[Monoclonal antibodies against human differentiated thymocyte antigens]

Hybridomas producing monoclonal antibodies against cortical thymocytes (IKO-11) and early T cell precursors (IKO-10) were obtained. Monoclonal IKO-11 antibodies reacted with 75 +/- 1.6% of thymocytes and IKO-10 with 2.5 +/- 0.5%. Thymocyte fractionation over 19-33% gradient showed IKO-10 antibodies to react with the first fraction containing large cells and IKO-11 antibodies with the 4th-6th fraction containing small cells. The antibodies did not react with peripheral blood cells from healthy donors but detected antigens in patients with T cell ALL. If IKO-10 antibodies reacted with T cell ALL, there was no IKO-11 antibody reaction and vice versa. IKO-10 antibodies recognized this antigen on the cell surface of T cell Molt-4, SKCO-3 and non-T, non-B ALL Reh-6 lines. IKO antibodies did not react with these cells.