The role of CD8+ T cells during allograft rejection.
Organ transplantation can be considered as replacement therapy for patients with end-stage organ failure. The percent of one-year allograft survival has increased due, among other factors, to a better understanding of the rejection process and new immunosuppressive drugs. Immunosuppressive therapy used in transplantation prevents activation and proliferation of alloreactive T lymphocytes, although not fully preventing chronic rejection. Recognition by recipient T cells of alloantigens expressed by donor tissues initiates immune destruction of allogeneic transplants. However, there is controversy concerning the relative contribution of CD4+ and CD8+ T cells to allograft rejection. Some animal models indicate that there is an absolute requirement for CD4+ T cells in allogeneic rejection, whereas in others CD4-depleted mice reject certain types of allografts. Moreover, there is evidence that CD8+ T cells are more resistant to immunotherapy and tolerance induction protocols. An intense focal infiltration of mainly CD8+CTLA4+ T lymphocytes during kidney rejection has been described in patients. This suggests that CD8+ T cells could escape from immunosuppression and participate in the rejection process. Our group is primarily interested in the immune mechanisms involved in allograft rejection. Thus, we believe that a better understanding of the role of CD8+ T cells in allograft rejection could indicate new targets for immunotherapy in transplantation. Therefore, the objective of the present review was to focus on the role of the CD8+ T cell population in the rejection of allogeneic tissue.
Bueno
V
V
Disciplina de Nefrologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brasil. valquiriabueno@hotmail.com
Pestana
J O M
JO
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D018925:Chemokines / Q000502:physiology; D016207:Cytokines / Q000502:physiology; D006084:Graft Rejection / Q000188:drug therapy / Q000276:immunology*; D006085:Graft Survival / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D014184:Transplantation, Homologous / Q000276:immunology
D018925:Chemokines; D016207:Cytokines; D007166:Immunosuppressive Agents