Arming of macrophages with lymphocytes from mice immunized with tumor tissue.

C57BL/6 macrophages are rendered specifically cytotoxic ("armed") by incubation with spleen cells from C57BL/6 mice sensitized in vivo with allogeneic P-815 mastocytoma cells. Data are presented which suggest that the cytotoxic activity of the macrophages is not due to the adherence of sensitized lymphocytes. The results indicate that it is the T-lymphocyte which is primarily involved in arming. Furthermore it is the cytotoxic and not the proliferating T-cell which is responsible for arming.