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Mazzoccoli L, Liu B. Dendritic Cells in Shaping Anti-Tumor T Cell Response. Cancers (Basel) 2024; 16:2211. [PMID: 38927916 PMCID: PMC11201542 DOI: 10.3390/cancers16122211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Among professional antigen-presenting cells, dendritic cells (DCs) orchestrate innate and adaptive immunity and play a pivotal role in anti-tumor immunity. DCs are a heterogeneous population with varying functions in the tumor microenvironment (TME). Tumor-associated DCs differentiate developmentally and functionally into three main subsets: conventional DCs (cDCs), plasmacytoid DCs (pDCs), and monocyte-derived DCs (MoDCs). There are two major subsets of cDCs in TME, cDC1 and cDC2. cDC1 is critical for cross-presenting tumor antigens to activate cytotoxic CD8+ T cells and is also required for priming earlier CD4+ T cells in certain solid tumors. cDC2 is vital for priming anti-tumor CD4+ T cells in multiple tumor models. pDC is a unique subset of DCs and produces type I IFN through TLR7 and TLR9. Studies have shown that pDCs are related to immunosuppression in the TME through the secretion of immunosuppressive cytokines and by promoting regulatory T cells. MoDCs differentiate separately from monocytes in response to inflammatory cues and infection. Also, MoDCs can cross-prime CD8+ T cells. In this review, we summarize the subsets and functions of DCs. We also discuss the role of different DC subsets in shaping T cell immunity in TME and targeting DCs for potential immunotherapeutic benefits against cancer.
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Affiliation(s)
- Luciano Mazzoccoli
- Division of Hematology, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA;
- The Pelotonia Institute for Immuno-Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Bei Liu
- Division of Hematology, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA;
- The Pelotonia Institute for Immuno-Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
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2
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Zogopoulos VL, Malatras A, Kyriakidis K, Charalampous C, Makrygianni EA, Duguez S, Koutsi MA, Pouliou M, Vasileiou C, Duddy WJ, Agelopoulos M, Chrousos GP, Iconomidou VA, Michalopoulos I. HGCA2.0: An RNA-Seq Based Webtool for Gene Coexpression Analysis in Homo sapiens. Cells 2023; 12:cells12030388. [PMID: 36766730 PMCID: PMC9913097 DOI: 10.3390/cells12030388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/09/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Genes with similar expression patterns in a set of diverse samples may be considered coexpressed. Human Gene Coexpression Analysis 2.0 (HGCA2.0) is a webtool which studies the global coexpression landscape of human genes. The website is based on the hierarchical clustering of 55,431 Homo sapiens genes based on a large-scale coexpression analysis of 3500 GTEx bulk RNA-Seq samples of healthy individuals, which were selected as the best representative samples of each tissue type. HGCA2.0 presents subclades of coexpressed genes to a gene of interest, and performs various built-in gene term enrichment analyses on the coexpressed genes, including gene ontologies, biological pathways, protein families, and diseases, while also being unique in revealing enriched transcription factors driving coexpression. HGCA2.0 has been successful in identifying not only genes with ubiquitous expression patterns, but also tissue-specific genes. Benchmarking showed that HGCA2.0 belongs to the top performing coexpression webtools, as shown by STRING analysis. HGCA2.0 creates working hypotheses for the discovery of gene partners or common biological processes that can be experimentally validated. It offers a simple and intuitive website design and user interface, as well as an API endpoint.
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Affiliation(s)
- Vasileios L. Zogopoulos
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Section of Cell Biology and Biophysics, Department of Biology, National and Kapodistrian University of Athens, 15701 Athens, Greece
| | - Apostolos Malatras
- Biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, 2029 Nicosia, Cyprus
| | - Konstantinos Kyriakidis
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Chrysanthi Charalampous
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Evanthia A. Makrygianni
- University Research Institute of Maternal and Child Health and Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Stéphanie Duguez
- Personalised Medicine Centre, School of Medicine, Ulster University, Derry-Londonderry BT47 6SB, UK
| | - Marianna A. Koutsi
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Marialena Pouliou
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Christos Vasileiou
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Engineering Design and Computing Laboratory, ETH Zurich, 8092 Zurich, Switzerland
| | - William J. Duddy
- Personalised Medicine Centre, School of Medicine, Ulster University, Derry-Londonderry BT47 6SB, UK
| | - Marios Agelopoulos
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - George P. Chrousos
- University Research Institute of Maternal and Child Health and Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Vassiliki A. Iconomidou
- Section of Cell Biology and Biophysics, Department of Biology, National and Kapodistrian University of Athens, 15701 Athens, Greece
| | - Ioannis Michalopoulos
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Correspondence:
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3
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Regulation of the BCR signalosome by the class II peptide editor, H2-M, affects the development and repertoire of innate-like B cells. Cell Rep 2022; 38:110200. [DOI: 10.1016/j.celrep.2021.110200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 09/23/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
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4
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Liu B, Feng S, Dairi G, Guan Q, Chafeeva I, Wang H, Liggins R, da Roza G, Kizhakkedathu JN, Du C. Transcriptome analysis of signaling pathways of human peritoneal mesothelial cells in response to different osmotic agents in a peritoneal dialysis solution. BMC Nephrol 2019; 20:181. [PMID: 31113397 PMCID: PMC6528310 DOI: 10.1186/s12882-019-1376-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 05/08/2019] [Indexed: 02/05/2023] Open
Abstract
Background Glucose is a primary osmotic agent in peritoneal dialysis (PD) solutions, but its long-term use causes structural alteration of the peritoneal membrane (PM). Hyperbranched polyglycerol (HPG) is a promising alternative to glucose. This study was designed to compare the cellular responses of human peritoneal mesothelial cells (HPMCs) to these two different osmotic agents in a hypertonic solution using transcriptome analysis. Methods Cultured HPMCs were repeatedly exposed to HPG-based or Physioneal 40 (PYS, glucose 2.27%) hypertonic solutions. Transcriptome datasets were produced using Agilent SurePrint G3 Human GE 8 × 60 microarray. Cellular signaling pathways were examined by Ingenuity Pathway Analysis (IPA). Protein expression was examined by flow cytometry analysis and Western blotting. Results The HPG-containing solution was better tolerated compared with PYS, with less cell death and disruption of cell transcriptome. The levels of cell death in HPG- or PYS- exposed cells were positively correlated with the number of affected transcripts (HPG: 128 at day 3, 0 at day 7; PYS: 1799 at day 3, 212 at day 7). In addition to more affected “biosynthesis” and “cellular stress and death” pathways by PYS, both HPG and PYS commonly affected “sulfate biosynthesis”, “unfolded protein response”, “apoptosis signaling” and “NRF2-mediated oxidative stress response” pathways at day 3. PYS significantly up-regulated HLA-DMB and MMP12 in a time-dependent manner, and stimulated T cell adhesion to HPMCs. Conclusion The lower cytotoxicity of hypertonic HPG solution is in agreement with its transient and minimal impact on the pathways for the “biosynthesis of cell constituents” and the “cellular stress and death”. The significant up-regulation of HLA-DMB and MMP12 by PYS may be part of its initiation of immune response in the PM.
