梅毒免疫相关基因的单核苷酸多态性研究

发布时间：2018-09-03 18:54

【摘要】：梅毒的免疫发病机制尚不明确。目前的研究认为,人体感染梅毒螺旋体后,体内将发生一系列复杂的细胞免疫和体液免疫,而这些免疫反应的类型、强度和持续时间将影响疾病的严重程度、病程及转归,这提示梅毒的遗传易感性可能与某些免疫相关基因存在关联。Toll样受体2(TLR2)作为一种天然免疫受体,通过识别梅毒螺旋体脂蛋白及细胞内信号传导,启动机体天然免疫和获得性免疫,并作为桥梁联系梅毒天然免疫和获得性免疫过程,对于维持免疫平衡和调节炎症反应强度具有重要意义。Th0细胞激活分化为Thl和Th2细胞,分泌相应的细胞因子引发细胞免疫和体液免疫,其细胞因子网络发挥重要的免疫调控作用。我们初步选定Toll样受体2 (TLR2)、Th1反应性细胞因子TNF-α、Th2反应性细胞因子IL-4作为本研究的目的基因,通过对这些基因SNP位点的分析,初步探讨其与梅毒易感性的关系。全文分为三个部分。第一部分梅毒患者的肿瘤坏死因子-α(TNF-α)基因单核苷酸多态性采集56例早期显性梅毒患者、38例早期潜伏梅毒患者和102例正常对照者外周静脉血,提取基因组DNA。应用MGB TaqMan荧光探针技术检测TNF-α基因-308 G/A和-238 G/A位点单核苷酸多态性,探讨这两个位点多态性与梅毒遗传易感性是否相关。结果发现：1.早期梅毒组TNF-α-308位点G、A等位基因的分布频率分别为0.926、0.074,对照组TNF-α-308位点G、A等位基因的分布频率分别为0.941、0.059,两组相比无显著差异(P0.05)；显性梅毒组TNF-α308位点G、A等位基因的分布频率分别为0.929、0.071,潜伏梅毒组TNF-α-308位点G、A等位基因的分布频率分别为0.921、0.079,两组相比无显著差异(P0.05)。2.早期梅毒组TNF-α238位点G、A等位基因的分布频率分别为0.968、0.032,对照组TNF-α238位点G、A等位基因的分布频率分别为0.975、0.025,两组相比无显著差异(P0.05)；显性梅毒组TNF-α-238位点G、A等位基因的分布频率分别为0.973、0.027,潜伏梅毒组TNF-α-238位点G、A等位基因的分布频率分别为0.961、0.039,两组相比无显著差异(P0.05) 结论：肿瘤坏死因子-α基因—308 G/A和238 G/A位点单核苷酸多态性与梅毒遗传易感性可能无显著相关。第二部分梅毒患者的白介素-4(IL 4)基因单核苷酸多态性通过分析早期梅毒患者白介素-4基因-590C/T位点单核苷酸多态性与梅毒易感性的关系,发现早期梅毒组IL-4-590位点C、T等位基因的分布频率分别为0.229、0.771,对照组IL-4-590位点C、T等位基因的分布频率分别为0.216、0.784,两组相比无显著差异(P0.05)；显性梅毒组IL-4-590位点C、T等位基因的分布频率分别为0.232、0.768,潜伏梅毒组IL-4-590位点C、T等位基因的分布频率分别为0.224、0.776,两组相比无显著差异(P0.05)。结论：白介素-4基因-590C/T位点单核苷酸多态性与梅毒遗传易感性可能无显著相关。第三部分梅毒患者的Toll样受体2(TLR2)基因单核苷酸多态性采用DNA测序法检测早期梅毒患者Toll样受体2(TLR2)基因Arg753Gln位点单核苷酸多态性与梅毒遗传易感性的关系。结果显示：各组TLR2Arg753Gln位点基因型均为GG型,GA、AA型缺如。早期梅毒组TLR2 Arg753Gln位点G、A等位基因的分布频率与对照组TLR2 Arg753Gln位点G、A等位基因的分布频率相比无显著差异；显性梅毒组TLR2 Arg753Gln位点G、A等位基因的分布频率与潜伏梅毒组TLR2 Arg753Gln位点G、A等位基因的分布频率相比无显著差异。结论：Toll样受体2(TLR2)基因Arg753Gln位点单核苷酸多态性与梅毒遗传易感性可能无显著相关。
[Abstract]:The immunopathogenesis of syphilis is still unclear. Current studies suggest that after infection with Treponema pallidum, a series of complex cellular and humoral immunity will occur in the body, and the type, intensity and duration of these immune responses will affect the severity, course and outcome of the disease, suggesting that the genetic susceptibility of syphilis may be related to a certain disease. Toll-like receptor 2 (TLR2), as a natural immune receptor, initiates innate and acquired immunity by recognizing Treponema pallidum lipoprotein and intracellular signal transduction, and serves as a bridge between innate and acquired immune processes of syphilis, thus maintaining immune balance and regulating inflammation. Th0 cells activate and differentiate into Thl and Th2 cells, secrete corresponding cytokines to induce cellular immunity and humoral immunity, and their cytokine networks play an important role in immune regulation. We initially selected Toll-like receptor 2 (TLR2), Th1 reactive cytokines TNF-a and Th2 reactive cytokines IL-4 as our study. Objective To explore the relationship between SNP loci of these genes and susceptibility to syphilis.
Part one single nucleotide polymorphisms of tumor necrosis factor alpha (TNF- alpha) gene in syphilis patients
Genomic DNA was extracted from peripheral venous blood of 56 patients with early dominant syphilis, 38 patients with early latent syphilis and 102 normal controls. Single nucleotide polymorphisms of TNF-alpha gene-308 G/A and-238 G/A were detected by MGB TaqMan fluorescence probe technique to explore whether the polymorphisms of these two loci were related to the genetic susceptibility to syphilis.
