Selective adsorption of immune DNA-synthesizing lymphocytes on corresponding target cells

Abstract

Lymphocytes of inbred lines of mice immunized with an allogeneic tumor were labeled with thymidine-H3 in vitro and in vivo, washed, and incubated with target cells in the presence of “cold” thymidine. Rapid and specific adsorption of the fraction of medium and small lymphocytes, synthesizing DNA, on the corresponding target cells was demonstrated by autoradiography. After preliminary incubation of unlabeled immune lymphocytes with target cells for 2 h, followed by the addition of thymidine-H3 to the culture medium at various time intervals, the percentage of labeled small and medium lymphocytes adsorbed on the target cells fell, to approach its initial level after contact for 8 h. It is postulated that the small and medium lymphocytes synthesizing DNA are “killers” that are not transformed into blast cells on contact with target cells.