1
|
Sengupta S, Zhang J, Reed MC, Yu J, Kim A, Boronina TN, Board NL, Wrabl JO, Shenderov K, Welsh RA, Yang W, Timmons AE, Hoh R, Cole RN, Deeks SG, Siliciano JD, Siliciano RF, Sadegh-Nasseri S. A cell-free antigen processing system informs HIV-1 epitope selection and vaccine design. J Exp Med 2023; 220:e20221654. [PMID: 37058141 PMCID: PMC10114365 DOI: 10.1084/jem.20221654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/01/2023] [Accepted: 03/23/2023] [Indexed: 04/15/2023] Open
Abstract
Distinct CD4+ T cell epitopes have been associated with spontaneous control of HIV-1 replication, but analysis of antigen-dependent factors that influence epitope selection is lacking. To examine these factors, we used a cell-free antigen processing system that incorporates soluble HLA-DR (DR1), HLA-DM (DM), cathepsins, and full-length protein antigens for epitope identification by LC-MS/MS. HIV-1 Gag, Pol, Env, Vif, Tat, Rev, and Nef were examined using this system. We identified 35 novel epitopes, including glycopeptides. Epitopes from smaller HIV-1 proteins mapped to regions of low protein stability and higher solvent accessibility. HIV-1 antigens associated with limited CD4+ T cell responses were processed efficiently, while some protective epitopes were inefficiently processed. 55% of epitopes obtained from cell-free processing induced memory CD4+ T cell responses in HIV-1+ donors, including eight of 19 novel epitopes tested. Thus, an in vitro processing system utilizing the components of Class II processing reveals factors influencing epitope selection of HIV-1 and represents an approach to understanding epitope selection from non-HIV-1 antigens.
Collapse
Affiliation(s)
- Srona Sengupta
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Graduate Program in Immunology and Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Josephine Zhang
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Madison C. Reed
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jeanna Yu
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Aeryon Kim
- Department of Inflammation and Oncology and Genome Analysis Unit, Amgen Research, Amgen Inc., South San Francisco, CA, USA
| | - Tatiana N. Boronina
- Department of Biological Chemistry, Mass Spectrometry and Proteomics Facility, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nathan L. Board
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - James O. Wrabl
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Kevin Shenderov
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robin A. Welsh
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Weiming Yang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew E. Timmons
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rebecca Hoh
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Robert N. Cole
- Department of Biological Chemistry, Mass Spectrometry and Proteomics Facility, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven G. Deeks
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Janet D. Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert F. Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, USA
| | | |
Collapse
|
2
|
Lorente E, Martín-Galiano AJ, Barnea E, Barriga A, Palomo C, García-Arriaza J, Mir C, Lauzurica P, Esteban M, Admon A, López D. Proteomics Analysis Reveals That Structural Proteins of the Virion Core and Involved in Gene Expression Are the Main Source for HLA Class II Ligands in Vaccinia Virus-Infected Cells. J Proteome Res 2019; 18:900-911. [PMID: 30629447 DOI: 10.1021/acs.jproteome.8b00595] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Protective cellular and humoral immune responses require previous recognition of viral antigenic peptides complexed with human leukocyte antigen (HLA) class II molecules on the surface of the antigen presenting cells. The HLA class II-restricted immune response is important for the control and the clearance of poxvirus infection including vaccinia virus (VACV), the vaccine used in the worldwide eradication of smallpox. In this study, a mass spectrometry analysis was used to identify VACV ligands bound to HLA-DR and -DP class II molecules present on the surface of VACV-infected cells. Twenty-six naturally processed viral ligands among the tens of thousands of cell peptides bound to HLA class II proteins were identified. These viral ligands arose from 19 parental VACV proteins: A4, A5, A18, A35, A38, B5, B13, D1, D5, D7, D12, D13, E3, E8, H5, I2, I3, J2, and K2. The majority of these VACV proteins yielded one HLA ligand and were generated mainly, but not exclusively, by the classical HLA class II antigen processing pathway. Medium-sized and abundant proteins from the virion core and/or involved in the viral gene expression were the major source of VACV ligands bound to HLA-DR and -DP class II molecules. These findings will help to understand the effectiveness of current poxvirus-based vaccines and will be important in the design of new ones.
Collapse
Affiliation(s)
| | | | - Eilon Barnea
- Department of Biology , Technion-Israel Institute of Technology , 32000 Haifa , Israel
| | | | | | - Juan García-Arriaza
- Department of Molecular and Cellular Biology , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid , Spain
| | | | | | - Mariano Esteban
- Department of Molecular and Cellular Biology , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid , Spain
| | - Arie Admon
- Department of Biology , Technion-Israel Institute of Technology , 32000 Haifa , Israel
| | | |
Collapse
|
3
|
Mettu RR, Charles T, Landry SJ. CD4+ T-cell epitope prediction using antigen processing constraints. J Immunol Methods 2016; 432:72-81. [PMID: 26891811 DOI: 10.1016/j.jim.2016.02.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 12/10/2015] [Accepted: 02/11/2016] [Indexed: 02/02/2023]
Abstract
T-cell CD4+ epitopes are important targets of immunity against infectious diseases and cancer. State-of-the-art methods for MHC class II epitope prediction rely on supervised learning methods in which an implicit or explicit model of sequence specificity is constructed using a training set of peptides with experimentally tested MHC class II binding affinity. In this paper we present a novel method for CD4+ T-cell eptitope prediction based on modeling antigen-processing constraints. Previous work indicates that dominant CD4+ T-cell epitopes tend to occur adjacent to sites of initial proteolytic cleavage. Given an antigen with known three-dimensional structure, our algorithm first aggregates four types of conformational stability data in order to construct a profile of stability that allows us to identify regions of the protein that are most accessible to proteolysis. Using this profile, we then construct a profile of epitope likelihood based on the pattern of transitions from unstable to stable regions. We validate our method using 35 datasets of experimentally measured CD4+ T cell responses of mice bearing I-Ab or HLA-DR4 alleles as well as of human subjects. Overall, our results show that antigen processing constraints provide a significant source of predictive power. For epitope prediction in single-allele systems, our approach can be combined with sequence-based methods, or used in instances where little or no training data is available. In multiple-allele systems, sequence-based methods can only be used if the allele distribution of a population is known. In contrast, our approach does not make use of MHC binding prediction, and is thus agnostic to MHC class II genotypes.
Collapse
Affiliation(s)
- Ramgopal R Mettu
- Department of Computer Science, Tulane University, New Orleans, LA, USA; Vector-Borne Infectious Diseases Research Center, Tulane University, New Orleans, LA, USA.
| | - Tysheena Charles
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, USA
| | - Samuel J Landry
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, USA
| |
Collapse
|
4
|
Mommen GPM, Marino F, Meiring HD, Poelen MCM, van Gaans-van den Brink JAM, Mohammed S, Heck AJR, van Els CACM. Sampling From the Proteome to the Human Leukocyte Antigen-DR (HLA-DR) Ligandome Proceeds Via High Specificity. Mol Cell Proteomics 2016; 15:1412-23. [PMID: 26764012 PMCID: PMC4824864 DOI: 10.1074/mcp.m115.055780] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 12/12/2022] Open
Abstract
Comprehensive analysis of the complex nature of the Human Leukocyte Antigen (HLA) class II ligandome is of utmost importance to understand the basis for CD4+ T cell mediated immunity and tolerance. Here, we implemented important improvements in the analysis of the repertoire of HLA-DR-presented peptides, using hybrid mass spectrometry-based peptide fragmentation techniques on a ligandome sample isolated from matured human monocyte-derived dendritic cells (DC). The reported data set constitutes nearly 14 thousand unique high-confident peptides, i.e. the largest single inventory of human DC derived HLA-DR ligands to date. From a technical viewpoint the most prominent finding is that no single peptide fragmentation technique could elucidate the majority of HLA-DR ligands, because of the wide range of physical chemical properties displayed by the HLA-DR ligandome. Our in-depth profiling allowed us to reveal a strikingly poor correlation between the source proteins identified in the HLA class II ligandome and the DC cellular proteome. Important selective sieving from the sampled proteome to the ligandome was evidenced by specificity in the sequences of the core regions both at their N- and C- termini, hence not only reflecting binding motifs but also dominant protease activity associated to the endolysosomal compartments. Moreover, we demonstrate that the HLA-DR ligandome reflects a surface representation of cell-compartments specific for biological events linked to the maturation of monocytes into antigen presenting cells. Our results present new perspectives into the complex nature of the HLA class II system and will aid future immunological studies in characterizing the full breadth of potential CD4+ T cell epitopes relevant in health and disease.
