title: Molecular epidemiology of human T-cell leukemia virus type I (HTLV-1) Brazil: the predominant HTLV-1s in South America differ from HTLV-ls of Japan and Africa, as well as those of Japanese immigrants and their relatives in Brazil.
abstract: To better understand the origin of human T-cell leukemia virus type l (HTLV-l) in South America, we conducted a phylogenetic study on 27 new HTLV-ls in Brazil. These were obtained from Brazilians of various ethnic origins, such as Japanese immigrants, whites, blacks and mulattos. We amplified and sequenced proviral DNAs of a part of the long terminal repeats. Phylogenetic trees revealed that all but 6 of the new isolates were not only similar to each other but also similar to HTLV-ls of other South American countries, including those from Amerindians. However, the isolates differed from the HTLV-ls of Africa and Japan. The other six isolates were from Japanese immigrants and were phylogenetically almost identical to HTLV-ls in Japan but different from the majority of South American HTLV-ls, including the other new Brazilian HTLV-ls. These findings indicate that the recent introduction of HTLV-1 from Japan is limited to Japanese immigrants. In addition, the results do not support the prevailing hypothesis that HTLV-ls in South America were introduced by blacks who were brought from Africa as slaves. Rather, these results suggest that the majority of HTLV-1s prevailing in South America have spread from Amerindians, some of whom are likely to have possessed this human retrovirus from the beginning of their settlement in South America.
authors.affiliation: Laboratory of Viral Pathogenesis, Institute for Virus Research Kyoto University, Kyoto, 606-8507, Japan. myamashi@virus.kyuoto-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yamashita
authors.forename: R
authors.initials: R
authors.lastname: Veronesi
authors.forename: M
authors.initials: M
authors.lastname: Menna-Barreto
authors.forename: W J
authors.initials: WJ
authors.lastname: Harrington
authors.forename: C
authors.initials: C
authors.lastname: Sampio
authors.forename: C
authors.initials: C
authors.lastname: Brites
authors.forename: R
authors.initials: R
authors.lastname: Badaro
authors.forename: A S
authors.initials: AS
authors.lastname: Andrade-Filho
authors.forename: S
authors.initials: S
authors.lastname: Okhura
authors.forename: T
authors.initials: T
authors.lastname: Igarashi
authors.forename: J
authors.initials: J
authors.lastname: Takehisa
authors.forename: T
authors.initials: T
authors.lastname: Miura
authors.forename: D
authors.initials: D
authors.lastname: Chamone
authors.forename: O
authors.initials: O
authors.lastname: Bianchini
authors.forename: C
authors.initials: C
authors.lastname: Jardim
authors.forename: S
authors.initials: S
authors.lastname: Sonoda
authors.forename: M
authors.initials: M
authors.lastname: Hayami
mesh_terms: D000328:Adult; D000349:Africa; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D004641:Emigration and Immigration; D005006:Ethnicity; D005260:Female; D015490:HTLV-I Infections / Q000453:epidemiology* / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007564:Japan / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D020079:Terminal Repeat Sequences / Q000235:genetics