title: Molecular characterization of long terminal repeat sequences from Brazilian human immunodeficiency virus type 1 isolates.
abstract: HIV-1 provirus activation is under control of the long terminal repeat (LTR)-5' viral promoter region, which presents remarkable genetic variation among HIV-1 subtypes. It is possible that molecular features of the LTR contribute to the unusual profile of the subtype C epidemic in the Brazilian Southern region. To characterize the LTR of Brazilian HIV isolates, we analyzed sequences from 21 infected individuals from Porto Alegre and Salvador cities. Sequences were compared with subtype B and C reference strains from different countries. Phylogenetic analysis showed that 17 (81%) samples were subtype B and four (19%) were subtype C. Common patterns of transcription factor binding sites (TFBS) in subtypes B and C sequences were confirmed and other potential TFBS specific for subtype C were found. Brazilian subtype C sequences contained an additional NF-κB biding site, as previously described for the majority of subtype C isolates. The high level of LTR polymorphisms identified in this study might be important for viral fitness.
authors.affiliation: Laboratório Avançado de Saúde Pública (LASP), Centro de Pesquisa Gonçalo Moniz (CPqGM), Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil.
authors.forename: Geraldo A
authors.initials: GA
authors.lastname: Ferraro
authors.forename: Joana P
authors.initials: JP
authors.lastname: Monteiro-Cunha
authors.forename: Flora M C
authors.initials: FM
authors.lastname: Fernandes
authors.forename: Aline C A
authors.initials: AC
authors.lastname: Mota-Miranda
authors.forename: Carlos
authors.initials: C
authors.lastname: Brites
authors.forename: Luiz C J
authors.initials: LC
authors.lastname: Alcantara
authors.forename: Bernardo
authors.initials: B
authors.lastname: Galvão-Castro
authors.forename: Mariza G
authors.initials: MG
authors.lastname: Morgado
mesh_terms: D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D004279:DNA, Viral / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D004279:DNA, Viral