The B7 family and cancer therapy: costimulation and coinhibition.
The activation and development of an adaptive immune response is initiated by the engagement of a T-cell antigen receptor by an antigenic peptide-MHC complex. The outcome of this engagement is determined by both positive and negative signals, costimulation and coinhibition, generated mainly by the interaction between the B7 family and their receptor CD28 family. The importance of costimulation and coinhibition of T cells in controlling immune responses is exploited by tumors as immune evasion pathways. Absence of the expression of costimulatory B7 molecules renders tumors invisible to the immune system, whereas enhanced expression of inhibitory B7 molecules protects them from effective T cell destruction. Therefore, the manipulation of these pathways is crucial for developing effective tumor immunotherapy. Translation of our basic knowledge of costimulation and coinhibition into early clinical trials has shown considerable promise.
Zang
Xingxing
X
Howard Hughes Medical Institute, Immunology Program, Ludwig Center of Cancer Immunotherapy, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Allison
James P
JP
D000818:Animals; D015703:Antigens, CD / Q000187:drug effects; D000943:Antigens, Differentiation / Q000187:drug effects; D018122:B7-1 Antigen / Q000235:genetics / Q000502:physiology*; D018106:CD28 Antigens / Q000235:genetics / Q000502:physiology; D060908:CTLA-4 Antigen; D019496:Cancer Vaccines / Q000494:pharmacology / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D009369:Neoplasms / Q000628:therapy*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D019496:Cancer Vaccines; C556707:Ctla4 protein, mouse