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Affiliation(s)
- Bin Liu
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.,General Hospital of Tianjin Medical University, No.154 Anshan Road, Heping District, Tianjin, 300052, China
| | - Shijian Feng
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.,Department of Urology, and Laboratory of Reconstructive Urology at the Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ghida Dairi
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.,Medicine and Medical Sciences Research Center, Deanship of Scientific Research, Umm Al Qura University, Mecca, Saudi Arabia
| | - Qiunong Guan
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Irina Chafeeva
- Centre for Blood Research, and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Hao Wang
- General Hospital of Tianjin Medical University, No.154 Anshan Road, Heping District, Tianjin, 300052, China
| | - Richard Liggins
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Gerald da Roza
- Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jayachandran N Kizhakkedathu
- Centre for Blood Research, and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Caigan Du
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada. .,Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC, V6H 3Z6, Canada.
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Dingman R, Balu-Iyer SV. Immunogenicity of Protein Pharmaceuticals. J Pharm Sci 2019; 108:1637-1654. [PMID: 30599169 PMCID: PMC6720129 DOI: 10.1016/j.xphs.2018.12.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 02/07/2023]
Abstract
Protein therapeutics have drastically changed the landscape of treatment for many diseases by providing a regimen that is highly specific and lacks many off-target toxicities. The clinical utility of many therapeutic proteins has been undermined by the potential development of unwanted immune responses against the protein, limiting their efficacy and negatively impacting its safety profile. This review attempts to provide an overview of immunogenicity of therapeutic proteins, including immune mechanisms and factors influencing immunogenicity, impact of immunogenicity, preclinical screening methods, and strategies to mitigate immunogenicity.
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Affiliation(s)
- Robert Dingman
- Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, New York 14214
| | - Sathy V Balu-Iyer
- Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, New York 14214.
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6
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Wang E, Adams S, Stroncek DF, Marincola FM. Human Leukocyte Antigen and Human Neutrophil Antigen Systems. Hematology 2018. [DOI: 10.1016/b978-0-323-35762-3.00113-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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7
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Hofmann MJ, Bracamonte SE, Eizaguirre C, Barluenga M. Molecular characterization of MHC class IIB genes of sympatric Neotropical cichlids. BMC Genet 2017; 18:15. [PMID: 28201988 PMCID: PMC5310070 DOI: 10.1186/s12863-017-0474-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/13/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The Major Histocompatibility Complex (MHC) is a key component of the adaptive immune system of all vertebrates and consists of the most polymorphic genes known to date. Due to this complexity, however, MHC remains to be characterized in many species including any Neotropical cichlid fish. Neotropical crater lake cichlids are ideal models to study evolutionary processes as they display one of the most convincing examples of sympatric and repeated parallel radiation events within and among isolated crater lakes. RESULTS Here, we characterized the genes of MHC class IIB chain of the Midas cichlid species complex (Amphilophus cf. citrinellus) including fish from five lakes in Nicaragua. We designed 19 new specific primers anchored in a stepwise fashion in order to detect all alleles present. We obtained 866 genomic DNA (gDNA) sequences from thirteen individuals and 756 additional sequences from complementary DNA (cDNA) of seven of those individuals. We identified 69 distinct alleles with up to 25 alleles per individual. We also found considerable intron length variation and mismatches of alleles detected in cDNA and gDNA suggesting that some loci have undergone pseudogenization. Lastly, we created a model of protein structure homology for each allele and identified their key structural components. CONCLUSIONS Overall, the Midas cichlid has one of the most diverse repertoires of MHC class IIB genes known, which could serve as a powerful tool to elucidate the process of divergent radiations, colonization and speciation in sympatry.
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Affiliation(s)
- Melinda J Hofmann
- Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal, 2, 28006, Madrid, Spain
| | - Seraina E Bracamonte
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Duesternbrooker weg 20, 24105, Kiel, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany
| | - Christophe Eizaguirre
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Duesternbrooker weg 20, 24105, Kiel, Germany
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
| | - Marta Barluenga
- Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal, 2, 28006, Madrid, Spain.
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8
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Rosskopf S, Jutz S, Neunkirchner A, Candia MR, Jahn-Schmid B, Bohle B, Pickl WF, Steinberger P. Creation of an engineered APC system to explore and optimize the presentation of immunodominant peptides of major allergens. Sci Rep 2016; 6:31580. [PMID: 27539532 PMCID: PMC4990899 DOI: 10.1038/srep31580] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/26/2016] [Indexed: 01/08/2023] Open
Abstract
We have generated engineered APC to present immunodominant peptides derived from the major aero-allergens of birch and mugwort pollen, Bet v 1142-153 and Art v 125-36, respectively. Jurkat-based T cell reporter lines expressing the cognate allergen-specific T cell receptors were used to read out the presentation of allergenic peptides on the engineered APC. Different modalities of peptide loading and presentation on MHC class II molecules were compared. Upon exogenous loading with allergenic peptides, the engineered APC elicited a dose-dependent response in the reporter T cells and the presence of chemical loading enhancers strongly increased reporter activation. Invariant chain-based MHC class II targeting strategies of endogenously expressed peptides resulted in stronger activation of the reporters than exogenous loading. Moreover, we used Bet v 1 as model allergen to study the ability of K562 cells to present antigenic peptides derived from whole proteins either taken up or endogenously expressed as LAMP-1 fusion protein. In both cases the ability of these cells to process and present peptides derived from whole proteins critically depended on the expression of HLA-DM. We have identified strategies to achieve efficient presentation of allergenic peptides on engineered APC and demonstrate their use to stimulate T cells from allergic individuals.
