Cloning of human lymphocytes reactive with autologous leukemia cells

The primed lymphocyte typing test has been used to detect leukemia-associated antigens, but interpretation has been difficult because of significant levels of reactivity with normal cells. Elimination of unwanted reactivities could be accomplished by (a) use of the patient's own lymphocytes as responders to the leukemia cells and (b) cloning of the responding cells. Cloning of antigen-activated human lymphocytes can be accomplished through the use of T-lymphocyte growth factor, which permits the long-term growth of antigen-activated lymphocytes. In the study reported here, the remission lymphocytes of a patient with acute myelogenous leukemia were sensitized in culture to the patient's own leukemic myeloblasts and then grown from wells containing one or a few replicating units. Sufficient cells of three clones were growth for further testing of specificity: one responded only to the sensitizing myeloblast but not to normal cells tested; one responded to the sensitizing myeloblasts and one allogeneic myeloblast but not to normal cells; and one responded to none of the cells tested, although it proliferated vigorously with growth factor alone. These results demonstrate the feasibility of cloning human lymphocytes putatively responsive to leukemia-associated antigens in order to improve their discriminatory capacity in the primed lymphocyte typing test. The response pattern observed was that expected of a clone responding to a leukemia-associated antigen.