CD28 costimulation: a source of Vav-1 for TCR signaling with the help of SLP-76?
T cells require dual stimulation to become activated. When T cells encounter antigen-presenting cells, both the T cell receptor (TCR) and the CD28 coreceptor are ligated and activated. Michel and Acuto discuss how the adaptor SLP-76, which is recruited to the activated TCR complex, and the Rho family guanosine triphosphatase exchanger Vav-1, which is recruited by the CD28 receptor and TCR, may form a macromolecular complex that results in T cells activation. Vav-1 may serve as a central integrator between CD28 signaling and TCR signaling through its indirect effects on phosphoinositide 3-kinase-dependent signaling.
Michel
Frédérique
F
Molecular Immunology Unit, Department of Immunology, Institut Pasteur, 25, rue du Dr. Roux, 75724 Paris, Cedex 15, France. fmichel@pasteur.fr
Acuto
Oreste
O
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D018106:CD28 Antigens / Q000502:physiology*; D018797:Cell Cycle Proteins; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D010750:Phosphoproteins / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology*
D048868:Adaptor Proteins, Signal Transducing; D018106:CD28 Antigens; D018797:Cell Cycle Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell; C092947:SLP-76 signal Transducing adaptor proteins; C496618:VAV1 protein, human