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Lunde E, Løset GÅ, Bogen B, Sandlie I. Stabilizing mutations increase secretion of functional soluble TCR-Ig fusion proteins. BMC Biotechnol 2010; 10:61. [PMID: 20735812 PMCID: PMC2936418 DOI: 10.1186/1472-6750-10-61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 08/24/2010] [Indexed: 12/02/2022] Open
Abstract
Background Whereas T cell receptors (TCRs) detect peptide/major histocompatibility complexes (pMHCs) with exquisite specificity, there are challenges regarding their expression and use as soluble detection molecules due to molecular instability. We have investigated strategies for the production of TCR-immunoglobulin (Ig) fusion proteins. Two different TCRs that are characteristic of a mouse model for idiotype (Id) dependent immune regulation were engineered. They are structurally unrelated with different variable (V), diversity (D) and joining (J) segments, but each share one V gene segment, either Vα or Vβ, with the well characterized murine TCR, 2C. Results Several TCR-Ig formats were assessed. In one, the TCR V domains were fused to Ig constant (C) regions. In others, the complete extracellular part of the TCR was fused either to a complete Ig or an Ig Fc region. All molecules were initially poorly secreted from eukaryotic cells, but replacement of unfavourable amino acids in the V regions improved secretion, as did the introduction of a disulfide bridge between the TCR C domains and the removal of an unpaired cysteine. A screening strategy for selection of mutations that stabilize the actual fusion molecules was developed and used successfully. Molecules that included the complete heterodimeric TCR, with a stabilizing disulfide bridge, were correctly folded as they bound TCR-specific antibodies (Abs) and detected pMHC on cells after specific peptide loading. Conclusions We show that fully functional TCR-Ig fusion proteins can be made in good yields following stabilizing engineering of TCR V and C region genes. This is important since TCR-Ig fusions will be important probes for the presence of specific pMHCs in vitro and in vivo. In the absence of further affinity maturation, the reagents will be very useful for the detection of kinetic stability of complexes of peptide and MHC.
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Affiliation(s)
- Elin Lunde
- Department of Molecular Biosciences, Centre for Immune Regulation, University of Oslo, Oslo 0316, Norway
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Maynard J, Adams EJ, Krogsgaard M, Petersson K, Liu CW, Garcia KC. High-level bacterial secretion of single-chain alphabeta T-cell receptors. J Immunol Methods 2005; 306:51-67. [PMID: 16198365 DOI: 10.1016/j.jim.2005.07.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Revised: 07/14/2005] [Accepted: 07/25/2005] [Indexed: 10/25/2022]
Abstract
While numerous antibody-antigen systems have been structurally characterized, studies of structurally analogous T-cell receptor MHC systems have lagged behind largely due to the lack of a general TCR expression system. Efforts to develop bacterial systems have resulted in low yields (< 0.5 mg/l) of active material which is prone to proteolysis and aggregation. Here we report a strategy to secrete folded, soluble single chain T-cell receptors (scTCR) in the Escherichia coli periplasm using three representative alphabeta TCRs (172.10, 1934.4/c19 and 2B4). Shake flask yields between 0.5 and 30 mg/l active, purified material were attained for all TCRs studied and found to depend on the introduction of solubility-increasing amino acid substitutions, skp chaperone co-expression and C-terminal fusion to a human kappa constant domain in the context of a tightly regulated expression vector. This system will greatly enable crystallographic, thermodynamic and other biophysical analyses of TCRs which require large quantities of homogeneous material.
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Affiliation(s)
- Jennifer Maynard
- Department of Microbiology and Immunology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94304, USA.
