Identification and sequence of a fourth human T cell antigen receptor chain.
Thymus-derived lymphocytes (T cells) use clonally distributed antigen receptors to recognize peptide fragments associated with products of the major histocompatibility complex (MHC) (refs 1-4). On most murine and human T cells the T cell receptor (TCR) is composed of disulphide-linked alpha and beta chains (TCR alpha/beta), each of which contains constant and variable domains, and which are associated with the invariant chains of the CD3 complex. It has been demonstrated, however, that a distinct CD3-associated TCR is expressed on a small subset of T cells or immature thymocytes which fail to express either CD4 or CD8 (refs 7-14), the molecules associated with class II or class I MHC antigen recognition. Instead of TCR alpha/beta, these cells express heterodimers of gamma and delta chains (TRC gamma/delta). The genes encoding alpha, beta, and gamma have been isolated and characterized. A new murine T cell receptor (Cx) gene which undergoes rearrangement and expression early during T cell ontogeny has recently been identified 5' of the murine J alpha C alpha gene locus. Here we isolate and sequence the homologous transcript from PEER, a human cell line that expresses a TCR gamma/delta, and show that it encodes a protein with characteristic V, D, J, and C segments. Using probes derived from this transcript, we have shown that both PEER and MOLT-13, another TCR gamma/delta-expressing cell line, rearrange this locus and express two sizes of transcripts differing in the 3' untranslated region. Using a synthetic peptide derived from the deduced C region sequence, we have prepared antisera that precipitates the delta chain of the TCR from both PEER and MOLT-13, thus demonstrating that Cx and its human homologue code for the delta chain of the TCR.
Loh
E Y
EY
Department of Medical Microbiology, Stanford University School of Medicine, California 94305.
Lanier
L L
LL
Turck
C W
CW
Littman
D R
DR
Davis
M M
MM
Chien
Y H
YH
Weiss
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*
D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell; D004247:DNA; D004262:DNA Restriction Enzymes