title: HIV type 1 envelope subtype C sequences from recent seroconverters in Zimbabwe.
abstract: HIV-1 envelope sequence patterns have implications for virus cell tropism and for the development of an effective vaccine. To identify the sequence characteristics of recently transmitted HIV-1 isolates in southern Africa, we sequenced the V3-V5 envelope regions of 24 male seroconverters in Harare, Zimbabwe. Each of the sequences clustered with previously reported subtype C isolates and there was a mean 17% intersequence pairwise genetic distance between the Zimbabwean isolates. Three isolates were syncytium inducing (SI). One of the SI isolates had an unusual GIGK crown and a deletion at codon 23; one had the codon 23 deletion alone; and one had a high net positive charge in the V3 loop. The extensive genetic diversity within the envelope of subtype C HIV-1 isolates must be considered in vaccine development. Further analysis of subtype C SI isolates and site-directed mutagenesis experiments are required to determine the molecular basis of SI activity in global HIV-1 isolates.
authors.affiliation: Center for AIDS Research, Stanford University School of Medicine, California 94305, USA.
authors.forename: M
authors.initials: M
authors.lastname: Batra
authors.forename: P C
authors.initials: PC
authors.lastname: Tien
authors.forename: R W
authors.initials: RW
authors.lastname: Shafer
authors.forename: C H
authors.initials: CH
authors.lastname: Contag
authors.forename: D A
authors.initials: DA
authors.lastname: Katzenstein
mesh_terms: D000595:Amino Acid Sequence; D015686:Gene Products, env / Q000737:chemistry / Q000235:genetics; D015752:Genes, env; D014644:Genetic Variation; D015483:HIV Antibodies / Q000097:blood; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D015030:Zimbabwe
chemical_list: D015686:Gene Products, env; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments