Single Nucleotide Polymorphism Of Immunity-related Genes In Syphilis

The immunological pathogenesis of syphilis is not completely clear. It is well recognized that the infection of Treponema pallidum(TP) will trigger a series of complex cellular and humoral immunities. The type, intensity and duration of these immunities can impact the severity, course and transmission of the disease. This probably indicates that there is an association of some immune-related genes and susceptibility with syphilis. As a natural immune receptor, toll-like receptor2(TLR2) can trigger natural and acquired immunities through recognization of lipopolysaccharide of Treponema pallidum and cell signal transduction, TLR2 plays a an important role in maintaining the balance of immunity and regulating the intensity of inflammatory response. ThO cells will activate, develop Thl or Th2 cells and produce relevant cytokines and chemokines. Cytokines play key role in the immune regulation. The Toll-like receptor 2 (TLR2)?Th1 cytokine TNF-??Th2 cytokine IL-4 are selected as target genes, and the single nucleotide polymorphism (SNP) of these immunity-related genes are analyzed to try to find the association of the locus of these SNPs and susceptibility with syphilis.Chapter?Tumor necrosis factor-a gene single nucleotide polymorphism in syphilis.To explore the association of TNF-a gene -308G/A and -238G/A single nucleotide polymorphism with susceptibility to syphilis, the genomic DNA was extracted from the blood samples of 56 early symptomatic syphilis patients,38 early latent syphilis patients, and 102 normal controls. Tumor Necrosis Factor-a gene-308G/A and -238G/A single nucleotide polymorphism of all subjects were detected by means of real-time quantitative fluorescent PCR.The results were as the follows:1. Frequencies of TNF-a gene-308 G, A alleles were 0.926,0.074 in the early syphilis group, and 0.941,0.059 in the controls, No significant difference was found (P>0.05). Frequencies of G, A alleles were 0.929, 0.071 in the early symptomatic syphilis group, and 0.921,0.079 in early latent syphilis group, No significant difference was found between these two groups (P>0.05).2. Frequencies of TNF-?gene -238 G, A alleles were 0.968,0.032 in the early syphilis group, and 0.975,0.025 in the controls, No significant difference was found(P>0.05). Frequencies of G, A alleles were 0.973,0.027 in the early symptomatic syphilis group, and 0.961,0.039 in early latent syphilis group, No significant difference was found between these two groups (P>0.05)From these results, the conclusion can be drawn that there is probably no evident association of tumor necrosis factor-a gene -308G/A and -238G/A single nucleotide polymorphism with the susceptibility to syphilis.Chapter?IL-4 gene single nucleotide polymorphism in syphilis.Through the analysis of the relationship between IL-4 gene -590C/T single nucleotide polymorphism and susceptibility to syphilis, it was found that the frequencies of C, T alleles were 0.229,0.771 in the early syphilis group, and 0.216,0.784 in the controls, No significant difference was found (P>0.05). Frequencies of C, T alleles were 0.232,0.768 in the early symptomatic syphilis group, and 0.224,0.776 in early latent syphilis group, No significant difference was found between these two groups (P>0.05). It is concluded that the single nucleotide polymorphism of IL-4 gene -590C/T is not associated with the susceptibility to syphilis.Chapter?Toll-like receptor 2 gene single nucleotide polymorphism in syphilis.The single nucleotide polymorphism of TLR2 Arg753Gln was examined by the DNA sequencing to investigate the association of TLR 2 gene polymorphism with susceptibility to syphilis. The result demonstrated that the genetype of all SNP locus was GG genetype, and GA, AA genetypes were not found. Frequencies of G, A alleles were 1.0 in the early syphilis and in the controls, No significant difference was found. Frequencies of G, A alleles were 1.0 in the early symptomatic syphilis group and in the early latent syphilis group, No significant difference was found between these two groups. It is concluded that there is probablely no evident association of single nucleotide polymorphism of TLR2 Arg753Gln with the susceptibility to syphilis.