Journal of AIDS & Clinical Research

Genetic Polymorphisms of the CX3CR1 Gene Associated with HIV-1 Infections in Kenyan Population

Abstract

Lamech M Mwapagha, Zipporah W Ng’ang’a, Shem P Mutuiri, Barbara B Miheso and Samoel A Khamadi

Introduction: Repeated exposure to Human Immunodeficiency Virus (HIV) does not always result in infection. Understanding the mechanisms that confer protection against progressive infection with HIV-1 may be useful in the development of appropriate interventions. The impact of CX3CR1 polymorphisms on human immunodeficiency virus type 1 (HIV-1) pathogenesis is controversial, with conflicting reports of their role in disease progression in HIV-1 infected individuals. The aim of this study is to characterize polymorphisms of the CX3CR1 co-receptor gene among HIV infected adults and infants in a Kenyan Population. Methods: Clinical samples were obtained from 200 HIV infected infants and 200 HIV infected adults and genotyped for the CX3CR1 gene 280M and 249I mutations. These were identified by PCR–RFLP analysis after amplification of a 588 base pair sequence of CX3CR1 gene. Results: In determining the presence of T280M and V249I haplotypes it was found that overall, infants had higher percentages of the wild type alleles at (42% and 45%), respectively compared to adults (37% and 36%) respectively. In the case of heterozygous mutants, adults had higher percentages (11% and 12%), respectively than among infants (7% and 4%), respectively. Adults also had higher percentages of homozygous mutants of (2%) compared to infants (1%). This study showed that the differences in mutations of CX3CR1 gene allele in I249 and M280 was p=0.075 and p=0.215, respectively which was not statistically significant (p>0.05). Conclusion: This study showed that CX3CR1 gene polymorphisms exist in Kenya though the numbers of mutations are at very low levels to warrant any meaningful impact in the population in terms of HIV-1 disease progression. It is probable that alternative mechanisms are operating in conferring resistance to HIV-I infection. Further in vitro cellular studies need to be carried out to determine the exact role of CX3CR1 gene mutations in HIV/AIDS pathogenesis.