点的多态性与迟发性AD(LOAD)的相关性.方法用常规方法从人外周血白细胞中抽提基因组DNA,PCR扩增出包含-48C/T多态性位点的基因片段,利用PCR-RFLP技术对-48C/T多态性位点进行基因分型,χ2检验分析-48C/T多态性位点基因型分布和等位基因频率.结果以33例AD病例和32例对照样品的外周血白细胞基因组DNA为模板,PCR扩增出了长度为344bp的包含-48C/T多态性位点的基因片段.基因分型结果表明,33例散发型AD的C和T等位基因频率分别为47%和53%,C/T和T/T基因型频率分别为94%和6%.而32例正常对照的C和T等位基因频率分别为48%和52%,C/T和T/T基因型频率分别为97%和3%.χ2检验结果显示,病例-对照样品间C和T等位基因频率及C/C、C/T和T/T基因型的分布均无显著性差异(χ2值分别为0.443和0.318,P>0.05).结论在我们研究的群体中,早老素-1基因启动子区-48C/T位点的多态性与LOAD无显著的遗传相关性.     

广东汉族正常人群TLR4基因单核苷酸多态性研究(英)

目的：人类Toll样受体4（TLR4）是先天免疫系统中一个重要的病原微生物识别受体。本研究将建立中国汉族正常人群TLR4基因座位的单核苷酸多态性图谱。方法：收集191例健康、无亲缘关系的中国广东汉族人外周血液,通过对TLR4基因的启动子区、3个外显子区以及它们周围的内含子区进行PCR扩增和测序,得到汉族正常人群TLR4基因座位单核苷酸多态性图谱及其频率分布特点。结果：共发现8个单核苷酸多态性位点,其中5个是首次发现的新位点。分布频率最高（0.283）的单核苷酸多态性位点是-1607 C/T。常见于高加索人中的2个非同义突变Asp299Gly和Thr399Ile在汉族人中没有被发现。中性检验显示汉族人群TLR4基因符合中性进化模型。结论：本研究建立了汉族正常人群TLR4基因座位的单核苷酸多态性图谱,发现了一些种族特异性的单核苷酸多态性位点,这些工作将为今后开展汉族人基因多态性与疾病相关性研究以及人群进化研究提供一定的帮助。     

广西人群TLR4基因3′-非编码区单核苷酸多态性的研究

目的通过对TLR4(Toll-like receptor 4)基因3′-非编码区单核苷酸多态性(single nucleotide polymorphism,SNP)基因型和等位基因的研究分析,了解其在广西地区人群的频率分布及其在不同地区、种族之间分布是否存在差异。方法采用DNA测序方法和单碱基延伸PCR技术检测广西地区人群TLR4基因3′-非编码区rs11536889G/C多态性,并比较广西地区人群与人类基因组计划研究的4个人群(欧洲、中国北京、日本、非洲)(http://www.ncbi.nlm.nih.gov/projects/SNP/)以及韩国地区人群SNP分型数据,以分析TLR4基因rs11536889G/C基因型和等位基因在不同地区人群中的分布差异。结果广西地区人群的TLR4基因3′-非编码区rs11536889G/C位点的分布频率在男性、女性组间无差异(P0.05)。与日本、韩国、中国北京地区人群比较分布差异无统计学意义(P0.05);而与欧洲、非洲地区人群比较,分布有显著性差异(P0.05)。结论广西地区人群TLR4基因3′-非编码区单核苷酸多态性与其它地区、种族人群之间存在统计学差异。     

中国九江汉族人群TLR2基因单核苷酸多态性与Graves病易感关系

目的:研究九江汉族人群TLR2基因多态性与Graves病的易感关系。方法:本研究采用特异性引物PCR方法,基于病例-对照研究的实验设计,对333例甲亢病例和368例正常对照的TLR2基因上的rs3804100和rs5743705位点进行了基因分型。结果:患者男女比例约为1∶2.6,女性有更高的患病风险;所有位点均符合哈迪-温伯格平衡。没有在总体病例、对照之间观察到多态位点基因型和等位基因频率的显著差异。然而,在对发病年龄和性别进行分层分析后发现,在GD早发病人中(≤40岁),SNP位点rs3804100的A/A基因型(P=0.013,OR=1.53,95%CI=1.11-2.12)以及A等位基因频率(P=0.020;OR=1.37;95%CI=1.05-1.79)显著高于正常对照组。结论:TLR2基因rs3804100位点的A/A基因型可能会显著增加人群40岁以前患GD的风险。     