The results showed that: 1. The distribution frequencies of G and A alleles at TNF-alpha-308 locus in early syphilis group were 0.926 and 0.074, respectively, while those at TNF-alpha-308 locus in control group were 0.941 and 0.059, respectively. There was no significant difference between the two groups (P 0.05); the distribution frequencies of G and A alleles at TNF-alpha-308 locus in dominant syphilis group were 0.929, 0.071, and 0.071, respectively. The distribution frequencies of G and A alleles at TNF-alpha-308 locus in syphilis group were 0.921 and 0.079, respectively. There was no significant difference between the two groups (P 0.05). 2. The distribution frequencies of G and A alleles at TNF-alpha-238 locus in early syphilis group were 0.968 and 0.032, respectively. The distribution frequencies of G and A alleles at TNF-alpha 238 locus in control group were 0.975 and 0.025, respectively. There was no significant difference between the two groups (P 0.05). The distribution frequencies of G and A alleles at TNF-alpha-238 locus in dominant syphilis group were 0.973 and 0.027, respectively, and those at TNF-alpha-238 locus G and A alleles in latent syphilis group were 0.961 and 0.039, respectively. There was no significant difference between the two groups (P 0.05).
Conclusion: The single nucleotide polymorphisms of tumor necrosis factor-alpha gene-308 G/A and 238 G/A may not be significantly associated with the genetic susceptibility to syphilis.
The second part is the single nucleotide polymorphism of interleukin -4 (IL 4) gene in syphilis patients.
By analyzing the relationship between the single nucleotide polymorphism of interleukin-4 gene-590C/T locus and the susceptibility to syphilis in early syphilis patients, it was found that the distribution frequencies of C and T alleles of IL-4-590 locus in early syphilis patients were 0.229, 0.771, and 0.216, 0.784 in control group, respectively. There was no significant difference between the two groups (P 0). The distribution frequencies of C and T alleles were 0.232 and 0.768 in dominant syphilis group and 0.224 and 0.776 in latent syphilis group, respectively. It's related.
The third part is single nucleotide polymorphisms of Toll like receptor 2 (TLR2) gene in syphilis patients.
The relationship between the single nucleotide polymorphism of Toll-like receptor 2 (TLR2) gene Arg753Gln and the genetic susceptibility to syphilis was detected by DNA sequencing. The results showed that the genotypes of TLR2Arg753Gln in each group were GG, GA and AA. The distribution frequencies of TLR2Arg753Gln G and A alleles in the early syphilis group and the control group were all GG, GA and AA deletions. There was no significant difference in the distribution frequencies of G and A alleles at 753Gln locus between dominant syphilis group and latent syphilis group. There may be no significant correlation between genetic susceptibility.
【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2010
【分类号】：R759.1

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