Peripheral blood leukocyte grafts that induce human to mouse graft-vs.-host disease reject allogeneic human skin grafts.

Allogeneic graft-versus-host disease is characterized by skin, gut, and bile duct destruction by relatively few donor type lymphocytes. In contrast, we can now show that human-to-mouse xenogeneic graft-versus-host disease is characterized by vasculitis and tumor-like infiltrations of the murine lymphohemopoietic organs with many human CD25+, HLA-DR+, CD4+ lymphoblasts. Using the technique of serial transplantation, it appears that at least 90% of the human lymphoblasts were unreactive to murine tissues. It is demonstrated consistently that the donor type lymphoblasts induced typical allogeneic rejection of distantly located full thickness human unmatched fetal skin grafts. The fact that the human grafts show primary immune responses in vivo indicates that the graft-versus-host disease murine model may be suitable for vaccination studies.