Although the structure of human T lymphoptropic virus type I (HTLV-I) has been known well, the function of some proteins encoded by HTLV-I PX region is not fully understood. Furthermore, the responses of the immune system to HTLV-I remain still unknown. Most of HTLV-I-infected individuals show a strong and persistently activated cytotoxic T-cell (CTL) response to the virus. The frequency of HTL...

Previous studies have demonstrated the presence of human T-lymphotropic virus type I (HTLV-I) andlor HTLV type I1 (HTLV-11) in certain populations in Data on qualified blood donors are limited primarily to those in the southeast region of Brazil, while the country's 8,400,000 square miles include diverse geographic, climatic, and sociodemographic characteristics. To assist in the formulation of...

UNLABELLED Human T-cell leukemia virus type 1 (HTLV-1) and type 2 (HTLV-2) are highly related retroviruses that transform T cells in vitro but have distinct pathological outcomes in vivo. HTLV-1 encodes a protein from the antisense strand of its proviral genome, the HTLV-1 basic leucine zipper factor (HBZ), which inhibits Tax-1-mediated viral transcription and promotes cell proliferation, a hig...

We compared the sensitivities of the prototype human T-cell lymphotropic virus type I (HTLV-I)- and HTLV-II-transformed cell lines, MT2 and Mo-T, with that of an HTLV-II-infected cell line, clone 19, established in our laboratory, in the immunofluorescence (IF) test for detection of antibody to HTLV-I and HTLV-II. In addition, IF antibody titers with the three antigens were determined, and the ...

Human T-cell leukemia virus type 1 (HTLV-1) but not HTLV-2 is associated with adult T-cell leukemia. We found that HTLV-2 Tax2 protein stimulated reporter gene expression regulated by the interleukin (IL)-2 promoter through the nuclear factor of activated T cells (NFAT) in a human T-cell line (Jurkat). However, the activity of HTLV-1 Tax1 was minimal in this system. T-cell lines immortalized by...

Synthetic peptides representing the immunodominant structural motifs of the envelope region of human T-lymphotropic virus types I (HTLV-I) (Env-1(191-214) and Env-5(242-257)) and II (HTLV-II) (Env-20(85-102 and Env-2(187-209)) were used to develop an enzyme immunoassay that could discriminate between HTLV-I and HTLV-II. Serum specimens from individuals whose infections were confirmed and typed ...

In this report, we describe a flow cytometric analysis of HTLV-I specific binding to fresh and cultured cells on a single cell basis. This assay uses rhodamine hydrocarbon tagged, purified HTLV-I virions according to the procedure originally described for avian retroviruses. Successful HTLV-I transmission was detected by analysis of integrated HTLV-I DNA, virion-associated reverse transcriptase...

Human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukemia/lymphoma (ATLL) occurs endemically in southwestern Japan, the Caribbean, and West Africa, but occurs sporadically in most of the rest of the world. However, because ATLL and non-HTLV-I associated T-cell neoplasms share overlapping clinicopathologic features, the prevalence of ATLL in nonendemic regions is unknown. ...

OBJECTIVES Human T-lymphotropic virus (HTLV)-1 causes T-cell leukaemia and myelopathy. Together with HTLV-2, it is endemic in some African nations. Seroprevalence data from Malawi are scarce, with no reports on associated disease incidence. HTLV seroprevalence and type were tested in 418 healthy mothers from Malawi. In addition, we tested the sera of 534 children to investigate mother-to-child ...