Two pathways of costimulation through CD28.
CD28 is recognized as the primary costimulatory molecule involved in the activation of naïve T cells. However, the biochemical signaling pathways that are activated by CD28 and how these pathways are integrated with TCR signaling are still not understood. We have recently shown that there are at least two independent activation pathways induced by CD28 costimulation. One is integrated with TCR signaling in the context of the immunological synapse and is mediated through transcriptional enhancement and the second is mediated through the induction of mRNA stability. Here, we review the immunological consequences and biochemical mechanisms associated with CD28 costimulation and discuss the major questions that need to be resolved to understand the molecular mechanisms that transduce CD28 costimulation.
Miller
Jim
J
The David H. Smith Center for Vaccine Biology and Immunology, Aab Institute for Biomedical Research, Rochester, NY, USA. jim_miller@urmc.rochester.edu
Baker
Christina
C
Cook
Kevin
K
Graf
Beth
B
Sanchez-Lockhart
Mariano
M
Sharp
Katherine
K
Wang
Xia
X
Yang
Barbara
B
Yoshida
Takeshi
T
D018106:CD28 Antigens / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D054992:Immunological Synapses / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D020871:RNA Stability / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015533:Transcriptional Activation / Q000276:immunology
D018106:CD28 Antigens; D011948:Receptors, Antigen, T-Cell