title: Genotypic and phenotypic analysis of the env gene from South African HIV-1 subtype B and C isolates.
abstract: The objective of the study was to assess the genotypic and phenotypic properties of 18 viral strains from human immunodeficiency virus-1 (HIV-1) positive patients and to identify subtype C isolates for vaccine design strategies. All the isolates were non-syncytium-inducing (NSI) in both the primary and MT-2 cell cultures. The amino acid charge of the V3 loop correlated with the NSI phenotype of the strains. The V3 competitive peptide enzyme immunoassay and DNA sequencing of the partial gp120 region gave concordant results on the 15 subtype C strains, whereas the three B genotypes gave a positive to B, a nonreactive to B, and a dual reaction to the B-D peptides, respectively. Sixteen of the isolates used only CCR5 as coreceptor whereas two isolates made use of additional coreceptors including CXCR4. In summary, all our subtype C isolates are NSI phenotypically and almost all of them use CCR5 exclusively as their coreceptor.
authors.affiliation: Department of Medical Virology, University of Stellenbosch and Tygerberg Hospital, Tygerberg, South Africa.
authors.forename: Florette K
authors.initials: FK
authors.lastname: Treurnicht
authors.forename: Tracey-Lee
authors.initials: TL
authors.lastname: Smith
authors.forename: Susan
authors.initials: S
authors.lastname: Engelbrecht
authors.forename: Matilda
authors.initials: M
authors.lastname: Claassen
authors.forename: Brenda A
authors.initials: BA
authors.lastname: Robson
authors.forename: Michelle
authors.initials: M
authors.lastname: Zeier
authors.forename: Estrelita Janse
authors.initials: EJ
authors.lastname: van Rensburg
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral / Q000235:genetics; D015752:Genes, env; D005838:Genotype; D015726:Giant Cells / Q000821:virology; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D019713:Receptors, CCR5 / Q000502:physiology; D019718:Receptors, CXCR4 / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013019:South Africa
chemical_list: D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019713:Receptors, CCR5; D019718:Receptors, CXCR4