Cytostatic effector cells generated in vivo against M locus determinants.
Cytostatic effector cells against M-locus (Mls) determinants were generated in mice by immunization with Mls incompatible lymphocytes. A post-labelling assay of 14C-labelled uridine uptake by macrophage targets was employed to meaure the inhibitory activity of the effector cells. Using lymphocytes from Mls pseudocongenic mice to immunize donors of effector cells, it was confirmed that the cytostatic effect was via the Mls determinants expressed on the macrophage targets. Cytotoxic effector cells against M-locus (Mls) determinants were not detected by the cell-mediated lympholysis assay (CML) in a five day mixed lymphocyte culture (MLC) between Mls incompatible lymphocytes. Specificity of cytotoxic cells generated by culturing in vivo preimmunized responder cells and Mls incompatible stimulator lymphocytes did not correlate with the Mls determinant of the stimulator lymphocytes.