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Borthwick N, Silva-Arrieta S, Llano A, Takiguchi M, Brander C, Hanke T. Novel Nested Peptide Epitopes Recognized by CD4 + T Cells Induced by HIV-1 Conserved-Region Vaccines. Vaccines (Basel) 2020; 8:E28. [PMID: 31963212 PMCID: PMC7157676 DOI: 10.3390/vaccines8010028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/07/2020] [Accepted: 01/10/2020] [Indexed: 11/29/2022] Open
Abstract
CD4+ T-cell responses play an important role in the immune control of the human immunodeficiency virus type 1 (HIV-1) infection and as such should be efficiently induced by vaccination. It follows that definition of HIV-1-derived peptides recognized by CD4+ T cells in association with HLA class II molecules will guide vaccine development. Here, we have characterized the fine specificity of CD4+ T cells elicited in human recipients of a candidate vaccine delivering conserved regions of HIV-1 proteins designated HIVconsv. The majority of these 19 most immunogenic regions contained novel epitopes, that is, epitopes not listed in the Los Alamos National Laboratory HIV Sequence Database, which were able in vitro to stimulate vaccinees' CD4+ T cells to proliferate and produce interferon-γ and tumor necrosis factor-α. Accumulation of HLA class II epitopes will eventually accelerate development of HIV-1 prophylactic and therapeutic vaccines.
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Affiliation(s)
| | - Sandra Silva-Arrieta
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Barcelona, Spain; (S.S.-A.); (A.L.); (C.B.)
| | - Anuska Llano
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Barcelona, Spain; (S.S.-A.); (A.L.); (C.B.)
| | - Masafumi Takiguchi
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 860-0811, Japan;
| | - Christian Brander
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Barcelona, Spain; (S.S.-A.); (A.L.); (C.B.)
- Faculty of Medicine, Universitat de Vic-Central de Catalunya (UVic-UCC), 08500 Vic, Spain
- Institució Catalana de Recerca I Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Tomáš Hanke
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK;
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 860-0811, Japan;
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Bhati M, Cole DK, McCluskey J, Sewell AK, Rossjohn J. The versatility of the αβ T-cell antigen receptor. Protein Sci 2014; 23:260-72. [PMID: 24375592 DOI: 10.1002/pro.2412] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 12/20/2013] [Accepted: 12/20/2013] [Indexed: 02/06/2023]
Abstract
The T-cell antigen receptor is a heterodimeric αβ protein (TCR) expressed on the surface of T-lymphocytes, with each chain of the TCR comprising three complementarity-determining regions (CDRs) that collectively form the antigen-binding site. Unlike antibodies, which are closely related proteins that recognize intact protein antigens, TCRs classically bind, via their CDR loops, to peptides (p) that are presented by molecules of the major histocompatibility complex (MHC). This TCR-pMHC interaction is crucially important in cell-mediated immunity, with the specificity in the cellular immune response being attributable to MHC polymorphism, an extensive TCR repertoire and a variable peptide cargo. The ensuing structural and biophysical studies within the TCR-pMHC axis have been highly informative in understanding the fundamental events that underpin protective immunity and dysfunctional T-cell responses that occur during autoimmunity. In addition, TCRs can recognize the CD1 family, a family of MHC-related molecules that instead of presenting peptides are ideally suited to bind lipid-based antigens. Structural studies within the CD1-lipid antigen system are beginning to inform us how lipid antigens are specifically presented by CD1, and how such CD1-lipid antigen complexes are recognized by the TCR. Moreover, it has recently been shown that certain TCRs can bind to vitamin B based metabolites that are bound to an MHC-like molecule termed MR1. Thus, TCRs can recognize peptides, lipids, and small molecule metabolites, and here we review the basic principles underpinning this versatile and fascinating receptor recognition system that is vital to a host's survival.
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Affiliation(s)
- Mugdha Bhati
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, 3800, Australia
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3
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Holland CJ, Cole DK, Godkin A. Re-Directing CD4(+) T Cell Responses with the Flanking Residues of MHC Class II-Bound Peptides: The Core is Not Enough. Front Immunol 2013; 4:172. [PMID: 23847615 PMCID: PMC3696884 DOI: 10.3389/fimmu.2013.00172] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/14/2013] [Indexed: 11/17/2022] Open
Abstract
Recombinant αβ T cell receptors, expressed on T cell membranes, recognize short peptides presented at the cell surface in complex with MHC molecules. There are two main subsets of αβ T cells: CD8(+) T cells that recognize mainly cytosol-derived peptides in the context of MHC class I (pMHC-I), and CD4(+) T cells that recognize peptides usually derived from exogenous proteins presented by MHC class II (pMHC-II). Unlike the more uniform peptide lengths (usually 8-13mers) bound in the MHC-I closed groove, MHC-II presented peptides are of a highly variable length. The bound peptides consist of a core bound 9mer (reflecting the binding motif for the particular MHC-II type) but with variable peptide flanking residues (PFRs) that can extend from both the N- and C-terminus of the MHC-II binding groove. Although pMHC-I and pMHC-II play a virtually identical role during T cell responses (T cell antigen presentation) and are very similar in overall conformation, there exist a number of subtle but important differences that may govern the functional dichotomy observed between CD8(+) and CD4(+) T cells. Here, we provide an overview of the impact of structural differences between pMHC-I and pMHC-II and the molecular interactions with the T cell receptor including the functional importance of MHC-II PFRs. We consider how factors such as anatomical location, inflammatory milieu, and particular types of antigen presenting cell might, in theory, contribute to the quantitative (i.e., pMHC ligand frequency) as well as qualitative (i.e., variable PFR) nature of peptide epitopes, and hence offer a means of control and influence of a CD4(+) T cell response. Lastly, we review our recent findings showing how modifications to MHC-II PFRs can modify CD4(+) T cell antigen recognition. These findings may have novel applications for the development of CD4(+) T cell peptide vaccines and diagnostics.
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Affiliation(s)
| | - David K. Cole
- Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - Andrew Godkin
- Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
- Department of Integrated Medicine, University Hospital of Wales, Cardiff, UK
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4
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Specificity and detection of insulin-reactive CD4+ T cells in type 1 diabetes in the nonobese diabetic (NOD) mouse. Proc Natl Acad Sci U S A 2011; 108:16729-34. [PMID: 21949373 DOI: 10.1073/pnas.1113954108] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In the nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D), an insulin peptide (B:9-23) is a major target for pathogenic CD4(+) T cells. However, there is no consensus on the relative importance of the various positions or "registers" this peptide can take when bound in the groove of the NOD MHCII molecule, IA(g7). This has hindered structural studies and the tracking of the relevant T cells in vivo with fluorescent peptide-MHCII tetramers. Using mutated B:9-23 peptides and methods for trapping the peptide in particular registers, we show that most, if not all, NOD CD4(+) T cells react to B:9-23 bound in low-affinity register 3. However, these T cells can be divided into two types depending on whether their response is improved or inhibited by substituting a glycine for the B:21 glutamic acid at the p8 position of the peptide. On the basis of these findings, we constructed a set of fluorescent insulin-IA(g7) tetramers that bind to most insulin-specific T-cell clones tested. A mixture of these tetramers detected a high frequency of B:9-23-reactive CD4(+) T cells in the pancreases of prediabetic NOD mice. Our data are consistent with the idea that, within the pancreas, unique processing of insulin generates truncated peptides that lack or contain the B:21 glutamic acid. In the thymus, the absence of this type of processing combined with the low affinity of B:9-23 binding to IA(g7) in register 3 may explain the escape of insulin-specific CD4(+) T cells from the mechanisms that usually eliminate self-reactive T cells.
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Jahn-Schmid B, Pickl WF, Bohle B. Interaction of allergens, major histocompatibility complex molecules, and T cell receptors: a 'ménage à trois' that opens new avenues for therapeutic intervention in type I allergy. Int Arch Allergy Immunol 2011; 156:27-42. [PMID: 21447957 DOI: 10.1159/000321904] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
T cells are major players in the initiation and perpetuation of the allergic immune response. In this review, we summarize the current knowledge on allergen recognition by T lymphocytes and address the components of the trimeric recognition complex: T cell receptors, major histocompatibility complex molecules, and allergen-derived peptides. Furthermore, possible implications of this scientific background for future therapeutic developments are discussed.
