IMMUNOSUPPRESSION BY BLOCKING T-CELL CO-STIMULATION SIGNAL 2 (B7/CD28 INTERACTION)

摘要

PPROBLEM TO BE SOLVED: To provide a means for promoting the unusual immunosuppression of a xenograft. PSOLUTION: There is provided the means and method for inhibiting T-cell mediated rejection of a xenografted organ by blocking the delivery (B7/CD28 interaction) of co-stimulatory signal 2 in order to prevent the activation of xenoreactive T-cells in the recipient. In a first aspect, the co-stimulation is prevented by administration to the organ recipient of a soluble form of CTLA-4 derived from the xenogeneic donor organism. This preferentially binds B7 on a xenograft and blocks the interaction between B7 on a xenogeneic donor cells and CD 28 on a recipient T-cells. In a second aspect, the co-stimulation is antagonized by developing such a ligand of CTLA-4 on a xenogeneic donor cells as is to bind CTLA-4 on a recipient's activated T-cells to thereby antagonize the signal 2. PCOPYRIGHT: (C)2011,JPO&INPIT