AEGiS-15IAC: Characterization of full-length HIV-1 genome obtained from recently infected subjects in Brazil.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Characterization of full-length HIV-1 genome obtained from recently infected subjects in Brazil.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. TuOrA1143)

Kallas EG, Sa Filho DJ, Bassichetto KC, Sanabani SS, Sabino E, Janini M, Diaz RS, Mesquita F
Federal University of Sao Paulo, Sao Paulo, Brazil

BACKGROUND: Recombination is recognized as one of the major mechanisms generating HIV-1 diversity. Recombinants have been identified in Brazil based on short genome fragments precluding a comprehensive appreciation of their structure. Full-length HIV-1 genome analysis in recently acquired infections will provide a more complete profile of strains being transmitted in a given moment in the epidemics.

METHODS: A network of clinics and laboratories was established to identify recently HIV-1 infected subjects using the STARHS algorithm. From June to August 2003, consecutive HIV-1 samples were screened, and recently infected volunteers were asked to participate in a prospective clinical and laboratory study. Clinical and laboratory evaluation was performed together with full genome characterization. Amplification of the near full-length proviral genome was carried out by nested PCR in five overlapping segments of 1.8-3kb each. PCR products were sequenced on both strands, phylogenetic analysis was performed using Neighbor Joining method, and recombination was evaluated by Bootscan.

RESULTS: Eleven subjects (10 male) median age 35 y-o (range, 20 to 68) were enrolled. Median CD4 T cell count was 481 cells/ml (range, 332 to 856) and HIV-RNA was 4.38 log10 (range, 3.00 to 5.62). Full-length genome sequencing revealed 8 strains from clade B, 2 B/F recombinants, and 1 from clade C. Both recombinants presented different break point profiles, which were identified at gag (p24), pol (integrase), and vif, in the first B/F strain, with env presenting a pure B profile. Breaking points were at gag (p24), pol (integrase), vif, and env at both gp120 and gp41 in the second B/F strain.

CONCLUSIONS: Recombination is playing an active role in the dynamics of the Brazilian HIV-1 epidemics. In a place where more than one clade cocirculate, it is expected that the prevalence of recombinant strains will increase over time. The monitoring the genetic diversity of transmitted HIV-1 strains will be of great importance to the understanding of the molecular epidemiology trends in a given place.

Keywords: AEGIS, HIV-1, Genes, gag, Genes, env, Genes, pol, Brazil, HIV Seropositivity, Recombination, Genetic, Genome, HIV-1 Reverse Transcriptase, Genome, Viral, Polymerase Chain Reaction, Prevalence, Epidemiology, Molecular, Male, genetics

040711
TuOrA1143