MODIFICATIONS OF CD8(-CELL FUNCTION DURING IN-VIVO MEMORY OR TOLERANCE INDUCTION() T)

Naive monoclonal T cells specific for the male antigen can be stimulat ed in vivo to eliminate male cells and become memory cells or to permi t survival of male cells and become tolerant. Memory cells responded t o TCR ligation by cyclic oscillations of calcium levels and immediate secretion of very high levels of IL-2 and interferon-gamma. Tolerant c ells did not proliferate in response to ionomycin and phorbol myristat e acetate, failing to mobilize calcium to produce IL-2 or express IL-2 R, but survived for long time periods in vivo and secreted IL-10. Thes e results emphasize that tolerance is not an absence of all functional activity and may be associated with modifications of behavior conferr ing important regulatory functions on tolerant T cells.