Innate immunity and graft rejection.

Although innate immunity evolved to combat pathogens, increasing awareness of a pivotal role in driving and shaping adaptive immunity has prompted this review on the role of innate immunity in graft rejection. We present evidence that grafts, especially xenografts, elicit innate responses, required for adaptive immunity. Particular attention is paid to studies by ourselves and others demonstrating the important role of innate immunity in T-cell trafficking. The mechanisms by which grafts elicit innate immunity are a fertile subject for further investigation and an important target for therapeutic intervention.