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Affiliation(s)
- Sandra Rosskopf
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Sabrina Jutz
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Alina Neunkirchner
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Martín R Candia
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Beatrice Jahn-Schmid
- Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Barbara Bohle
- Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Winfried F Pickl
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Peter Steinberger
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
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9
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Lei W, Fang W, Lin Q, Zhou X, Chen X. Characterization of a non-classical MHC class II gene in the vulnerable Chinese egret (Egretta eulophotes). Immunogenetics 2015; 67:463-72. [PMID: 26033691 DOI: 10.1007/s00251-015-0846-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/16/2015] [Indexed: 11/28/2022]
Abstract
Genes of the major histocompatibility complex (MHC) are valuable makers of adaptive genetic variation in evolutionary ecology research, yet the non-classical MHC genes remain largely unstudied in wild vertebrates. In this study, we have characterized the non-classical MHC class II gene, Egeu-DAB4, in the vulnerable Chinese egret (Ciconiiformes, Ardeidae, Egretta eulophotes). Gene expression analyses showed that Egeu-DAB4 gene had a restricted tissue expression pattern, being expressed in seven examined tissues including the liver, heart, kidney, esophagus, stomach, gallbladder, and intestine, but not in muscle. With respect to polymorphism, only one allele of exon 2 was obtained from Egeu-DAB4 using asymmetric PCR, indicating that Egeu-DAB4 is genetically monomorphic in exon 2. Comparative analyses showed that Egeu-DAB4 had an unusual sequence, with amino acid differences suggesting that its function may differ from those of classical MHC genes. Egeu-DAB4 gene was only found in 30.56-36.56 % of examined Chinese egret individuals. Phylogenetic analysis showed a closer relationship between Egeu-DAB4 and the DAB2 genes in nine other ardeid species. These new findings provide a foundation for further studies to clarify the immunogenetics of non-classical MHC class II gene in the vulnerable Chinese egret and other ciconiiform birds.
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Affiliation(s)
- Wei Lei
- Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China,
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10
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Birkholz J, Doganci A, Darstein C, Gehring S, Zepp F, Meyer CU. IL-27 improves migrational and antiviral potential of CB dendritic cells. Hum Immunol 2014; 75:584-91. [PMID: 24530744 DOI: 10.1016/j.humimm.2014.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 01/03/2014] [Accepted: 02/04/2014] [Indexed: 11/18/2022]
Abstract
Interleukin (IL)-27 is known to be increased considerably in cord blood (CB) dendritic cells (DCs) after TLR ligation. Previously, we demonstrated that also basal IL-27 levels are higher in CB DCs. Here, we examined effects of IL-27 on monocyte derived dendritic cells (moDCs) to approach its particular role in the specialized immune system of the human neonate. Exogenous IL-27 promotes IL-27 transcription in CB and adult blood (AB) moDCs. IL-27 acts on CB moDCs primarily by significantly augmenting IL-27 protein, secondarily by increasing transcription of CXCL10 among other chemokines, chemokine receptor CCR1, interferon stimulated genes, transcription factor IRF8 and genes involved in antigen presentation. Furthermore, CB moDCs respond to IL-27 with augmented IL-8 and Tumor necrosis factor (TNF)-α. The results suggest that IL-27 enhances migrational and antiviral properties of CB dendritic cells.
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Affiliation(s)
- Julia Birkholz
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany.
| | - Aysefa Doganci
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany
| | - Claudia Darstein
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany
| | - Stephan Gehring
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany
| | - Fred Zepp
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany
| | - Claudius U Meyer
- Pediatric Immunology Mainz, Children's Hospital, Medical Center of the Johannes Gutenberg University Mainz, Germany
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11
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Hablützel PI, Volckaert FAM, Hellemans B, Raeymaekers JAM. Differential modes of MHC class IIB gene evolution in cichlid fishes. Immunogenetics 2013; 65:795-809. [PMID: 23989891 DOI: 10.1007/s00251-013-0725-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 07/29/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Pascal I Hablützel
- Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Ch. Deberiotstraat, 32, B-3000, Leuven, Belgium,
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12
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HLA-DO increases bacterial superantigen binding to human MHC molecules by inhibiting dissociation of class II-associated invariant chain peptides. Hum Immunol 2013; 74:1280-7. [PMID: 23756162 DOI: 10.1016/j.humimm.2013.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 05/17/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022]
Abstract
HLA-DO (H2-O in mice) is an intracellular non-classical MHC class II molecule (MHCII). It forms a stable complex with HLA-DM (H2-M in mice) and shapes the MHC class II-associated peptide repertoire. Here, we tested the impact of HLA-DO and H2-O on the binding of superantigens (SAgs), which has been shown previously to be sensitive to the structural nature of the class II-bound peptides. We found that the binding of staphylococcal enterotoxin (SE) A and B, as well as toxic shock syndrome toxin 1 (TSST-1), was similar on the HLA-DO(+) human B cell lines 721.45 and its HLA-DO(-) counterpart. However, overexpressing HLA-DO in MHC class II(+) HeLa cells (HeLa-CIITA-DO) improved binding of SEA and TSST-1. Accordingly, knocking down HLA-DO expression using specific siRNAs decreased SEA and TSST-1 binding. We tested directly the impact of the class II-associated invariant chain peptide (CLIP), which dissociation from MHC class II molecules is inhibited by overexpressed HLA-DO. Loading of synthetic CLIP on HLA-DR(+) cells increased SEA and TSST-1 binding. Accordingly, knocking down HLA-DM had a similar effect. In mice, H2-O deficiency had no impact on SAgs binding to isolated splenocytes. Altogether, our results demonstrate that the sensitivity of SAgs to the MHCII-associated peptide has physiological basis and that the effect of HLA-DO on SEA and TSST-1 is mediated through the inhibition of CLIP release.
