Memory T Cells in Vascularized Composite Allotransplantation

Abstract

Memory T cells are generated as part of the body's primary immune response to infection and environmental exposure so that a primed and more rapid response can be mounted in subsequent encounters. While beneficial in response to subsequent pathogen exposures, the unique characteristics of memory T cells such as their longevity, distinct trafficking patterns to multiple body sites, and cross-reactivity with donor antigens, have been demonstrated to represent a formidable barrier to successful transplantation and tolerance induction in both animal research models and clinical studies. In the context of vascularized composite allotransplantation (VCA) where acute rejection episodes are frequent despite chronic immunosuppression, current research efforts are directed toward immunosuppression minimization or complete withdrawal of immunosuppression through the attainment of transplantation tolerance. This review focuses on the potential roles of memory T cells on the rejection process at the level of the skin and the outcome of immunologic protocols for tolerance induction in VCA.