title: Basic science for the clinician 55: CTLA-4.
abstract: In physiological systems, for every "yang," there must be a "yin," for uncontrolled systems can run amok. This is the case for the T-cell compartment of the immune system, where activation must be modulated, dampened, and ultimately reversed; to not apply the brakes leads to dire consequences. In less than 20 years, CTLA-4 has emerged from being an orphan, next becoming a physiological star with ever-emerging effects, and finally to being a therapeutic target-an impressive example of evolution and one that continues. Understanding the costimulatory effects and mechanisms of CTLA-4 and the redundancies intrinsic to costimulation is important in understanding T-cell function and dysfunction in disease. A future article in this series will describe inducible T-cell costimulator, which is a normal by-pass to CTLA-4's effects.
authors.affiliation: Division of Rheumatology, Department of Medicine, University of Medicine and Dentistry of New Jersey Y Robert Wood Johnson Medical School, 1 RW Johnson Pl, New Brunswick, NJ 08903-001, USA. lensigal@gmail.com
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Sigal
mesh_terms: D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology; D060908:CTLA-4 Antigen / Q000737:chemistry / Q000502:physiology* / Q000627:therapeutic use; D020022:Genetic Predisposition to Disease; D006801:Humans; D008213:Lymphocyte Activation; D011110:Polymorphism, Genetic; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D060908:CTLA-4 Antigen