Human T-cell lymphotropic virus type-II (HTLV-II) infection is endemic in indigenous groups in the Americas and injection drug users (IDUs) worldwide. In Peru, HTLV-II infection was previously identified in two indigenous Amazonians. We examined risk factors for HTLV-II infection in 2,703 Peruvian men who have sex with men (MSM): 35 (1.3%) were HTLV-II positive. HTLV-II infection was associated...

Type 1 immunity appears to be diminished in healthy Japanese carriers of human T-lymphotropic virus type I (HTLV-I), but type 2 status remains undetermined. To further examine the subclinical effect of HTLV-I on host immunity, we measured serum antibodies to the Epstein-Barr virus (EBV) in 415 healthy Japanese adults to broadly characterize type 1 status. Levels of the type 2 biomarkers total i...

We report characterization of a human T-cell lymphotropic virus type II (HTLV-II) isolated from an interleukin 2-dependent CD8 T-cell line derived from peripheral blood mononuclear cells of a healthy, HTLV-1I-seropositive female Bakola Pygmy, aged 59, living in a remote equatorial forest area in south Cameroon. This HTLV-II isolate, designated PYGCAM-1, reacted in an indirect immunofluorescence...

Retroviruses can be classified according to the morphology of their virion core or according to sequence homologies that become evident after phylogenetic analyses. Human T-lymphotropic virus type 1 (HTLV-1) is a member of the deltatype retrovirus group, other members of which include HTLV types 2, 3 and 4, bovine leukaemia virus (BLV), and simian T-cell leukaemia virus (STLV) types 1, 2 and 3 ...

Human T-cell leukemia virus type 1 (HTLV-1), the causative agent of adult T-cell leukemia, is transmitted vertically via breastfeeding. We have previously demonstrated that lactoferrin, a major milk protein, enhances HTLV-1 replication, at least in part by upregulating the HTLV-1 long terminal repeat promoter. We now report that HTLV-1 infection can induce lactoferrin gene expression. Coculture...

Peripheral blood mononuclear cells (PBMC) from three adult male squirrel monkeys (Saïmiri sciureus) were transformed by human T-cell leukemia/lymphoma virus type I (HTLV-I) by cocultivation with lethally irradiated human MT-2 cells. Three permanent monkey T-cell lines producing HTLV-I were obtained and characterized. Six weeks after inoculation seroconversion was observed in three of three monk...

The human T-lymphotropic viruses (HTLVs) types 1 and 2 originated independently and are related to distinct lineages of simian T-lymphotropic viruses (STLV-1 and STLV-2, respectively). These facts, along with the finding that HTLV-1 diversity appears to have resulted from multiple cross-species transmissions of STLV-1, suggest that contact between humans and infected nonhuman primates (NHPs) ma...

The prevalence of human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 in blood donors in Guyana has never been estimated. We evaluated the prevalence of these viruses in blood donors by enzyme-linked immunosorbent assay and Western blotting and showed a prevalence of HTLV-1 of 1.3%; no HTLV-2 was detected. Female donors had a much higher HTLV-1 seroprevalence (3.6%) than male donors (0.7...