Localization of HTLV-I-associated antigens in adult T cell leukemia cells and HTLV-I-infected cell line cells

: Localization of HTLV-I-associated antigens was studied in adult T cell leukemia (ATL) cells and HTLV-I-infected cell line cells using monoclonal and human polyclonal antibodies against the viral-related antigens. Two monoclonal antibodies that we obtained by hybridoma technique reacted with HTLV-I-virus core antigens, P19 and P24, respectively. Human anti-HTLV-I-antibodies, which were purified from sera from ATL patients reacted with not only HTLV-I virus particles but also their precursors located in the cytoplasm. In tumor cells freshly isolated from ATL patients, no expression of the virus antigens was observed. When the cells were cultured for several days, the virus antigens were defined in about 3-5% of the cultured cells by the monoclonal antibodies, and in 5-10% by the purified human anti-HTLV-I antibodies. Addition of 5-iodo-2'-deoxyuridine to the culture inhibited cell growth, and at the same time, increased the percentage of the virus antigen-positive cells. Established HTLV-I-infected cell lines showed different cytological profiles from the original ATL cells in the viral replication and morphology.