[PDF][PDF] Cytotoxic T lymphocyte antigen-4 accumulation in the immunological synapse is regulated by TCR signal strength

JG Egen, JP Allison - Immunity, 2002 - cell.com
JG Egen, JP Allison
Immunity, 2002cell.com
CD28 and CTLA-4 engagement with B7 expressed by APCs generates critical regulatory
signals for T cell activation. CD28 is expressed on the T cell surface and enhances T cell
expansion, while CTLA-4 localizes primarily to an intracellular compartment and inhibits T
cell proliferation. We demonstrate that CTLA-4 has several unique trafficking properties that
may regulate its ability to attenuate a T cell response. Importantly, accumulation of CTLA-4 at
the immunological synapse is proportional to the strength of the TCR signal, suggesting that …
Abstract
CD28 and CTLA-4 engagement with B7 expressed by APCs generates critical regulatory signals for T cell activation. CD28 is expressed on the T cell surface and enhances T cell expansion, while CTLA-4 localizes primarily to an intracellular compartment and inhibits T cell proliferation. We demonstrate that CTLA-4 has several unique trafficking properties that may regulate its ability to attenuate a T cell response. Importantly, accumulation of CTLA-4 at the immunological synapse is proportional to the strength of the TCR signal, suggesting that cells receiving stronger stimuli are more susceptible to CTLA-4-mediated inhibition. This may represent a novel feedback control mechanism in which a stimulatory signal regulates the recruitment of an inhibitory receptor to a functionally relevant site on the cell surface.
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