TY - CHAP M1 - Book, Section TI - Functions of Tlymphocytes: T-Cell Receptors for Antigen A1 - McClanahan, Fabienne A1 - Gribben, John A2 - Kaushansky, Kenneth A2 - Lichtman, Marshall A. A2 - Prchal, Josef T. A2 - Levi, Marcel M. A2 - Press, Oliver W. A2 - Burns, Linda J. A2 - Caligiuri, Michael Y1 - 2015 N1 - T2 - Williams Hematology, 9e AB - SUMMARYAll T cells express a receptor for antigen that is formed by two polymorphic polypeptides that invariably are associated with a collection of invariant proteins, namely CD3γ, CD3δ, CD3ε, and CD247.* These invariant proteins are necessary for surface expression and signaling by the T-cell receptor. The two polypeptides that form the T-cell receptor on most T cells are termed α and β. A small subset of T cells has receptors formed by different polypeptides termed γ and δ. The polypeptides of the T-cell receptor have a diversity that is comparable to that estimated for immunoglobulin molecules. However, unlike immunoglobulins, the T-cell receptors recognize small fragments of antigen only if they are presented to them by defined major histocompatibility complex molecules on the plasma membrane of another cell, the antigen-presenting cell. The response of the T cell to antigen depends on the intensity of the signal generated by ligation of the T-cell receptor, and is modified by the simultaneous ligation of other accessory molecules. Interactions at the contact sites between T-cells and antigen-presenting cells 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 and/or programmed cell death. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - hemonc.mhmedical.com/content.aspx?aid=1121097214 ER -