Abstract:
Expression of CC chemokine receptor 5 (CCR5), the major co-receptor for HIV-1 cell
entry, and its ligands (RANTES, MIP-1 & MIP-1β) are widely regarded as central to the
pathogenesis of HIV-1 infection. RANTES (regulated on activation normal T cell
expressed and secreted) potently suppresses in vitro replication of the R5 strains of HIV-1, which use CCR5 as a co-receptor. Previous studies have shown that RANTES gene
polymorphisms lead to altered gene expression and influence the natural course of HIV
infection. In this study, existence and frequencies of RANTES-28 (C→G) alleles
polymorphisms in persons in Nairobi were determined using PCR-RFLP. Allele
frequencies for RANTES-403 (G→A) were estimated by use of haplotype model. Forty
four percent of HIV positive persons had the RANTES-403 & -28 G-C Haplotype
compared to fifty percent of HIV negative blood donors. There was no significant
difference (P>0.05) in the frequencies of each RANTES genotypes and haplotypes single
nucleotide polymorphisms (SNPs). The distribution of these haplotypes is in Hardy–
Weinberg equilibrium, indicating a lack of selection for or against each SNP. RANTES
mutant frequency was one percent for both categories indicating low frequency of gene
responsible for high RANTES secretion. This suggests that the Nairobi population lacks
the beneficial high RANTES levels.
