Transmission of Human Immunodeficiency Virus Type-1 gag and env

Abstract

Human immunodeficiency virus (HIV) type 1 isolates obtained from four transmitter-recipient pairs were studied to determine patterns of virus selection following transmission and the number and origin of virus variants. Three patient pairs were homosexual men in whom virus was transmitted sexually; the fourth recipient was infected by needle stick injury. Analysis of the p17 gag and V3 regions revealed that these regions were highly conserved upon transmission. The earliest virus population observed in recipients following mv transmission was of the NSI phenotype, even when the donor was of mixed NSIISI phenotype. Transmission of the Sl phenotype as minor variants within one recipient occurred. P17 and V3 sequences in these SI clones were coselected, demonstrating a high degree of homology with transmitter predominant strain V3 and p17 sequences. These strains did not predominate in the host populations despite their capacity for faster growth to higher titres than NSI viruses. The precise mechanism determining how such clones are selected remains unknown.