HVEM, a cosignaling molecular switch, and its interactions with BTLA, CD160 and LIGHT

Abstract

[EN] Temporal and spatial expression of cosignaling receptors and their ligands regulates the early stages of T-cell activation (signal 1, T-cell receptor (TCR) signaling and signal 2, costimulation/ coinhibition), clonal expansion and T-cell survival during their differentiation towards effector T cells. Once the inflammatory stimulus is eliminated, effector T cells return to homeostasis after undergoing a contraction phase by activation-induced cell death and the intervention of ligands for coinhibitory receptors, leaving a population of long-term memory T cells. The expression of ligands for coinhibitory receptors on hematopoietic cells and, more importantly, on non-hematopoietic cells of peripheral tissues is a key process in tuning the functional activity of effector T cells to prevent excess tissue inflammation that may lead to immunopathology and subsequent tissue dysfunction