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4
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Abstract
Exciting breakthroughs in the last two years have begun to elucidate the structural basis of cellular immune recognition. Crystal structures have been determined for full-length and truncated forms of alpha beta T cell receptor (TCR) heterodimers, both alone and in complex with their peptide-MHC (pMHC) ligands or with anti-TCR antibodies. In addition, a truncated CD8 coreceptor has been visualized with a pMHC. Aided in large part by the substantial body of knowledge accumulated over the last 25 years on antibody structure, a number of general conclusions about TCR structure and its recognition of antigen can already be derived from the relatively few TCR structures that have been determined. Small, but important, variations between TCR and antibody structures bear on their functional differences as well as on their specific antigen recognition requirements. As observed in antibodies, canonical CDR loop structures are already emerging for some of the TCR CDR loops. Highly similar docking orientations of the TCR V alpha domains in the TCR/pMHC complex appear to play a primary role in dictating orientation, but the V beta positions diverge widely. Similar TCR contact positions, but whose exact amino acid content can vary, coupled with relatively poor interface shape complementarity, may explain the flexibility and short half-lives of many TCR interactions with pMHC. Here we summarize the current state of this field, and suggest that the knowledge gap between the three-dimensional structure and the signaling function of the TCR can be bridged through a synthesis of molecular biological and biophysical techniques.
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Affiliation(s)
- K C Garcia
- Scripps Research Institute, Department of Molecular Biology, La Jolla, California 92037, USA.
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Pecorari F, Tissot AC, Plückthun A. Folding, heterodimeric association and specific peptide recognition of a murine alphabeta T-cell receptor expressed in Escherichia coli. J Mol Biol 1999; 285:1831-43. [PMID: 9917415 DOI: 10.1006/jmbi.1998.2422] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In a systematic study of the murine T-cell receptor UZ3-4, expressed and refolded from inclusion bodies in Escherichia coli, it was found that functional molecules can be obtained only under a very narrow set of conditions. The refolded T-cell receptor UZ3-4 specifically recognizes its cognate peptide (from mycobacterial Hsp60) in the context of H-2Db, but not another peptide bound to H-2Db, and the dissociation constant was determined by BIAcore as 10(-4) M. Using T-cell receptor constructs comprising all extracellular domains (ValphaCalpha and VbetaCbeta), found to be necessary for stability of the final product, significant amounts of native molecules were obtained only if the intermolecular Calpha-Cbeta disulfide bridge bond was deleted, even though the interaction between the complete alpha and beta-chain was determined to be very weak and fully reversible (KD approximately 10(-7) to 10(-6) M). Fusion of Jun and Fos to the constant domains also decreased the folding yield, because of premature association of intermediates leading to aggregation. Furthermore, only in a very narrow set of concentrations of oxidized and reduced glutathione, native disulfide bonds dominated. This shows that T-cell receptor domains are very prone to aggregation and misassociation during folding, compounded by incorrect disulfide bond formation. Once folded, however, the heterodimeric molecule is very stable and could be concentrated to millimolar concentration.
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Affiliation(s)
- F Pecorari
- Biochemisches Institut, Universität Zürich, Winterthurerstr. 190, Zürich, CH-8057, Switzerland
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6
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Molloy PE, Harris WJ, Strachan G, Watts C, Cunningham C. Production of soluble single-chain T-cell receptor fragments in Escherichia coli trxB mutants. Mol Immunol 1998; 35:73-81. [PMID: 9683253 DOI: 10.1016/s0161-5890(98)00019-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Antibodies and T cell receptors (TCR) both belong to the immunoglobulin superfamily whose members are characterised by the possession of one or more immunoglobulin domains. The production of soluble single chain antibody fragments in Escherichia coli has, in recent years, become a routine laboratory procedure. In contrast, the production of T cell receptors in bacteria has remained problematic as the majority of the recombinant protein is insoluble. In this paper we show that single chain TCR produced in E. coli BL21 (DE3) and directed to the periplasm was also insoluble and that this was in part due to the failure of the cell protein processing machinery to cleave the pelB leader sequence. This problem was overcome by expressing the single chain TCR in the cytoplasm of E. coli which carry an inactive thioredoxin reductase gene. This strain allows the formation of disulphide bonds in the cell cytoplasm which we believe encourages the correct folding of the recombinant protein. We have constructed both a human and mouse single chain TCR in these bacteria and demonstrated using BIAcore technology that these molecules have folded in a conformation which allows their recognition by conformational specific ligands. In addition, we have used one of our soluble single chain TCR preparations to isolate a TCR specific Fab molecule from a phage antibody library.
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Affiliation(s)
- P E Molloy
- Department of Molecular and Cell Biology, Institute of Medical Science, Foresterhill, Aberdeen, Scotland
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7
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Lebedeva MI, Fields BA, Spits H, Panchamoorthy G, Brenner MB, Mariuzza RA. Cloning, expression, and crystallization of the V delta domain of a human gamma delta T-cell receptor. Protein Sci 1996; 5:2638-42. [PMID: 8976572 PMCID: PMC2143324 DOI: 10.1002/pro.5560051226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
T-lymphocytes recognize a wide variety of antigens through highly diverse cell-surface glycoproteins known as T-cell receptors (TCRs). These disulfide-linked heterodimers are composed of alpha and beta or gamma and delta polypeptide chains consisting of variable (V) and constant (C) domains non-covalently associated with at least four invariant chains to form the TCR-CD3 complex. It is well established that alpha beta TCRs recognize antigen in the form of peptides bound to molecules of the major histocompatibility complex (MHC); furthermore, information on the three-dimensional structure of alpha beta TCRs has recently become available through X-ray crystallography. In contrast, the antigen specificity of gamma delta TCRs is much less well understood and their three-dimensional structure is unknown. We have cloned the delta chain of a human TCR specific for the MHC class I HLA-A2 molecule and expressed the V domain as a secreted protein in the periplasmic space of Escherichia coli. Following affinity purification using a nickel chelate adsorbent, the recombinant V delta domain was crystallized in a form suitable for X-ray diffraction analysis. The crystals are orthorhombic, space group P2(1)2(1)2 with unit cell dimensions a = 69.9, b = 49.0, c = 61.6 A. and diffract to beyond 2.3 A resolution. The ability of a V delta domain produced in bacteria to form well-ordered crystals strongly suggests that the periplasmic space can provide a suitable environment for the correct in vivo folding of gamma delta TCRs.
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Affiliation(s)
- M I Lebedeva
- Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville 20850, USA
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Fields BA, Mariuzza RA. Structure and function of the T-cell receptor: insights from X-ray crystallography. IMMUNOLOGY TODAY 1996; 17:330-6. [PMID: 8763819 DOI: 10.1016/0167-5699(96)10020-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- B A Fields
- Maryland Biotechnology Institute, Rockville 20850, USA
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9
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Schodin BA, Schlueter CJ, Kranz DM. Binding properties and solubility of single-chain T cell receptors expressed in E. coli. Mol Immunol 1996; 33:819-29. [PMID: 8811077 DOI: 10.1016/0161-5890(96)00038-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The diversity and domain structure of alpha beta T cell receptors (TCR) are similar to immunoglobulins based on sequence homologies, but the three-dimensional structure of the alpha beta-heterodimer has not been solved. To begin structure/function studies, we have compared the properties of a soluble single-chain V alpha V beta TCR (scTCR) expressed in three E. coli systems. The V alpha and V beta regions were expressed with pelB or ompA signal sequences or as a thioredoxin fusion protein. The scTCRs were detected only in the insoluble fraction of the cells and could be solubilized in guanidine and renatured to obtain properly folded scTCR from each system. Only a small fraction (1-5%) of the ompA and pelB scTCRs folded properly. In contrast, the thioredoxin fusion protein exhibited high total yields and a solubility that was ten times higher than the other scTCRs. The thioredoxin fusion protein also bound specifically to the peptide/MHC ligand with a KD of approximately 0.7 microM, as shown by a competitive inhibition assay with Fab fragments that recognize the MHC complex. Furthermore, estimates from saturation binding with antibodies that react with the native TCR indicated that up to 80% of the thioredoxin fusion protein was in the properly folded form. The improved yield, solubility, and binding activity of the thioredoxin-scTCR should make it useful for various structure/ function studies.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Escherichia coli/genetics
- Genetic Vectors/immunology
- H-2 Antigens/chemistry
- H-2 Antigens/genetics
- Humans
- Molecular Sequence Data
- Peptides/chemistry
- Peptides/genetics
- Protein Binding/genetics
- Protein Binding/immunology
- Protein Conformation
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
- Solubility
- Thioredoxins/chemistry
- Thioredoxins/genetics
- Transcription, Genetic/immunology
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Affiliation(s)
- B A Schodin
- Department of Biochemistry, University of Illinois, Urbana 61801, USA
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Popov S, Hubbard JG, Ward ES. A novel and efficient route for the isolation of antibodies that recognise T cell receptor V alpha(s). Mol Immunol 1996; 33:493-502. [PMID: 8700165 DOI: 10.1016/0161-5890(96)00020-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Studies of the T cell repertoire have been hindered by the lack of antibodies that recognise V region families, particularly for V alpha regions. In this report, single chain Fv (scFv) fragments have been isolated that recognise both recombinant V alpha(s) and native V alpha(s) on the surface of T cells. Mice have been immunised with purified soluble T cell receptors (TCRs) and antibody heavy and light chain variable domain (VH and VL, respectively) genes isolated from splenocytes using the polymerase chain reaction (PCR). The VH and VL genes have been assembled as scFv gene libraries and a bacteriophage display system used to isolate scFvs that recognise a soluble V alpha. Five scFvs have been purified and characterised in detail using enzyme-linked immunosorbent assays (ELISAs) and flow cytometry. Three of these five scFvs recognise native V alpha(s) on the surface of T cell hybridomas. This method therefore offers a rapid route to the generation of scFvs that recognise native TCRs and can readily be extended to the production of anti-human TCR antibodies for use in therapy and diagnosis.
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Affiliation(s)
- S Popov
- Department of Microbiology and Cancer Immunobiology Center, University of Texas Southwestern Medical Center, Dallas 75235-8576, U.S.A
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Abstract
Recently developed methodologies for the production of the soluble extracellular domains of alpha beta TCRs have allowed several biophysical characterizations. The thermodynamic and kinetic parameters associated with specific ligand interactions between the TCR and MHC-peptide complexes, as well as superantigens, are now being established. Crystallographic studies of isolated TCR fragments have yielded the structures of a V alpha domain and the two extracellular domains of a beta-chain. These investigations are beginning to allow a new visualization of antigen recognition and T-cell activation processes.
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Affiliation(s)
- D H Fremont
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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Novotny J, Bajorath J. Computational biochemistry of antibodies and T-cell receptors. ADVANCES IN PROTEIN CHEMISTRY 1996; 49:149-260. [PMID: 8908299 DOI: 10.1016/s0065-3233(08)60490-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- J Novotny
- Department of Macromolecular Modeling, Bristol-Myers Squibb Research Institute, Princeton, New Jersey 08540, USA
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13
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Ishii Y, Nakano T, Honma N, Yuyama N, Yamada Y, Watarai H, Tomura T, Sato M, Tsumura H, Ozawa T. Preparation of soluble recombinant T cell receptor alpha chain by using a calmodulin fusion expression system. J Immunol Methods 1995; 186:27-36. [PMID: 7561145 DOI: 10.1016/0022-1759(95)00126-u] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have isolated a full length T cell receptor alpha chain (TCR alpha) cDNA derived from a bee venom phospholipase A2-specific mouse suppressor T cell hybridoma. A bacterial fusion expression system was constructed using rat calmodulin as a fusion partner for production of soluble TCR alpha. In this system, calmodulin-TCR alpha fusion protein was expressed at a high level in the soluble fraction of bacterial cell lysate, and could be purified by binding of calmodulin portion of the protein to phenyl-Sepharose. Using this system, fusion proteins containing a TCR alpha peptide corresponding to the complete extracellular region, V alpha-J alpha region or C alpha extracellular region were isolated. TCR alpha peptides were then released from the fusion proteins by digestion with thrombin which recognizes a linker sequence between calmodulin portion and TCR alpha segment. Polyclonal antibodies against constant region of TCR alpha chain (C alpha) were obtained by immunization of rabbits with the recombinant C alpha peptide. ELISA for TCR protein was established by using the polyclonal antibodies and the monoclonal antibody specific for C alpha region.