Collapse
Affiliation(s)
- Geert P M Mommen
- From the ‡Institute for Translational Vaccinology, P.O. Box 450, 3720 AL Bilthoven, the Netherlands; §Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Science Faculty, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Fabio Marino
- §Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Science Faculty, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; ¶Netherlands Proteomics Centre, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Hugo D Meiring
- From the ‡Institute for Translational Vaccinology, P.O. Box 450, 3720 AL Bilthoven, the Netherlands
| | - Martien C M Poelen
- ‖Centre for Infectious Disease Control, National Institute for Public Health and the Environment, P.O. Box 1, 3720 AL Bilthoven, the Netherlands
| | | | - Shabaz Mohammed
- §Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Science Faculty, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; ¶Netherlands Proteomics Centre, Padualaan 8, 3584 CH Utrecht, the Netherlands; **Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, OX13TA, Oxford, United Kingdom; ‡‡Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, United Kingdom
| | - Albert J R Heck
- §Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Science Faculty, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; ¶Netherlands Proteomics Centre, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Cécile A C M van Els
- ‖Centre for Infectious Disease Control, National Institute for Public Health and the Environment, P.O. Box 1, 3720 AL Bilthoven, the Netherlands;
| |
Collapse
|
5
|
Antibodies reactive to cleaved sites in complement proteins enable highly specific measurement of soluble markers of complement activation. Mol Immunol 2015; 66:164-70. [DOI: 10.1016/j.molimm.2015.02.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/27/2015] [Accepted: 02/27/2015] [Indexed: 01/11/2023]
|
6
|
The mechanisms of action of vaccines containing aluminum adjuvants: an in vitro vs in vivo paradigm. SPRINGERPLUS 2015; 4:181. [PMID: 25932368 PMCID: PMC4406982 DOI: 10.1186/s40064-015-0972-0] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/08/2015] [Indexed: 12/23/2022]
Abstract
Adjuvants such as the aluminum compounds (alum) have been dominantly used in many vaccines due to their immunopotentiation and safety records since 1920s. However, how these mineral agents influence the immune response to vaccination remains elusive. Many hypotheses exist as to the mode of action of these adjuvants, such as depot formation, antigen (Ag) targeting, and the induction of inflammation. These hypotheses are based on many in vitro and few in vivo studies. Understanding how cells interact with adjuvants in vivo will be crucial to fully understanding the mechanisms of action of these adjuvants. Interestingly, how alum influences the target cell at both the cellular and molecular level, and the consequent innate and adaptive responses, will be critical in the rational design of effective vaccines against many diseases. Thus, in this review, mechanisms of action of alum have been discussed based on available in vitro vs in vivo evidences to date.
Collapse
|
7
|
Glover MS, Shi L, Fuller DR, Arnold RJ, Radivojac P, Clemmer DE. On the split personality of penultimate proline. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:444-52. [PMID: 25503299 PMCID: PMC4336576 DOI: 10.1007/s13361-014-1049-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/03/2014] [Accepted: 11/10/2014] [Indexed: 05/12/2023]
Abstract
The influence of the position of the amino acid proline in polypeptide sequences is examined by a combination of ion mobility spectrometry-mass spectrometry (IMS-MS), amino acid substitutions, and molecular modeling. The results suggest that when proline exists as the second residue from the N-terminus (i.e., penultimate proline), two families of conformers are formed. We demonstrate the existence of these families by a study of a series of truncated and mutated peptides derived from the 11-residue peptide Ser(1)-Pro(2)-Glu(3)-Leu(4)-Pro(5)-Ser(6)-Pro(7)-Gln(8)-Ala(9)-Glu(10)-Lys(11). We find that every peptide from this sequence with a penultimate proline residue has multiple conformations. Substitution of Ala for Pro residues indicates that multiple conformers arise from the cis-trans isomerization of Xaa(1)-Pro(2) peptide bonds as Xaa-Ala peptide bonds are unlikely to adopt the cis isomer, and examination of spectra from a library of 58 peptides indicates that ~80% of sequences show this effect. A simple mechanism suggesting that the barrier between the cis- and trans-proline forms is lowered because of low steric impedance is proposed. This observation may have interesting biological implications as well, and we note that a number of biologically active peptides have penultimate proline residues.
Collapse
Affiliation(s)
- Matthew S. Glover
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Liuqing Shi
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Daniel R. Fuller
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Randy J. Arnold
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Predrag Radivojac
- Department of Computer Science and Informatics, Indiana University, Bloomington, IN 47405, USA
| | - David E. Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
8
|
Schmitt EG, Haribhai D, Jeschke JC, Co DO, Ziegelbauer J, Yan K, Iwakura Y, Mishra MK, Simpson P, Salzman NH, Williams CB. Chronic follicular bronchiolitis requires antigen-specific regulatory T cell control to prevent fatal disease progression. THE JOURNAL OF IMMUNOLOGY 2013; 191:5460-76. [PMID: 24163409 DOI: 10.4049/jimmunol.1301576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To study regulatory T (Treg) cell control of chronic autoimmunity in a lymphoreplete host, we created and characterized a new model of autoimmune lung inflammation that targets the medium and small airways. We generated transgenic mice that express a chimeric membrane protein consisting of hen egg lysozyme and a hemoglobin epitope tag under the control of the Clara cell secretory protein promoter, which largely limited transgene expression to the respiratory bronchioles. When Clara cell secretory protein-membrane hen egg lysozyme/hemoglobin transgenic mice were crossed to N3.L2 TCR transgenic mice that recognize the hemoglobin epitope, the bigenic progeny developed dense, pseudo-follicular lymphocytic peribronchiolar infiltrates that resembled the histological pattern of follicular bronchiolitis. Aggregates of activated IFN-γ- and IL-17A-secreting CD4(+) T cells as well as B cells surrounded the airways. Lung pathology was similar in Ifng(-/-) and Il17a(-/-) mice, indicating that either cytokine is sufficient to establish chronic disease. A large number of Ag-specific Treg cells accumulated in the lesions, and Treg cell depletion in the affected mice led to an interstitial spread of the disease that ultimately proved fatal. Thus, Treg cells act to restrain autoimmune responses, resulting in an organized and controlled chronic pathological process rather than a progressive disease.
Collapse
Affiliation(s)
- Erica G Schmitt
- Section of Rheumatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Pos W, Sethi DK, Call MJ, Schulze MSED, Anders AK, Pyrdol J, Wucherpfennig KW. Crystal structure of the HLA-DM-HLA-DR1 complex defines mechanisms for rapid peptide selection. Cell 2013; 151:1557-68. [PMID: 23260142 DOI: 10.1016/j.cell.2012.11.025] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/15/2012] [Accepted: 11/14/2012] [Indexed: 12/18/2022]
Abstract
HLA-DR molecules bind microbial peptides in an endosomal compartment and present them on the cell surface for CD4 T cell surveillance. HLA-DM plays a critical role in the endosomal peptide selection process. The structure of the HLA-DM-HLA-DR complex shows major rearrangements of the HLA-DR peptide-binding groove. Flipping of a tryptophan away from the HLA-DR1 P1 pocket enables major conformational changes that position hydrophobic HLA-DR residues into the P1 pocket. These conformational changes accelerate peptide dissociation and stabilize the empty HLA-DR peptide-binding groove. Initially, incoming peptides have access to only part of the HLA-DR groove and need to compete with HLA-DR residues for access to the P2 site and the hydrophobic P1 pocket. This energetic barrier creates a rapid and stringent selection process for the highest-affinity binders. Insertion of peptide residues into the P2 and P1 sites reverses the conformational changes, terminating selection through DM dissociation.
Collapse
Affiliation(s)
- Wouter Pos
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | | | | | | | | | | | | |
Collapse
|
10
|
Alum increases antigen uptake, reduces antigen degradation and sustains antigen presentation by DCs in vitro. Immunol Lett 2012; 147:55-62. [PMID: 22732235 PMCID: PMC3477319 DOI: 10.1016/j.imlet.2012.06.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 06/13/2012] [Accepted: 06/15/2012] [Indexed: 02/02/2023]
Abstract
Aluminium adjuvants (alum) have been the only widely approved adjuvants for use in human vaccines since the 1920s, however, the mechanism of action of these adjuvants remains elusive. Due to increasing demand for novel adjuvants, a clearer understanding of the mechanisms that allow these important agents to affect adaptive immune responses will make a significant contribution to the rational design of future vaccines. Using a novel approach to tracking antigen and antigen presentation, we demonstrate that alum induces higher antigen accumulation and increased antigen presentation by dendritic cells (DCs) in vitro. Antigen accumulation was 100-fold higher and antigen presentation 10-fold higher following alum treatment when compared with soluble protein alone. We also observed that alum causes an initial reduction in presentation compared with soluble antigen, but eventually increases the magnitude and duration of antigen presentation. This was associated with reduced protein degradation in DCs following alum treatment. These studies demonstrate the dynamic alterations in antigen processing and presentation induced by alum that underlie enhanced DC function in response to this adjuvant.
