Interplay between HIV-1 and Host Genetic Variation: A Snapshot into Its Impact on AIDS and Therapy Response

Abstract

As of February 2012, 50 circulating recombinant forms (CRFs) have been reported for HIV-1 while one CRF for HIV-2. Also according to HIV sequence compendium 2011, the HIV sequence database is replete with 414,398 sequences. The fact that there are CRFs, which are an amalgamation of sequences derived from six or more subtypes (CRF27_cpx (cpx refers to complex) is a mosaic with sequences from 6 different subtypes besides an unclassified fragment), serves as a testimony to the continual divergent evolution of the virus with its approximate 1% per year rate of evolution, and this phenomena per se poses tremendous challenge for vaccine development against HIV/AIDS, a devastating disease that has killed 1.8 million patients in 2010. Here, we explore the interaction between HIV-1 and host genetic variation in the context of HIV/AIDS and antiretroviral therapy response.

Analysis of HIV-1 Protease Gene Reveals Frequent Multiple Infections Followed by Recombination among Drug Treated Individuals Living in São Paulo and Santos, Brazil

“…One of the outcomes of HIV-1 multiple infections is the recombination between distinct viral populations [2] . Recombination can lead to evolutionary leaps and facilitate the emergence of particles with different phenotypic characteristics and may accelerate the process of viral adaptation to a host or host population [64] , [65] . Lately, a steady increase in the numbers of reported HIV-1 recombinant strains have been observed in the Brazilian epidemic [54] – [57] .…”

Spatiotemporal Dynamics of HIV Distribution Pattern and Application of Indigenous Bioresources and Microbicides in Expanding Preventive Options

“…There also exists the HIV subtype-2 (HIV-2), which is relatively less pathogenic in comparison to HIV-1 [44]. The occurrence of CRF is closely linked to the dynamism of the HIV infection and epidemic and obviously to failure of most specific therapeutic target in eliminating the virus [45][46][47]. The study of the distribution pattern of the various subtypes is therefore highly crucial for effective HIV management especially in endemic regions of the world.…”

“…Recombination events between subtypes lead not only to an ever increasing diversity of the HIV strains [49] but also presents astonishing scenarios of emerging strains with resistance to the common antiviral drugs [50,51]. The numbers of CRFs are increasing astronomically global, partly because of the emergence of recombinants of the various subtypes in various local epidemiological regions [46]. There has also been a correlation between the emergence of divergent subtypes in a population and the teeming occurrence of disease cases.…”

Dearth of full-length HIV-1 sequences obscures the true HIV-1 genetic subtypes distribution in sub-Saharan Africa

“…Comprehensive understanding of disease process and effective interventions could arise from correlating genomic profile of HIV with that of patients (Sampathkumar et al, 2012). With HIV subtypes playing important roles in transmission and outcome of disease, it becomes imperative for the actual distribution of subtypes to be known.…”