TLR7基因单核苷酸多态性与江苏淮安哮喘患者易感性的相关性研究

目的:探讨Toll样受体7(TLR7)基因rs179009、rs179019、rs5935436位点多态性与江苏淮安地区汉族人群支气管哮喘的相关性。方法:采用病例对照方法,以聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法比较158例支气管哮喘组与137例健康对照组之间基因型、等位基因频率的差异。结果:哮喘组TLR7基因rs179009、rs170019位点基因型及等位基因型频率与对照组相比差异有统计学意义(P<0.05)。rs5935436位点基因型及等位基因型频率在哮喘组和对照组间差异均无统计学意义(P>0.05)。结论:TLR7基因rs179009位点和rs179019位点的多态性可能与江苏淮安地区汉族人群哮喘相关;而rs5935436位点的多态性可能与江苏淮安地区汉族人群哮喘无关。     

TGF-β1和ADAM33基因交互作用与儿童哮喘易感性及严重程度相关性

目的:探讨转化生长因子β1(TGF-β1)和解整合素金属蛋白酶33(ADAM33)基因单核苷酸多态性与儿童哮喘易感性及严重程度相关性。方法:采用以医院为基础的病例对照研究(110例哮喘患儿和144例对照)方法,三个多态性位点(V4、T2、T869C)用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)技术进行基因分型,应用MDR软件分析基因各位点之间交互作用。结果:TGF-β1基因的T869C位点基因型及等位基因频率分布在哮喘组和对照组比较差异均无统计学意义(P>0.05)。哮喘组ADAM33基因V4位点C和T2位点A等位基因频率显著高于对照组(P<0.01),而V4位点的CC基因型及T2位点的GA基因型分布在轻中度哮喘组与对照组比较差异无统计学意义(P>0.05),T2位点的AA基因型分布在重度哮喘与对照组比较无显著性差异(P>0.05)。MDR交互作用分析显示,ADAM33基因V4和T2位点构成的2个位点最佳模型;ADAM33基因位点V4、T2和TGF-β1位点T869C构成的3个位点最佳模型两组比较均有统计学差异(P<0.05)。结论:ADAM33基因V4和T2位点与儿童哮喘发生及其严重程度相关,同时TGF-β1基因T869C位点与ADAM33基因V4和T2位点均具有明显交互作用     

PINK1基因多态位点IVS5-5G＞A可能增加中国人晚发性帕金森病的发病风险

目的探讨PINK1基因第5外显子上游调控区IVS5-5G>A多态位点与散发晚发性帕金森病(Parkinson disease,PD)发病风险的关联性。方法对IVS5-5G>A多态位点是否可能影响mRNA剪接进行了生物信息学分析。采用病例-对照的方法对382例散发晚发性PD病例和336名匹配的对照进行了PINK1基因IVS5-5G>A多态与中国汉族人散发晚发性帕金森病的发病风险的关联研究。基因型分型采用聚合酶链反应,变性高效液相色谱和测序相结合的方法。等位基因频率和基因型频率分布差异的比较采用卡方检验。结果生物信息学分析内含子区IVS5-5G>A多态位点位于第5外显子剪接受点区域内,可能是影响基因表达的调控区功能性单核苷酸多态性。PINK1基因IVS5-5G>A多态性与中国人散发晚发性PD发病风险之间存在有统计学意义的相关性(OR=1.95,95%CI:1.29～2.94,P=0.0012)。携有A等位基因的纯合子(AA)发病风险明显增加(OR=2.45,95%CI:1.27～4.72,P=0.009)。结论研究结果证实PINK1基因IVS5-5G>A多态性可能是中国人晚发PD的一个危险因素。     

Characterization and functional investigation of single nucleotide polymorphisms (SNPs) in the human TLR5 gene

