Transduction of signal generated from the antigenic receptor of T lymphocytes

Abstract

T lymphocytes, in contrast to B lymphocytes which bind free antigens in a native form, recognize little antigenic peptides displayed on histocompatibility molecules in the surface of specialized or target cells. For this, mature T lymphocytes have a group of membrane proteins that together are named TCR complex. This group of polypeptide chains expresses in the membrane and has a double function: to recognize the antigenic fragments bound to histocompatibility molecules and to transmit signals arisen from the recognition to the inner of the lymphocyte. The consequences of these signals can vary from functional activation to anergia or apoptosis. Thanks to intensive research in this area in the last years, many new proteins involved in signal transduction to T lymphocytes and their mechanisms, have been revealed. In this review, we examine the models that explain the dynamic of TCR ligation, the main signal transduction pathways, the pharmacological agents that allow its study and human diseases that show, in their physiopathologic mechanisms, alterations in signaling pathways via TCR.