In this study we present phylogenetic tree analysis data for 70 international human immunodeficiency virus (HIV-1) isolates. For 55 isolates the complete gag gene was cloned and sequenced. When combined with 15 previously published gag sequences, phylogenetic tree analysis revealed 6 HIV-1 genetic subtypes that appear equidistant from one another. Similar branching patterns and clustering were obtained with different tree-building algorithms and the same subtypes emerged on protein sequence comparisons. Twenty-five percent of the isolates sequenced belonged to one of the three previously unrecognized subtypes. Surprisingly, several genetic subtypes appear to enjoy an almost global geographic dispersal, although local clusters of genetically related viruses were also observed. A preliminary comparison of the in vitro neutralization titers of sera corresponding to viruses in two of the HIV-1 subtypes revealed subtype-specific neutralization with little cross-reactivity between the two groups. HIV-1 exhibits considerable genetic variation among isolates from different geographic locales. Antigenic and immunological differences among the genetic subtypes should be considered in development of vaccine candidates and planning of vaccine efficacy trials.
|Original language||English (US)|
|Journal||AIDS research and human retroviruses|
|Issue number||SUPPL. 1|
|State||Published - Jan 1 1993|
ASJC Scopus subject areas
- Infectious Diseases