Toll-like receptors recognize pathogen-associated molecular patterns (PAMPs) and TLR5 is the pathogen recognition receptor (PRR) for bacterial flagellin. Patients carrying a R392 stop polymorphism display an inflammatory phenotype and increased susceptibility to pneumonia caused by the flagellated bacteria Legionella pneumophila. While this suggests that TLR5 mutations may be clinically relevant, functional data are not available for the majority of the other TLR5 polymorphisms. We have characterized all known single nucleotide polymorphisms (SNPs) of TLR5 for their functional relevance upon stimulation in transiently transfected CHO-K1 cells. Among the 13 missense SNPs of TLR5 reported in the human genetic databases, three SNPs (c.1174C>T, p.R392X; c.2081A>G, p.D694G; and c.2464C>T, p.L822F) were found to be functionally relevant in transiently transfected CHO-K1 cells. The prevalences of these functionally relevant SNPs in our investigation were 11.9 %, 0 %, and 0 %, in healthy donors. The p.D694G and p.L822F SNPs are of low frequency in the Caucasian population though further investigations of the common p.R392X variant alone or of functional relevant TLR5 SNPs in combination with other TLR SNPs will elucidate their possible role on disease susceptibility in humans and may facilitate clinical diagnosis.     

Contribution of Toll like receptor polymorphisms to dengue susceptibility and clinical outcome among eastern Indian patients

Dengue infection has been one of the major public health concerns in India causing simple dengue fever (DF) to severe dengue infection. In the present study, contribution of TLR3, 7 and 8 polymorphisms towards dengue disease susceptibility and severity among Eastern Indian patients was analysed. Genomic DNA was extracted from blood of 201 dengue infected patients and 157 healthy individuals, followed by genotyping of eight polymorphisms of TLR3 (rs3775290), TLR7 (rs5741880, rs3853839, rs179008 and rs179010) and TLR8 (rs3764879, rs3764880 and rs5744080) genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Functional analyses of the polymorphisms were predicted. Genotypic association of polymorphisms, alone and in combination, with dengue disease susceptibility and development of WHO-defined warning signs among patients was calculated by using SPSS software. TLR7-rs179008 & TLR8-rs3764880 were implicated to be non-synonymous polymorphisms. Specific genotypes of majority of the analysed TLR polymorphisms exhibited significant positive association with disease susceptibility. CC/C and AA/A of TLR7-rs179008 (p < 0.0001) and TLR8-rs3764880 (p < 0.00001) respectively were significantly associated with development of warning signs among dengue infected patients. Particular genotypic combinations of rs3853839-rs5744080 and rs179008-rs3764880 increased the risk of dengue infectivity, whereas, presence of last combination was more prevalent among dengue patients with warning signs. Thus these polymorphic variants of TLR3, 7 and 8 might act as potential prognostic biomarkers for predicting disease severity among dengue virus infected patients.     

A polymorphism in melanoma differentiation-associated gene 5 may be a risk factor for enterovirus 71 infection

Enterovirus 71 (EV71) infection has a wide variety of clinical manifestations, from no symptoms to fatal disease. Host immune response may be a determinant of disease severity. We investigated the association of polymorphisms in three pattern recognition receptor (PRR) genes—toll-like receptor 3 (TLR3) (rs3775291), retinoic acid-inducible gene I (RIG-I) (rs10813831) and melanoma differentiation-associated gene 5 (MDA5) (rs1990760)—with the severity of EV71 infection. Polymorphisms of candidate genes in 87 EV71-infected patients and 57 asymptomatic controls were detected. Binary logistic regression analysis revealed statistically significant differences in polymorphism of MDA5 (rs1990760) between patients with severe EV71 infection and asymptomatic controls in an additive model (OR 0.424, 95% CI 0.213-0.845, p 0.015) and a dominant model (OR 0.256, 95% CI 0.103-0.635, p 0.003). Polymorphism of MDA5 (rs1990760) (OR 0.399, 95% CI 0.199-0.798, p 0.009) was found to be associated with the severity of EV71 infection with the analysis of ordinal logistic regression. These results indicated the association between MDA5 (rs1990760) polymorphism and an increased risk of a severe EV71 infection in Chinese children, which offers potential for investigating the innate immune mechanism of EV71 infection and identifying at-risk infants, for whom a preventive strategy may reduce the severity of EV71 infection.     