Collapse
|
11
|
Call MJ. Small molecule modulators of MHC class II antigen presentation: Mechanistic insights and implications for therapeutic application. Mol Immunol 2011; 48:1735-43. [DOI: 10.1016/j.molimm.2011.05.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 05/23/2011] [Accepted: 05/24/2011] [Indexed: 02/02/2023]
|
12
|
Hastings KT, Cresswell P. Disulfide reduction in the endocytic pathway: immunological functions of gamma-interferon-inducible lysosomal thiol reductase. Antioxid Redox Signal 2011; 15:657-68. [PMID: 21506690 PMCID: PMC3125571 DOI: 10.1089/ars.2010.3684] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Gamma-interferon-inducible lysosomal thiol reductase (GILT) is constitutively expressed in most antigen presenting cells and is interferon γ inducible in other cell types via signal transducer and activator of transcription 1. Normally, N- and C-terminal propeptides are cleaved in the early endosome, and the mature protein resides in late endosomes and lysosomes. Correspondingly, GILT has maximal reductase activity at an acidic pH. Monocyte differentiation via Toll-like receptor 4 triggers secretion of a disulfide-linked dimer of the enzymatically active precursor, which may contribute to inflammation. GILT facilitates major histocompatibility complex (MHC) class II-restricted processing through reduction of protein disulfide bonds in the endocytic pathway and is hypothesized to expose buried epitopes for MHC class II binding. GILT can also facilitate the transfer of disulfide-containing antigens into the cytosol, enhancing their cross-presentation by MHC class I. A variety of antigens are strongly influenced by GILT-mediated reduction, including hen egg lysozyme, melanocyte differentiation antigens, and viral envelope glycoproteins. In addition, GILT is conserved among lower eukaryotes and likely has additional functions. For example, GILT expression increases the stability of superoxide dismutase 2 and decreases reactive oxygen species, which correlates with decreased cellular proliferation. It is also a critical host factor for infection with Listeria monocytogenes.
Collapse
Affiliation(s)
- Karen Taraszka Hastings
- Department of Basic Medical Sciences, The University of Arizona College of Medicine, Phoenix, Arizona 85004,
| | | |
Collapse
|
13
|
Dai YD, Marrero IG, Gros P, Zaghouani H, Wicker LS, Sercarz EE. Slc11a1 enhances the autoimmune diabetogenic T-cell response by altering processing and presentation of pancreatic islet antigens. Diabetes 2009; 58:156-64. [PMID: 18984740 PMCID: PMC2606865 DOI: 10.2337/db07-1608] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Efforts to map non-major histocompatibility complex (MHC) genes causing type 1 diabetes in NOD mice identified Slc11a1, formerly Nramp1, as the leading candidate gene in the Idd5.2 region. Slc11a1 is a membrane transporter of bivalent cations that is expressed in late endosomes and lysosomes of macrophages and dendritic cells (DCs). Because DCs are antigen-presenting cells (APCs) known to be critically involved in the immunopathogenic events leading to type 1 diabetes, we hypothesized that Slc11a1 alters the processing or presentation of islet-derived antigens to T-cells. RESEARCH DESIGN AND METHODS NOD mice having wild-type (WT) or mutant Slc11a1 molecules and 129 mice having WT or null Slc11a1 alleles were examined for parameters associated with antigen presentation. RESULTS We found that Slc11a1 enhanced the presentation of a diabetes-related T-cell determinant of GAD65, and its function contributed to the activation of a pathogenic T-cell clone, BDC2.5. An enhanced generation of interferon (IFN)-gamma-producing T-cells was also associated with functional Slc11a1. The alteration of immune responsiveness by Slc11a1 genotype did not correlate with altered MHC class II expression in DCs; however, functional Slc11a1 was associated with accelerated phagocytosis and phagosomal acidification in DCs. CONCLUSIONS The association of variants encoding Slc11a1 with type 1 diabetes may reflect its function in processing and presentation of islet self-antigens in DCs. Thus, non-MHC genes could affect the MHC-restricted T-cell response through altered antigen processing and presentation.
Collapse
Affiliation(s)
- Yang D Dai
- Division of Immune Regulation, Torrey Pines Institute for Molecular Studies, San Diego, California, USA.
| | | | | | | | | | | |
Collapse
|
14
|
Nielsen M, Lundegaard C, Lund O. Prediction of MHC class II binding affinity using SMM-align, a novel stabilization matrix alignment method. BMC Bioinformatics 2007; 8:238. [PMID: 17608956 PMCID: PMC1939856 DOI: 10.1186/1471-2105-8-238] [Citation(s) in RCA: 426] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Accepted: 07/04/2007] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Antigen presenting cells (APCs) sample the extra cellular space and present peptides from here to T helper cells, which can be activated if the peptides are of foreign origin. The peptides are presented on the surface of the cells in complex with major histocompatibility class II (MHC II) molecules. Identification of peptides that bind MHC II molecules is thus a key step in rational vaccine design and developing methods for accurate prediction of the peptide:MHC interactions play a central role in epitope discovery. The MHC class II binding groove is open at both ends making the correct alignment of a peptide in the binding groove a crucial part of identifying the core of an MHC class II binding motif. Here, we present a novel stabilization matrix alignment method, SMM-align, that allows for direct prediction of peptide:MHC binding affinities. The predictive performance of the method is validated on a large MHC class II benchmark data set covering 14 HLA-DR (human MHC) and three mouse H2-IA alleles. RESULTS The predictive performance of the SMM-align method was demonstrated to be superior to that of the Gibbs sampler, TEPITOPE, SVRMHC, and MHCpred methods. Cross validation between peptide data set obtained from different sources demonstrated that direct incorporation of peptide length potentially results in over-fitting of the binding prediction method. Focusing on amino terminal peptide flanking residues (PFR), we demonstrate a consistent gain in predictive performance by favoring binding registers with a minimum PFR length of two amino acids. Visualizing the binding motif as obtained by the SMM-align and TEPITOPE methods highlights a series of fundamental discrepancies between the two predicted motifs. For the DRB1*1302 allele for instance, the TEPITOPE method favors basic amino acids at most anchor positions, whereas the SMM-align method identifies a preference for hydrophobic or neutral amino acids at the anchors. CONCLUSION The SMM-align method was shown to outperform other state of the art MHC class II prediction methods. The method predicts quantitative peptide:MHC binding affinity values, making it ideally suited for rational epitope discovery. The method has been trained and evaluated on the, to our knowledge, largest benchmark data set publicly available and covers the nine HLA-DR supertypes suggested as well as three mouse H2-IA allele. Both the peptide benchmark data set, and SMM-align prediction method (NetMHCII) are made publicly available.
Collapse
Affiliation(s)
- Morten Nielsen
- Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, Lyngby, Denmark
| | - Claus Lundegaard
- Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, Lyngby, Denmark
| | - Ole Lund
- Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, Lyngby, Denmark
| |
Collapse
|
15
|
Moss CX, Tree TI, Watts C. Reconstruction of a pathway of antigen processing and class II MHC peptide capture. EMBO J 2007; 26:2137-47. [PMID: 17396153 PMCID: PMC1852786 DOI: 10.1038/sj.emboj.7601660] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Accepted: 02/26/2007] [Indexed: 11/10/2022] Open
Abstract
Endocytosed antigens are proteolytically processed and small amounts of peptides captured by class II MHC molecules. The details of antigen proteolysis, peptide capture and how destruction of T-cell epitopes is avoided are incompletely understood. Using the tetanus toxin antigen, we show that the introduction of 3-6 cleavage sites is sufficient to trigger a partially unfolded conformation able to bind to class II MHC molecules. The known locations of T-cell epitopes and protease cleavage sites predict that large domains of processed antigen (8-35 kDa) are captured under these conditions. Remarkably, when antigen is bound to the B-cell antigen receptor (BCR), processing can trigger a concerted 'hand-over' reaction whereby BCR-associated processed antigen is captured by neighbouring class II MHC molecules. Early capture of minimally processed antigen and confinement of the processing and class II MHC loading reaction to the membrane plane may improve the likelihood of T-cell epitope survival in the class II MHC pathway and may help explain the reciprocal relationships observed between B- and T-cell epitopes in many protein antigens and autoantigens.
Collapse
Affiliation(s)
- Catherine X Moss
- Division of Cell Biology & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Timothy I Tree
- Department of Immunobiology, King's College London, Guy's King's & St Thomas' School of Medicine, London, UK
| | - Colin Watts
- Division of Cell Biology & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK. Tel.: +44 1382 384233; Fax: +44 1382 385783; E-mail:
| |
Collapse
|
16
|
Hastings KT, Lackman RL, Cresswell P. Functional Requirements for the Lysosomal Thiol Reductase GILT in MHC Class II-Restricted Antigen Processing. THE JOURNAL OF IMMUNOLOGY 2006; 177:8569-77. [PMID: 17142755 DOI: 10.4049/jimmunol.177.12.8569] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ag processing and presentation via MHC class II is essential for activation of CD4(+) T lymphocytes. gamma-IFN-inducible lysosomal thiol reductase (GILT) is present in the MHC class II loading compartment and has been shown to facilitate class II Ag processing and recall responses to Ags containing disulfide bonds such as hen egg lysozyme (HEL). Reduction of proteins within the MHC class II loading compartment is hypothesized to expose residues for class II binding and protease trimming. In vitro analysis has shown that the active site of GILT involves Cys(46) and Cys(49), present in a CXXC motif that shares similarity with the thioredoxin family. To define the functional requirements for GILT in MHC class II Ag processing, a GILT-deficient murine B cell lymphoma line was generated and stably transduced with wild-type and cysteine mutants of GILT. Intracellular flow cytometric, immunoblotting, and immunofluorescence analyses demonstrated that wild-type and mutant GILT were expressed and maintained lysosomal localization. Transduction with wild-type GILT reconstituted MHC class II processing of a GILT-dependent HEL epitope. Mutation of either Cys(46) or Cys(49) abrogated MHC class II processing of a GILT-dependent HEL epitope. In addition, biochemical analysis of these mutants suggested that the active site facilitates processing of precursor GILT to the mature form. Precursor forms of GILT-bearing mutations in Cys(200) or Cys(211), previously found to display thiol reductase activity in vitro, could not mediate Ag processing. These studies demonstrate that the thiol reductase activity of GILT is its essential function in MHC class II-restricted Ag processing.
