title: Genotypic characteristics of HIV type 1 based on gp120 hypervariable region 3 of isolates from Southern Brazil.
abstract: The aim of this study was to investigate HIV-1 molecular diversity and the epidemiological profile of HIV-1-infected patients from Ribeirão Preto, Brazil. A nested PCR followed by sequencing of a 302-base pair fragment of the env gene (C2-V3 region) was performed in samples from HIV-1-positive patients. A total of 45 sequences were aligned with final manual adjustments. The phylogenetic analyses showed a higher prevalence of HIV-1 subtype B in the studied population (97.8%) with only one sample yielding an F1 subtype. The viral genotyping prediction showed that CCR5 tropism was the most prevalent in the studied cohort. Geno2pheno analysis showed that R5 and CXCR4 prediction were 69% and 31%, respectively. There was no statistical significance, either in viral load or in CD4(+) T cell count when R5 and X4 prediction groups were compared. Moreover, the GPGR tetramer was the most common V3 loop core motif identified in the HIV-1 strains studied (34.1%) followed by GWGR, identified in 18.1% of the samples. The high level of B subtype in this Brazilian population reinforces the nature of the HIV epidemic in Brazil, and corroborates previous data obtained in the Brazilian HIV-infected population.
authors.affiliation: Program of Graduate Studies on Applied and Basic Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Rafael F O
authors.initials: RF
authors.lastname: Franca
authors.forename: Luiza A
authors.initials: LA
authors.lastname: Castro-Jorge
authors.forename: Roberto J P
authors.initials: RJ
authors.lastname: Neto
authors.forename: Daniel M M
authors.initials: DM
authors.lastname: Jorge
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Lima
authors.forename: Jeová K B
authors.initials: JK
authors.lastname: Colares
authors.forename: Sérgio O
authors.initials: SO
authors.lastname: Paula
authors.forename: Benedito A Lopes
authors.initials: BA
authors.lastname: da Fonseca
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology*; D015331:Cohort Studies; D022801:Complementarity Determining Regions / Q000235:genetics* / Q000276:immunology; D058872:Epidemics; D005260:Female; D015752:Genes, env; D005838:Genotype; D015699:HIV Envelope Protein gp120 / Q000235:genetics* / Q000276:immunology; D015658:HIV Infections / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D019713:Receptors, CCR5 / Q000235:genetics / Q000276:immunology; D054387:Receptors, CXCR / Q000235:genetics / Q000276:immunology; D019562:Viral Load
chemical_list: D022801:Complementarity Determining Regions; D015699:HIV Envelope Protein gp120; D019713:Receptors, CCR5; D054387:Receptors, CXCR