Transplantation and cytokines.

Transplantation of foreign tissue initiates complex inflammatory responses that are mediated by cytokines and that, in the absence of immunosuppression, usually result in acute graft rejection and graft destruction. Thus, the study of cytokines in transplantation research has been pursued with great interest. Cytokine biology has evolved from an era that focused on the identification and cataloguing of newly discovered cytokines to one that addresses (1) the complexity of cytokine interactions with other cytokines, with other biologic mediators, and with the extracellular matrix; and (2) the diversity of cytokine effects upon both lymphoid and nonlymphoid cell types. This article reviews the basic principles of transplant immunology and discusses experimental data regarding the role of prototypic cytokines in allograft rejection, in general, and liver allograft rejection, in particular.