Collapse
Affiliation(s)
- K Taraszka Hastings
- Department of Dermatology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | | |
Collapse
|
17
|
Lovitch SB, Pu Z, Unanue ER. Amino-terminal flanking residues determine the conformation of a peptide-class II MHC complex. THE JOURNAL OF IMMUNOLOGY 2006; 176:2958-68. [PMID: 16493054 DOI: 10.4049/jimmunol.176.5.2958] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The peptide spanning residues 48-62 of hen egg white lysozyme presented by I-A(k) molecules gives rise to two T cell populations, types A and B, that recognize distinct conformers of the complex generated in late and recycling endosomes. The class II-like accessory molecule H2-DM functions as a conformational editor, eliminating the type B conformer in late endosomes. Here, we show that the conformation of the complex, and its susceptibility to editing by H2-DM, are determined by peptide amino-terminal flanking residues. Elimination of these residues abolished editing, permitting formation of the type B conformer in late endosomes. Substitutions at P(-2) affected the stability of the type B conformer, preventing its formation and/or editing, without hindering peptide binding or formation of the type A conformer of the complex. We conclude that interactions involving amino-terminal flanking residues stabilize peptide-MHC conformers and confer resistance to editing by H2-DM, influencing the nature of the T cell repertoire.
Collapse
Affiliation(s)
- Scott B Lovitch
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | |
Collapse
|
18
|
Felix NJ, Suri A, Walters JJ, Horvath S, Gross ML, Allen PM. I-Ep-Bound Self-Peptides: Identification, Characterization, and Role in Alloreactivity. THE JOURNAL OF IMMUNOLOGY 2006; 176:1062-71. [PMID: 16393994 DOI: 10.4049/jimmunol.176.2.1062] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
T cell recognition of peptide/allogeneic MHC complexes is a major cause of transplant rejection. Both the presented self-peptides and the MHC molecules are involved; however, the molecular basis for alloreactivity and the contribution of self-peptides are still poorly defined. The murine 2.102 T cell is specific for hemoglobin(64-76)/I-Ek and is alloreactive to I-Ep. The natural self-peptide/I-Ep complex recognized by 2.102 remains unknown. In this study, we characterized the peptides that are naturally processed and presented by I-Ep and used this information to define the binding motif for the murine I-Ep class II molecule. Interestingly, we found that the P9 anchor residue preferred by I-Ep is quite distinct from the residues preferred by other I-E molecules, although the P1 anchor residue is conserved. A degree of specificity for the alloresponse was shown by the lack of stimulation of 2.102 T cells by 19 different identified self-peptides. The binding motif was used to search the mouse genome for candidate 2.102 reactive allopeptides that contain strong P1 and P9 anchor residues and possess previously identified allowable TCR contact residues. Two potential allopeptides were identified, but only one of these peptides, G protein-coupled receptor 128, was able to stimulate 2.102 T cells. Thus, the G protein-coupled receptor 128 peptide represents a candidate allopeptide that is specifically recognized by 2.102 T cells bound to I-Ep and was identified using bioinformatics. These studies highlight the specific involvement of self-peptides in alloreactivity.
Collapse
Affiliation(s)
- Nathan J Felix
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | | | | | | | |
Collapse
|
19
|
Baratin M, Bonin K, Daniel C. Frontline: Peripheral priming of alloreactive T cells by the direct pathway of allorecognition. Eur J Immunol 2005; 34:3305-14. [PMID: 15484192 DOI: 10.1002/eji.200425309] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent studies, though controversial, have suggested that secondary lymphoid organs may not constitute an essential site for the initiation of immune responses to transplant antigens. However, this issue has never been examined in the context of direct and indirect allorecognition. Here, we characterized immune responses arising in draining lymph nodes and skin allografts, in a murine model based on a single T cell clonotype where these two pathways can be independently studied. In this model, graft rejection by the direct or the indirect pathway occurred with similar kinetics, although initiation of the alloreactive responses was clearly different. During indirect responses, expansion and activation of alloreactive T cells were first observed in draining lymph nodes, at day 7 post-transplant, and graft-infiltrating T cells were observed later, at day 11. In striking contrast, directly activated alloreactive T cells were detected at an early stage inside the graft, and only later in the draining lymph nodes, after skin allograft rejection was almost completed. These results suggest that sensitization of naive T cells through the direct pathway could take place outside secondary lymphoid organs.
Collapse
Affiliation(s)
- Myriam Baratin
- Institut National de la Recherche Scientifique-Institut Armand-Frappier, Université du Québec, Laval, Canada
| | | | | |
Collapse
|
20
|
Suri A, Unanue ER. The murine diabetogenic class II histocompatibility molecule I-Ag7: structural and functional properties and specificity of peptide selection. Adv Immunol 2005; 88:235-65. [PMID: 16227092 DOI: 10.1016/s0065-2776(05)88007-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The onset of type 1 diabetes mellitus (T1DM) is directly linked to the expression of class II MHC molecules. The NOD mouse, which is an excellent animal model for the human disease, expresses the I-Ag7 molecule that shares many features with the human diabetogenic class II MHC alleles. In this review, the structural, biochemical, and biological properties of the I-Ag7 molecules and how they relate to onset of diabetes is discussed. In particular, the focus is on the unique properties of peptide selection by I-Ag7 that reveal the preferred binding motif of diabetogenic MHC molecules and its role in display of peptides derived from islet beta cells.
Collapse
Affiliation(s)
- Anish Suri
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | |
Collapse
|
21
|
Thai R, Moine G, Desmadril M, Servent D, Tarride JL, Ménez A, Léonetti M. Antigen Stability Controls Antigen Presentation. J Biol Chem 2004; 279:50257-66. [PMID: 15364925 DOI: 10.1074/jbc.m405738200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We investigated whether protein stability controls antigen presentation using a four disulfide-containing snake toxin and three derivatives carrying one or two mutations (L1A, L1A/H4Y, and H4Y). These mutations were anticipated to increase (H4Y) or decrease (L1A) the antigen non-covalent stabilizing interactions, H4Y being naturally and frequently observed in neurotoxins. The chemically synthesized derivatives shared similar three-dimensional structure, biological activity, and T epitope pattern. However, they displayed differential thermal unfolding capacities, ranging from 65 to 98 degrees C. Using these differentially stable derivatives, we demonstrated that antigen stability controls antigen proteolysis, antigen processing in antigen-presenting cells, T cell stimulation, and kinetics of expression of T cell determinants. Therefore, non-covalent interactions that control the unfolding capacity of an antigen are key parameters in the efficacy of antigen presentation. By affecting the stabilizing interaction network of proteins, some natural mutations may modulate the subsequent T-cell stimulation and might help microorganisms to escape the immune response.
Collapse
Affiliation(s)
- Robert Thai
- Département d'Ingénierie et d'Etudes des Protéines, Commissariat à l'Energie Atomique, C.E. Saclay, 91191 Gif-sur-Yvette, France
| | | | | | | | | | | | | |
Collapse
|
22
|
Watts C. The exogenous pathway for antigen presentation on major histocompatibility complex class II and CD1 molecules. Nat Immunol 2004; 5:685-92. [PMID: 15224094 DOI: 10.1038/ni1088] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The endosomes and lysosomes of antigen-presenting cells host the processing and assembly reactions that result in the display of peptides on major histocompatibility complex (MHC) class II molecules and lipid-linked products on CD1 molecules. This environment is potentially hostile for T cell epitope and MHC class II survival, and the influence of regulators of protease activity and specialized chaperones that assist MHC class II assembly is crucial. At present, evidence indicates that individual proteases make both constructive and destructive contributions to antigen processing for MHC class II presentation to CD4 T cells. Some features of CD1 antigen capture within the endocytic pathway are also discussed.
Collapse
Affiliation(s)
- Colin Watts
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
| |
Collapse
|
23
|
Sauvé D, Baratin M, Leduc C, Bonin K, Daniel C. Alloantibody production is regulated by CD4+ T cells' alloreactive pathway, rather than precursor frequency or Th1/Th2 differentiation. Am J Transplant 2004; 4:1237-45. [PMID: 15268724 DOI: 10.1111/j.1600-6143.2004.00520.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Although CD4(+) T cells play an important role in the regulation of allograft rejection, the exact mechanisms by which they operate and the actual contribution of direct and indirect alloreactivity pathways remain to be fully characterized. Previous studies have established a possible relationship between the indirect alloreactivity pathway and antibody production, but interpretation of these results have been complicated by shortcomings inherent to the models used in these studies. To address this issue, we have developed a model based on TCR transgenic mice derived from a CD4(+) T-cell clone which recognize specific alloantigens by both alloreactivity pathways. Skin allografts on alphabeta T-cell deficient mice adoptively transferred with transgenic CD4(+) T cells were rejected without significant delay between the two alloreactivity pathways. No IgG alloantibody was produced following allograft rejection by the direct alloreactivity pathway alone. Importantly, production of antibodies against alloantigens of the direct pathway was shown to require help from CD4(+) T cells activated by the indirect pathway. These results indicate that the events leading to the initiation of immune responses responsible for graft rejection are clearly dependent on the population of antigen-presenting cells involved in T- and B-lymphocyte activation.