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Affiliation(s)
- Beatrice Jahn-Schmid
- Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria. beatrice.jahn-schmid @ meduniwien.ac.at
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6
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Johnson KL, Ovsyannikova IG, Poland GA, Muddiman DC. Identification of class II HLA-DRB1*03-bound measles virus peptides by 2D-liquid chromatography tandem mass spectrometry. J Proteome Res 2006; 4:2243-9. [PMID: 16335972 DOI: 10.1021/pr0501416] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two-dimensional liquid chromatography (2D-LC), combined with gas phase fractionation tandem mass spectrometry, was used to identify 13 naturally processed peptides originating from measles virus that were presented by HLA-DRB1*03 class II molecules. The peptides are from three of the six measles structural proteins: phosphoprotein, nucleocapsid, and hemagglutinin. These peptides provide an important first step toward understanding the mechanism of immune response to measles virus and development of a new generation of peptide-based vaccines.
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Affiliation(s)
- Kenneth L Johnson
- Mayo Proteomics Research Center, Mayo Vaccine Research Group, Program in Translational Immunovirology and Biodefense, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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Calvo-Calle JM, Oliveira GA, Nardin EH. Human CD4+ T cells induced by synthetic peptide malaria vaccine are comparable to cells elicited by attenuated Plasmodium falciparum sporozoites. THE JOURNAL OF IMMUNOLOGY 2006; 175:7575-85. [PMID: 16301667 DOI: 10.4049/jimmunol.175.11.7575] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptide vaccines containing minimal epitopes of protective Ags provide the advantages of low cost, safety, and stability while focusing host responses on relevant targets of protective immunity. However, the limited complexity of malaria peptide vaccines raises questions regarding their equivalence to immune responses elicited by the irradiated sporozoite vaccine, the "gold standard" for protective immunity. A panel of CD4+ T cell clones was derived from volunteers immunized with a peptide vaccine containing minimal T and B cell epitopes of the Plasmodium falciparum circumsporozoite protein to compare these with previously defined CD4+ T cell clones from volunteers immunized with irradiated P. falciparum sporozoites. As found following sporozoite immunization, the majority of clones from the peptide-immunized volunteers recognized the T* epitope, a predicted universal T cell epitope, in the context of multiple HLA DR and DQ molecules. Peptide-induced T cell clones were of the Th0 subset, secreting high levels of IFN-gamma as well as variable levels of Th2-type cytokines (IL-4, IL-6). The T* epitope overlaps a polymorphic region of the circumsporozoite protein and strain cross-reactivity of the peptide-induced clones correlated with recognition of core epitopes overlapping the conserved regions of the T* epitope. Importantly, as found following sporozoite immunization, long-lived CD4+ memory cells specific for the T* epitope were detectable 10 mo after peptide immunization. These studies demonstrate that malaria peptides containing minimal epitopes can elicit human CD4+ T cells with fine specificity and potential effector function comparable to those elicited by attenuated P. falciparum sporozoites.
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Zhu H, Liu K, Cerny J, Imoto T, Moudgil KD. Insertion of the dibasic motif in the flanking region of a cryptic self-determinant leads to activation of the epitope-specific T cells. THE JOURNAL OF IMMUNOLOGY 2005; 175:2252-60. [PMID: 16081793 DOI: 10.4049/jimmunol.175.4.2252] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Efficient induction of self tolerance is critical for avoiding autoimmunity. The T cells specific for the well-processed and -presented (dominant) determinants of a native self protein are generally tolerized in the thymus, whereas those potentially directed against the inefficiently processed and presented (cryptic) self epitopes escape tolerance induction. We examined whether the crypticity of certain determinants of mouse lysozyme-M (ML-M) could be attributed to the nonavailability of a proteolytic site, and whether it could be reversed to immunodominance by engraftment of a novel cleavage site in the flanking region of the epitope. Using site-directed mutagenesis, we created the dibasic motif (RR or RK; R = arginine, K = lysine), a target of intracellular proteases, in the region adjoining one of the three cryptic epitopes (46-61, 66-79, or 105-119) of ML-M. Interestingly, the mutated lysozyme proteins, but not unmutated ML-M, were immunogenic in mice. The T cell response to the altered lysozyme was attributable to the efficient processing and presentation of the previously cryptic epitope, and this response was both epitope and MHC haplotype specific. In addition, the anti-self T cell response was associated with the generation of autoantibodies against self lysozyme. However, the results using one of three mutated lysozymes suggested that the naturally processed, dibasic motif-marked epitope may not always correspond precisely to the cryptic determinant within a synthetic peptide. This is the first report describing the circumvention of self tolerance owing to the targeted reversal of crypticity to dominance in vivo of a specific epitope within a native self Ag.
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Affiliation(s)
- Hui Zhu
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Meiring HD, Kuipers B, van Gaans-van den Brink JAM, Poelen MCM, Timmermans H, Baart G, Brugghe H, van Schie J, Boog CJP, de Jong APJM, van Els CACM. Mass tag-assisted identification of naturally processed HLA class II-presented meningococcal peptides recognized by CD4+ T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2005; 174:5636-43. [PMID: 15843563 DOI: 10.4049/jimmunol.174.9.5636] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The meningococcal class I outer membrane protein porin A plays an important role in the development of T cell-dependent protective immunity against meningococcal serogroup B infection and is therefore a major component of candidate meningococcal vaccines. T cell epitopes from porin A are poorly characterized because of weak in vitro memory T cell responses against purified Ag and strain variation. We applied a novel strategy to identify relevant naturally processed and MHC class II-presented porin A epitopes, based on stable isotope labeling of Ag. Human immature HLA-DR1-positive dendritic cells were used for optimal uptake and MHC class II processing of (14)N- and (15)N-labeled isoforms of the neisserial porin A serosubtype P1.5-2,10 in bacterial outer membrane vesicles. HLA-DR1 bound peptides, obtained after 48 h of Ag processing, contained typical spectral doublets in mass spectrometry that could easily be assigned to four porin A regions, expressed at diverging densities ( approximately 30-4000 copies/per cell). Epitopes from two of these regions are recognized by HLA-DR1-restricted CD4(+) T cell lines and are conserved among different serosubtypes of meningococcal porin A. This mass tag-assisted approach provides a useful methodology for rapid identification of MHC class II presented bacterial CD4(+) T cell epitopes relevant for vaccine development.
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Affiliation(s)
- Hugo D Meiring
- Laboratory of Analytical Chemistry, National Institute of Public Health and the Environment, Bilthoven, The Netherlands
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10
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Williams KM, Bigley EC. Identification of an I-Ed-restricted T-cell epitope of Escherichia coli outer membrane protein F. Infect Immun 2004; 72:3907-13. [PMID: 15213134 PMCID: PMC427395 DOI: 10.1128/iai.72.7.3907-3913.2004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
A predominant T-cell epitope of Escherichia coli outer membrane protein F (OmpF) that encompasses amino acids 295 to 314 was identified in H-2(d) mice. BALB/c-derived T-cell hybridomas generated against this region were CD3(+), CD4(+), CD8(-), and T-cell receptor alphabeta(+) and secreted TH-1-associated cytokines (interleukin-2 [IL-2] and gamma interferon), but not a TH-2-associated cytokine (IL-4), when restimulated with peptide 295-314. Class II(+) mouse lymphoma (A20) cells, but not class II(-) mouse mastocytoma (P815) cells, supported IL-2 secretion of hybridomas when substituted for syngeneic splenocytes as antigen-presenting cells (APCs). Antibodies specific for I-E(d) blocked IL-2 secretion by hybridomas, but I-A(d)-specific antiserum did not. When transfected L cells expressing I-A(d) (AalphaAbeta(d)), I-E(d) (EalphaEbeta(d)), or the hybrid molecule I-EalphaAbeta(d) were used as APCs, hybridomas recognized peptide only when presented by the I-E(d)-transfected cells. When peptide 295-314 truncated at either the C or the N terminus of the sequence was used, the minimal epitope was determined. Critical residues were determined by using alanine-substituted peptide analogues. T-cell hybridomas were only stimulated by peptides that encompassed amino acids 295 to 303 (9-mer), and the core sequence required a minimum of three additional amino acids at either the amino or the carboxy terminus to induce IL-2 secretion. Critical residues were determined to be phenylalanine at position 295, threonine at position 300, and tyrosines at positions 301 and 302. This study is the first to identify a minimal T-cell epitope and major histocompatibility complex restriction element of the OmpF protein and confirms previous observations that there is considerable degeneracy in the length of peptides that can bind I-E(d) and variability in the amino acid composition of the C and N termini of these peptides.
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Affiliation(s)
- Kristina M Williams
- Center for Food Safety and Applied Nutrition, Immunobiology Branch, Food and Drug Administration, 8301 Muirkirk Road, Laurel, MD 20708, USA.
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11
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Patil NS, Wong DL, Collier KD, McDonald HC. Fluorescent derivatization of a protease antigen to track antigen uptake and processing in human cell lines. BMC Immunol 2004; 5:12. [PMID: 15222895 PMCID: PMC459215 DOI: 10.1186/1471-2172-5-12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 06/28/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We have devised a simple and efficient fluorescence-based method to track antigen uptake and processing in human B lymphoblastoid cells (B-LCL). Fluorescein labelled subtilisin was used to optimize antigen uptake conditions and identify processed peptides from human cell lines. RESULTS Fluorescein labelled subtilisin conjugates had 0.06 to 2 moles of fluorescein per subtilisin molecule. High performance liquid chromatography and mass spectrometry (NanoESI-LC/MS/MS) analysis identified fluorescein conjugated to K141, K256, and the N terminus. Conjugates retained antigenic specificity to subtilisin specific antibodies and could be processed by whole cell extracts into low molecular weight fragments at pH 5.2. Maximal antigen uptake and processing occurred when PMSF (phenylmethylsulfonyl fluoride) inhibited subtilisin conjugate was incubated with cells at 100-200 microg/ml for 16 to 24 hr. Once optimal uptake conditions were established, processed subtilisin peptides were isolated and identified from human cell lines. CONCLUSION Our studies show that FITC-conjugation provides an efficient tool to track the uptake and processing of this protease antigen and to facilitate identification of processed antigenic peptides from human cell lines.
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Affiliation(s)
- Namrata S Patil
- Genencor International Inc., 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - David L Wong
- Genencor International Inc., 925 Page Mill Road, Palo Alto, CA 94304, USA
| | | | - Hugh C McDonald
- Genencor International Inc., 925 Page Mill Road, Palo Alto, CA 94304, USA
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Brown WC, Palmer GH, Brayton KA, Meeus PFM, Barbet AF, Kegerreis KA, McGuire TC. CD4+ T lymphocytes from Anaplasma marginale major surface protein 2 (MSP2) vaccinees recognize naturally processed epitopes conserved in MSP3. Infect Immun 2004; 72:3688-92. [PMID: 15155686 PMCID: PMC415717 DOI: 10.1128/iai.72.6.3688-3692.2004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Major surface protein 2 (MSP2) and MSP3 of the persistent bovine ehrlichial pathogen Anaplasma marginale are immunodominant proteins that undergo antigenic variation. The recently completed sequence of MSP3 revealed blocks of amino acids in the N and C termini that are conserved with MSP2. This study tested the hypothesis that CD4+ T cells specific for MSP2 recognize naturally processed epitopes conserved in MSP3. At least one epitope in the N terminus and two in the C terminus of MSP2 were also processed from MSP3 and presented to CD4+ T lymphocytes from MSP2-immunized cattle. This T-lymphocyte response to conserved and partially conserved epitopes may contribute to the immunodominance of MSP2 and MSP3.
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Affiliation(s)
- Wendy C Brown
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA.
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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.
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Affiliation(s)
- Eli E Sercarz
- Torrey Pines Institute for Molecular Studies, San Diego, California 92121, USA.
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Park JH, Lee YJ, Kim KL, Cho EW. Selective isolation and identification of HLA-DR-associated naturally processed and presented epitope peptides. Immunol Invest 2003; 32:155-69. [PMID: 12916706 DOI: 10.1081/imm-120022976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Activation of CD4 helper T-cells is mediated by the presentation of antigenic peptides in context of self-MHC class II molecules. So far, the rules after which antigen-presenting cells (APC) select a particular epitope within a given protein antigen have been not fully elucidated. Nevertheless, immunoaffinity purification of APC-derived MHC class II molecules and the subsequent elutions of their with associated naturally processed and presented peptide epitopes (NPPE) have helped tremendously in understanding the nature of this rather complex process. In the present study, a novel approach for identifying such NPPEs is introduced, which is based on the culture of APCs in a completely protein-free medium during the antigen presenting process. These APCs do still express a high level of MHC class II as determined by HLA-DR cell surface staining, but the repertoire of the associated NPPEs is drastically reduced when compared to peptides eluted from cells maintained under normal culture condition. Actually, reverse phase-high pressure liquid chromatography (RP-HPLC) revealed that the entire NPPE repertoire consisted of less than ten major peaks, which is more than a 100-fold reduction of background peptide peaks as seen in cells from serum-containing culture conditions. Feeding APCs with exogenous antigens further confirmed the advantage of this novel system. While exogenous antigen-derived peptide peaks in an NPPE-eluate from RP-HPLC are hardly to detect by conventional procedures, the very low background of serum- and protein-free cultured APCs immensely facilitated this process, providing an improved tool for the identification and characterization of NPPEs.
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Affiliation(s)
- Jung-Hyun Park
- Laboratory of Functional Proteomics, Korea Research Institute of Bioscience and Biotechnology, Yusong, Taejon, South Korea
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Zou J, Turner AN, Phelps RG. Mass and composition matrix-assisted laser desorption ionization time of flight analysis enabling inference of the sequence of most peptides where the protein of origin is known. Anal Chem 2003; 75:2653-62. [PMID: 12948133 DOI: 10.1021/ac026435h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mass spectrometers combining matrix-assisted laser-desorption ionization (MALDI) and time-of-flight analysis are among the most widely used in peptide analysis. They excel at accurate mass determinations on complex samples but, compared with tandem instruments, have very limited capacity to determine amino acid sequence through daughter ion analysis. Here we have investigated the sequence information that can be inferred from the masses of peptides in the special circumstance in which the peptides are known to be sub-sequences of known parent sequences. We show how sequence can be inferred from the measured m/z of a peptide (mass analysis) and examine the parameters that influence the level of confidence that can be placed in "inferred sequences". We further describe how specific amino acid modifications can be used with MALDI-TOF analysis to obtain partial composition information and demonstrate that combined mass and composition (MAC) analysis enables the sequences of most peptide ions to be inferred with very high confidence.
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Affiliation(s)
- Juan Zou
- MRC Centre for Inflammation Research (Renal Autoimmunity Group), University of Edinburgh, Edinburgh, United Kingdom
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16
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Doh H, Roh S, Lee KW, Kim K. Response of primed human PBMC to synthetic peptides derived from hepatitis B virus envelope proteins: a search for promiscuous epitopes. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2003; 35:77-85. [PMID: 12589960 DOI: 10.1016/s0928-8244(02)00461-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This investigation was aimed at identifying effective T helper cell epitopes to the hepatitis B virus in humans. A panel of synthetic peptides that represent the hepatitis B virus whole envelope proteins was examined for their capability to stimulate peripheral blood mononuclear cells from human subjects infected with hepatitis B virus naturally. In addition, a large number of subjects were examined and their human leukocyte antigen (HLA) class II allele types were identified to determine whether the helper T cell epitope is specific for a particular HLA allele or 'promiscuous'. The peptides of the amino acid residues 52-67, 110-125, 190-205, and 228-243 appeared to be immunogenic, and particularly, the 52-67 residue was the most promiscuous epitope peptide. These results would contribute to the better understanding of the helper T cell responses to the hepatitis B virus and provide a useful way in designing epitope-based vaccines and future therapeutic strategies.
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Affiliation(s)
- Hyounmie Doh
- Division of Molecular Life Sciences and College of Pharmacy, Ewha Womans University, 11 Daehyun-Dong, Seoul 120-750, South Korea
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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.
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Affiliation(s)
- Carlos Velazquez
- Department of Pathology and Immunology, Washington University School of Medicine, Washington University, St. Louis, Missouri 63110, USA
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18
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Arnold PY, La Gruta NL, Miller T, Vignali KM, Adams PS, Woodland DL, Vignali DAA. The majority of immunogenic epitopes generate CD4+ T cells that are dependent on MHC class II-bound peptide-flanking residues. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:739-49. [PMID: 12097376 DOI: 10.4049/jimmunol.169.2.739] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptides bind to MHC class II molecules with a defined periodicity such that the peptide-flanking residues (PFRs) P-1 and P11, which lie outside the core binding sequence (P1-P9), are solvent exposed and accessible to the TCR. Using a novel MHC class II:peptide binding assay, we defined the binding register for nine immunogenic epitopes to formally identify the flanking residues. Seven of the nine epitopes, restricted by H-2A(k), H-2A(g7), or H-2E(k), were found to generate T cells that were completely dependent on either P-1 or P11, with dependency on P-1 favored over P11. Such PFR dependency appears to be influenced by the type of amino acid exposed, in that residues that can form salt bridges or hydrogen bonds are favored over small or hydrophobic residues. Peptides containing alanine substitutions at P-1 or P11 in place of PFRs that mediate dependency were considerably less immunogenic and mediated a substantially reduced in vitro recall response to the native protein, inferring that PFR recognition increases immunogenicity. Our data suggest that PFR recognition is a common event characteristic of all MHC class II-restricted T cell responses. This key feature, which is not shared by MHC class I-restricted responses, may underlie the broad functional diversity displayed by MHC class II-restricted T cells.
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Affiliation(s)
- Paula Y Arnold
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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19
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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.
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Affiliation(s)
- Emil R Unanue
- Washington University School of Medicine, Department of Pathology and Immunology, St. Louis, MO 63110, USA.
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20
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Norimine J, Suarez CE, McElwain TF, Florin-Christensen M, Brown WC. Immunodominant epitopes in Babesia bovis rhoptry-associated protein 1 that elicit memory CD4(+)-T-lymphocyte responses in B. bovis-immune individuals are located in the amino-terminal domain. Infect Immun 2002; 70:2039-48. [PMID: 11895969 PMCID: PMC127881 DOI: 10.1128/iai.70.4.2039-2048.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Babesia bovis rhoptry-associated protein 1 (RAP-1), which confers partial protection against B. bovis challenge, is recognized by antibodies and T lymphocytes from cattle that have recovered from infection and are immune to subsequent challenge. RAP-1 is a 60-kDa protein with an N-terminal (NT) region that contains four cysteine residues conserved among all Babesia RAP-1 family members and a C-terminal (CT) region that contains multiple, degenerate, tandem 23-amino-acid (aa) repeats. To define the location of CD4(+)-T-cell epitopes for vaccine development using a recombinant protein or minigene construct, a series of truncated recombinant RAP-1 proteins and peptides were tested for stimulation of T-cell lines derived from B. bovis-immune cattle. CD4(+)-T-cell lines from three B. bovis-immune cattle with different DRB3 haplotypes responded to the NT region of RAP-1, whereas T cells from only one animal responded weakly to the CT region. T-cell lines from the three individuals recognized two to six NT-region peptides spanning aa 134 to 316 and representing at least four dominant epitopes. Using RAP-1-specific CD4(+)-T-cell clones, two NT-region epitopes, EYLVNKVLYMATMNYKT (aa 187 to 203) and EAPWYKRWIKKFR (aa 295 to 307), and one CT-region repeat epitope, FREAPQATKHFL, which is present twice at aa positions 391 to 402 and 414 to 425, were identified. Several peptides representing degenerate repeats of the agonist CT-region peptide FREAPQATKHFL neither stimulated responses of T-cell clones specific for this peptide nor inhibited responses to the agonist peptide. Upon stimulation with specific antigen, T-cell clones specific for NT or CT epitopes produced gamma interferon. The presence of T-helper-cell epitopes in the NT domain of RAP-1, which is highly conserved among otherwise antigenically different strains of B. bovis, supports the inclusion of this region in vaccine constructs to be tested in cattle.
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Affiliation(s)
- Junzo Norimine
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology Animal Disease Research Unit, Washington State University, Pullman, Washington 99164, USA
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21
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Shen CR, Ward FJ, Devine A, Luross JA, Lowrey PA, Wraith DC, Elson CJ, Barker RN. Characterization of the dominant autoreactive T-cell epitope in spontaneous autoimmune haemolytic anaemia of the NZB mouse. J Autoimmun 2002; 18:149-57. [PMID: 11908947 DOI: 10.1006/jaut.2001.0579] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NZB mice spontaneously develop autoimmune haemolytic anaemia (AIHA) due to a T helper-dependent autoantibody response against the erythrocyte anion channel protein, Band 3. Here, we characterize the recognition of the Band 3 sequence 861-874, which carries the dominant, I-E(d)-restricted T cell epitope. The ability of N and C-terminal truncated versions of peptide 861-874 to elicit NZB splenic T-cell proliferation indicated that the core epitope spans residues 862-870. Next, a set of alanine substitution analogues was tested to determine which residues functioned either as MHC anchor or TCR contact residues. A combination of proliferation and MHC:peptide binding assays identified residues 862(L), 864(V), 865(L), and 869(K) as I-E(d) anchor residues, and 868(V) as the only TCR contact residue. The ability of the wild-type sequence 861-874 to compete with a high affinity reference peptide for binding to I-E(d) indicates that the escape of pathogenic NZB T cells from purging of the autoreactive repertoire cannot be attributed to ineffective presentation of peptide 861-874 by its restricting element. It will now be possible to design altered peptide ligands of Band 3 861-874, in order to further dissect the mechanisms responsible for the maintenance and loss of T cell tolerance to RBC autoantigens, and to modulate the immune response in AIHA.
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MESH Headings
- Amino Acid Motifs
- Anemia, Hemolytic, Autoimmune/etiology
- Anemia, Hemolytic, Autoimmune/genetics
- Anemia, Hemolytic, Autoimmune/immunology
- Animals
- Anion Exchange Protein 1, Erythrocyte/chemistry
- Anion Exchange Protein 1, Erythrocyte/genetics
- Anion Exchange Protein 1, Erythrocyte/immunology
- Anion Exchange Protein 1, Erythrocyte/metabolism
- Autoantigens/chemistry
- Autoantigens/genetics
- Autoantigens/metabolism
- Binding Sites
- Binding, Competitive
- Histocompatibility Antigens Class II/metabolism
- Immunodominant Epitopes/chemistry
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/metabolism
- In Vitro Techniques
- Lymphocyte Activation
- Mice
- Mice, Inbred NZB
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Protein Binding
- T-Lymphocytes/immunology
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Affiliation(s)
- Chia-Rui Shen
- Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, AB25 2ZD, UK
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22
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Abstract
The function of MHC class II molecules is to bind peptides derived from antigens that access the endocytic route of antigen presenting cells and display them on the plasma membrane for recognition by CD4(+) T cells. Formation of the MHC II-peptide complexes entails the confluence of the antigens and the MHC II molecules in the same compartments of the endocytic route. There, both the antigens and the MHC II molecules undergo a series of orchestrated changes that involve proteases, other hydrolases and chaperones, culminating in the generation of a wide repertoire of MHC II-peptide combinations. All the events that lead to formation of MHC II-peptide complexes show a considerable degree of flexibility; this lack of strict rules is advantageous in that it provides T cells with the maximum amount of information, ensuring that pathogens do not go undetected.
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Affiliation(s)
- J A Villadangos
- The Walter and Eliza Hall Institute of Medical Research, P.O. The Royal Melbourne Hospital, 3050, Victoria, Melbourne, Australia.
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23
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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.
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Affiliation(s)
- C Velazquez
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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24
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Liu H, Rhodes M, Wiest DL, Vignali DA. On the dynamics of TCR:CD3 complex cell surface expression and downmodulation. Immunity 2000; 13:665-75. [PMID: 11114379 DOI: 10.1016/s1074-7613(00)00066-2] [Citation(s) in RCA: 283] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
TCR downmodulation following ligation by MHC:peptide complexes is considered to be a pivotal event in T cell activation. Here, we analyzed the dynamics of TCR:CD3 cell surface expression on resting and antigen-activated T cells. We show that the TCR:CD3 complex is very stable and is rapidly internalized and recycled in resting T cells. Surprisingly, the internalization rate is not increased following TCR ligation by MHC:peptide complexes, despite significant TCR downmodulation, suggesting that constitutive internalization rather than ligation-induced downmodulation serves as the force that drives serial ligation. Furthermore, TCR downmodulation is mediated by the intracellular retention of ligated complexes and degradation by lysosomes and proteasomes. Thus, our data demonstrate that ligation induces TCR downmodulation by preventing recycling rather than inducing internalization.
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Affiliation(s)
- H Liu
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38101, USA
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25
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Latek RR, Petzold SJ, Unanue ER. Hindering auxiliary anchors are potent modulators of peptide binding and selection by I-Ak class II molecules. Proc Natl Acad Sci U S A 2000; 97:11460-5. [PMID: 11016975 PMCID: PMC17222 DOI: 10.1073/pnas.210384197] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Selection of particular antigen-derived peptides by class II MHC molecules determines the population of complexes represented on the antigen-presenting cell surface and available for T cell receptor engagement. This discriminating selection process results from unique interactions between the spectrum of peptides generated during antigen processing and the MHC molecules. Here, we examined the selection of peptides by the class II MHC, I-A(k). Our results indicate that although peptide primary anchors are key in MHC binding, auxiliary anchors are a powerful regulatory component in the selection of peptides by I-A(k). Study of the segments surrounding the dominant hen egg white lysozome(48-61) epitope demonstrates that auxiliary anchors also are involved in determining the binding register of I-A(k) along an extended peptide. In addition, we found that unique combinations of auxiliary anchors can act in concert to modulate the binding of peptides to I-A(k).
