Inhibition by cholesterylphosphorylserine of T-cell-mediated immune responses in mice

The synthetic analogue of phosphatidylserine, cholesterylphosphorylserine (CPHS) inhibits T-cell-mediated immune responses in mice. Tested in cultured mouse spleen cells, CPHS inhibits concanavalin A-induced activation of DNA synthesis (IC50, 3.5 microM). Injected i.p. during the efferent phase, CPHS (25-100 mg/kg) inhibits the manifestations of delayed-type of hypersensitivity. The compound (25 mg/kg i.p., daily) reduces the acute graft-versus-host reaction when given for 5 days to donor mice before the isolation of spleen cells used for the inoculum. These data suggest that the addition of a phosphorylserine group to a steroid ring may produce immunoregulatory compounds.