Collapse
Affiliation(s)
- Dominike Sauvé
- Institut National de la Recherche Scientifique-Institut Armand-Frappier, Université du Québec, Laval, Québec, Canada
| | | | | | | | | |
Collapse
|
24
|
Abstract
Ever since the emergence of models for the processing and presentation of antigenic determinants by MHC class II molecules, the main view has been that proteins are unfolded, enzymatically cleaved into peptide lengths of about 12-25 amino acids and then loaded onto MHC class II molecules. There is, however, an alternative model stating that partially intact unfolding antigens are first bound by MHC class II molecules and then trimmed to fragments of a smaller size while remaining bound to the MHC class II molecule. In this analysis, we make the case that a considerable portion of the elutable peptide cargo belongs to this latter class.
Collapse
Affiliation(s)
- Eli E Sercarz
- Torrey Pines Institute for Molecular Studies, San Diego, California 92121, USA.
| | | |
Collapse
|
25
|
Yoshitomi T, Hirahara K, Kawaguchi J, Serizawa N, Taniguchi Y, Saito S, Sakaguchi M, Inouye S, Shiraishi A. Three T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, retain their immunogenicity and tolerogenicity in a linked peptide. Immunology 2002; 107:517-22. [PMID: 12460197 PMCID: PMC1782819 DOI: 10.1046/j.1365-2567.2002.01534.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2002] [Revised: 08/14/2002] [Accepted: 08/30/2002] [Indexed: 11/20/2022] Open
Abstract
It has been demonstrated in detail that administration of a dominant T-cell determinant to animals induces activation or immunological tolerance of T cells. However, it has not been determined whether multiple T-cell determinants, when integrated into a single peptide, retain their potential to induce T-cell activation and tolerance. We prepared a synthetic peptide comprising three T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, and investigated the immunogenicity and tolerogenicity of each T-cell determinant in the linked peptide by means of lymph node cell proliferation assays using mice. Lymph node cells from mice immunized with each of the three T-cell determinants proliferated against the linked peptide in a dose-dependent manner, similar to that of the immunized peptide. Lymph node cells from mice immunized with the linked peptide proliferated against all of the three T-cell determinants. In addition, the degree of proliferation against the three T-cell determinants occurred according to their original immunogenicity, as observed in the native protein antigens. Oral administration of the linked peptide to mice before they were immunized with Cry j 1 and Cry j 2 inhibited lymph node cell proliferation against the three T-cell determinants, depending on the dose of the linked peptide administered. In conclusion, it was demonstrated that three T-cell determinants retain their original immunogenicity and tolerogenicity in a linked peptide comprising them.
Collapse
Affiliation(s)
- Tomomi Yoshitomi
- Sankyo Co., Ltd, Tokyo, Japan, Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Velazquez C, Vidavsky I, van der Drift K, Gross ML, Unanue ER. Chemical identification of a low abundance lysozyme peptide family bound to I-Ak histocompatibility molecules. J Biol Chem 2002; 277:42514-22. [PMID: 12055186 DOI: 10.1074/jbc.m202316200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The processing by antigen-presenting cells (APC) of the protein hen egg-white lysozyme (HEL) results in the selection of a number of peptide families by the class II major histocompatibility complex (MHC) molecule, I-A(k). Some of these families are expressed in very small amounts, in the order of a few picomoles/10(9) APC. We detected these peptides from an extract of class II MHC molecules by using monoclonal anti-peptide antibodies to capture the MHC-bound peptides prior to their examination by HPLC tandem mass spectrometry. Here, we have identified several members of a family of peptides encompassing residues 20-35, which represent less than 1% of the total HEL peptides. Binding analysis indicated that the core segment of the family was represented by residues 24-32 (SLGNWVCAA). Asn-27 (shown in boldface) is the main MHC-binding residue, mapped as interacting with the P4 pocket of the I-A(k) molecule. Analysis of several T cell hybridomas indicated that three residues contacted the T cell receptor: Tyr-23 (P-1), Leu-25 (P3), and Trp-28 (P5). The HEL peptides isolated from the APC extract were sulfated on Tyr-23, but further analysis showed that this modification did not occur physiologically but took place during the peptide isolation.
Collapse
Affiliation(s)
- Carlos Velazquez
- Department of Pathology and Immunology, Washington University School of Medicine, Washington University, St. Louis, Missouri 63110, USA
| | | | | | | | | |
Collapse
|
27
|
Arentz-Hansen H, McAdam SN, Molberg Ø, Fleckenstein B, Lundin KEA, Jørgensen TJD, Jung G, Roepstorff P, Sollid LM. Celiac lesion T cells recognize epitopes that cluster in regions of gliadins rich in proline residues. Gastroenterology 2002; 123:803-9. [PMID: 12198706 DOI: 10.1053/gast.2002.35381] [Citation(s) in RCA: 269] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Celiac disease is a gluten-induced enteropathy that shows a strong association with HLA-DQ2 and -DQ8. Gluten-specific T cells, invariably restricted by DQ2 or DQ8, can be isolated from celiac lesions. Such gut-derived T cells have a preference for recognition of gluten that has been specifically deamidated by tissue transglutaminase. Only a few gliadin T-cell epitopes have been identified by earlier work. The aim of this study was to perform a systematic characterization of DQ2-restricted T-cell epitopes in alpha- and gamma-gliadins. METHODS Epitopes were identified by mass spectrometry analysis of peptide fragments of recombinant gliadins and by use of synthetic peptides. RESULTS We identified several new gamma-gliadin epitopes and an additional alpha-gliadin epitope. Interestingly, these and the previously identified epitopes are not randomly scattered across the gliadins but cluster in regions of the proteins with high content of proline residues. CONCLUSIONS Several DQ2-restricted T-cell epitopes exist in gliadin that are located in regions rich in proline. This likely reflects epitope selection at the levels of digestive and antigen-presenting cell processing, transglutaminase-mediated deamidation, and/or peptide binding to DQ2.
Collapse
Affiliation(s)
- Helene Arentz-Hansen
- Institute of Immunology and Department of Medicine, Rikshopitalet, University of Oslo, Oslo, Norway
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
The disease mechanisms of complex inflammatory disorders are difficult to define because of extensive interactions between genetic and environmental factors. Coeliac disease is a typical complex inflammatory disorder, but this disease is unusual in that crucial genetic and environmental factors have been identified. This knowledge has allowed functional studies of the predisposing HLA molecules, the identification of antigenic epitopes and detailed studies of disease-relevant T cells in coeliac disease. This dissection of the pathogenic mechanisms of coeliac disease has uncovered principles that are relevant to other chronic inflammatory diseases.
Collapse
Affiliation(s)
- Ludvig M Sollid
- Institute of Immunology, Rikshospitalet, University of Oslo, 0027 Oslo, Norway.
| |
Collapse
|
29
|
Abstract
The phenomenon of antigen processing and presentation and the concept that T cells recognize peptides resulting from the partial catabolism of proteins, are relatively new. These concepts were first recognized and developed at a time when lymphocyte immunity - the adaptive system - and cellular immunity, with its major component of activated macrophages, were not perceived as part of one integrated system. To me, it was the fundamental findings on the role of major histocompatibility (MHC) molecules that set the framework for understanding how phagocytes and the antigen presenting cell (APC) system interact with the adaptive cellular system, in a truly symbiotic relationship (1). In this chapter we make a historical review of the developments that, in my biased opinion, led to the understanding of antigen presentation as a central event. I emphasize my own work, placing it in my perspective of how I saw the field moving.
Collapse
Affiliation(s)
- Emil R Unanue
- Washington University School of Medicine, Department of Pathology and Immunology, St. Louis, MO 63110, USA.
| |
Collapse
|
30
|
Pu Z, Carrero JA, Unanue ER. Distinct recognition by two subsets of T cells of an MHC class II-peptide complex. Proc Natl Acad Sci U S A 2002; 99:8844-9. [PMID: 12084929 PMCID: PMC124386 DOI: 10.1073/pnas.092260499] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We examine here the nature of the differential recognition by CD4+ T cells of a single peptide from hen-egg white lysozyme (HEL) presented by I-A(k) class II MHC molecules. Two subsets of T cells (called A and B) interact with the same peptide, each in unique ways that reflect the nature of the complex of peptide and MHC. We show that the A and B set of T cells can be distinguished by their functional interaction with the three T cell receptor (TCR) contact residues of the bound peptide. The dominant peptide of HEL selected from processing is bound in a single register where a critical TCR contact residue is situated about the middle of the core segment of the peptide: all T cells establish functional contact with it. Three sets of T cells, however, can be distinguished by their differential recognition of two TCR contacts situated at the amino and carboxyl sides of the central TCR contact residue. Type A T cells, the conventional cells that see the peptide after processing of HEL, need to recognize all three TCR contact residues. In contrast, the type B T cells recognize the peptide given exogenously, but not when processed: these T cells recognize either one of the peripheral TCR contact residues, indicating a much more flexible interaction of peptide with I-A(k) molecules. We discuss the mode of generation of the various T cells and their biological relevance.
