T CELL RECEPTOR VARIABLE GENE USAGE IN A SPECIFIC CYTOTOXIC T CELL RESPONSE Primary Structure of the Antigen-MHC Receptor of Four Hapten-specific Cyotoxic T Cell Clones

Abstract

Lymphocytes are capable of specifically recognizing foreign antigens and thus play an essential role in the immune system . B cells, a subset of lymphocytes, use immunoglobulins as cell surface receptors for foreign antigens (1). When B cells are stimulated by antigens, they differentiate to plasma cells and produce immunoglobulins in a soluble form . Taking advantage of plasma cell dyscrasias, the molecular basis of antigen recognition by immunoglobulins was studied earlier than that of the other subset of lymphocytes, the T cells (2, 3). However, during the last few years the structure of T cell receptor (TcR)' was identified and the genes encoding TcR were isolated (4-7) . The genomic organization of the genes for immunoglobulins (8, 9) and the TcR (10-15) are similar, and it is likely that these gene families originate from the same ancestral gene (16) . Immunoglobulins are composed of two heavyand light-chain disulfide-linked heterodimers, whereas one set of disulfide-linked a and ,Q glycoproteins forms a functional T cell receptor (17, 18) . These chains are assembled from noncontiguous variable (V) ; in the case of immunoglobulin heavy chain and the 0 chain of TcR, diversity (D) ; joining (J) ; and constant (C) gene segments . After somatic rearrangement, V, D, and J gene segments are joined and encode the variable region of the molecule . It has been shown that the variable regions of the immunoglobulin heavy chain (V ) and the light chain (V,,) form the antigen-binding pocket that interacts with the foreign antigen (19) . Considering the similarities at the genomic level of the immunoglobulin and the TcR, the variable region of the TcR should form the antigen recognition site . However, two major differences between the structure and recognition of the B and T cell receptors exist . The assembly of the light and heavy chains of

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@inproceedings{Iwamoto2003TCR, title={T CELL RECEPTOR VARIABLE GENE USAGE IN A SPECIFIC CYTOTOXIC T CELL RESPONSE Primary Structure of the Antigen-MHC Receptor of Four Hapten-specific Cyotoxic T Cell Clones}, author={Aikichi Iwamoto and Pamela S Ohashi and Hanspeter Pircher and C L Walker and Effie E. Michalopoulos and Fabio Rupp and Hans Hengartner and Tak W Mak}, year={2003} }