title: Discovery of a new human T-cell lymphotropic virus (HTLV-3) in Central Africa.
abstract: Human T-cell Leukemia virus type 1 (HTLV-1) and type 2 (HTLV-2) are pathogenic retroviruses that infect humans and cause severe hematological and neurological diseases. Both viruses have simian counterparts (STLV-1 and STLV-2). STLV-3 belongs to a third group of lymphotropic viruses which infect numerous African monkeys species. Among 240 Cameroonian plasma tested for the presence of HTLV-1 and/or HTLV-2 antibodies, 48 scored positive by immunofluorescence. Among those, 27 had indeterminate western-blot pattern. PCR amplification of pol and tax regions, using HTLV-1, -2 and STLV-3 highly conserved primers, demonstrated the presence of a new human retrovirus in one DNA sample. tax (180 bp) and pol (318 bp) phylogenetic analyses demonstrated the strong relationships between the novel human strain (Pyl43) and STLV-3 isolates from Cameroon. The virus, that we tentatively named HTLV-3, originated from a 62 years old Bakola Pygmy living in a remote settlement in the rain forest of Southern Cameroon. The plasma was reactive on MT2 cells but was negative on C19 cells. The HTLV 2.4 western-blot exhibited a strong reactivity to p19 and a faint one to MTA-1. On the INNO-LIA strip, it reacted faintly with the generic p19 (I/II), but strongly to the generic gp46 (I/II) and to the specific HTLV-2 gp46. The molecular relationships between Pyl43 and STLV-3 are thus not paralleled by the serological results, as most of the STLV-3 infected monkeys have an "HTLV-2 like" WB pattern. In the context of the multiple interspecies transmissions which occurred in the past, and led to the present-day distribution of the PTLV-1, it is thus very tempting to speculate that this newly discovered human retrovirus HTLV-3 might be widespread, at least in the African continent.
authors.affiliation: Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France. scalatt@pasteur.fr
authors.forename: Sara
authors.initials: S
authors.lastname: Calattini
authors.forename: Sébastien Alain
authors.initials: SA
authors.lastname: Chevalier
authors.forename: Renan
authors.initials: R
authors.lastname: Duprez
authors.forename: Sylviane
authors.initials: S
authors.lastname: Bassot
authors.forename: Alain
authors.initials: A
authors.lastname: Froment
authors.forename: Renaud
authors.initials: R
authors.lastname: Mahieux
authors.forename: Antoine
authors.initials: A
authors.lastname: Gessain
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002163:Cameroon; D002460:Cell Line; D004279:DNA, Viral / Q000097:blood; D017977:Deltaretrovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D006800:Deltaretrovirus Infections / Q000821:virology; D015684:Gene Products, pol / Q000235:genetics; D016356:Gene Products, tax / Q000235:genetics; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D030282:Primate T-lymphotropic virus 3; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D015684:Gene Products, pol; D016356:Gene Products, tax