Molecular cloning and chromosomal localization of the human T-cell receptor zeta chain: distinction from the molecular CD3 complex.

Abstract

The T-cell antigen receptor (TCR) is a multisubunit receptor complex specific to T cells subserving both antigen recognition and signal transduction functions. The { chain of the TCR is a component of all surface receptor complexes. This chain was first identified in murine T cells by virtue of the fact that it coinmunoprecipitates with the TCR complex using antibodies directed against either the clonespecific subunits or invariant CD3 subunits of the receptor.Recently, we have isolated a cDNA encoding the murine C. Using this as a probe, we have now isolated cDNAs encoding the human {. Sequence analysis of cDNAs encoding human and murine { reveals that it is a highly conserved protein. In addition to amino acid homology, there is remarkable interspecies conservation in the nucleotide sequence of the 5' and 3' untranslated regions of the C mRNA. The previously characterized invariant 6, E, and y chains of the TCR, referred to as the CD3 complex, share significant sequence and structural homology with each other and are all located within 300 kilobases of each other on human chromosome 11 (11q23). Chas no sequence similarity to the CD3 chains and the localization of the human C gene to the centromeric region of chromosome 1 underscores the fact that it is a distinct genetic component of the TCR.Initiation of a normal immune response requires recognition of foreign antigen by T lymphocytes. This occurs when antigen-presenting cells bearing major histocompatibility complex (MHC) molecules bound with the appropriate antigen interact with T-cell receptors that recognize the MHCantigen complex as foreign. The T-cell antigen receptor (TCR) is a complex multisubunit structure whose components have been divided by both nomenclature and presumed function into two groups. The first group consists of the antigen recognition components of the receptor or Ti. On most T cells these components consist of a-j3 heterodimers, which are products of rearranged genes and are expressed in a clonally restricted manner (1-3). These clonotypic elements are immunoglobulin-like structures with constant and variable domains. The second group of receptor components are those that are constant in sequence for all T cells and are presumed to function primarily in signal transduction (4-11).The invariant 6, e, and y chains are collectively referred to as the CD3 complex. The members of the CD3 complex are related by amino acid sequence and are all members of the immunoglobulin gene superfamily (11-18). In addition, the CD3 components are all clustered within 300 kilobases (kb) of each other on human chromosome 11q23. The genes for the CD3 6 and y reside within 1.6 kb of each other (19-21).More recently, another invariant chain, ', has been discovered as part of the murine receptor complex (7). Although a (25,26). We have demonstrated that in human peripheral blood lymphocytes as in murine hybridomas this tyrosine kinase results in the tyrosine phosphorylation of ; with an increase in its apparent molecular mass from 16 to 21 kDa (27,...

A specific defect in CD3 gamma-chain gene transcription results in loss of T-cell receptor/CD3 expression late after human immunodeficiency virus infection of a CD4+ T-cell line.

“…Mature (23)(24)(25)(26)(27)(28). In the absence of any one chain, the TCR/CD3 complex cannot be correctly assembled and transported to the plasma membrane (18 Functionally, the loss of TCR/CD3 in HIV-infected T cells would significantly inhibit their ability to respond immunologically.…”

“…3E). The intensity of these spots in the 355 patterns is related to the number of methionine and cysteine residues in each protein chain (23)(24)(25)(26)(27)(28). TCR/CD3 polypeptides were essentially absent from the infected cell surface (Fig.…”

“…The TCR a-and E-chain (TCR-a and TCR-f3) probes (23,24) were kindly provided by Tak Mak; the CD3-e probe (25), generated by polymerase chain reaction to the entire e-chain coding region, by Jason Loveridge (Institute for Molecular Medicine, Oxford, England); the CD3-; probe (26) by Allan Weissman; and the CD3-y probe (27) by M. J. Crumpton. The CD3-6 probe (28) Fig.…”

“…Human TCR-a is a glycoprotein of 43-49 kDa, TCR-f3 a glycoprotein of 38-44 kDa, CD3-y a glycoprotein of 25-28 kDa, CD3-8 a 20-kDa glycoprotein, CD3-e a 25-kDa nonglycoprotein, and CD3-; a 16-kDa nonglycoprotein (23)(24)(25)(26)(27)(28). Spots corresponding to the TCR/CD3 chains are indicated with circles in Fig.…”

Forced Expression of the Fc Receptor γ-Chain Renders Human T Cells Hyperresponsive to TCR/CD3 Stimulation

“…Single-stranded cDNA was synthesized from 1 g total RNA by using the avian myeloblastoma virus reverse transcriptase-based reverse transcription system from Promega (Madison, WI) and oligo-dT primer. The primers for Fc⑀RI␥ chain were synthesized by Sigma-Aldrich and are as follows: forward 5Ј-CCT GGG AGA GCC TCA GCT CTG CTA TAT C-3Ј (sense bp 79 -106), reverse 5Ј-GAA TAT GAC CGC ATC TAT TGT AAA G-3Ј (antisense bp 311-287) (23). Reverse transcription products were PCR amplified with a high fidelity PCR system (Boehringer Mannheim, Indianapolis, IN).…”