%A Milka Alejandra Rodriguez
%T Investigation of Viral Genetic and Biologic Determinants of HIV-1 Subtype C Predominance in India
%X In India, HIV-1 subtype C has been the predominant subtype throughout the course of the HIV-1 epidemic, regardless of geographic region in the country. We hypothesize that the dominance of HIV-1 subtype C compared to other subtypes in India is due to enhanced replication fitness and/or enhanced transmission efficiency of this subtype across the mucosal surface over other subtypes present in India. The specific aims of this project are: (1) to compare the replication fitness between Indian HIV-1 subtype A and subtype C; (2) to evaluate the transmission efficiency of Indian HIV-1 subtype A and subtype C across the mucosa of cervical tissue; and (3) to determine the role of the LTR and env gene in replication fitness and transmission efficiency. Replication fitness was assessed using a dual infection growth competition assay. We observed that primary HIV-1 subtype C isolates had higher overall relative fitness and transmission efficiency than primary subtype A isolates in PBMC and in an ex vivo cervical tissue derived organ culture, respectively. Furthermore, a comparison of replicative fitness between a subtype A/subtype C half genome chimeric virus and parental subtype A virus indicates that the higher replication fitness and transmission efficiency of subtype C virus over subtype A virus from India is not due to the env gene alone. We have also characterized the genetic structure and functional characteristics of subtype A and subtype C LTRs from India. Despite their apparent variability, no significant difference was observed in the transcriptional activity between the LTRs of subtype A and subtype C. Therefore, the LTR region alone is not responsible for higher replication fitness of subtype C over subtype A. The findings presented in this study are significant for public health because an understanding of the mechanism of the asymmetric distribution of HIV-1 subtypes in India is an important component in the development of strategies to control HIV-1 infection in this country.
%D 2007
%K  India; HIV-1; replication fitness; subtype C
%I University of Pittsburgh
%L pittir8858