Genetic variation in the TNF receptor-associated factor 6 gene is associated with susceptibility to sepsis-induced acute lung injury

ABSTRACT: BACKGROUND: Recent studies showed that overwhelming inflammatory response mediated by the toll-like receptor (TLR)-related pathway was important in the development of acute lung injury (ALI). The aim of this study was to determine whether common genetic variation in four genes of the TLR signaling pathway were associated with sepsis-induced ALI susceptibility and risk of death in Chinese Han population. METHODS: Fourteen tag single nucleotide polymorphisms (tagSNPs) in MyD88, IRAK1, IRAK4 and TRAF6 were genotyped in samples of sepsis-induced ALI (n = 272) and sepsis alone patients (n = 276), and tested for association in this case-control collection. Then, we investigated correlation between the associated SNP and the mRNA expression level of the corresponding gene. And we also investigated correlation between the associated SNP and tumor necrosis factor alpha (TNF-alpha) as well as interleukin-6 (IL-6) concentrations in peripheral blood mononuclear cells (PBMCs) exposed to lipopolysaccharides (LPS) ex vivo. The mRNA expression level was determined using real-time quantitative Polymerase Chain Reaction (PCR) assays, and concentrations of TNF-alpha and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The association analysis revealed that rs4755453, an intronic SNP of TRAF6, was significantly associated with susceptibility to sepsis-induced ALI. The C allele frequency of rs4755453 in the sepsis alone group was significantly higher than that in the sepsis-induced ALI group (P = 0.00026, odds ratio (OR) = 0.52, 95% confidence interval (CI) 0.37-0.74). These associations remained significant after adjustment for covariates in multiple logistic regression analysis and for multiple comparisons. TRAF6 mRNA expression levels in PBMCs from homozygotes of the rs4755453G allele were significantly higher than that in heterozygotes and homozygotes of the rs4755453C allele at baseline (P = 0.012 and P = 0.003, respectively) as well as after LPS stimulation (P = 0.009 and P = 0.005). Moreover, the concentrations of TNF-alpha and IL-6 in cell culture supernatants were also significantly higher in the subjects with rs4755453GG genotype than in subjects with CG and CC genotype. None of the 14 tagSNPs showed associations with risk of death and severity among ALI cases. CONCLUSIONS: Our findings indicated that common genetic variants in TRAF6 were significantly associated with susceptibility to sepsis-induced ALI in Chinese Han population. This was the first genetic evidence supporting a role for TRAF6 in ALI.     

Toll‐like receptor polymorphism in host immune response to infectious diseases: A review

Immunopolymorphism is considered as an important aspect behind the resistance or susceptibility of the host to an infectious disease. Over the years, researchers have explored many genetic factors for their role in immune surveillance against infectious diseases. Polymorphic characters in the gene encoding Toll‐like receptors (TLRs) play profound roles in inducing differential immune responses by the host against parasitic infections. Protein(s) encoded by TLR gene(s) are immensely important due to their ability of recognizing different types of pathogen associated molecular patterns (PAMPs). This study reviews the polymorphic residues present in the nucleotide or in the amino acid sequence of TLRs and their influence on alteration of inflammatory signalling pathways promoting either susceptibility or resistance to major infectious diseases, including tuberculosis, leishmaniasis, malaria and filariasis. Population‐based studies exploring TLR polymorphisms in humans are primarily emphasized to discuss the association of the polymorphic residues with the occurrence and epidemiology of the mentioned infectious diseases. Principal polymorphic residues in TLRs influencing immunity to infection are mostly single nucleotide polymorphisms (SNPs). I602S (TLR1), R677W (TLR2), P554S (TLR3), D299G (TLR4), F616L (TLR5), S249P (TLR6), Q11L (TLR7), M1V (TLR8), G1174A (TLR9) and G1031T (TLR10) are presented as the major influential SNPs in shaping immunity to pathogenic infections. The contribution of these SNPs in the structure‐function relationship of TLRs is yet not clear. Therefore, molecular studies on such polymorphisms can improve our understanding on the genetic basis of the immune response and pave the way for therapeutic intervention in a more feasible way.     

