| Introduction Since the beginning of the epidemic of acquired immunodeficiency syndrome (AIDS), accumlated evidence has demonstrated that genetic factors are involved in the process of HIV-1 infection and AIDS pathogenesis.The entry of HIV-1 into CD4+T cells is mediated by the interactions between the viral envelope glycoproteins, the CD4 receptor and HIV-1 coreceptors. On primary infection, HIV-1 coreceptors are the chemokinereceptors CCR5 (CC chemokine receptor 5), conjugated by HIV-1 R5 strain, during the later stage of infection, the CXCR4 used by HIV-1 X4 strain.The CCR5 ligands such as RANTES (regulated on activation, normal T cell expressed and secrected), MIP-1 , and MIP-1 , and the CXCR4 ligand SDF-1 all are potent inhibitors of HIV-1 cell entry and replication. Allelic variants in the HIV-1 coreceptors and their natural ligand genes have been shown to modify HIV-1 transmission and disease progression.Three single nucleotide polymorphism (SNP) sites, -28G/C and -403G/A in the promoter region, Inl.lT/C in first intron of RANTES had been identified. The -28G variant, but not -403A, was reported to up-regulate RANTES gene transcription in one study, whereas -403A was reported to up-regulate RANTES transcription in a second study without consideration of -28C/G. The -403-28 AG haplotype was shown to be associated with a slower rate of CD4+ T cell depletion in HIV-1 infected Japanese. In European Americans (EA) the compound genotype GC/AC was reported to be associated with more susceptible to HIV-1 infection but resistant to AIDS progression when compared with genotype GC/GC in one study, but to be susceptible to both HIV-1 infection and AIDS progression in another. No effect on HIV-1 infection and AIDS progression by these variants had been reported in African Americans. The diminished transcription of RANTES afforded by the In1.1C regulatory allele is consistent with increased HIV-1spread leading to accelerated progression to AIDS.Considering the potential interaction of these three RANTES gene polymorphisms and the RANTES gene diversity nature of different ethnic groups, we tested the frequencies of three SNPs in the RANTES gene region (-403G/A, -28C/G in the promoter, Inl .IT/C in the first intron) and compared their genotypes on healthy population and HIV-1 infected population in Han Chinese, evaluated their risk of both HIV-1 infection and AIDS progression. Materials and Methods Study Population.Including 202 cases of healthy group and 287 cases of HIV-1 infected group of Han Chinese. Unlinked healthy samples collected from physical examination individuals in out-patient department of 302 Hospital from 2000 to 2001.A total of 287 HIV-1 infected individuals were evaluated, of 231 blood donors and intravenous drug users form Henan and Hebei province and Xinjiang Uygur municipality; of 56 HIV-1 infected by sexual contact from Guangdong province.Additional 40 cases of HIV-1 infected Han Chinese blood donors from Henan province, were genotyped for allele frequencies, Compared relationship between allele frequencies and plasma viral load, CD4+ cell count and CD4+/CD8+ ratio correlated with AIDS progression.Genotyping of RANTES Gene PolymorphismsPCR restriction fragment length polymorphisms (PCR/RFLP) were used for genotyping.RANTES-403 and -28 fragment PCR used nested-PCR. Outside forward primers were, 5'-acttttcccaaaggtcgcrt and reverse, 5'-cacgtgctgtcttgatcctc.SNPs -403G/A and -28C/G, In1.1T/C were genotyped by PCR/RFLP with primers and endonuclease restriction enzymes as follows:-403G/A forward primer, 5'-caagaaattcccacaagaggactca and reverse, 5'-agttcctgcttattcaatcacagatcgta, using RSA I for digestion; -28C/G, forward primer, 5'-ggtaaaactaaggatgtcagcaga , and reverse,5'-ctcaggctggcgctttatagggcgaatt ,using EcoR I for digestion; Inl.lT/C, forward primer, 5'-cctggtcttgaccaccaca and reverse,5'-gctgacaggcatgagtcaga , using M>oII for digestion.Selective proportion PCR products had been sequenced by the same... |
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