QUANTITATIVE STUDIES ON THE BEHAVIOR OF SENSITIZED LYMPHOCYTES IN VITRO. II. INHIBITORY INFLUENCE OF THE IMMUNE SUPPRESSOR, IMURAN, ON THE DESTRUCTIVE REACTION OF SENSITIZED LYMPHOID CELLS AGAINST HOMOLOGOUS TARGET CELLS.

The cytocidal effect of specifically sensitized lymphoid cells on homologous target cells in culture can be inhibited by small quantities of an imidazole derivative of 6-mercaptopurine (imuran). This inhibition takes place only in the continuous presence of this drug, and at concentrations which apparently do not affect the viability of the attacking lymphoid cells. These results seem to support the contention that RNA-dependent protein synthesis on the part of the lymphoid cells is necessary for a destructive interaction between sensitized node cells and homologous target cells in vitro.