The expanding B7 superfamily: increasing complexity in costimulatory signals regulating T cell function.
Upon encounter with specific antigen, naïveT helper precursor (THP) cells become activated. This event is regulated not only by engagement of the T cell receptor (TCR) with peptide presented in the context of major histocompatibility complex (MHC) class II molecules but by a number of costimulatory signals. CD28 engagement by B7-1 and B7-2 on resting THP cells provides a critical signal for initial cell cycle progression, interleukin 2 production and clonal expansion. However, largely as a consequence of the unraveling of the human genome, it is becoming clear that B7-1 and B7-2 are part of a larger family T of related counter-receptors that play an essential role in regulating the fate of primed, rather then resting,THP cells. These molecules play an important sequential role and act, together with B7-1- and B7-2-primed T cells, in the acquisition of effector function and/or tolerance induction.
Coyle
A J
AJ
Millennium Pharmaceuticals Inc, Inflammation Division, Cambridge, MA 02139, USA. Coyle@mpi.com
Gutierrez-Ramos
J C
JC
D000069594:Abatacept; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology; D000943:Antigens, Differentiation / Q000276:immunology; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000276:immunology; D060908:CTLA-4 Antigen; D016207:Cytokines / Q000096:biosynthesis; D005544:Forecasting; D006801:Humans; D018796:Immunoconjugates; D060945:Inducible T-Cell Co-Stimulator Ligand; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D018448:Models, Immunological; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497964:CD86 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C497965:Cd86 protein, mouse; C556707:Ctla4 protein, mouse; D016207:Cytokines; D018796:Immunoconjugates; D060945:Inducible T-Cell Co-Stimulator Ligand; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; D000069594:Abatacept