Allografting with immunosuppression is accompanied by chronic rejection and continuing response of the host to infections. Upon first encounter with allogeneic and bacterial antigens the naive T and B cells react within days. Simultaneously cohorts of memory cells are created characterized by rapid response to the second antigenic stimulus. A number of unanswered questions remains as to whether where are the memory cells located, do they persist in the region of the first encounter with antigens or are they mobilized from the bone marrow and spleen, do they react differently to allogeneic and bacterial antigens, are they sensitive to the immunosuppressive drugs? This review cumulates recent data on the subject. Scanty information points to the necessity of more intensive studies on memory cells to allogeneic, bacterial and self-antigens after transplantation in the environment saturated with immunosuppressive drugs.

Keywords: Allograft, Bacteria, Infection, Rejection, Memory Cells