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Affiliation(s)
- Y Ishii
- Division of Immunobiology, La Jolla Institute for Allergy and Immunology, CA 92037, USA
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Davodeau F, Houde I, Boulot G, Romagné F, Necker A, Canavo N, Peyrat M, Hallet M, Vié H, Jacques Y. Secretion of disulfide-linked human T-cell receptor gamma delta heterodimers. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)82278-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Basi GS, Riggs MB, Nash K, Singer R. Antibodies to soluble human T cell receptor beta chain recognize multiple epitopes on cell surface TcR. J Immunol Methods 1992; 155:175-91. [PMID: 1385533 DOI: 10.1016/0022-1759(92)90284-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The T cell receptor (TcR) is an integral membrane protein occurring as a disulfide linked heterodimer, non-covalently associated with CD3 on the surface of T lymphocytes. Antibodies to the TcR have been shown to be effective for treating autoimmune disorders in animals. We describe here a method for producing antibodies to cell surface determinants of the human TcR, using a soluble form of the receptor as antigen. Soluble V alpha 1.2, V beta 8.1, V beta 11 TcR chains are expressed from a construct in which the extracellular domains of the TcR are fused to the mouse gamma 2a heavy chain constant region lacking the CH1 domain. These chimeric molecules contain both immunoglobulin and TcR determinants, as revealed by antibody probes. Amino-terminal sequence analysis of a chimeric V beta 8.1 molecule indicates that the TcR leader peptide is correctly processed from the soluble form. Antibodies raised against the soluble human V beta 8.1 molecule recognize the native determinants on Jurkat cells, and on natural T cells derived from resting human peripheral blood lymphocytes. Epitope mapping studies using competitive binding assays suggest that the anti-V beta 8 antibodies produced using soluble antigen recognize multiple overlapping determinants on the cell surface form of the TcR.
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Affiliation(s)
- G S Basi
- Protein Design Labs, Inc., Mountain View, CA 94043
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Abstract
This study describes the secretion and purification of T cell receptor (TCR) V alpha, V beta domains and single chain V alpha-V beta fragments (scTCRs) from recombinant Escherichia coli cells. The TCR V alpha and V beta genes are derived from a T cell hybridoma that is associated with disease pathogenesis in murine experimental allergic encephalomyelitis (EAE). Circular dichroism (c.d.) analyses of the single domains and the scTCR indicate that they are folded into beta-pleated sheet structures similar to those of immunoglobulin variable domains. The secreted TCR fragments can be purified in milligram quantities, and could therefore be used in high-resolution structural studies, in immunization to generate anti-clonotypic antibodies or in vaccination.
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Affiliation(s)
- E S Ward
- Cancer Immunobiology Center, University of Texas Southwestern Medical Center, Dallas 75235-8576
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Ward ES. Expression and secretion of T-cell receptor V alpha and V beta domains using Escherichia coli as a host. Scand J Immunol 1991; 34:215-20. [PMID: 1830971 DOI: 10.1111/j.1365-3083.1991.tb01539.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An expression system for the production of recombinant T-cell receptor (TCR) variable domains would, inter alia, allow structural studies to be carried out and provide protein for the generation of anti-clonotypic antibodies. In this report the V alpha and V beta domain genes have been isolated from a T-cell hybridoma which is associated with the pathogenesis of experimental allergic encephalomyelitis (EAE) in the H-2u mouse. These have been expressed as secreted domains in Escherichia coli, using secretion vectors previously used for the production of immunoglobulin fragments. Both V alpha and V beta domains are secreted in milligram quantities into the culture supernatant, although the levels of the V alpha domain are about 10-20 fold higher than those of the V beta domain. This expression system offers a rapid route for the production of recombinant TCRs in soluble form.