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13
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Painter CA, Stern LJ. Conformational variation in structures of classical and non-classical MHCII proteins and functional implications. Immunol Rev 2013; 250:144-57. [PMID: 23046127 DOI: 10.1111/imr.12003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent structural characterizations of classical and non-classical major histocompatibility complex class II (MHCII) proteins have provided a view into the dynamic nature of the MHCII-peptide binding groove and the role that structural changes play in peptide loading processes. Although there have been numerous reports of crystal structures for MHCII-peptide complexes, a detailed analysis comparing all the structures has not been reported, and subtle conformational variations present in these structures may not have been fully appreciated. We compared the 91 MHCII crystal structures reported in the PDB to date, including an HLA-DR mutant particularly susceptible to DM-mediated peptide exchange, and reviewed experimental and computational studies of the effect of peptide binding on MHCII structure. These studies provide evidence for conformational lability in and around the α-subunit 3-10 helix at residues α48-51, a region known to be critical for HLA-DM-mediated peptide exchange. A biophysical study of MHC-peptide hydrogen bond strengths and a recent structure of the non-classical MHCII protein HLA-DO reveal changes in the same region. Conformational variability was observed also in the vicinity of a kink in the β-subunit helical region near residue β66 and in the orientation and loop conformation in the β2 Ig domain. Here, we provide an overview of the regions within classical and non-classical MHCII proteins that display conformational changes and the potential role that these changes may have in the peptide loading/exchange process.
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Affiliation(s)
- Corrie A Painter
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, USA
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14
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Chazara O, Tixier-Boichard M, Morin V, Zoorob R, Bed’Hom B. Organisation and diversity of the class II DM region of the chicken MHC. Mol Immunol 2011; 48:1263-71. [DOI: 10.1016/j.molimm.2011.03.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 02/20/2011] [Accepted: 03/14/2011] [Indexed: 01/14/2023]
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Abstract
BACKGROUND INFORMATION DC (dendritic cells) continuously capture pathogens and process them into small peptides within the endolysosomal compartment, the MIIC (MHC class II-containing compartment). In MIICs peptides are loaded on to MHC class II and rapidly redistributed to the cell surface. This redistribution is accompanied by profound changes of the MIICs into tubular structures. An emerging concept is that MIIC tubulation provides a means to transport MHC class II-peptide complexes to the cell surface, either directly or through vesicular intermediates. To obtain spatial information on the reorganization of the MIICs during DC maturation, we performed electron tomography on cryo-immobilized and freeze-substituted mouse DCs after stimulation with LPS (lipopolysaccharide). RESULTS In non-stimulated DCs, MIICs are mostly spherical. After 3 h of LPS stimulation, individual MIICs transform into tubular structures. Three-dimensional reconstruction showed that the MIICs frequently display fusion profiles and after 6 h of LPS stimulation, MIICs become more interconnected, thereby creating large MIIC reticula. Microtubules and microfilaments align these MIICs and reveal physical connections. In our tomograms we also identified a separate population of MIIC-like intermediates, particularly at extended ends of MIIC tubules and in close proximity to the trans-Golgi network. No fusion events were captured between reticular MIICs and the plasma membrane. CONCLUSIONS Our results indicate that MIICs have the capacity to fuse together, whereby the cytoskeleton possibly provides a scaffold for the MIIC shape change and directionality. MIIC-like intermediates may represent MHC class II carriers.
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16
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Weaver JM, Sant AJ. Understanding the focused CD4 T cell response to antigen and pathogenic organisms. Immunol Res 2009; 45:123-43. [PMID: 19198764 DOI: 10.1007/s12026-009-8095-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Immunodominance is a term that reflects the final, very limited peptide specificity of T cells that are elicited during an immune response. Recent experiments in our laboratory compel us to propose a new paradigm for the control of immunodominance in CD4 T cell responses, stating that immunodominance is peptide-intrinsic and is dictated by the off-rate of peptides from MHC class II molecules. Our studies have revealed that persistence of peptide:class II complexes both predicts and controls CD4 T cell immunodominance and that this parameter can be rationally manipulated to either promote or eliminate immune responses. Mechanistically, we have determined that DM editing in APC is a key event that is influenced by the kinetic stability of class II:peptide complexes and that differential persistence of complexes also impacts the expansion phase of the immune response. These studies have important implications for rational vaccine design and for understanding the immunological mechanisms that limit the specificity of CD4 T cell responses.
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Affiliation(s)
- Jason M Weaver
- David H. Smith Center for Vaccine Biology and Immunology, AaB Institute of Biomedical Sciences, Department of Microbiology and Immunology, University of Rochester, NY 14642, USA
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17
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Zhang H, Hong H, Li D, Ma S, Di Y, Stoten A, Haig N, Di Gleria K, Yu Z, Xu XN, McMichael A, Jiang S. Comparing pooled peptides with intact protein for accessing cross-presentation pathways for protective CD8+ and CD4+ T cells. J Biol Chem 2009; 284:9184-91. [PMID: 19193636 DOI: 10.1074/jbc.m809456200] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To better understand the mechanisms of intracellular trafficking and presentation of exogenous peptides by antigen-presenting cells (APC), we compared the handling of overlapping 24-mer peptides from HIV Nef either mixed or covalently linked in tandem in one protein. Once internalized, peptides trafficked not only to endosomes but also to cytosol, and activated CD8(+) and CD4(+) T cells. In contrast, whole protein was found to traffic only to the endosomal compartments, and primarily activated CD4(+) T cells. Finally, with adjuvant, overlapping peptides were capable of protecting against lethal viral challenge, whereas the intact protein was less protective. These data suggest that overlapping long peptides are cross-presented through more varied intracellular routes and are more efficient in priming protective immunity than the whole protein.
