TY - CHAP M1 - Book, Section TI - Functions of T Lymphocytes: T-Cell Receptors for Antigen A1 - Lucas, Fabienne A1 - Gribben, John A2 - Kaushansky, Kenneth A2 - Prchal, Josef T. A2 - Burns, Linda J. A2 - Lichtman, Marshall A. A2 - Levi, Marcel A2 - Linch, David C. PY - 2021 T2 - Williams Hematology, 10e AB - SUMMARYAll T cells express an antigen receptor formed by two polymorphic polypeptides that are invariably associated with the CD3 complex containing CD3γ, CD3δ, CD3ε, and ζ subunits, as well as multiple accessory molecules. These proteins are necessary for surface expression and signaling by the T-cell receptor (TCR). On most T cells, the TCR is formed by α and β polypeptides. In a small T-cell subset, receptors are formed by γ and δ polypeptides. The diversity of these TCR polypeptides is comparable to that estimated for immunoglobulin (Ig) molecules. However, unlike Igs, TCR antigen recognition requires antigen presentation by defined major histocompatibility complex molecules on the plasma membrane of another cell, the antigen-presenting cell (APC). T-cell response to antigen depends on the intensity of the signal generated by ligation of the TCR and is modified by the simultaneous ligation of other accessory molecules. Interactions at the contact sites between T cells and APCs are organized in the immunologic synapse. The outcome of T-cell antigen recognition can range from immune activation and T-cell proliferation to specific T-cell tolerance or programmed cell death. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1180471791 ER -