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Engelhard VH. The contributions of mass spectrometry to understanding of immune recognition by T lymphocytes. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2007; 259:32-39. [PMID: 18167512 PMCID: PMC1920184 DOI: 10.1016/j.ijms.2006.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Over the last 15 years, the ability of mass spectrometry to analyze complex peptide mixtures and identify individual species has provided unprecedented insights into the repertoire of peptide antigens displayed by MHC molecules and recognized by T lymphocytes. These include: understanding the peptide binding specificity of MHC molecules; understanding of roles of different intracellular components of the antigen processing pathways in determining the peptide display; and identification of a large number of individual peptide antigens associated with infectious diseases, cancer, and transplant rejection that have provided the basis for new immunologically based therapies. This review will summarize the impact that the application of mass spectrometry has had on these advances, with particular attention to the contributions of Professor Donald Hunt and members of his laboratory, and point out the opportunities for future work.
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Affiliation(s)
- Victor H Engelhard
- Carter Immunology Center and Department of Microbiology, University of Virginia School of Medicine, PO Box 801386, Charlottesville, VA USA 22908
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Hornell TMC, Solheim JC, Myers NB, Gillanders WE, Balendiran GK, Hansen TH, Connolly JM. Alloreactive and Syngeneic CTL Are Comparably Dependent on Interaction with MHC Class I α-Helical Residues. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.6.3217] [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
The molecular basis for the difference in the strength of T cell responses to self vs alloantigens is unknown, but may reflect how T cells are selected in the thymus. Because T cells with a high affinity for foreign as opposed to self MHC molecules are able to mature, it has been proposed that alloreactive T cells may be more strongly dependent upon interaction with MHC residues than are self-restricted T cells. This study was undertaken to rigorously address this hypothesis. Whereas other studies have compared self vs alloantigen recognition of different MHC alleles by a single T cell clone, we have compared self vs alloantigen recognition of a single MHC allele, H-2Ld, by a large panel of self-restricted and alloreactive T cell clones. Target cells expressing Ld molecules mutated at several different potential TCR contact residues were analyzed to determine which residues are important for recognition by self-restricted vs alloreactive T cells. We unequivocally demonstrate that self-restricted and alloreactive T cells do not differ, but rather are comparably dependent on interaction with MHC residues. Importantly, both self-restricted and alloreactive T cells are dependent upon the same MHC residues as primary contacts and, in addition, share a common recognition pattern of Ld. Furthermore, our analysis enables us to provide a model for allotype-specific T cell recognition of Ld vs Kb class I molecules.
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Affiliation(s)
- Tara M. C. Hornell
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
| | - Joyce C. Solheim
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
| | - Nancy B. Myers
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
| | - William E. Gillanders
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
| | | | - Ted H. Hansen
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
| | - Janet M. Connolly
- *Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110; and
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Montoya M, Del Val M. Intracellular Rate-Limiting Steps in MHC Class I Antigen Processing. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.4.1914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Quantitative aspects of the endogenous pathway of Ag processing and presentation by MHC class I molecules to CD8+ CTL were analyzed over a wide range of Ag expression in recombinant vaccinia virus-infected cells expressing β-galactosidase as model Ag. Only the amount of starting Ag was varied, leaving other factors unaltered. Below a certain level of Ag synthesis, increasing protein amounts led to a sharp rise in recognition by CTL. Higher levels of Ag expression led to a saturation point, which intracellularly limited the number of naturally processed peptides bound to MHC and thereby also CTL recognition. The rate-limiting step was located at the binding of the antigenic peptide to MHC inside the vaccinia virus-infected cell or before this event.
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Affiliation(s)
- María Montoya
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
| | - Margarita Del Val
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
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Münz C, Obst R, Osen W, Stevanović S, Rammensee HG. Alloreactivity as a Source of High Avidity Peptide-Specific Human CTL. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.1.25] [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
PBL from HLA-A2− or HLA-A3− donors were stimulated with synthetic peptide libraries fitting HLA-A2 or HLA-A3 motifs and presented on HLA-A2- or HLA-A3-expressing TAP− cells. Peptide library-specific allorestricted CTL were found to constitute up to half the alloreactive CTL response and occurred at twofold lower frequency than autologous peptide library-specific CTL. This indicates that positive selection by one particular MHC class I molecule is not absolutely essential for the generation of CTL restricted to the same molecule. However, positive selection increases their frequency. The CTL obtained differed greatly both with respect to peptide dependency and peptide specificity. Determination of the peptide avidity for one representative CTL clone, 10F4, proved that the method described here allows the stimulation of high avidity cytotoxic T cells. This approach involving in vitro stimulation of T cells restricted toward a MHC molecule that was not present during their negative selection might therefore offer the possibility of isolating CTL against self and foreign peptides with varying avidities. Such T cells might indeed be useful for tumor immunotherapy.