Collapse
Affiliation(s)
- Zheng Pu
- Department of Pathology and Immunology, and Center for Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | |
Collapse
|
31
|
Neveu R, Auriault C, Angyalosi G, Georges B. Evidences of conformational changes in class II Major Histocompatibility Complex molecules that affect the immunogenicity. Mol Immunol 2002; 38:661-7. [PMID: 11858821 DOI: 10.1016/s0161-5890(01)00106-7] [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: 10/18/2022]
Abstract
The N-terminal part of class II-associated invariant chain peptide (CLIP) is assumed to interact with an accessory peptide-binding site on the class II Major Histocompatibility Complex (MHC) molecule, and promote a conformational modification. We have linked this immunoregulatory segment (residues 81-88) to the N-terminus of the influenza hemagglutinin (HA) 307-319 epitope in order to evaluate relationships between the MHC conformational changes and their implication in immune responses. Our chimeric peptide, named CLIP-HA, bind with the same affinity to class II HLA-DR1 molecules as the HA peptide, and is normally recognized by HA-specific T cells. Interestingly, the presence of the N-terminal CLIP region enhances the rate of association to soluble DR1 molecules but prevents the formation of SDS-resistant complexes. These features suggest the existence of HLA-DR1 conformational changes induced by the chimeric peptide. Furthermore, while in vitro HA and CLIP-HA peptides associated to DR1 could not be differentiated based on T-cell recognition, in vivo the CLIP residues strongly impaired the immunogenicity of HA epitope as assessed in HLA-DR1 transgenic mice. Our study demonstrates for the first time that MHC conformational changes, revealed at molecular level, may influence the immunogenicity.
Collapse
Affiliation(s)
- Raphaële Neveu
- SEDAC-Therapeutics Inc., Institut de Biologie de Lille, Lille, France
| | | | | | | |
Collapse
|
32
|
Dai G, Steede NK, Landry SJ. Allocation of helper T-cell epitope immunodominance according to three-dimensional structure in the human immunodeficiency virus type I envelope glycoprotein gp120. J Biol Chem 2001; 276:41913-20. [PMID: 11551929 DOI: 10.1074/jbc.m106018200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The specificity and intensity of CD4(+) helper T-cell responses determine the effectiveness of immune effector functions. Promiscuously immunodominant helper T-cell epitopes in the human immunodeficiency virus (HIV) envelope glycoprotein gp120 could be important in the development of broadly protective immunity, but the underlying mechanisms of immunodominance and promiscuity remain poorly defined. In this study, gp120 helper T-cell epitopes were systematically mapped in CBA/J and BALB/c mice by restimulation assays using a set of overlapping peptides spanning the entire sequence of the gp120 encoded by HIV strain 89.6. The results were analyzed in the context of the HIV gp120 structure determined by x-ray crystallography. One major finding was that all of the promiscuously immunodominant gp120 sequences are located in the outer domain. Further analyses indicated that epitope immunogenicity in the outer domain correlates with structural disorder in adjacent N-terminal segments, as indicated by crystallographic B-factors or sequence divergence. In contrast, the correlation was poor when the analysis encompassed the entire gp120 sequence or was restricted to only the inner domain. These findings suggest that local disorder promotes the processing and presentation of adjacent epitopes in the outer domain of gp120 and therefore reveal how three-dimensional structure shapes the profile of helper T-cell epitope immunogenicity.
Collapse
Affiliation(s)
- G Dai
- Department of Biochemistry, Tulane University Health Sciences Center, New Orleans, Louisiana 70112, USA
| | | | | |
Collapse
|
33
|
Godkin AJ, Smith KJ, Willis A, Tejada-Simon MV, Zhang J, Elliott T, Hill AV. Naturally processed HLA class II peptides reveal highly conserved immunogenic flanking region sequence preferences that reflect antigen processing rather than peptide-MHC interactions. THE JOURNAL OF IMMUNOLOGY 2001; 166:6720-7. [PMID: 11359828 DOI: 10.4049/jimmunol.166.11.6720] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
MHC class II heterodimers bind peptides 12-20 aa in length. The peptide flanking residues (PFRs) of these ligands extend from a central binding core consisting of nine amino acids. Increasing evidence suggests that the PFRs can alter the immunogenicity of T cell epitopes. We have previously noted that eluted peptide pool sequence data derived from an MHC class II Ag reflect patterns of enrichment not only in the core binding region but also in the PFRS: We sought to distinguish whether these enrichments reflect cellular processes or direct MHC-peptide interactions. Using the multiple sclerosis-associated allele HLA-DR2, pool sequence data from naturally processed ligands were compared with the patterns of enrichment obtained by binding semicombinatorial peptide libraries to empty HLA-DR2 molecules. Naturally processed ligands revealed patterns of enrichment reflecting both the binding motif of HLA-DR2 (position (P)1, aliphatic; P4, bulky hydrophobic; and P6, polar) as well as the nonbound flanking regions, including acidic residues at the N terminus and basic residues at the C terminus. These PFR enrichments were independent of MHC-peptide interactions. Further studies revealed similar patterns in nine other HLA alleles, with the C-terminal basic residues being as highly conserved as the previously described N-terminal prolines of MHC class II ligands. There is evidence that addition of C-terminal basic PFRs to known peptide epitopes is able to enhance both processing as well as T cell activation. Recognition of these allele-transcending patterns in the PFRs may prove useful in epitope identification and vaccine design.
Collapse
Affiliation(s)
- A J Godkin
- Nuffield Department of Medicine, Molecular Immunology Group, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|
34
|
Colledge L, Sun MY, Lin W, Blackburn CC, Reay PA. Differing processing requirements of four recombinant antigens containing a single defined T-cell epitope for presentation by major histocompatibility complex class II. Immunology 2001; 103:343-50. [PMID: 11454063 PMCID: PMC1783251 DOI: 10.1046/j.1365-2567.2001.01254.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2000] [Revised: 03/08/2001] [Accepted: 03/28/2001] [Indexed: 11/20/2022] Open
Abstract
A set of predictive rules governing the likelihood of generating a particular peptide-major histocompatibility complex (MHC) class II complex from an intact antigen has not been fully elucidated. We investigated the influence of positional and structural constraints in the region of the epitope by designing a set of recombinant antigens that each contained the well-characterized T-cell epitope moth cytochrome c (MCC) (88-103), which is specifically recognized by the monoclonal antibody (mAb) D4 when complexed with H-2Ek. Our model antigens contained MCC(88-103) either peripherally, at or towards the C-terminus, or internally. Their abilities to bind directly to soluble H-2Ek, and the extent of D4 epitope formation from them by antigen processing-competent and -incompetent cell lines, were determined. Here we report that three of these four antigens yielded MCC(88-103)/H-2Ek complexes independently of the conventional MHC class II antigen-processing and presentation pathway, and in each case the epitope was carried peripherally; two bound directly as intact proteins, probably as a result of spatial separation of the epitope from the major globular domain, and one was processed to peptide by a cell-surface protease. One protein, which carried the epitope inserted into an internal loop, acted as a conventional processing-dependent MCC(88-103) delivery vehicle. Thus, this epitope has different presentation requirements depending on its context. These antigens constitute a panel whose framework could be modified to further define predictive rules for antigen processing for presentation through the different MHC class II complex-generating pathways.
Collapse
Affiliation(s)
- L Colledge
- Nuffield Department of Clinical Medicine, John Radcliffe Hospital, Oxford, UK.
| | | | | | | | | |
Collapse
|
35
|
Bumann D. In vivo visualization of bacterial colonization, antigen expression, and specific T-cell induction following oral administration of live recombinant Salmonella enterica serovar Typhimurium. Infect Immun 2001; 69:4618-26. [PMID: 11402006 PMCID: PMC98539 DOI: 10.1128/iai.69.7.4618-4626.2001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Live attenuated Salmonella strains that express a foreign antigen are promising oral vaccine candidates. Numerous genetic modifications have been empirically tested, but their effects on immunogenicity are difficult to interpret since important in vivo properties of recombinant Salmonella strains such as antigen expression and localization are incompletely characterized and the crucial early inductive events of an immune response to the foreign antigen are not fully understood. Here, methods were developed to directly localize and quantitate the in situ expression of an ovalbumin model antigen in recombinant Salmonella enterica serovar Typhimurium using two-color flow cytometry and confocal microscopy. In parallel, the in vivo activation, blast formation, and division of ovalbumin-specific CD4(+) T cells were followed using a well-characterized transgenic T-cell receptor mouse model. This combined approach revealed a biphasic induction of ovalbumin-specific T cells in the Peyer's patches that followed the local ovalbumin expression of orally administered recombinant Salmonella cells in a dose- and time-dependent manner. Interestingly, intact Salmonella cells and cognate T cells seemed to remain in separate tissue compartments throughout induction, suggesting a transport of killed Salmonella cells from the colonized subepithelial dome area to the interfollicular inductive sites. The findings of this study will help to rationally optimize recombinant Salmonella strains as efficacious live antigen carriers for oral vaccination.
