Single Nucleotide Polymorphism Of Genes Related With HIV Infection In Male Homosexuality And The Functional Verification Of DEFB1 Rs11362 Polymorphism

Background: The male homosexuality becomes to the high risk of HIV-exposure and HIV-infection population due to the physical structure and high risk sexual behaviors, while there are differences among individuals in susceptibility of HIV. Host's genetic variation, such as single nucleotide polymorphism, may play an important role in HIV infection of individual differences. It was paid attention to screen host genes or genetic polymorphism loci which associated with the HIV susceptibility in male homosexuality population.Objective: To screen host genes or genetic polymorphism loci which associated with the HIV susceptibility in male homosexuality population, and detect influence of polymorphism on genetic function.Methods: 1. Use the case-control study and convenient sampling to collect HIV+ individuals as cases and HIV- indivisuals as controls; 2. Select the potential candidate SNPs from genes associated with HIV infection by setting the MAF standard, with the functional SNPs to be priorities. These SNPs were genotyped by Matrix Assisted Laser Desorption Ionization Time Of Flight Mass Spectrometry(MALDI-TOF-MS); 3.Construct promoter fragment- p GL3-Basic recombinant plasmid, then transfect the recombinant plasmid into eukaryotic cells, at last detect the expression activity.Results: 1. There were no differences between case and control groups in sociodemographic characteristics and risk of HIV exposure; 2. 24 SNPs were genotyped in 176 HIV+ and 207 HIV-, and 19 SNPs conformed to Hardy-Weinberg Equilibrium. The results showed that rs3775291 of TLR3 coding region may be associated with the infection of HIV. The distribution of alleles and genotypes showed significant differences between the case and control groups(allele: ?(17)=8.105, P=0.004; genotype: ?(17)=9.410, P=0.009), frequency of T allele were higher in control than case group(38.2% vs. 28.4%), indicating that T allele may reduce risk of HIV infection(OR=0.643, 95%CI 0.474-0.872). For the model analysis, the recessive model(CC+CT vs.TT) showed significant difference between two groups(OR=0.372, 95%CI 0.186-0.744, P=0.004). The DEFB1 gene promoter polymorphism rs11362 might be associated with the HIV infection that the distribution of alleles showed significant difference between case and control groups, with P=0.03. G allale of rs11362 may be a risk factor during HIV infection(OR=1.384, 95%CI 1.031-1.857), and the model(AA+GA vs. GG) showed significant difference between two groups(OR=1.629, 95%CI 1.076-2.465, P=0.021); 3. The recombinant DEFB1-promoter- p GL3-Basic of different rs11362 genotypes were cloned successfully. As can be seen from the comparison with the blank control group, promoter of DEFB1 can initiate the gene expression effectively. The relative enzyme activity of rs11362-G plasmid was hagher than rs11362-A plasmid(P <0.01).Conclusion: 1. This project detected 24 SNPs which may be associated with HIV infection successfully, 19 of the SNPs conformed to Hardy-Weinberg Equilibrium. 2. It was suggested that the rs3775291 polymorphism of TLR3 gene and rs11362 polymorphism of DEFB1 promoter may be associated with HIV infection. 3. Target fragment of DEFB1 promoter which was cloned into p GL3-Basic vector initiated downstream gene expression effectively and specifically. The relative enzyme activity of rs11362-G plasmid was higher than rs11362-A type plasmid.