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Affiliation(s)
- Christian Münz
- *Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany; and
- †Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, NY 10021
| | - Reinhard Obst
- *Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany; and
| | - Wolfram Osen
- *Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany; and
| | - Stefan Stevanović
- *Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany; and
| | - Hans-Georg Rammensee
- *Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany; and
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Paradela A, García-Peydró M, Vázquez J, Rognan D, López de Castro JA. The Same Natural Ligand Is Involved in Allorecognition of Multiple HLA-B27 Subtypes by a Single T Cell Clone: Role of Peptide and the MHC Molecule in Alloreactivity. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.10.5481] [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
The human alloreactive CTL clone 27S69, raised against B*2705, cross-reacts with B*2702 and B*2703, but not with B*2701, B*2704, B*2706, or B*2710. Its natural epitope was identified by electrospray/ion trap mass spectrometry, as the proteasome-derived RRFFPYYV octamer. This is the first HLA-B27 ligand shown to be immunogenic in alloreactivity. The RRFFPYYVY nonamer, also found in the B*2705-bound peptide pool, was recognized much less efficiently, demonstrating that an alloreactive CTL distinguishes between very similar natural ligands. Molecular modeling suggested that this was due to the different conformation of each peptide in complex with B*2705. B*2702- and B*2703-RMA-S cells were lysed by CTL 27S69 when sensitized with the octamer, demonstrating that cross-reaction with these subtypes is through recognition of the same peptide as in B*2705. B*2704-, B*2706-, and B*2710-RMA-S cells were not sensitized for lysis, in spite of efficient binding of the octamer, indicating that polymorphism in these subtypes directly impairs allorecognition. B*2701-RMA-S and -C1R cells were sensitized for lysis by the octamer, suggesting lack of the endogenous peptide epitope on this subtype. Absence of the octamer in the B*2701-bound peptide pool further suggested that B*2701 polymorphism impairs the generation of this peptide.
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Affiliation(s)
- Alberto Paradela
- *Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Facultad de Ciencias, Madrid, Spain; and
| | - Marina García-Peydró
- *Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Facultad de Ciencias, Madrid, Spain; and
| | - Jesús Vázquez
- *Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Facultad de Ciencias, Madrid, Spain; and
| | | | - José A. López de Castro
- *Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Facultad de Ciencias, Madrid, Spain; and
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Shi Y, Smith KD, Lutz CT. TAP-Independent MHC Class I Peptide Antigen Presentation to Alloreactive CTL Is Enhanced by Target Cell Incubation at Subphysiologic Temperatures. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.9.4305] [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
We investigated the peptide dependency of a group of CD8+ anti-HLA-B7 alloreactive CTL. The CTL killed target cells after acid denaturation of more than 98% of target cell surface peptide/MHC class I complexes. The CTL also killed TAP− HLA-B7-transfected T2 (T2B7) cells. The killing was enhanced by target cell incubation at 26°C. Despite these findings, which suggested peptide-independent allorecognition, CTL-mediated cytolysis was reduced or abolished by several point mutations affecting the HLA-B7 peptide-binding groove. Acid denaturation of HLA complexes on T2B7 cells prohibited CTL recognition. CTL recognition was restored by T2B7 cell incubation with β2-microglobulin and a single HPLC fraction containing peptides extracted from TAP+HLA-B7+ cells, but not by any of a panel of 17 synthetic HLA-B7-binding peptides. These findings indicated that CTL allorecognition was peptide specific. Sensitizing peptide was extracted from T2B7 cells only after incubation at 26°C. The amount of peptide detected in TAP+ cells was at least 10-fold and 100-fold greater than that detected in TAP− cells incubated at 26°C and at 37°C, respectively. TAP-independent peptide epitope presentation was sensitive to treatment with brefeldin A, but not sensitive to treatment with chloroquine, consistent with an endogenous peptide source. We propose that subphysiologic temperature incubation can enhance peptide/MHC class I presentation in the total absence of TAP function.
