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Sciammas R, Bluestone JA. HSV-1 Glycoprotein I-Reactive TCRγδ Cells Directly Recognize the Peptide Backbone in a Conformationally Dependent Manner. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.10.5187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Despite the description of numerous antigenic ligands recognized by TCRγδ cells, detailed information concerning the structural nature of these antigenic epitopes is lacking. In addition, the recent descriptions of human TCRγδ cells recognizing mycobacterium-derived low m.w. lipid molecules confirms that the spectrum and nature of biologic structures that are capable of being recognized by TCRγδ cells are unclear. We have previously described a murine TCRγδ cell clone, TgI4.4, that is reactive to herpes simplex virus (HSV)-1 glycoprotein I (gI). Unlike TCRαβ-mediated, MHC-restricted Ag recognition but similar to Ig Ag recognition, TgI4.4 recognizes purified gI directly, in the absence of Ag processing or presentation. Since gI is a complex glycoprotein, the nature of the antigenic epitope was investigated. First, gI recognition by TgI4.4 is conformationally dependent, as revealed by denaturation and proteolytic experiments. Secondly, the epitope recognized by TgI4.4 was mapped to the amino terminus by using insertion mutants of gI. Lastly, TgI4.4 recognizes the gI protein directly since completely deglycosylated forms of gI are efficiently recognized. Therefore, TCRγδ cells are capable of recognizing a variety of molecular structures, including proteins. The ability of TgI4.4 to recognize a nonglycosylated form of gI suggests that HSV-1 recognition by TCRγδ cells in vivo is not limited by cell-specific glycosylation patterns or glycosylation-dependent conformational influences.
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Affiliation(s)
- Roger Sciammas
- Committee on Immunology and Ben May Institute for Cancer Research, University of Chicago, Chicago, IL 60637
| | - Jeffrey A. Bluestone
- Committee on Immunology and Ben May Institute for Cancer Research, University of Chicago, Chicago, IL 60637
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Bukowski JF, Morita CT, Band H, Brenner MB. Crucial Role of TCRγ Chain Junctional Region in Prenyl Pyrophosphate Antigen Recognition by γδ T Cells. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.1.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Human γδ T cells recognize prenyl pyrophosphate Ags and their analogues in a Vγ2Vδ2 TCR-dependent manner. Few data are available regarding the TCR structural requirements for recognition of such prenyl pyrophosphate Ags by γδ T cells. Presently, we made chain pair switch, chimeric, and site mutant γδ TCRs and transfected them into TCR− mutant Jurkat T cells to examine the effects of changing the TCRγ junctional region sequences on reactivity to prenyl pyrophosphate Ags. Substitution of the TCRγ junctional region (N and J) sequences from an Ag-reactive TCR with TCRγ junctional region sequences from an Ag-nonreactive TCR abrogated reactivity to the prenyl pyrophosphate Ag isopentenyl pyrophosphate and to its synthetic analogue ethyl pyrophosphate but not to a mycobacterial supernatant containing a mixture of prenyl pyrophosphate Ags. Substitution of only the TCRγ N nucleotide region with that from this Ag-nonreactive TCR destroyed reactivity to isopentenyl pyrophosphate and to the mycobacterial supernatant. Substitution of the entire Vδ2 chain from the Ag-reactive TCR with a Vδ1 chain from an Ag-nonreactive TCR yielded a prenyl pyrophosphate Ag-nonreactive TCR. Thus, using TCR mutagenesis and TCR transfectants, we show that γδ TCR reactivity to prenyl pyrophosphate Ags is dependent upon the junctional region of the TCRγ chain and upon pairing of Vγ2 and Vδ2 TCR chains. These structural requirements of TCRγδ recognition of prenyl pyrophosphates distinguish this reactivity from that of protein superantigens and emphasize the importance of the TCRγ CDR3 loop and adjacent residues.
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Affiliation(s)
- Jack F. Bukowski
- Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Craig T. Morita
- Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Hamid Band
- Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Michael B. Brenner
- Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115
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