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Affiliation(s)
- Hongwei Zhang
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, United Kingdom
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18
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Yaneva R, Springer S, Zacharias M. Flexibility of the MHC class II peptide binding cleft in the bound, partially filled, and empty states: A molecular dynamics simulation study. Biopolymers 2009; 91:14-27. [DOI: 10.1002/bip.21078] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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19
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Sofra V, Mansour S, Liu M, Gao B, Primpidou E, Wang P, Li S. Antigen-loaded ER microsomes from APC induce potent immune responses against viral infection. Eur J Immunol 2008; 39:85-95. [DOI: 10.1002/eji.200838443] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Harstad H, Lukacs MF, Bakke HG, Grimholt U. Multiple expressed MHC class II loci in salmonids; details of one non-classical region in Atlantic salmon (Salmo salar). BMC Genomics 2008; 9:193. [PMID: 18439319 PMCID: PMC2386828 DOI: 10.1186/1471-2164-9-193] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Accepted: 04/28/2008] [Indexed: 11/18/2022] Open
Abstract
Background In teleosts, the Major Histocompatibility Complex (MHC) class I and class II molecules reside on different linkage groups as opposed to tetrapods and shark, where the class I and class II genes reside in one genomic region. Several teleost MHC class I regions have been sequenced and show varying number of class I genes. Salmonids have one major expressed MHC class I locus (UBA) in addition to varying numbers of non-classical genes. Two other more distant lineages are also identifyed denoted L and ZE. For class II, only one major expressed class II alpha (DAA) and beta (DAB) gene has been identified in salmonids so far. Results We sequenced a genomic region of 211 kb encompassing divergent MHC class II alpha (Sasa-DBA) and beta (Sasa-DBB) genes in addition to NRGN, TIPRL, TBCEL and TECTA. The region was not linked to the classical class II genes and had some synteny to genomic regions from other teleosts. Two additional divergent and expressed class II sequences denoted DCA and DDA were also identified in both salmon and trout. Expression patterns and lack of polymorphism make these genes non-classical class II analogues. Sasa-DBB, Sasa-DCA and Sasa-DDA had highest expression levels in liver, hindgut and spleen respectively, suggestive of distinctive functions in these tissues. Phylogenetic studies revealed more yet undescribed divergent expressed MHC class II molecules also in other teleosts. Conclusion We have characterised one genomic region containing expressed non-classical MHC class II genes in addition to four other genes not involved in immune function. Salmonids contain at least two expressed MHC class II beta genes and four expressed MHC class II alpha genes with properties suggestive of new functions for MHC class II in vertebrates. Collectively, our data suggest that the class II is worthy of more elaborate studies also in other teleost species.
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Affiliation(s)
- Håvard Harstad
- Department of Basic Science and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway.
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21
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Nanda NK, Bikoff EK. DM peptide-editing function leads to immunodominance in CD4 T cell responses in vivo. THE JOURNAL OF IMMUNOLOGY 2006; 175:6473-80. [PMID: 16272301 DOI: 10.4049/jimmunol.175.10.6473] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DM functions as a peptide editor for MHC class II-bound peptides. We examined the hypothesis that DM peptide editing plays a key role in focusing the in vivo CD4 T cell responses against complex pathogens and protein Ags to only one, or at most a few, immunodominant peptides. Most CD4 T cells elicited in the wild-type BALB/c (H-2d) mice infected with Leishmania major predominantly recognize a single epitope 158-173 within Leishmania homologue of activated receptor for c-kinase (LACK), as is the case when these mice are immunized with rLACK. Using DM-deficient (DM-/-) H-2d mice, we now show that in the absence of DM, the in vivo CD4 T cell responses to rLACK are skewed away from the immunodominant epitopes and are diversified to include two novel epitopes (LACK 33-48 and 261-276). DM-/- B10.BR (H-2k) mice showed similar results. These results constitute the first demonstration of the role of DM peptide editing in sculpting the specificity and immunodominance in in vivo CD4 T cell responses.
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Affiliation(s)
- Navreet K Nanda
- Departments of Microbiology and Immunology, and Oncology, Lombardi Cancer Center, Georgetown University Medical Center, Washington DC 20057, USA.
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22
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Hansen TH, Lybarger L, Yu L, Mitaksov V, Fremont DH. Recognition of open conformers of classical MHC by chaperones and monoclonal antibodies. Immunol Rev 2005; 207:100-11. [PMID: 16181330 DOI: 10.1111/j.0105-2896.2005.00315.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is considerable evidence that the conformation and stability of class I and class II major histocompatibility complex (MHC) proteins is dependent upon high-affinity peptide ligation, but structural data for an empty MHC protein unfortunately is lacking. However, several monoclonal antibodies (mAbs) that specifically detect open MHC conformers have been characterized, and they provide insights into the changes associated with peptide loading and unloading. Here, the structural changes make the argument that certain of these open conformer-specific mAbs recognize analogous MHC segments as the molecular chaperones tapasin and DM. MHC residues located in regions flanking the peptide-terminal anchoring pockets have been implicated in both chaperone and monoclonal antibody binding. Indeed, we propose these regions serve as peptide-binding hinges that are uniquely accessible in open MHC.
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Affiliation(s)
- Ted H Hansen
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA.
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23
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Sant AJ, Chaves FA, Jenks SA, Richards KA, Menges P, Weaver JM, Lazarski CA. The relationship between immunodominance, DM editing, and the kinetic stability of MHC class II:peptide complexes. Immunol Rev 2005; 207:261-78. [PMID: 16181342 DOI: 10.1111/j.0105-2896.2005.00307.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Immunodominance refers to the restricted antigen specificity of T cells detected in the immune response after immunization with complex antigens. Despite the presence of many potential peptide epitopes within these immunogens, the elicited T-cell response apparently focuses on a very limited number of peptides. Over the last two decades, a number of distinct explanations have been put forth to explain this very restricted specificity of T cells, many of which suggest that endosomal antigen processing restricts the array of peptides available to recruit CD4 T cells. In this review, we present evidence from our laboratory that suggest that immunodominance in CD4 T-cell responses is primarily due to an intrinsic property of the peptide:class II complexes. The intrinsic kinetic stability of peptide:class II complexes controls DM editing within the antigen-presenting cells and thus the initial epitope density on priming dendritic cells. Additionally, we hypothesize that peptides that possess high kinetic stability interactions with class II molecules display persistence at the cell surface over time and will more efficiently promote T-cell signaling and differentiation than competing, lower-stability peptides contained within the antigen. We discuss this model in the context of the existing data in the field of immunodominance.
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Affiliation(s)
- Andrea J Sant
- David H. Smith Center for Vaccine Biology and Immunology, Aab Institute and Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA.