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Affiliation(s)
- R R Latek
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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26
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Bonomi G, Moschella F, Ombra MN, Del Pozzo G, Granier C, De Berardinis P, Guardiola J. Modulation of TCR recognition of MHC class II/peptide by processed remote N- and C-terminal epitope extensions. Hum Immunol 2000; 61:753-63. [PMID: 10980386 DOI: 10.1016/s0198-8859(00)00147-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N- and C-terminal extensions of naturally processed MHC class II-bound peptides may affect TCR recognition. In fact, residues immediately flanking the minimal epitope on either side can contact the MHC groove and modify the interaction with a TCR. We report now that residues much farther away from the peptide core can also modulate TCR recognition in a functional antigen presentation system. To show this, we isolated from the same donor DR5-restricted T cell clones, specific for the HIV-1 RT(248-262) sequence and differing in their ability to respond to recombinant antigens obtained by insertion of the epitope in different positions of schistosomal, human, or murine glutathione-S-transferase (GST). We found that the reactivity profile of individual clones was related to their TCR fine specificity, suggesting that processing can generate determinants focused onto the same epitope, but antigenically distinct. In addition, we analyzed the response of this panel of T-helper cell clones against GST-derived recombinant antigens in which the epitope was flanked by stretches of polyalanine or polyserine on either side. These spacers had different effects on TCR recognition suggesting that secondary structures outside the core peptide may influence MHC/epitope complex recognition over a distance of 15-30 residues from the determinant.
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Affiliation(s)
- G Bonomi
- International Institute of Genetics and Biophysics, CNR, Naples, Italy.
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27
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Vidal K, Daniel C, Vidavsky I, Nelson CA, Allen PM. Hb(64-76) epitope binds in different registers and lengths to I-Ek and I-Ak. Mol Immunol 2000; 37:203-12. [PMID: 10930627 DOI: 10.1016/s0161-5890(00)00048-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The nature of peptide binding to MHC molecules is intrinsically degenerate, in what, one given MHC molecule can accommodate numerous peptides which are structurally diverse, and one given peptide can bind to different alleles. The structure of the MHC class II molecules allows peptides to extend out of the binding groove at both ends and these residues can potentially influence the stability and persistence of peptide/class II complexes. We have previously shown that both I-E(k) and I-A(k)-restricted T cell hybridomas could be generated against the Hb(64-76) epitope. In this study, we characterized the binding register of the Hb(64-76) epitope to I-A(k), and showed that it was shifted by one residue in comparison to its binding to I-E(k), and did not use a dominant anchor residue at P1. This conclusion was further supported by the modeling of the Hb(64-76) epitope bound to I-A(k), which revealed that all of its putative anchor residues fit into their corresponding pockets. We identified the naturally processed Hb epitopes presented by both I-E(k) and I-A(k), and found that they consisted of different species. Those associated with I-A(k) being 20-22 residues long, whereas, those found to I-E(k) contained 14-16 residues. These findings suggested that the lack of a dominant P1 anchor could be compensated by the selection of longer peptides. Overall, these studies revealed the Hb(64-76) epitope bound to I-E(k) and I-A(k) in distinct registers and lengths, demonstrating the plasticity MHC molecules have in generating distinct TCR ligands from the same amino acid sequence.
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Affiliation(s)
- K Vidal
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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28
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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.
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Affiliation(s)
- H K Kang
- Department of Microbiology, Northwestern University Medical School, Chicago, IL 60611, USA
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29
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McFarland BJ, Sant AJ, Lybrand TP, Beeson C. Ovalbumin(323-339) peptide binds to the major histocompatibility complex class II I-A(d) protein using two functionally distinct registers. Biochemistry 1999; 38:16663-70. [PMID: 10600129 DOI: 10.1021/bi991393l] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteins of the class II major histocompatibility complex (MHC) bind antigenic peptides that are subsequently presented to T cells. Previous studies have shown that most of the residues required for binding of the chicken ovalbumin (Ova) 323-339 peptide to the I-A(d) MHC class II protein are contained within the shorter 325-336 peptide. This observation is somewhat inconsistent with the X-ray structure of the Ova peptide covalently attached to I-A(d) ( structure) in which residues 323 and 324 form binding interactions with the protein. A second register for the Ova(325-336) peptide is proposed where residues 326 and 327 occupy positions similar to residues 323 and 324 in the structure. Two Ova peptides that minimally encompass the and alternate registers, Ova(323-335) and Ova(325-336), respectively, were found to dissociate from I-A(d) with distinct kinetics. The dissociation rates for both peptides were enhanced when the His81 residue of the MHC beta-chain was replaced with an asparagine. In the structure the betaH81 residue forms a hydrogen bond to the backbone carbonyl of I323. If the Ova(325-336) peptide were also bound in the register, there would be no comparable hydrogen-bond acceptor for the betaH81 side chain that could explain this peptide's sensitivity to the betaH81 replacement. The Ova(323-335) peptide that binds in the register does not stimulate a T-cell hybridoma that is stimulated by Ova(325-336) bound in the alternate register. These results demonstrate that a single peptide can bind to an MHC peptide in alternate registers producing distinct T-cell responses.
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Affiliation(s)
- B J McFarland
- Department of Chemistry, University of Washington, Seattle 98195, USA
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30
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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.
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Affiliation(s)
- R R Latek
- Center for Immunology, Washington University School of Medicine, St Louis, Missouri 63110, USA
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31
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Peakman M, Stevens EJ, Lohmann T, Narendran P, Dromey J, Alexander A, Tomlinson AJ, Trucco M, Gorga JC, Chicz RM. Naturally processed and presented epitopes of the islet cell autoantigen IA-2 eluted from HLA-DR4. J Clin Invest 1999; 104:1449-57. [PMID: 10562307 PMCID: PMC409844 DOI: 10.1172/jci7936] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/1999] [Accepted: 10/05/1999] [Indexed: 12/22/2022] Open
Abstract
During immune responses, antigen-presenting cells (APCs) process antigens and present peptide epitopes complexed with human leukocyte antigen (HLA) molecules. CD4 cells recognize these naturally processed and presented epitopes (NPPEs) bound to HLA class II molecules. Epitope identification is important for developing diagnostic and therapeutic tools for immune-mediated diseases and providing insight into their etiology, but current approaches overlook effects of natural processing on epitope selection. We have developed a technique to identify NPPEs using mass spectrometry (MS) after antigen is targeted onto APCs using a lectin-based antigen delivery system (ADS). We applied the technique to identify NPPEs of the intracellular domain of the type 1 diabetes mellitus-associated (type 1 DM-associated) autoantigen insulinoma-associated-2 (IA-2ic), presented by HLA-DR4 (0401). IA-2ic-derived NPPEs eluted from HLA-DR4 constitute 6 sets of peptides nested around distinct core regions. Synthetic peptides based on these regions bind HLA-DR4 and elicit primary T-cell proliferation frequently in HLA-DR4-positive type 1 DM patients, but rarely in non-HLA-DR4 patients, and in none of the HLA-DR4 nondiabetic controls we tested. This flexible, direct approach identifies an HLA allele-specific map of NPPEs for any antigen, presented by any HLA class II molecule. This method should enable a greater understanding of epitope selection and lead to the generation of sensitive and specific reagents for detecting autoreactive T cells.
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Affiliation(s)
- M Peakman
- Department of Immunology, Guy's, King's and St. Thomas' School of Medicine, King's College London, Denmark Hill Campus, London SE5 9PJ, United Kingdom.
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32
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Major histocompatibility complex–derived peptides as novel forms of immunosuppression. Curr Opin Organ Transplant 1999. [DOI: 10.1097/00075200-199909000-00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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33
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Prisco A, Bonomi G, Moschella F, Ombra MN, De Berardinis P, Guardiola J. In vitro immunization with a recombinant antigen carrying the HIV-1 RT248-262 determinant inserted at different locations results in altered TCRVB region usage. Hum Immunol 1999; 60:755-63. [PMID: 10527382 DOI: 10.1016/s0198-8859(99)00055-5] [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: 10/17/2022]
Abstract
Immunodominance or cripticity of a peptide-borne determinant may be influenced by the protein context in which the epitope is embedded. In this frame, we previously showed that certain human T cell clones, derived from different donors, may differentially recognize the RT248-262 helper determinant depending on whether it is provided to the presenting cells as a synthetic peptide or as a recombinant carrier protein to which the sequence of interest is fused. We now report that, upon in vitro immunization of human PBL with autologous APC, the epitope-specific TCRVB repertoire obtained when selection is applied by pulsing the APC with the cognate synthetic peptide is different from that found when a recombinant protein is used in which the antigenic sequence is placed at either a N-terminal or C-terminal location of the GST carrier. As the TCRVB distribution is not a function of the APC used, we propose that processing of different recombinant molecules containing the same epitope may generate MHC/peptide complexes which, being antigenically diverse, may recruit distinct TCR specificities. These findings may be relevant for evaluating and predicting the immunogenic potential of subunit vaccines based on synthetic peptides or on recombinant proteins as compared to the native antigen.
