BLOCKADE OF CD40-CD154 INTERFERES WITH HUMAN T-CELL ENGRAFTMENT IN SCID MICE

Antibodies to the ligand for CD40 (CD154) have been shown to exert pro found effects on the development of cell-mediated; immune responses in : mice. The present study shows that an antibody to human CD154 (hCD40 L) inhibits in vivo Tetanus toroid (TT) specific secondary antibody re sponses in-hu-PBL-scid mice, as well as the expansion of xenoreactive human T cells in the scid mice, A possible; cause for the reduced expa nsion of xenoreactive, human T cells, was the decreased-expression of murine B7.;1 and B7.,2 caused by the administration of anti-hCD40L.: T herefore, it may be that defective maturation of murine antigen-presen ting cells impeded the priming and expansion of human xenoreactive T c ells. (C) 1998 Elsevier Science Inc.