Characterization of new non-T, non-B acute lymphoblastic leukemia cell lines: analysis of surface antigens by quantitative cellular radioimmunoassay and flow cytometry.

Two novel acute lymphoblastic leukemia (ALL) cell lines, HOON and HYON, have been established from patients with non-T, non-B ALL. The cell lines have been characterized and shown to express phenotypic markers on non-T, non-B ALL. By indirect immunofluorescence and flow cytometry they express Ia and common ALL (CALLA) antigens and are reactive with monoclonal antibodies BA-1, BA-2 and OKT-9. However, the cells do not express detectable amounts of B1 antigen or of cytoplasmic mu chain, which are markers of pre-B cells. Quantitation of Ia and CALLA antigens on HOON and HYON cell lines using a cellular radioimmunoassay revealed that both cells bind high levels of anti-Ia antibodies, 110 X 10(4) molecules per cell, and low levels of anti-CALLA antibodies, 7 X 10(4) molecules per cell. Although both HOON and HYON carry equivalent amounts of Ia on their surface, only the former is a good stimulator of the one-way mixed lymphocyte reaction.