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Affiliation(s)
- A Prisco
- International Institute of Genetics and Biophysics, Naples, Italy
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34
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Vignali DAA, Vignali KM. Profound Enhancement of T Cell Activation Mediated by the Interaction Between the TCR and the D3 Domain of CD4. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.3.1431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
CD4 plays an important role in the activation and development of CD4+ T cells. This is mediated via its bivalent interaction with MHC class II molecules and the TCR:CD3 complex through p56lck. Recent studies have implicated a third site of interaction between the membrane-proximal extracellular domains of CD4 and the TCR. Due to these multiple interactions, direct evidence for the functional importance of this extracellular association has remained elusive. Furthermore, the residues that mediate this interaction are unknown. In this study, we analyzed the function of 61 CD4 mutants. Alanine substitution of just 2 residues, either Q114/F182 or F182/F201, which are partially buried and located close to the D2/D3 interface, completely abrogated CD4 function. Direct evidence for the functional importance of TCR:CD4.D3 interaction was obtained using an anti-CD3fos:anti-CD4jun-bispecific Ab. Surprisingly, it induced strong T cell activation in hybridomas transfected with cytoplasmic-tailless CD4, despite the lack of association with either p56lck or MHC class II molecules. However, this effect was completely abrogated with the CD4 mutants Q114A/F182A or F182A/F201A. These data demonstrate that TCR:CD4.D3 interaction can have a profound effect on T cell activation and obviates the need for receptor oligomerization.
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Affiliation(s)
- Dario A. A. Vignali
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
- †Department of Pathology, University of Tennessee Medical Center, Memphis, TN 38163
| | - Kate M. Vignali
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
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35
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Carson RT, Desai DD, Vignali KM, Vignali2 DAA. Cutting Edge: Immunoregulation of Th Cells by Naturally Processed Peptide Antagonists. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Th cells recognize protein Ags as short peptides bound to MHC class II molecules. Altered peptide ligands can antagonize (inhibit) T cell responses to stimulatory peptides. Peptides generated by APC may contain peptide flanking residues (PFR), which lie outside the minimal binding epitope and can be recognized by the TCR. Our data show that PFR-dependent T cells were found to be potently antagonized by peptides that lack PFR and responded poorly to native protein or the immunogenic epitope delivered by a recombinant influenza virus. These data provide the first evidence that Ag processing generates both stimulatory and antagonist peptides from a single immunogenic epitope, an observation that may have important implications for T cell immunoregulation and autoimmunity.
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Affiliation(s)
- Richard T. Carson
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
| | - Dharmesh D. Desai
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
| | - Kate M. Vignali
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
| | - Dario A. A. Vignali2
- *Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38101; and
- †Department of Pathology, University of Tennessee Medical Center, Memphis, TN 38163
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36
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Gugasyan R, Vidavsky I, Nelson CA, Gross ML, Unanue ER. Isolation and Quantitation of a Minor Determinant of Hen Egg White Lysozyme Bound to I-Ak by Using Peptide-Specific Immunoaffinity. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.11.6074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We report here the identification and quantitation of a minor epitope from hen egg white lysozyme (HEL) isolated from the class II MHC molecule I-Ak of APCs. We isolated and concentrated the peptides from the I-Ak extracts by a peptide-specific mAba, followed by their examination by electrospray mass spectrometry. This initial step improved the isolation, recovery, and quantitation and allowed us to identify 13 different minor peptides using the Ab specific for the HEL tryptic fragment 34–45. The HEL peptides varied on both the amino and carboxy termini. The shortest peptide was a 13-mer (residues 33–45), and the longest peptide was a 19-mer (residues 31–49). The two most abundant were 31–47 (1.3 pmol) and 31–46 (1 pmol), while the least abundant were 31–45 (40 fmol) and 32–45 (4 fmol). Only 0.3% of the total class II molecules were occupied by this family of HEL peptides. The amount of the 31–47 peptide, the predominant member of this series, was 22 times lower than that of 48–62, the major epitope of HEL. The 31–47 peptide bound about 20-fold weaker to I-Ak compared with the dominant 48–62 peptide. Thus, the lower abundance of the minor epitope correlated with its weaker binding strength.
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Affiliation(s)
- Raffi Gugasyan
- *Department of Pathology and Center for Immunology, Washington University School of Medicine, and
| | - Ilan Vidavsky
- †Department of Chemistry, Washington University, St. Louis, MO 63110
| | - Christopher A. Nelson
- *Department of Pathology and Center for Immunology, Washington University School of Medicine, and
| | - Michael L. Gross
- †Department of Chemistry, Washington University, St. Louis, MO 63110
| | - Emil R. Unanue
- *Department of Pathology and Center for Immunology, Washington University School of Medicine, and
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37
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Young SP, Epstein E, Potter V. Determinant capture by MHC class II DR3 during processing of mycobacteria leprae 65kD heat shock protein by human B cells. Hum Immunol 1998; 59:259-64. [PMID: 9619764 DOI: 10.1016/s0198-8859(98)00019-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Using T cell immunoblotting we have characterised the immunogenic fragments derived from the Mycobacteria Leprae 65kD heat shock protein that become associated with MHC class II DR3 during processing by a human B cell line. After 5 h incubation with antigen, a peptide of approximately 12kD (approximately 110 amino acids) was the only major fragment found associated with the class II MHC. The association of this oligopeptide was abolished if an excess of a synthetic peptide representing the minimal epitope was included in the culture or when cells were incubated at 4 degrees C. This suggests that the generation of this moiety is dependent on cell metabolism and that its binding to MHC is specific. This large fragment may represent an intermediate in the processing pathway, directly demonstrating the role of MHC in determinant capture during antigen degradation.
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Affiliation(s)
- S P Young
- Department of Rheumatology, University of Birmingham, UK.
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38
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Moudgil KD, Sercarz EE, Grewal IS. Modulation of the immunogenicity of antigenic determinants by their flanking residues. IMMUNOLOGY TODAY 1998; 19:217-20. [PMID: 9613039 DOI: 10.1016/s0167-5699(97)01233-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- K D Moudgil
- La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA
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39
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Malcherek G, Wirblich C, Willcox N, Rammensee HG, Trowsdale J, Melms A. MHC class II-associated invariant chain peptide replacement by T cell epitopes: engineered invariant chain as a vehicle for directed and enhanced MHC class II antigen processing and presentation. Eur J Immunol 1998; 28:1524-33. [PMID: 9603457 DOI: 10.1002/(sici)1521-4141(199805)28:05<1524::aid-immu1524>3.0.co;2-t] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Proteolysis of the invariant chain (li) leads to the generation of abundant MHC class II-associated invariant chain peptides (CLIP), which bind in the MHC class II binding groove via supermotifs in a manner similar to that of antigenic peptides. We have engineered an li vector with the capacity to express any antigenic peptide of interest instead of CLIP, for T cell stimulation. When peripheral blood mononuclear cells (PBMC) were pulsed with li hybrids encoding T cell epitopes of tetanus toxin or acetylcholine receptor, stimulation of T cells was dramatically enhanced compared to stimulation after priming with either the native or recombinant proteins. Site-specific insertion of antigenic sequences into the CLIP region promoted enhanced antigenicity of li hybrids which were shown to be processed intracellularly in a chloroquine-sensitive compartment. Naturally processed T helper epitopes were visualized directly on the surface of PBMC and identified as analogs of CLIP associated with MHC class II molecules. This novel li vector provides a flexible and efficient system for the delivery of defined peptide epitopes to T cells which might be useful in the development of specific vaccines and in the study of intracellular processing.
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MESH Headings
- Amino Acid Sequence
- Antigen Presentation/genetics
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/immunology
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/metabolism
- Genetic Vectors/chemical synthesis
- Genetic Vectors/immunology
- HLA-DR4 Antigen/metabolism
- Histocompatibility Antigens Class I/metabolism
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/immunology
- Histocompatibility Antigens Class II/metabolism
- Humans
- Intracellular Fluid/metabolism
- Lymphocyte Activation
- Molecular Sequence Data
- Protein Binding/genetics
- Protein Engineering
- Receptors, Cholinergic/genetics
- Receptors, Cholinergic/immunology
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Tetanus Toxin/genetics
- Tetanus Toxin/immunology
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Affiliation(s)
- G Malcherek
- Department of Neurology, University of Tübingen, Germany.
