The immunological synapse and CD28-CD80 interactions.
According to the two-signal model of T cell activation, costimulatory molecules augment T cell receptor (TCR) signaling, whereas adhesion molecules enhance TCR-MHC-peptide recognition. The structure and binding properties of CD28 imply that it may perform both functions, blurring the distinction between adhesion and costimulatory molecules. Our results show that CD28 on naïve T cells does not support adhesion and has little or no capacity for directly enhancing TCR-MHC-peptide interactions. Instead of being dependent on costimulatory signaling, we propose that a key function of the immunological synapse is to generate a cellular microenvironment that favors the interactions of potent secondary signaling molecules, such as CD28.
Bromley
S K
SK
Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis MO, USA.
Iaboni
A
A
Davis
S J
SJ
Whitty
A
A
Green
J M
JM
Shaw
A S
AS
Weiss
A
A
Dustin
M L
ML
D018122:B7-1 Antigen / Q000235:genetics / Q000378:metabolism*; D018106:CD28 Antigens / Q000737:chemistry / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D017261:Glycosylphosphatidylinositols / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
D018122:B7-1 Antigen; D018106:CD28 Antigens; D017261:Glycosylphosphatidylinositols; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D011993:Recombinant Fusion Proteins; D018799:Intercellular Adhesion Molecule-1