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24
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Abstract
Peptide loading of major histocompatibility class II molecules is catalyzed in late endosomal and lysosomal compartments of cells by the catalytic action of human leukocyte antigen (HLA)-DM (H-2M in mice). In B cells, dendritic cells and thymic epithelial cells, the peptide loading of class II molecules is modified by the expression of the non-classical class II molecule, HLA-DO (H-2O in mice). Collectively, studies to date support that DO/H-2O expression inhibits the presentation of antigens acquired by cells via fluid phase endocytosis. However, in B cells, the expression of H-2O promotes the presentation of antigens internalized by the B-cell receptor. In this review, we summarize the literature pertaining to DO assembly, transport, and function, with an emphasis on the function of DO/H-2O.
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Affiliation(s)
- Lisa K Denzin
- Sloan-Kettering Institute, Immunology Program, Memorial Sloan-Kettering Cancer Center, NY 10021, USA.
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25
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Ballingall KT, McKeever DJ. Conservation of promoter, coding and intronic regions of the non-classical MHC class II DYA gene suggests evolution under functional constraints. Anim Genet 2005; 36:237-9. [PMID: 15932405 DOI: 10.1111/j.1365-2052.2005.01281.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The major histocompatibility complex (MHC) in ruminants contains a unique pair of class II genes (DYA and DYB) of unknown function. As functional genes show higher levels of nucleotide conservation than pseudogenes we compared the DYA genes from sheep and cattle, two species which diverged from a common ancestor approximately 20 million years ago. Comparative analysis identified levels of nucleotide conservation in immediate promoter (97%), coding (94%) and intronic regions (91%) comparable with functional MHC genes. The Ovar-DYA transcript revealed an open reading frame encoding a 288 amino acid protein compared with a 253 amino acid protein associated with the BoLA-DYA transcript. A dinucleotide deletion in exon 4 of the Ovar-DYA transcript combined with alternative exon 5 splice sites introduces unusual diversity to the cytoplasmic domain of the Ovar-DYalpha polypeptide. The degree of conservation between these class II MHC genes is consistent with evolution under purifying selection suggesting that these genes retain a unique function in ruminants.
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Affiliation(s)
- K T Ballingall
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 OPZ, UK.
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26
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Peters NC, Hamilton DH, Bretscher PA. Analysis of cytokine-producing Th cells from hen egg lysozyme-immunized mice reveals large numbers specific for "cryptic" peptides and different repertoires among different Th populations. Eur J Immunol 2005; 35:56-65. [PMID: 15597327 DOI: 10.1002/eji.200425581] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We employed an optimized ex vivo enzyme-linked immunospot assay for enumerating and defining the peptide specificity of all the hen egg lysozyme (HEL)-specific Th cells producing IL-2, IFN-gamma, or IL-4, in different lymphoid organs of HEL-immunized BALB/c and CBA mice. Previous studies, employing T cell proliferation assays, demonstrated that lymph node cells from BALB/c mice immunized with HEL emulsified in complete Freund's adjuvant (CFA) are specific for HEL(105-120). In contrast, we found that the spleens of BALB/c mice immunized with HEL/CFA, or with heat-aggregated HEL on aluminum hydroxide adjuvant, contain IL-4-producing T cells specific for other HEL peptides, previously characterized as "cryptic", with consistent responses to HEL(11-25). The Th repertoire expressed in different lymphoid organs of the same immunized mouse can be different, as can the repertoire of Th cells producing different cytokines and present in one lymphoid organ. In addition, we found that the repertoire of Th cells generated depends upon the adjuvant employed. Lastly, the summation of responses elicited by a panel of non-overlapping HEL peptides is equal to that elicited by HEL. This high-resolution study thus illustrates that the Th repertoire generated upon HEL immunization depends upon diverse parameters, and that the natural processing of HEL gives rise to more diverse peptides then previously evident from studies employing T cell proliferation assays.
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Affiliation(s)
- Nathan C Peters
- Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon S7N 5E5, Canada.
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27
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28
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Wilson NS, Villadangos JA. Regulation of Antigen Presentation and Cross-Presentation in the Dendritic Cell Network: Facts, Hypothesis, and Immunological Implications. Adv Immunol 2005; 86:241-305. [PMID: 15705424 DOI: 10.1016/s0065-2776(04)86007-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Dendritic cells (DCs) are central to the maintenance of immunological tolerance and the initiation and control of immunity. The antigen-presenting properties of DCs enable them to present a sample of self and foreign proteins, contained within an organism at any given time, to the T-cell repertoire. DCs achieve this communication with T cells by displaying antigenic peptides bound to MHC I and MHC II molecules. Here we review the studies carried out over the past 15 years to characterize these antigen presentation mechanisms, emphasizing their significance in relation to DC function in vivo. The life cycles of different DC populations found in vivo are described. Furthermore, we provide a critical assessment of the studies that examine the mechanisms controlling DC MHC class II antigen presentation, which have often reached contradictory conclusions. Finally, we review findings pertaining to the biological mechanisms that enable DCs to present exogenous antigens on their MHC class I molecules, a process known as cross-presentation. Throughout, we highlight what we consider to be major knowledge gaps in the field and speculate on possible directions for future research.
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Affiliation(s)
- Nicholas S Wilson
- Immunology Division and The Cooperative Research Center for Vaccine Technology, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia
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29
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Ishri RK, Menzies S, Hersey P, Halliday GM. Rapid downregulation of antigen processing enzymes in ex vivo generated human monocyte derived dendritic cells occur endogenously in extended cultures. Immunol Cell Biol 2004; 82:239-46. [PMID: 15186253 DOI: 10.1046/j.1440-1711.2004.01237.x] [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: 11/20/2022]
Abstract
Dendritic cells, the most potent antigen presenting cells, have been shown in murine models to induce immune responses against many antigens. Their role in the initiation of antitumour immunity has received enormous attention. Their ability to process and present antigen is dependent on their state of maturation. This study examines the activity of human monocyte-derived dendritic cells at two different time points and the corresponding changes in the proteolytic enzyme activity. Dendritic cells were produced from peripheral blood mononuclear cells of normal volunteers. Plastic adherent cells were cultured for 5 or 7 days with recombinant human (rh)GM-CSF and rhIL-4. Flow cytometry showed that day 5 dendritic cells (DC) were less mature than day 7 DC as indicated by the expression of CD1a, CD11c, CD14, CD80, CD83, CD86 and MHC-II. Proteolytic activity of the enzymes cathepsin C and cathepsin G and phagocytosis of particulate antigens also showed significant differences between d5 dendritic cells and d7 dendritic cells. Allogeneic costimulatory activity of d7 dendritic cells was also significantly increased. Induction of immunity requires active presentation of antigens by antigen processing cells on their MHC-I and/or MHC-II molecules. Study of peptide carriers and peptide precursor molecules showed a significant decrease in CLIP levels in the day 7 DC, suggesting their decreased ability to process antigens but no difference in their ability to load MHC-II molecules. These findings indicate that the length of time in culture, in the absence of exogenous maturation - inducing stimuli affects dendritic cell maturation. Intracellular enzymatic activities of dendritic cells also changed rapidly with small changes in phenotype.
