Gene polymorphisms in CCR5, CCR2, CX3CR1, SDF-1 and RANTES in exposed but uninfected partners of HIV-1 infected individuals in North India

Repeated exposure to human immunodeficiency virus (HIV) does not always result in infection. Understanding the mechanisms that give protection against progressive infection with HIV may help in the development of a vaccine. In order to determine the influence of host genetic factors on HIV resistance, we studied 35 exposed but uninfected (EU) partners of HIV-1 infected individuals for polymorphisms in multiple chemokine and chemokine receptor genes and compared the results with those for 75 HIV-1 seronegative normal healthy controls (HC) and 50 HIV infected controls. There was no association between CCR5-Δ32, CCR2-64I, CX3CR1-280 M, CX3CR1-249I, SDF-3′A, RANTES-28G and RANTES-403A polymorphisms and susceptibility against HIV in our cohort of EU individuals. An increased frequency of SDF-1 3′A and RANTES-403A genotypes was present in EU individuals but the difference was not statistically significant when compared to healthy and HIV infected controls. These observations suggest that mechanisms other than genetic mutations of these genes might be responsible for resistance to HIV infection in these individuals.