Establishment and characterization of an HTLV-I cell line from a Taiwanese patient with HTLV-I-associated myelopathy.

We describe a Taiwanese woman with chronic progressive myelopathy, in whom Western blot analysis of the serum and cerebrospinal fluid (CSF) displayed positive reactions to human T-lymphotropic virus type I (HTLV-I) proteins, p19, p24, p28, p36, gp46 and p53. HTLV-I proviral genomes were detected in the peripheral blood mononuclear cells (PBMC) and CSF cells by nested polymerase chain reaction and Southern blot hybridization. HTLV-I was successfully isolated from PBMC stimulated with interleukin-2 (IL-2). The established cell line, named THAM-1, was an IL-2-independent T-cell line with CD2+, CD3+, CD4+, CD25+ and HLA-DR+. Retrovirus particles with type C morphology were observed in the THAM-1 cells by electron microscopy, and HTLV-I-related antigens were also demonstrated by immunocytochemical staining and Western blot assay. Southern blot analysis revealed that HTLV-I proviral genomes were integrated into the THAM-1 cellular DNA. In Northern blot analysis, two extra-species of RNA were detected in addition to three typical viral transcripts. For the first time, an HTLV-I-producing T cell line was established from a patient with HTLV-I-associated myelopathy in Taiwan, an HTLV-I non-endemic area.