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Affiliation(s)
- R K Ishri
- Dermatology Laboratories, Melanoma and Skin Cancer Research Institute, Royal Prince Alfred Hospital, University of Sydney, NSW, Australia
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30
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Abstract
The ability of DNA vaccines to provide effective immunological protection against infection and tumors depends on their ability to generate good CD4+ and CD8+ T-cell responses. Priming of these responses is a property of dendritic cells (DCs), and so the efficacy of DNA-encoded vaccines is likely to depend on the way in which the antigens they encode are processed by DCs. This processing could either be via the synthesis of the vaccine-encoded antigen by the DCs themselves or via its uptake by DCs following its synthesis in bystander cells that are unable to prime T cells. These different sources of antigen are likely to engage different antigen-processing pathways, which are the subject of this review. Understanding how to access different processing pathways in DCs may ultimately aid the rational development of plasmid-based vaccines to pathogens and to cancer.
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Affiliation(s)
- Mark Howarth
- Cancer Sciences Division, University of Southampton School of Medicine, Southampton General Hospital, Southampton, UK
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31
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Poloso NJ, Muntasell A, Roche PA. MHC class II molecules traffic into lipid rafts during intracellular transport. THE JOURNAL OF IMMUNOLOGY 2004; 173:4539-46. [PMID: 15383586 DOI: 10.4049/jimmunol.173.7.4539] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
There have been many studies demonstrating that a portion of MHC class II molecules reside in detergent-insoluble membrane domains (commonly referred to as lipid rafts). We have proposed that the function of raft association is to concentrate specific MHC class II-peptide complexes in plasma membrane microdomains that can facilitate efficient T cell activation. We now show that MHC class II becomes lipid raft associated before binding antigenic peptides. Using pulse-chase radiolabeling techniques, we find that newly synthesized MHC class II and MHC class II-invariant chain complexes initially reside in a detergent-soluble membrane fraction and acquire detergent insolubility as they traffic to lysosomal Ag processing compartments. Monensin, an inhibitor of protein transport through the Golgi apparatus, blocks association of newly synthesized MHC class II with lipid rafts. Treatment of cells with leupeptin, which inhibits invariant chain degradation, leads to the accumulation of MHC class II in lipid rafts within the lysosome-like Ag-processing compartments. Raft fractionation of lysosomal membranes confirmed the presence of MHC class II in detergent-insoluble microdomains in Ag-processing compartments. These findings indicate that newly synthesized MHC class II complexes are directed to detergent-insoluble lipid raft microdomains before peptide loading, a process that may facilitate the loading of similar peptides on MHC class II complexes in these microdomains.
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Affiliation(s)
- Neil J Poloso
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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32
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Röhn TA, Boes M, Wolters D, Spindeldreher S, Müller B, Langen H, Ploegh H, Vogt AB, Kropshofer H. Upregulation of the CLIP self peptide on mature dendritic cells antagonizes T helper type 1 polarization. Nat Immunol 2004; 5:909-18. [PMID: 15322540 DOI: 10.1038/ni1108] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Accepted: 07/28/2004] [Indexed: 11/10/2022]
Abstract
Dendritic cells (DCs) initiate and regulate immunity against foreign and self antigens. Here we identified more than 200 individual major histocompatibility complex class II-associated peptides on human DCs and found that mature DCs selectively upregulated the self peptide CLIP. CLIP cosegregated together with foreign antigenic peptides in tetraspan microdomains on the surface and localized to DC-T cell synapses. The increased representation of CLIP-major histocompatibility complex class II complexes favored polarization of autologous naive T cells toward the nonpolarized and T helper type 2 (T(H)2) phenotype. There was also a considerably higher T(H)2/T(H)1 ratio in H2-DM-deficient mice, which have a CLIP(hi) phenotype, in contrast to wild-type, CLIP(lo) mice. Thus, the self peptide CLIP on DCs qualifies as an endogenous regulator in priming of T helper cells by antagonizing the polarization toward the T(H)1 phenotype.
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Affiliation(s)
- Till A Röhn
- Basel Institute for Immunology, Basel, Switzerland
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33
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Affiliation(s)
- Christopher W Cutler
- Department of Periodontics, School of Dental Medicine, Stony Brook University, New York, USA
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34
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Preynat-Seauve O, Coudurier S, Favier A, Marche PN, Villiers C. Oxidative stress impairs intracellular events involved in antigen processing and presentation to T cells. Cell Stress Chaperones 2004; 8:162-71. [PMID: 14627202 PMCID: PMC514868 DOI: 10.1379/1466-1268(2003)008<0162:osiiei>2.0.co;2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
For T cells to recognize foreign antigens, the latter must be processed into peptides and associated to major histocompatibility complex (MHC) class II molecules by antigen-presenting cells (APC). APCs frequently operate under stress conditions induced by tissue damage, antigens, or inflammatory reactions. We analyze the effects of oxidative stress on intracellular processing using APC B cell lines. Before being tested for APC function, B cells (IIA1.6) were exposed for 2 hours to hydrogen peroxide (H2O2), a treatment that impairs their capacity to stimulate specific T cell clones. Because paraformaldehyde-fixed H2O2-treated B cells can still present extracellular peptides to T cell clones, the intracellular events of processing were investigated. Purified lysosomes from H2O2-treated B cells show increased proteolytic activity and increased generation of antigenic peptides. In addition, H2O2 treatment targets antigens to compartments that express low levels of MHC II and proteins (H-2M, H-2O) required for peptide loading onto this molecule. Finally, we suggest that impairment of antigen processing by oxidative stress reduces the induction of a T cell's response because H2O2 decreases the activation of naive T lymphocytes by dendritic cells. Together, these data indicate that oxidative stress inhibits the capacity of APCs to process antigens and to initiate a primary T cell response. The role of such modifications on the outcome of the specific immune response is discussed.