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Affiliation(s)
- E S Ward
- Cancer Immunobiology Center, University of Texas Southwestern Medical Center, Dallas
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Bismuth G, Gouy H, Mariuzza RA, Vaquero C, Theodorou I, Debre P. A human TCR-Ig chimeric protein used to generate a TCR alpha chain variable region-specific mAb. Mol Immunol 1990; 27:1127-36. [PMID: 2147229 DOI: 10.1016/0161-5890(90)90101-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In a recent report, a construction containing the alpha chain-variable region (V alpha) coding sequence of a cDNA clone derived from a diphtheria toxoid-specific human T cell (P28), fused to a human immunoglobulin kappa light chain constant region (Ck), was used stably to transfect a murine myeloma cell. In the present study, these transfected cells were employed as an immunogen to raise a mAb, termed 1C5V alpha, specific both for the V alpha Ck chimeric protein secreted by the transfectant and the P28 T cell antigen receptor-V alpha region. mAb 1C5V alpha specifically immunoprecipitates the V alpha Ck protein as a family of 32-35 kDa bands present in the 35S-methionine-labeled culture supernatant from the transfected cells. It specifically binds clone P28. Surface molecules recognized by mAb 1C5V alpha are physically linked to the CD3 molecules since cell treatment with either 1C5V alpha or anti-CD3 mAbs caused the simultaneous down-regulation of the CD3/TCR molecular complex. This link is further supported by immunoprecipitation experiments. Thus, both the 1C5V alpha and the anti-CD3 mAbs precipitate the 16-28 kDa CD3 molecules and the disulfide-linked form of P28 TCR from 125I-labeled P28 T cells. Studies performed in order to define whether a stimulus directly acting on the TCR-V alpha region may trigger the intracellular events observed during human T cell activation showed that (a) mAb 1C5V alpha efficiently triggers the phospholipase C transduction pathway revealed by an accelerated phosphoinositides turn-over and an increased production of phosphorylated derivatives of inositol phosphates; (b) mAb 1C5V alpha induces an up-regulation of IL2R mRNA, accompanied by a slight increase of IL2 and IFN alpha mRNA transcripts evidently amplified in the presence of PMA; (c) soluble mAb 1C5V alpha is strongly mitogenic together with PMA. These results provide the first evidence for the structural authenticity of a secreted water-soluble chimeric form of the variable region of a human TCR alpha chain. They further demonstrate that such chimeric proteins may be valuable tool to further dissect the various functional structure of the human TCR.
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MESH Headings
- Antibodies, Monoclonal/biosynthesis
- Humans
- Immunization/methods
- Immunoglobulin kappa-Chains/genetics
- Immunoglobulin kappa-Chains/immunology
- Lymphocyte Activation
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/physiology
- Receptors, Antigen, T-Cell, alpha-beta
- Recombinant Fusion Proteins/immunology
- T-Lymphocytes/immunology
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Affiliation(s)
- G Bismuth
- Laboratoire d'Immunologie Cellulaire et Tissulaire, CNRS UA, Hôpital de la Pitié-Salpêtrière, Paris, France
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19
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Affiliation(s)
- C M Gorman
- Cell Genetics Department, Genentech Inc., South San Francisco, CA 94080
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20
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Gascoigne NR. Transport and secretion of truncated T cell receptor beta-chain occurs in the absence of association with CD3. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38847-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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