Collapse
Affiliation(s)
- D Bumann
- Abteilung Molekulare Biologie, Max-Planck-Institut für Infektionsbiologie, D-10117 Berlin, Germany.
| |
Collapse
|
36
|
Serwold T, Gaw S, Shastri N. ER aminopeptidases generate a unique pool of peptides for MHC class I molecules. Nat Immunol 2001; 2:644-51. [PMID: 11429550 DOI: 10.1038/89800] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We define here the specificity and significance of proteases in the endoplasmic reticulum (ER) that generate peptides for presentation by major histocompatibility complex (MHC) class I molecules. We show that aminopeptidases efficiently trimmed all residues except proline that flank the NH2-termini of antigenic precursors in the ER and caused an accumulation of X-P-Xn peptides. An aminopeptidase inhibitor blocked peptide trimming in the ER and, consequently, the generation of peptide-loaded MHC molecules. Peptide trimming in the ER is therefore a key step in the MHC class I antigen-processing pathway and also explains the paradox of why many MHC class I molecules display peptides with the X-P-Xn motif despite the inability of the transporter associated with antigen processing to transport such peptides from the cytoplasm.
Collapse
Affiliation(s)
- T Serwold
- Division of Immunology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
| | | | | |
Collapse
|
37
|
Peterson DA, DiPaolo RJ, Kanagawa O, Unanue ER. Cutting edge: a single MHC anchor residue alters the conformation of a peptide-MHC complex inducing T cells that survive negative selection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:5874-7. [PMID: 11342600 DOI: 10.4049/jimmunol.166.10.5874] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We generated transgenic mice that expressed hen egg-white lysozyme (HEL) under a class II MHC promoter. The A7 line expressed HEL with a point mutation in the Asp(52) residue, the main anchor amino acid responsible for the selection of the chemically dominant family of peptides (52-60) by I-A(k) molecules. Mice expressing HEL with Ala(52) were completely unresponsive when immunized with the same protein, i.e., HEL A52. However, the same mice immunized with wild-type HEL elicited T cells that recognized a conformation of the 52-61 core sequence uniquely different between Asp(52) and Ala(52) containing peptides. Importantly, some T cells also recognized the HEL A52 peptide given exogenously but not the same peptide processed from HEL A52 protein. Thus, a core MHC anchor residue influences markedly the specificity of the T cells. We discuss the relevance of these findings to autoimmunity and vaccination with altered peptides.
Collapse
Affiliation(s)
- D A Peterson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | | | |
Collapse
|
38
|
Velazquez C, DiPaolo R, Unanue ER. Quantitation of lysozyme peptides bound to class II MHC molecules indicates very large differences in levels of presentation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:5488-94. [PMID: 11313387 DOI: 10.4049/jimmunol.166.9.5488] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Knowing the abundance of peptides presented by MHC molecules is a crucial aspect for understanding T cell activation and tolerance. In this report we determined the relative abundance of four distinct peptide families after the processing of the model Ag hen egg-white lysozyme. The development of a sensitive immunochemical approach reported here made it possible to directly quantitate the abundance of these four epitopes presented by APCs, both in vitro and in vivo. We observed a wide range of presentation among these four different epitopes presented on the surface of APCs, with 250-fold differences or more between the most abundant epitope (48-63) and the least abundant epitopes. Importantly, we observe similar ratios of presentation from APCs in vitro as well as from APCs from the spleens and thymi of hen egg-white lysozyme transgenic mice. We discuss the relationship between the amount of peptide presented and their binding to I-A(k) molecules, immunogenicity, and tolerogenicity.
Collapse
Affiliation(s)
- C Velazquez
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | |
Collapse
|
39
|
Gugasyan R, Velazquez C, Vidavsky I, Deck BM, van der Drift K, Gross ML, Unanue ER. Independent selection by I-Ak molecules of two epitopes found in tandem in an extended polypeptide antigen. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:3206-13. [PMID: 10975836 DOI: 10.4049/jimmunol.165.6.3206] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The protein hen egg white lysozyme (HEL) contains two segments, in tandem, from which two families of peptides are selected by the class II molecule I-Ak, during processing. These encompass peptides primarily from residues 31-47 and 48-63. Mutant HEL proteins were created with changes in residues 52 and 55, resulting in a lack of binding and selection of the 48-63 peptides to I-Ak molecules. Such mutant HEL proteins donated the same amount of 31-47 peptide as did the unmodified protein. Other mutant HEL molecules containing proline residues at residue 46, 47, or 48 resulted in extensions of the selected 31-47 or 48-62 families to their overlapping regions (in the carboxyl or amino termini, respectively). However, the amount of each family of peptide selected was not changed. We conclude that the presence or absence of the major peptide from HEL does not influence the selection of other epitopes, and that these two families are selected independently of each other.
Collapse
Affiliation(s)
- R Gugasyan
- Departments of Pathology and Immunology and Chemistry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Pathak SS, Blum JS. Endocytic recycling is required for the presentation of an exogenous peptide via MHC class II molecules. Traffic 2000; 1:561-9. [PMID: 11208144 DOI: 10.1034/j.1600-0854.2000.010706.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Exogenous antigenic peptides captured and presented in the context of major histocompatibility (MHC) class II molecules on APC, have been employed as potent vaccine reagents capable of activating cellular immune responses. Binding and presentation of select peptide via surface class II molecules has been reported. Here, a role for endocytosis and early endosomes in the presentation of exogenous peptides via MHC class II molecules is described. T cell recognition of a 14 amino acid human serum albumin-derived peptide in the context of HLA-DR4 was observed only with metabolically active APC. The delayed kinetics and temperature dependence of functional peptide presentation via APC, were consistent with a requirement for peptide internalization to early endosomal compartments prior to T cell recognition. Ablating endocytosis by exposing cells to inhibitors of ATP production completely blocked the display of functional peptide:class II complexes on the surface of the APC. Presentation of the peptide was also found to be sensitive to primaquine, a drug that perturbs the recycling of transport vesicles containing endocytic receptors and mature class II complexes. Functional presentation of the endocytosed peptide was dependent upon these mature class II complexes, as inhibitor studies ruled out a requirement for newly synthesized class II molecules. N-terminal processing of the endocytosed peptide was observed upon trafficking through endosomal compartments and linked to the formation of functional peptide:class II complexes. These findings establish a novel mechanism for regulating class II-restricted peptide presentation via the endocytic pathway.
Collapse
Affiliation(s)
- S S Pathak
- Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, IN, USA
| | | |
Collapse
|
41
|
Shi YP, Das P, Holloway B, Udhayakumar V, Tongren JE, Candal F, Biswas S, Ahmad R, Hasnain SE, Lal AA. Development, expression, and murine testing of a multistage Plasmodium falciparum malaria vaccine candidate. Vaccine 2000; 18:2902-14. [PMID: 10812234 DOI: 10.1016/s0264-410x(00)00045-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A synthetic gene encoding twelve B cell epitopes, six T-cell proliferative epitopes, and three cytotoxic T lymphocyte (CTL) epitopes from nine stage-specific antigens, representing the sporozoite, liver stage, asexual blood-stage, and sexual-stage antigens of Plasmodium falciparum, was constructed by assembling overlapping oligonucleotides followed by PCR extension and annealing. A three-step PCR protocol using twelve long oligonucleotides was employed to generate a 1053 base-pair synthetic gene, the identity of which was confirmed by sequencing. This synthetic gene, named CDC/NII MAL VAC-1, was cloned, and the recombinant protein was expressed in the Baculovirus Expression Vector System (BEVS). The selection of malarial epitopes for inclusion in this vaccine construct was based on immunoepidemiological studies in malaria endemic area, in vitro, and in vivo protection studies in model systems. The 41 kDa BEVS-expressed recombinant protein reacted with mouse antibodies specific for individual B cell epitopes in the vaccine construct and with sera from clinically immune Kenyan adults. An immunization study in three strains of mice that differ at the H-2 locus demonstrated that the BEVS-expressed recombinant protein is immunogenic; the candidate vaccine antigen induced high titer antibodies, and lymphocyte proliferative and IFN-gamma responses. These results demonstrate that individual B and T cell epitopes can be assembled to create synthetic genes that encode proteins capable of eliciting specific antibody and T cell responses.
