T cell receptor interactions with peptide/major histocompatibility complex (pMHC) ligands control the selection of T cells in the thymus as well as their homeostasis in peripheral lymphoid organs. Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56 lck . Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca 2 + responses to subsequent TCR engagement by anti-CD3 or nominal antigen. Adaptation to peripheral pMHC contact may be important for regulating naive CD4 T cell responsiveness.
Smith, K., Seddon, B., Purbhoo, M. A., Zamoyska, R., Fisher, A. G., & Merkenschlager, M. (2001). Sensory adaptation in naive peripheral CD4 T cells. The Journal of Experimental Medicine, 194(9), 1253–61. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11696591 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC2195983