ENHANCEMENT OF NONSPECIFIC RESISTANCE BY LIPOSOME-ENCAPSULATED IMMUNOMODULATORS DOES NOT AFFECT SKIN-GRAFT REJECTION IN MICE

Administration of liposome-encapsulated immunomodulating agents muramy l tripeptide phosphatidyl ethanolamine (LE-MTPPE) or interferon-gamma (LE-IFN-gamma), or co-encapsulated MTPPE and IFN-gamma (LE-(MTPPE/IFN- gamma)) resulted in a dramatic increase of the nonspecific antimicrobi al resistance in mice, as shown before, This kind of treatment is espe cially of use in immunocompromised hosts who are prone to severe infec tions, Application of these immunomodulators might protect these patie nts, e.g., transplant recipients, from opportunistic infections, Howev er, accelerated rejection of the graft, resulting from augmentation of the antimicrobial defense in a nonspecific way, has to be avoided. In this study, the effect of treatment with LE-MTPPE, LE-IFN-gamma, or L E-(MTPPE/IFN-gamma) on skin graft rejection in mice was investigated, It was found that prophylactic treatment of skin-grafted mice with imm unomodulating formulations did not influence rejection of the graft, M oreover, in T cell-depleted mice, which showed a prolonged graft survi val compared with immunocompetent recipients, the administration of im munomodulators did not change the survival time of the grafts compared with T cell-depleted mice that did not receive immunomodulators, The results clearly show that, in this experimental setting, application o f the antimicrobial resistance-enhancing formulations (LE-MTPPE, LE-IF N-gamma, and LE-(MTPPE/IFN-gamma)) is allowed in graft-bearing recipie nts, without influencing graft survival.