Collapse
MESH Headings
- Adult
- Amino Acid Sequence
- Animals
- Antibodies, Protozoan/biosynthesis
- Antigens, Protozoan/administration & dosage
- Antigens, Protozoan/biosynthesis
- Antigens, Protozoan/genetics
- Antigens, Protozoan/isolation & purification
- Baculoviridae/genetics
- Genetic Vectors/administration & dosage
- Genetic Vectors/chemical synthesis
- Genetic Vectors/immunology
- Humans
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/chemical synthesis
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria, Falciparum/genetics
- Malaria, Falciparum/immunology
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
Collapse
Affiliation(s)
- Y P Shi
- National Center for Infectious Diseases, United States Department of Health and Human Service, Atlanta, GA 30341-3717, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Freed JH, Marrs A, VanderWall J, Cohen PL, Eisenberg RA. MHC class II-bound self peptides from autoimmune MRL/lpr mice reveal potential T cell epitopes for autoantibody production in murine systemic lupus erythematosus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:4697-705. [PMID: 10779775 DOI: 10.4049/jimmunol.164.9.4697] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The systemic lupus erythematosus-like syndrome in MRL/lpr mice involves high-titered IgG autoantibodies, particularly antinuclear Abs that target histones, DNA, and RNA particles. Although T cell help is required for the generation of antinuclear Abs, the epitopes recognized by such helper T cells are unknown. To address this question, we isolated and sequenced self peptides bound by MHC class II molecules from MRL/lpr mice. We identified a number of peptides that are not seen in similar preparations from nonautoimmune C3H animals. The "abnormal" peptide donors include histone, a protein component of a small nuclear ribonucleoprotein, ribosomal proteins, and RNA processing enzymes. We postulate that the peptides from these donors are T cell epitopes required for the generation of the most frequent antinuclear Abs specificities seen in MRL/lpr mice.
Collapse
Affiliation(s)
- J H Freed
- Division of Basic Immunology, Department of Medicine, National Jewish Medical and Research Center, Denver, CO 80206, USA.
| | | | | | | | | |
Collapse
|
43
|
Abstract
Antigen-presenting cells (APC) degrade proteins intracellularly to generate peptides, which are then bound by products of the major histocompatibility complex (MHC) and exposed on the surface of the APC for recognition by T cells. The supply of antigenic peptides and their association with MHC molecules requires the concerted action of a cohort of accessory molecules that includes chaperones, transporters of peptides, and the proteases that degrade the antigens.
Collapse
Affiliation(s)
- J A Villadangos
- Department of Immunology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | | |
Collapse
|
44
|
Kang HK, Mikszta JA, Deng H, Sercarz EE, Jensen PE, Kim BS. Processing and reactivity of T cell epitopes containing two cysteine residues from hen egg-white lysozyme (HEL74-90). JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:1775-82. [PMID: 10657624 DOI: 10.4049/jimmunol.164.4.1775] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Ag processing and structural requirements involved in the generation of a major T cell epitope from the hen egg-white lysozyme protein (HEL74-88), containing two cysteine residues at positions 76 and 80, were investigated. Several T cell hybridomas derived from both low responder (I-Ab) and high responder (I-Ak) mice recognize this region. These hybridomas are strongly responsive to native HEL, but unresponsive to the reduced and carboxymethylated protein. Air-oxidized HEL74-88 peptide was unable to bind I-Ak molecules and failed to stimulate T cells in the absence of intracellular Ag processing. Further functional competition assays showed that alkylation of cysteine residues with bulky methyl groups interferes with the contacts for the MHC class II molecules (I-Ak) of high responder mice and the I-Ab-restricted TCR of low responder mice. Serine substitutions of the cysteine residues of HEL74-88 either enhanced or abrogated T cell stimulation by the peptides without significant alterations in the class II binding. These results suggest that the cysteine residues of peptides must be free from disulfide bonding for efficient stimulation of T cells and yet frequently used modifications of cysteine residues may not be suitable for peptide-based vaccine development.
Collapse
Affiliation(s)
- H K Kang
- Department of Microbiology, Northwestern University Medical School, Chicago, IL 60611, USA
| | | | | | | | | | | |
Collapse
|
45
|
Nakagawa TY, Rudensky AY. The role of lysosomal proteinases in MHC class II-mediated antigen processing and presentation. Immunol Rev 1999; 172:121-9. [PMID: 10631942 DOI: 10.1111/j.1600-065x.1999.tb01361.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The recent analysis of cathepsin-deficient mice has shed light upon the role of lysosomal proteinases in the MHC class II processing and presentation pathway. Ubiquitous expression and involvement in the terminal degradation of proteins that intersect the endocytic pathway were previously perceived to be the hallmarks of these proteinases. However, recent evidence has demonstrated that several cathepsins are expressed in a tissue-specific fashion and that partial proteolysis of specific biological targets is a key function of cathepsins in antigen processing. Our work has focused on the differential expression of the cysteine proteinases cathepsins L (CL) and S (CS) and its pertinence to the generation of MHC class II: peptide complexes. Analysis of CL-deficient mice revealed a profound defect in invariant chain degradation in thymic cortical epithelial cells but not in bone marrow-derived antigen-presenting cells (APCs) (B cells, dendritic cells, and macrophages). The tissue-specific deficiency reflected the restricted pattern of expression of CL and CS in these cell types--CL is expressed in thymic cortical epithelial cells but not in DC or B cells, while CS exhibits the opposite expression pattern. The differential expression of proteinases by distinct APCs may affect the types of peptides that are presented to T cells and thereby the immune responses that are ultimately generated.
Collapse
Affiliation(s)
- T Y Nakagawa
- Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | | |
Collapse
|
46
|
Abstract
Important quantitative parameters can be utilized to define the selection and the immunogenicity of protein antigens precisely at a biochemical and a cellular level. Here we describe a naturally processed family of peptides comprising the dominant hen egg white lysozyme epitope, its major contribution to surface I-Ak molecules, the primary and auxiliary peptide anchors involved in its selection, and its display of T-cell receptor contacts. In addition, we explore the importance of the processing events that lead to the generation of residues flanking the minimal core epitope, the quantification of T-cell responses directed toward the epitope, and the ability of the dominant epitope to form two unique conformations within the binding groove. Lastly, we address the relationship between this dominant and a minor lysozyme epitope.
Collapse
Affiliation(s)
- R R Latek
- Center for Immunology, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | | |
Collapse
|
47
|
Peterson DA, DiPaolo RJ, Kanagawa O, Unanue ER. Quantitative analysis of the T cell repertoire that escapes negative selection. Immunity 1999; 11:453-62. [PMID: 10549627 DOI: 10.1016/s1074-7613(00)80120-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mice expressing hen egg-white lysozyme (HEL) as a transgene are unresponsive to immunization with the HEL protein. Profound tolerance was found even in situations where the amounts of l-A(k)-peptide complexes was 100 or less per APC. Among the few T cells that escaped tolerance, we did not observe differential responses to the different HEL epitopes, perhaps because of the very high sensitivity of the negative selection process. The same HEL transgenic mice that did not respond to HEL responded to immunization with the 46-61 peptide of HEL. These peptide-specific T cells that escaped negative selection belonged to a set that reacted with a particular conformer of the HEL peptide-l-A(k) (type B). The presence of type B reactive T cells should be considered in autoimmunity.
Collapse
Affiliation(s)
- D A Peterson
- Center for Immunology and Department of Pathology, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | | | | | | |
Collapse
|
48
|
Unanue ER. Rous-Whipple Award Lecture. Chemical features of peptide selection by the class II histocompatibility molecules. THE AMERICAN JOURNAL OF PATHOLOGY 1999; 154:651-64. [PMID: 10079241 PMCID: PMC1866414 DOI: 10.1016/s0002-9440(10)65311-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/11/1998] [Indexed: 11/22/2022]
Affiliation(s)
- E R Unanue
- Department of Pathology and Center for Immunology, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA.
| |
Collapse
|
49
|
Schaible UE, Collins HL, Kaufmann SH. Confrontation between intracellular bacteria and the immune system. Adv Immunol 1999; 71:267-377. [PMID: 9917916 DOI: 10.1016/s0065-2776(08)60405-8] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- U E Schaible
- Max-Planck Institute for Infection Biology, Berlin, Germany
| | | | | |
Collapse
|
50
|
Abstract
We studied in patients with hairy cell leukemia (HCL) whether autoreactive T cells could be isolated with specific reactivity to the HCL cells. HCL cells were activated via triggering of CD40 on the cell membrane and used as stimulator cells to generate autologous T-cell clones. Two types of CD4+BV2+ T-cell clones with different CDR3 rearrangements and one type of CD4+BV8S3+ T-cell clone were generated from the spleen or blood. These clones specifically recognized the autologous HCL cells, without reactivity to autologous peripheral blood mononuclear cells (PBMC), phytohemagglutinin blasts, or Epstein-Barr virus–transformed B cells in a primed lymphocyte test. Blocking and panel studies using HCL cells from 11 other patients showed that recognition of the HCL cells by the BV2+ T cells was restricted by HLA-DQA1*03/DQB1*0301, and the BV8S3+ T cells were restricted by DPB1*04. The T-cell clones did not recognize DPB1*04+ or DQ3+ PBMC from healthy donors or DP/DQ matched malignant cells from patients with other hematologic malignancies, except for one patient with acute lymphoblastic leukemia. These HCL-specific T-cell clones may be used for the detection of an HCL-specific tumor antigen.
Collapse
|