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40
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Lo-Man R, Langeveld JPM, Martineau P, Hofnung M, Meloen RH, Leclerc C. Immunodominance Does Not Result from Peptide Competition for MHC Class II Presentation. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.4.1759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
Competition for binding to MHC class II molecules between processed peptides derived from a single protein Ag is considered an important parameter leading to the presentation of a limited set of peptides by APCs. We tested the relevance of this competition process in a model Ag, the MalE protein, by deleting T cell epitopes or by introducing a competitor T cell peptide. We identified in DBA/1 (I-Aq) mice six immunodominant T cell determinants in the MalE sequence, 89–95, 116–123, 198–205, 211–219, 274–281, and 335–341. Synthetic peptides carrying these determinants were classified in three groups as weak, intermediate, or strong I-Aq binders in competition experiments with the PreS:T peptide of hepatitis B surface Ag. In vivo, synthetic MalE peptides with weak and intermediate MHC binding capacity were inhibited in their capacity to stimulate proliferative response in the presence of the PreS:T competitor peptide, whereas the strongest MHC binder was not. Strikingly, the insertion of the potent competitor PreS:T peptide into the MalE sequence, as a single copy or as four copies, did not inhibit the proliferative response to the six immunodominant peptides of the recipient protein. Moreover, deletion in the protein sequence disrupting either the weak (198–205) or strong (335–341) MHC binding determinant of MalE did not modify the proliferative response to the remaining T cell determinants as compared with wild-type MalE protein. Altogether, these results show that peptide competition for MHC binding may not represent the most important event in processes leading to immunodominance.
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Affiliation(s)
| | - Jan P. M. Langeveld
- ‡Institute for Animal Science and Health (ID-DLO), Lelystad, The Netherlands
| | - Pierre Martineau
- †Unité de Programmation Moléculaire et Toxicologie Génétique (CNRS-URA1444), Institut Pasteur, Paris, France; and
| | - Maurice Hofnung
- †Unité de Programmation Moléculaire et Toxicologie Génétique (CNRS-URA1444), Institut Pasteur, Paris, France; and
| | - Robert H. Meloen
- ‡Institute for Animal Science and Health (ID-DLO), Lelystad, The Netherlands
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41
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Van de Water J, Deininger SO, Macht M, Przybylski M, Gershwin ME. Detection of molecular determinants and epitope mapping using MALDI-TOF mass spectrometry. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1997; 85:229-35. [PMID: 9400622 DOI: 10.1006/clin.1997.4434] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J Van de Water
- Department of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California at Davis 95616, USA
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42
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Carson RT, Vignali KM, Woodland DL, Vignali DA. T cell receptor recognition of MHC class II-bound peptide flanking residues enhances immunogenicity and results in altered TCR V region usage. Immunity 1997; 7:387-99. [PMID: 9324359 DOI: 10.1016/s1074-7613(00)80360-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Naturally processed MHC class II-bound peptides possess ragged NH2 and COOH termini. It is not known whether these peptide flanking residues (PFRs), which lie outside the MHC anchor residues, are recognized by the TCR or influence immunogenicity. Here we analyzed T cell responses to the COOH-terminal PFR of the H-2A(k) immunodominant epitope of hen egg lysozyme (HEL) 52-61. Surprisingly, the majority of T cells were completely dependent on, and specific for, the COOH-terminal PFR of the immunogen. In addition, there were striking correlations between TCR V beta usage and PFR dependence. We hypothesize that the V alpha CDR1 region recognizes NH2-terminal PFRs, while the V beta CDR1 region recognizes COOH-terminal PFRs. Last, peptides containing PFRs were considerably more immunogenic and mediated a greater recall response to the HEL protein. These results demonstrate that PFRs, which are a unique characteristic of peptides bound to MHC class II molecules, can have a profound effect on TCR recognition and T cell function. These data may have important implications for peptide-based immunotherapy and vaccine development.
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Affiliation(s)
- R T Carson
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101, USA
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43
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Abstract
The hierarchy of display of determinants on a protein antigen is of critical importance with respect to which T cells will be selected during thymic development, as well as in the induction of mature responses. Activation of T cells will be dependent on unfolding, reduction and chain cleavage of the antigen, and the vagaries of competition with other determinants as well as hindrance in access to the major histocompatibility complex (MHC) or subsequently of the MHC/peptide complex to the T cell receptor. We here focus on a description of the parameters that determine the generation and display of determinants on MHC class II molecules by different types of antigen presenting cells in different locations.
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Affiliation(s)
- S C Schneider
- Department of Microbiology and Molecular Genetics, University of California-Los Angeles, USA
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44
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Nepom GT, Domeier ME, Ou D, Kovats S, Mitchell LA, Tingle AJ. Recognition of contiguous allele-specific peptide elements in the rubella virus E1 envelope protein. Vaccine 1997; 15:648-52. [PMID: 9178465 DOI: 10.1016/s0264-410x(96)00194-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Peptides which bind to human HLA-DRB1 class II molecules in an allele-specific fashion were derived from the immunodominant E1 envelope protein of rubella virus. Two nonoverlapping E1 peptide epitopes were recognized by rubella virus-specific T cells in the context of independent HLA alleles when presented either separately or as a contiguous polypeptide containing both epitopes. Direct binding analysis of potential peptide epitopes to distinct HLA molecules provides a direct approach for selecting antigenic peptides useful for epitope-based vaccine targeted to multiple HLA types.
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Affiliation(s)
- G T Nepom
- Virginia Mason Research Center, Seattle, WA 98101, USA
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45
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Wen R, Broussard DR, Surman S, Hogg TL, Blackman MA, Woodland DL. Carboxy-terminal residues of major histocompatibility complex class II-associated peptides control the presentation of the bacterial superantigen toxic shock syndrome toxin-1 to T cells. Eur J Immunol 1997; 27:772-81. [PMID: 9079821 DOI: 10.1002/eji.1830270328] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Previous studies have shown that the presentation of some bacterial superantigens by major histocompatibility complex (MHC) class II molecules is strongly influenced by class II-associated peptides. For example, presentation of the toxic shock syndrome toxin-1 (TSST-1) superantigen by antigen-processing-defective T2-I-Ab cells (which expresses I-Ab that is either empty or associated with invariant chain-derived peptides) can be strongly enhanced by some, but not other, I-Ab-binding peptides. Here we investigate the contribution of I-Ab-associated peptides in the presentation of TSST-1 to T cells. The data show that overlapping peptides expressing the same core I-Ab-restricted epitope, but with various N and C termini, can differ profoundly in their ability to promote TSST-1 presentation to T cells. Analysis of altered and truncated peptides indicates that residues at the C-terminal end of the peptide have a dramatic effect on TSST-1 presentation. This effect does not involve a cognate interaction between the peptide and the TSST-1 molecule, but appears to depend on the length of the C-terminal region. These data are consistent with crystallographic studies suggesting that TSST-1 may interact with the C-terminal residues of MHC class II-associated peptides. We also examined the capacity of naturally processed peptides to promote TSST-1 binding using a superantigen blocking assay. The data demonstrated that a naturally processed epitope is dominated by peptides that do not promote strong TSST-1 binding to I-Ab. Taken together, these data suggest that TSST-1 binding to MHC class II molecules is controlled by the C-terminal residues of the associated peptide, and that many naturally processed peptide/class II complexes do not present TSST-1 to T cells. Thus, the peptide dependence of TSST-1 binding to class II molecules may significantly reduce the capacity of TSST-1 to stimulate T cells.
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Affiliation(s)
- R Wen
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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46
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Diepolder HM, Jung MC, Wierenga E, Hoffmann RM, Zachoval R, Gerlach TJ, Scholz S, Heavner G, Riethmüller G, Pape GR. Anergic TH1 clones specific for hepatitis B virus (HBV) core peptides are inhibitory to other HBV core-specific CD4+ T cells in vitro. J Virol 1996; 70:7540-8. [PMID: 8892873 PMCID: PMC190822 DOI: 10.1128/jvi.70.11.7540-7548.1996] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A strong and transient hepatitis B virus core (HBc)-specific CD4+ T-cell response has been shown to be associated with viral elimination in acute self-limited hepatitis B but to be absent in chronic hepatitis B. So far, little is known about immunological mechanisms involved in the regulation of the HBc-specific CD4+ T-cell response. We studied 28 patients with acute hepatitis B, and frequently a sudden decrease in the HBc-specific CD4+ T-cell response was found between 4 and 8 weeks after disease onset. Thirty-two CD4+ T-cell clones specific for amino acids 50 to 69, 81 to 105, 117 to 131, or 141 to 165 of HBc were isolated from a patient shortly before the peripheral blood mononuclear cell response to most HBc-derived peptides abruptly disappeared. TH1 clones, but not TH0 clones, could be anergized in vitro by stimulation with specific peptides even in the presence of costimulatory cells. Moreover, when anergic cells were mixed with responsive cells, the proliferation of HBc-specific TH1 or TH0 clones was inhibited antigen specifically by anergic cells. The unusual susceptibility of HBc-specific TH1 clones to anergy induction in vitro as well as their potential to inhibit other HBc-specific TH1 and TH0 clones suggests that anergy induction may be involved in the downregulation of the virus-specific immune response during acute hepatitis B in vivo.