Association of polymorphisms of innate immunity-related genes and tuberculosis susceptibility in Mongolian population

BackgroundsGenetic polymorphism of the toll-like receptor 2, 4 (TLR2, TLR4) and natural resistance-associated macrophage protein 1 (NRAMP1) genes may affect host immune response to Mycobacterium tuberculosis (Mtb) and lead to the variation of susceptibility to tuberculosis (TB) in humans. However, the association of single nucleotide polymorphisms (SNP) in these genes and the susceptibility to TB in Mongolian population has not been investigated.MethodsWe conducted a genetic association study including 197 Mongolian TB patients and 217 Mongolian healthy controls in Inner Mongolia, China. DNA of blood samples was extracted and genotyped for 5 SNPs in TLR4, 4 SNPs in TLR2 and 5 SNPs in NRAMP1 by next-generation sequencing. A logistic regression was performed and odds ratios (OR) with 95% confidence intervals (CI) were calculated to estimate the risk at TB by each SNP.ResultsThe most significant locus associated with the susceptibility to TB was TLR4 rs11536889. The frequency for allele C of TLR4 rs11536889 was 16.0% in TB patients and 23.5% in healthy controls, respectively. Rs11536889 C/C genotype of TLR4 was significantly associated with the low susceptibility against TB compared to G/G genotype in the dominant model (OR 0.62, 95% CI 0.41–0.94).ConclusionsThe TLR4 rs11536889 polymorphisms might be an indicative of the low susceptibility to TB in Mongolian population, which provides valuable information for the generation of effective strategy or measurement against TB in Mongolian population.     

Role of IL-10 gene polymorphisms on the susceptibility for esophageal cancer and its association with environmental factors

We conducted a hospital-based case-control study to investigate the association of three common SNPs (-1082G/A rs1800896, -819T/C rs1800871, and -592A/C rs1800872) of IL-10 gene polymorphisms with the susceptibility to esophageal cancer in a Chinese population. 246 patients with pathologically proven esophageal cancer and 492 healthy control subjects were collected in our study. Genotyping of IL-10-1082G/A rs1800896, -819T/C rs1800871, and -592A/C rs1800872 was performed using the Sequenom MassARRAY platform (Sequenom; San Diego, CA). Unconditional logistic regression analyses showed that subjects carrying the AA genotype and GA+AA genotype of IL-10-1082G/A rs1800896 were associated with an increased risk of esophageal cancer, and the adjusted ORs (95% CI) were 2.19 (1.31-3.64) and 1.44 (1.05-1.99), respectively. However, we did not find significant association of IL-10-819T/C rs1800871 and -592A/C rs1800872 with the development of esophageal cancer. By stratification analysis, we found that IL-10-1082G/A rs1800896 polymorphism has no significant association with smoking, drinking and family history of cancer in the first relatives in esophageal cancer risk (P>0.05). In conclusion, IL-10-1082G/A rs1800896 genetic variation may be employed as candidate biomarkers for the prediction of susceptibility in esophageal cancer.     

No associations established between single nucleotide polymorphisms in human Toll‐like receptor 2 and Toll‐interacting protein and Staphylococcus aureus bloodstream infections

