Characterization of HIV type 1 tat sequences associated with perinatal transmission.
Human immunodeficiency virus type 1 (HIV-1) tat exon I sequences were analyzed from six mother-infant pairs after perinatal transmission. The tat open reading frame was maintained in 140 of the 154 clones analyzed, with a 90.9% frequency of intact tat open reading frames. In addition, a low degree of heterogeneity was observed in tat sequences within mothers, within infants, and between epidemiologically linked mother-infant pairs. However, the distances of tat sequences between epidemiologically unlinked individuals were greater than in epidemiologically linked mother-infant pairs. The infant sequences showed amino acid sequence patterns similar to those present in their respective mothers. The functional domains required for Tat function, including amino-terminal, cysteine-rich, core and basic regions, which constitute domains for activation and RNA binding, were highly conserved in most of the sequences. Phylogenetic analysis of 154 mother-infant tat sequences showed that they formed distinct clusters for each mother-infant pair and grouped with subtype B sequence. These findings suggest that an intact and functional tat gene is conserved in HIV-1 mother-infant isolates that are involved in perinatal transmission.
Husain
M
M
Department of Microbiology and Immunology, College of Medicine, University of Arizona Health Sciences Center, Tucson, Arizona 85724, USA.
Hahn
T
T
Yedavalli
V R
VR
Ahmad
N
N
D000328:Adult; D000595:Amino Acid Sequence; D002675:Child, Preschool; D005091:Exons; D005260:Female; D015756:Genes, tat; D015658:HIV Infections / Q000635:transmission / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology*; D016415:Sequence Alignment