Despite the importance of programmed death-1 (PD-1) for T cell inhibition, little is known about its intracellular trafficking or requirements for localization to the immunological synapse. Here, we show that in activated T cells, PD-1 is present at the plasma membrane, near the Golgi and in the trans-Golgi network. Unlike CD28 and CTLA-4, PD-1 accumulation at the synapse is extensive only when T cells interact with dendritic cells (DCs) expressing high B7-DC levels. However, B7-H1 is also critically important, especially when the DCs have little B7-DC. Despite this preference, B7-H1-/- DCs elicit greater cytokine secretion than B7-DC-/- DCs during T cell restimulation, possibly because they also express less B7-DC. PD-1 and CD28 have similar kinetics of synaptic accumulation, suggesting that the process involves T cell receptor-triggered cytoskeletal reorganization followed by ligand binding.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Nov 6 2007|
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