Staphylococcus aureus bloodstream infections (SABSI) are associated with high morbidity and mortality. The Toll‐like receptor 2 (TLR2) and Toll‐interacting protein (TOLLIP) are important in recognition and regulation of human innate immunity response to S. aureus. Single nucleotide polymorphisms (SNPs) in the TLR2 and TOLLIP encoding genes have been associated with disease, including BSI. The aim of this study was to examine potential associations between a selection of SNPs in the genes encoding TLR2 and TOLLIP, and predisposition, severity, and outcome of SABSI. All patients ≥18 years of age with at least one S. aureus positive blood culture collected from March 2011 through February 2014 at Akershus University Hospital, Lørenskog, Norway, were considered for inclusion. Patients attending elective orthopaedic surgery (total hip and knee replacements, lumbar surgery) served as a control group. The TLR2 Arg753Gln, TLR2 Pro631His, TOLLIP rs5743942, and rs5743867 polymorphisms were analysed using TaqMan SNP Genotyping Assays. A total of 209 SABSI patients and 295 controls were included. The TLR2 Arg753Gln and TLR2 Pro631His polymorphisms were infrequent with no homozygotes and <10% heterozygotes. The included TLR2 and TOLLIP polymorphisms were not associated with susceptibility to SABSI, severity, 30‐day all‐cause mortality, or SABSI caused by the clonal complex 30 (CC30) genotype.     

Genetic variations in toll-like receptor pathway and lung function decline in Cystic Fibrosis patients

The toll-like receptor (TLR) family maintains pulmonary homeostasis by pathogen recognition, clearance and regulation of inflammation. Genes affecting inflammation response play a key role in modifying Cystic fibrosis (CF) lung disease severity. We assessed the impact of single nucleotide polymorphisms (SNPs) of TLR genes (TLR1 to TLR10, CD14, lipopolyssacharide-binding protein (LBP)) on lung function in CF patients. Each SNP was tested for time-dependent effect on FEV1, using six genetic models. In addition, we investigated associations between SNP genotypes and extreme subject specific slopes of FEV1 decline. Variant alleles of polymorphisms of TLR2 rs1898830, rs5743708, and rs3804100 demonstrated a consistent association with lung disease severity (p = 0.008, p = 0.006 and p = 0.029 respectively). Patients homozygous for variant C allele of TLR5 polymorphism rs5744174 are more frequently associated with extreme fast FEV1 decline (OR: 20 (95% Confidence Interval:1.85–216.18)). Patients homozygous AA for TLR1 polymorphism rs5743551 are more frequently associated with faster decline of FEV1 compared to heterozygous genotype (OR:7.33 (95% CI:1.63–33.11). Our findings indicate that variations in TLR1, TLR2 and TLR5 genes may influence CF lung function decline. Further functional analysis is required to provide new insights into the pathogenesis of TLRs in CF lung disease severity.     

Association between TLR2 polymorphisms (− 196–174 Ins/Del,R677W,R753Q,and P631H) and schizophrenia in a Tunisian population

Since immune dysregulation has been well studied in schizophrenia pathophysiology, recent studies showed a potent role of TLR2 in neuroinflammation process underlying schizophrenia pathogenesis. However, the genetic predisposition is still unclear. Thus, we hypothesized that TLR2 polymorphisms − 196–174 Ins/Del (rs111200466), R753Q (rs5743708), R677W (rs121917864), and P631H (rs5743704) could be involved in schizophrenia predisposition. A case–control study was performed on a Tunisian population composed of 250 healthy controls and 250 patients genotyped by PCR–RFLP. Genotype and allele distribution were evaluated with sex, schizophrenia subtypes, and other clinical features. We also assessed a haplotype analysis for TLR2 polymorphisms with schizophrenia. Our results showed higher ins/del genotype frequency in healthy women compared to patients (p = 0.006; OR = 0.2). In the other hand, logistic regression showed higher ins/del genotype frequency in controls compared to paranoid patients (p = 0.05; OR = 0.48, adjusted). Frequencies of CT and T allele of R677W were significantly higher in patients compared to controls (p < 10⁻⁴, OR = 10.39; p < 10⁻⁴, OR = 4, adjusted, respectively). R753Q polymorphism was exclusively detected in patients (GA + AA = 2.5%) particularly in men with disorganized subtype. P631H did not show any association with schizophrenia. Finally, haplotype analysis showed that InsGTC and delGTC were associated with higher risk of schizophrenia (p = 0.0001, OR = 8.58; p = 0.04, OR = 5.01, respectively). In the Tunisian population, our results suggested that TLR2 R677W could be associated with susceptibility for schizophrenia, while − 196–174 Ins/Del suggested a trend of protection in women. Otherwise, R753Q could have an effect on schizophrenia especially for disorganized subgroup.