B/F INTER-SUBTYPE RECOMBINANTS OF HIGHLY SIMILAR BUT NOT IDENTICAL STRUCTURE RECOVERED FROM ARGENTINA, URUGUAY AND BOLIVIA AND CHARACTERIZED BY FULL GENOME ANALYSIS.

CARR, J.K;; AVILA, M;; GÓMEZ CARRILLO M,; NEGRETE, M; RUSSELL, K; MCCUTCHAN, F

Buenos Aires

Conferencia; The 1st IAS Conference on HIV Pathogenesis and treatment-; 2001

International AIDS Society

Objective: To more fully describe the genetic diversity of HIV-1 in South America by full genome sequencing. Methods: DNA extracted from purified PBMC from HIV-infected patients from Argentina, Uruguay and Bolivia was used to amplify full genomes of HIV-1. These were sequenced using the ABI 3100 automated capillary sequencer and then phylogeneticly analyzed. Results: All of the viruses that were screened as subtype F by envelope HMA were found to be BF recombinants. All had a related structure in some genome regions but were variable in others. In Argentina, the recombinants have been recovered from vertically infected children born in 1986 and 1987, which suggests that they have been in circulation since that time. No geographic clustering was seen separating the viruses from Argentina, Uruguay and Bolivia. In general, the gag and integrase genes derive from subtype F, while the 3half of the reverse transcriptase gene and vpu derive from subtype B. Other regions of the genome, including envelope, are variable in their subtype structure. If a common ancestor gave rise to the recombinants, a great deal of diversification has occurred since that time, obscuring genetic evidence for a common source. Conclusions: BF recombinants of related but not identical structure have been in circulation in southern South America since the middle of the 1980’s. They have been found from Tierra del Fuego, at the southern tip of Argentina, to Bolivia. Characterization of the HIV-1 epidemic in South America as principally subtypes B and F will need revision in the light of these results.