INHIBITION BY CHOLESTERYLPHOSPHORYLSERINE OF T-CELL-MEDIATED IMMUNE-RESPONSES IN MICE

The synthetic analogue of phosphatidylserine, cholesterylphosphorylser ine (CPHS) inhibits T-cell-mediated immune responses in mice. Tested i n cultured mouse spleen cells, CPHS inhibits concanavalin A-induced ac tivation of DNA synthesis (IC50, 3.5 mu M). Injected i.p. during the e fferent phase, CPHS (25-100 mg/kg) inhibits the manifestations of dela yed-type of hypersensitivity. The compound (25 mg/kg i.p., daily) redu ces the acute graft-versus-host reaction when given for 5 days to dono r mice before the isolation of spleen cells used for the inoculum. The se data suggest that the addition of a phosphorylserine group to a ste roid ring may produce immunoregulatory compounds.