1-4 Clonal Selection of Antigen-Specific Lymphocytes Flashcards
B cell antigen receptor
The complex of membrane immunoglobulin that recognizes antigen and a heterodimer of Igα and Igβ that signals antigen recognition in B lymphocytes.
Clonal Deletion
Elimination of potentially self-reactive lymphocytes. Immature lymphocytes undergo programmed cell death after binding to antigen; in this way, cells bearing receptors that recognize self are deleted before they are capable of participating in immune responses. This is a major mechanism of immune tolerance.
Clonal Expansion
The selective proliferation of mature naive lymphocytes that encounter antigen. Only those lymphocytes berating receptors specifically recognizing antigen are activated to proliferate and differentiate into effector cells.
Clonal Selection
The process whereby potentially self-reactive lymphocytes are eliminated during ontogeny whereas mature lymphocytes recognizing non-self antigens are selectively expanded.
Constant region (C region)
Region of a lymphocyte receptor for antigen that does not participate in antigen binding and does not vary between cells of different antigen specificities.
Heavy Chain
The immunoglobulin heavy chains are the larger of the two kinds of polypeptide chains in the immunoglobulin molecule. Each light chain has a variable region contributing to the antigen-binding site, and a constant region that mediates the effector function of the molecule.
Immune Tolerance
Non-responsiveness of the adaptive immune system to antigen.
Immunoglobulin superfamily
Family of proteins containing at least one immunoglobulin-like domain and for which the Ig-like domains is a major structural element.
Light Chain
The immunoglobulin light chains are the smaller of the two kinds of chains in the immunoglobulin molecule. Each has a variable region contributing to the antigen-binding site, and a constant region containing a cysteine by which it makes a disulfide bond with the constant region of the heavy chain.
T cell receptor (TCR)
The complex of variable chains wherby T cells recognize antigen and signaling chains whereby antigen recognition is signaled to the cell interior.
Variable Region (V region)
Region of a lymphocyte receptor for antigen that participates in antigen binding and varies between cells of different antigen specificities.