Self-recognition promotes the foreign antigen sensitivity of naive T lymphocytes

摘要: Major histocompatibility complex (MHC) class I and II molecules are highly polymorphic proteins that bind present foreign peptides to the clonally distributed αβ receptors (TCR) of T lymphocytes. As a population, immature lymphocytes generated in thymus express very diverse set TCR specificities. A process positive selection filters this broad repertoire optimize peripheral cells for antigen recognition context available MHC products. Only those precursor whose TCRs generate an adequate but not excessive signalling response self-peptides bound expressed undergo successful maturation1. Here we show post-thymic self-recognition facilitates reactivity mature cells. Both experimental physiological interruption T-cell contact with self-peptide ligands leads rapid decline sensitivity stimuli. Because adaptive immune system must be recruited early infectious when is limiting2, these findings suggest ensures predictable self-ligands, which turn promotes efficient responses pathogens.