In vitro antibody-dependent cellular cytotoxicity against human T-cell leukemia/lymphoma virus (HTLV)-producing cells.

Human T-cell leukemia/lymphoma virus (HTLV)-producing cells were lysed by peripheral mononuclear cells (PMNC) from both anti-HTLV antibody-positive and -negative healthy persons in the presence of natural humoral antibodies against HTLV-related antigens (antibody-dependent cellular cytotoxicity, ADCC). PMNC from patients with T-cell leukemia, however, did not possess the positive reaction even in the presence of natural antibodies. In contrast, when the antibodies were absent, no cytotoxicity was caused by PMNC from any donors. Additionally, the complement present in the antibody-positive plasma did not contribute to humoral antibody-dependent cytotoxicity in the presence of plasma without PMNC. Therefore, ADCC against HTLV-producing cells may correlate with the prophylaxis of HTLV-induced malignancy in vivo.