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Affiliation(s)
- H M Diepolder
- Institute for Immunology, University of Munich, Germany
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47
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Mendel Kerlero de Rosbo N, Ben-Nun A. Delineation of the minimal encephalitogenic epitope within the immunodominant region of myelin oligodendrocyte glycoprotein: diverse V beta gene usage by T cells recognizing the core epitope encephalitogenic for T cell receptor V beta b and T cell receptor V beta a H-2b mice. Eur J Immunol 1996; 26:2470-9. [PMID: 8898962 DOI: 10.1002/eji.1830261030] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The nature of the autoimmune T cell response to myelin oligodendrocyte glycoprotein (MOG), recently recognized as a potential target antigen in multiple sclerosis (MS), has not yet been characterized, in contrast to the T cell reactivity to other potential target antigens in MS such as myelin basic protein and proteolipid protein. Here, we show that the encephalitogenicity of the recombinant Ig-like domain of human MOG is associated, in H-2 b mice, with an immunodominant T cell reactivity against a single region of MOG spanning amino acids 35-55, accounting for the previously reported strong encephalitogenic activity of pMOG 35-55. A single injection of pMOG 35-55 with or without administration of pertussis toxin was sufficient to induce severe clinical experimental autoimmune encephalomyelitis (EAE) in H-2 b mice. Encephalitogenic pMOG 35-55-specific T cell lines derived from C3H.SW (V beta b) mice were diverse in their TCR V beta gene usage (V beta 1, V beta 6, V beta 8 and V beta 15), although V beta 8.2 was most predominantly expressed (48%). However, V beta 8 + T cells may only be part of the encephalitogenic MOG-specific T cell repertoire in H-2 b mice, as demonstrated by the susceptibility of C57L (V beta a) mice to disease induced by pMOG 35-55. Encephalitogenic T cell lines from V beta a mice were also diverse in their TCR V beta gene usage (V beta 1, V beta 2, V beta 6, V beta 14 and V beta 16). Such a heterogeneous TCT V beta gene expression by pMOG 35-55/I-A b-reactive T cells from both V beta a and V beta b H-2 b mice suggested multiple epitopes within pMOG 35-55. Analysis of the pattern of reactivity by pMOG 35-55-reactive T cells to a set of truncated peptides was not commensurate with independent nested epitopes, but revealed a requirement for recognition of a core sequence, YRSPFSRVV (pMOG 40-48). However, optimal stimulation was obtained with longer peptides, with each additional amino acid flanking either the N or the C terminus differentially increasing the stimulatory capacity of pMOG 40-48. Nonetheless, pMOG 40-48 was the minimal encephalitogenic epitope for both V beta a and V beta b mice. Thus, the T cell reactivity against the immunodominant encephalitogenic region of MOG is characterized by a diverse V beta gene usage and a requirement for the same core epitope. This pattern of reactivity may favor epitope-directed, rather than TCR-targeted, approaches to immunospecific therapy for MOG-related autoimmune disease.
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48
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Posch PE, Hurley CK, Geluk A, Ottenhoff TH. The impact of DR3 microvariation on peptide binding: the combinations of specific DR beta residues critical to binding differ for different peptides. Hum Immunol 1996; 49:96-105. [PMID: 8872163 DOI: 10.1016/0198-8859(96)00061-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
HLA-DR molecules are a group of highly polymorphic glycoprotein heterodimers that present peptide antigens to T lymphocytes for immune surveillance. To assess the significance of limited polymorphism on the functional differentiation of DR molecules, the binding of several immunogenic peptides to the DR3 microvariants [DR(alpha, beta 1*0302) and DR(alpha, beta 1*0301)] and to mutants of these DR3 molecules was examined. This analysis has shown that each residue (DR beta 26, DR beta 28, DR beta 47, and DR beta 86), which differentiates these two DR3 molecules, contributes to their functional distinction and that the relative contribution of each residue varies for different peptide/DR3 complexes. For example, DR beta 28 and DR beta 86 controlled the mycobacterium tuberculosis 65-kD heat shock protein peptides 3-13 and 4-15 (HSP) binding specificity to DR (alpha, beta 1*0301). [HSP does not bind to DR(alpha, beta 1*0302)], whereas DR beta 26, DR beta 28, and DR beta 86 controlled the influenza hemagglutinin peptide 306-318 (HA) binding specificity to DR(alpha, beta 1*0302). [HA does not bind to DR(alpha, beta 1*0301).] In comparison, DR beta 86 alone controlled the binding level difference of sperm whale myoglobin peptide 132-151 (SWM) and of myelin basic protein peptide 152-170 (MBP) [both bind to DR(alpha, beta 1*0301) at levels five times greater than to DR(alpha, beta 1*0302)] to the DR3 molecules. Although not critical, additional DR beta residues influenced the binding level of individual peptides of each of the DR3 molecules and, again, the combinations of these residues differed for different peptide/DR3 complexes. These data showed that individual DR residues vary in their relative contribution to the interaction between a specific DR molecule and different peptides and that limited polymorphism can create substantial differences in the peptide binding profiles among DR molecules.
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Affiliation(s)
- P E Posch
- Department of Microbiology and Immunology, Georgetown University School of Medicine, Washington, DC 20007, USA
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49
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Phelps RG, Turner AN, Rees AJ. Direct identification of naturally processed autoantigen-derived peptides bound to HLA-DR15. J Biol Chem 1996; 271:18549-53. [PMID: 8702503 DOI: 10.1074/jbc.271.31.18549] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Biochemical analysis of HLA class II-associated peptides from antigen-pulsed cells is a potentially useful approach to the analysis of antigen processing and presentation because it examines directly which antigen-derived peptides are presented. This is especially advantageous in the analysis of self-antigen presentation where conventional approaches utilizing antigen-specific T cells may be biased by the presence of self-tolerance. However, successful biochemical analysis has been reported for only one exogenous antigen and no autoantigens. We have used a novel analytical approach coupling biochemical data with the reported properties of class II-associated peptides to characterize the peptides derived from a clinically relevant autoantigen presented on the disease-associated class II type. Incubating the target of autoimmune attack in patients with Goodpasture's disease, the 230-amino acid NC1 domain of the alpha3 chain of type IV collagen (Goodpasture antigen, alpha3(IV)NC1), with human B cells homozygous for HLA-DR15, the allele carried by 80% of patients, we find that alpha3(IV)NC1 is presented as at least two sets of three to five peptides centered on common core sequences (nested sets). Synthetic peptides containing these core sequences bind to HLA-DR15 with intermediate affinity (IC50, 1.1-6 microM).
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Affiliation(s)
- R G Phelps
- Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, AB9 2ZD Scotland, United Kingdom
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50
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Larsen SL, Pedersen LO, Buus S, Stryhn A. T cell responses affected by aminopeptidase N (CD13)-mediated trimming of major histocompatibility complex class II-bound peptides. J Exp Med 1996; 184:183-9. [PMID: 8691132 PMCID: PMC2192675 DOI: 10.1084/jem.184.1.183] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Endocytosed protein antigens are believed to be fragmented in what appears to be a balance between proteolysis and MHC-mediated epitope protection, and the resulting peptide-MHC complexes are transported to the surface of the antigen-presenting cells (APC) and presented to T cells. The events that lead to antigenic peptide generation and the compartments where antigen processing takes place remains somewhat enigmatic. The importance of intracellular antigen processing has been well established; however, it is unclear whether additional processing occurs at the APC surface. To follow antigen processing, we have identified a pair of T cell hybridomas that recognize a long vs. a short version of the same epitope. We have used prefixed APC and various protease inhibitors to demonstrate that the APC surface has a considerable potential for antigen processing. Specific antibodies further identified the exopeptidase Aminopeptidase N (APN, CD13) as one of the enzymes involved in the observed cell-surface antigen processing. The NH2-terminal end of the longer peptide could, even while bound to major histocompatibility complex (MHC) class II molecules, be digested by APN with dramatic consequences for T cell antigen recognition. This could be demonstrated both in cell-free systems using purified reagents and in cellular systems. Thus, MHC class II and APN may act in concert to generate the final T cell epitopes.
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Affiliation(s)
- S L Larsen
- Department of Experimental Immunology, University of Copenhagen, Denmark
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