SYSTEMIC IMMUNE-RESPONSE TO PERIPHERAL-NERVE TRANSPLANTS ACROSS MAJORHISTOCOMPATIBILITY CLASS-I AND CLASS-II BARRIERS

The use of peripheral nerve transplantation in limb reconstruction has been limited by tissue rejection. In order to identify the major hist ocompatibility antigens involved in tissue rejection, mutant strains o f inbred mice! differing from the parent strain (C57BL/16) by either m ajor histocompatibility complex Class I (B6.C-H2(bml) mice) or Class I I (B6.C-H2(bml2) mice), were used in models of nerve transplantation. One, 2, and 3 weeks after nerve or skin transplantation, the immune re sponse in the recipient animal was monitored with use of lymphocyte-de pendent cytotoxicity and complement-dependent cytotoxicity assays. Ski n transplants were used for comparison as the gold standard of a nonva scularized graft with an easily observable success or failure. There w as no significant cellular immune response by the lymphocyte-mediated cytotoxicity assay when nerve or skin transplants involved an isolated Class-I or Class-II mismatch, but there was a significant response 2 weeks after transplantations across a combined Class-I and Class-II ba rrier for nerve (p < 0.04) or skin (p < 0.03). An antibody response to the grafts occurred for both skin and nerve transplants but only when a combined barrier was involved. This preliminary study, using a mous e model, suggests that nerve transplantation may be performed without systemic evidence of rejection with only a partial cross match of the major histocompatibility complexes, thus decreasing the complexity of tissue typing necessary for tissue banking.