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Affiliation(s)
- Yan Shi
- *Pathology and
- ‡Graduate Program in Immunology and
| | | | - Charles T. Lutz
- *Pathology and
- ‡Graduate Program in Immunology and
- §Molecular Biology, University of Iowa, Iowa City, IA 52242
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Wang W, Man S, Gulden PH, Hunt DF, Engelhard VH. Class I-Restricted Alloreactive Cytotoxic T Lymphocytes Recognize a Complex Array of Specific MHC-Associated Peptides. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.3.1091] [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
A major issue in understanding alloreactive T cell responses is whether the Ags recognized reside in allogeneic MHC proteins themselves regardless of the structure of the associated peptides or whether specific peptides presented by allogeneic MHC proteins determine each epitope. We developed HLA-A*0201-specific alloreactive human CD8+ CTL lines and clones to address this issue. Acid treatment of HLA-A*0201+ target cells resulted in the loss of Ab-defined epitopes as well as recognition by all alloreactive CTL. In the presence of brefeldin A, no class I molecules were re-expressed at the surface of the acid-treated cells. Addition of a mixture of synthetic peptides corresponding to known, naturally processed, HLA-A*0201-associated peptides together with exogenous human β2m restored binding by specific Ab but not recognition by alloreactive CTL. However, addition of a more complex mixture of peptides directly extracted from HLA-A*0201 reconstituted CTL recognition. This demonstrates that these alloreactive CTL recognize specific peptides and not a common peptide-dependent conformation of HLA-A*0201. Reverse phase HPLC fractionation of the extracted peptides resulted in the loss of recognition by CTL lines from three individuals. This was not due to the loss of specific peptide species because repooling of the HPLC fractions led to a recovery of recognition. Furthermore, three HLA-A*0201-alloreactive CTL clones recognized single distinct peptide peaks from the same HPLC fractionation. These data suggest that the epitopes recognized in allogeneic responses to HLA-A*0201 are complex, and the response is a result of recognition of multiple unique peptide-MHC complexes.
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Affiliation(s)
- Wei Wang
- *Department of Microbiology and the Beirne Carter Center for Immunology Research, and
| | - Stephen Man
- *Department of Microbiology and the Beirne Carter Center for Immunology Research, and
| | - Pamela H. Gulden
- ‡Department of Chemistry, University of Virginia, Charlottesville, VA 22901
| | - Donald F. Hunt
- †Department of Pathology, University of Virginia, Charlottesville, VA 22908; and
- ‡Department of Chemistry, University of Virginia, Charlottesville, VA 22901
| | - Victor H. Engelhard
- *Department of Microbiology and the Beirne Carter Center for Immunology Research, and
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Mayrand SM, Schwarz DA, Green WR. An Alternative Translational Reading Frame Encodes an Immunodominant Retroviral CTL Determinant Expressed by an Immunodeficiency-Causing Retrovirus. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.1.39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Recognition of virus-infected or transformed cells by CD8+ CTL requires a trimolecular complex composed of MHC class I, β2-microglobulin, and a specific foreign peptide composed of 8 to 10 linear amino acids. The generation of such CTL epitopes has traditionally been thought to be from the primary open reading frame encoding the viral or tumor-associated proteins. In this report it is demonstrated that a viral CTL epitope can also be generated from an alternative reading frame. Using a combination of synthetic peptides and Sindbis or vaccinia expression systems, MHC class I Kd-restricted BALB/cByJ CTL directed against defective gag gene constructs of the LP-BM5 virus complex that causes murine AIDS were shown to have specificity for the antigenic peptide SYNTGRFPPL. This epitope is generated in a novel fashion from the second open reading frame (ORF2) of both the defective and ecotropic helper virus components of LP-BM5. Importantly, lysis of target cells expressing BM5 ecotropic helper, and/or defective viral gag, demonstrated that the SYNTGRFPPL epitope is generated during the course of a normal retroviral infection. Furthermore, MAIDS-resistant BALB/cByJ mice also generated secondary restimulated CTL specific for SYNTGRFPPL following in vivo priming with the LP-BM5 retroviral complex. These data suggest that retroviruses, and potentially other viruses and foreign genes, are capable of expressing T cell epitopes from alternative open reading frames. If one considers the influence of self peptides on T cell development, these “alternative reading frame-derived” peptides could provide an important additional influence on the functional T cell repertoire.
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Affiliation(s)
- Shawn-Marie Mayrand
- *Department of Microbiology and the Norris Cotton Cancer Center, Dartmouth Medical School, Lebanon, NH 03756
| | - David A. Schwarz
- †Department of Biology, Universitiy of California at San Diego, San Diego, CA 92093
| | - William R. Green
- *Department of Microbiology and the Norris Cotton Cancer Center, Dartmouth Medical School, Lebanon, NH 03756
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