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 profound effects on the development of cell-mediated; immune responses in: mice. The present study shows that an antibody to human CD154 (hCD40L) inhibits in vivo Tetanus toroid (TT) specific secondary antibody responses 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 expansion of xenoreactive, human T cells, was the decreased-expression of murine B7.;1 and B7.,2 caused by the administration of anti-hCD40L.: Therefore, it may be that defective maturation of murine antigen-presenting cells impeded the priming and expansion of human xenoreactive T cells. (C) 1998 Elsevier Science Inc.