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Affiliation(s)
- Olivier Preynat-Seauve
- Laboratoire d'immunochimie, INSERM U548, ICH/DRDC/CEA-Grenoble, Université Joseph Fourier, 38054 Grenoble Cedex 09, France
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35
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Abstract
Tapasin plays an important role in the quality control of major histocompatibility complex (MHC) class I assembly, but its precise function in this process remains controversial. Whether tapasin participates in the assembly of HLA-G has not been studied. HLA-G, an MHC class Ib molecule that binds a more restricted set of peptides than class Ia molecules, is a particularly interesting molecule, because during assembly, it recycles between the endoplasmic reticulum (ER) and the cis-Golgi until it is loaded with a high affinity peptide. We have taken advantage of this unusual trafficking property of HLA-G and its requirement for high affinity peptides to demonstrate that a critical function of tapasin is to transform class I molecules into a high affinity, peptide-receptive form. In the absence of tapasin, HLA-G molecules cannot bind high affinity peptides, and an abundant supply of peptides cannot overcome the tapasin requirement for high affinity peptide loading. The addition of tapasin renders HLA-G molecules capable of loading high affinity peptides and of transporting to the surface, suggesting that tapasin is a prerequisite for the binding of high-affinity ligands. Interestingly, the "tapasin-dependent" HLA-G molecules are not empty in the absence of tapasin but are in fact associated with suboptimal peptides and continue to recycle between the ER and the cis-Golgi. Together with the finding that empty HLA-G heterodimers are strictly retained in the ER and degraded, our data suggest that MHC class I molecules bind any available peptides to avoid ER-mediated degradation and that the peptides are in turn replaced by higher affinity peptides with the aid of tapasin.
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Affiliation(s)
- Boyoun Park
- Graduate School of Biotechnology, Korea University, Seoul 136-701, Korea
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36
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Koonce CH, Wutz G, Robertson EJ, Vogt AB, Kropshofer H, Bikoff EK. DM loss in k haplotype mice reveals isotype-specific chaperone requirements. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:3751-61. [PMID: 12646641 DOI: 10.4049/jimmunol.170.7.3751] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DM actions as a class II chaperone promote capture of diverse peptides inside the endocytic compartment(s). DM mutant cells studied to date express class II bound by class II-associated invariant chain-derived peptide (CLIP), a short proteolytic fragment of the invariant chain, and exhibit defective peptide-loading abilities. To evaluate DM functional contributions in k haplotype mice, we engineered a novel mutation at the DMa locus via embryonic stem cell technology. The present experiments demonstrate short-lived A(k)/CLIP complexes, decreased A(k) surface expression, and enhanced A(k) peptide binding activities. Thus, we conclude that DM loss in k haplotype mice creates a substantial pool of empty or loosely occupied A(k) conformers. On the other hand, the mutation hardly affects E(k) activities. The appearance of mature compact E(k) dimers, near normal surface expression, and efficient Ag presentation capabilities strengthen the evidence for isotype-specific DM requirements. In contrast to DM mutants described previously, partial occupancy by wild-type ligands is sufficient to eliminate antiself reactivity. Mass spectrometry profiles reveal A(k)/CLIP and a heterogeneous collection of relatively short peptides bound to E(k) molecules. These experiments demonstrate that DM has distinct roles depending on its specific class II partners.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigen Presentation/genetics
- Antigens, Differentiation, B-Lymphocyte/biosynthesis
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Crosses, Genetic
- Female
- Gene Deletion
- H-2 Antigens/genetics
- Haplotypes
- Histocompatibility Antigens Class II/biosynthesis
- Histocompatibility Antigens Class II/classification
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/metabolism
- Histocompatibility Antigens Class II/physiology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Knockout
- Molecular Chaperones/classification
- Molecular Chaperones/physiology
- Molecular Sequence Data
- Muramidase/immunology
- Muramidase/metabolism
- Peptide Fragments/genetics
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- RNA Editing/immunology
- Self Tolerance/genetics
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Affiliation(s)
- Chad H Koonce
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
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37
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Belmares MP, Busch R, Wucherpfennig KW, McConnell HM, Mellins ED. Structural factors contributing to DM susceptibility of MHC class II/peptide complexes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:5109-17. [PMID: 12391227 DOI: 10.4049/jimmunol.169.9.5109] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptide loading of MHC class II (MHCII) molecules is assisted by HLA-DM, which releases invariant chain peptides from newly synthesized MHCII and edits the peptide repertoire. Determinants of susceptibility of peptide/MHCII complexes to DM remain controversial, however. Here we have measured peptide dissociation in the presence and the absence of DM for 36 different complexes of varying intrinsic stability. We found large variations in DM susceptibility for different complexes using either soluble or full-length HLA-DM. The DM effect was significantly less for unstable complexes than for stable ones, although this correlation was modest. Peptide sequence- and allele-dependent interactions along the entire length of the Ag binding groove influenced DM susceptibility. We also observed differences in DM susceptibility during peptide association. Thus, the peptide repertoire displayed to CD4(+) T cells is the result of a mechanistically complicated editing process and cannot be simply predicted from the intrinsic stability of the complexes in the absence of DM.
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38
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Khalil H, Deshaies F, Bellemare-Pelletier A, Brunet A, Faubert A, Azar GA, Thibodeau J. Class II transactivator-induced expression of HLA-DO(beta) in HeLa cells. TISSUE ANTIGENS 2002; 60:372-82. [PMID: 12492813 DOI: 10.1034/j.1399-0039.2002.600504.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
HLA-DO is an intracellular nonclassical MHC class II molecule expressed in the endocytic pathway of B lymphocytes. It shapes the repertoire of peptides bound to classical class II molecules such as HLA-DR by regulating the activity of HLA-DM. Using a peptide corresponding to the cytoplasmic tail of HLA-DO(beta), we have developed a mouse monoclonal antibody, HKC5. Immunofluorescence microscopy revealed that HKC5 recognizes HLA-DO molecules present in the endoplasmic reticulum as well as those in vesicular compartments of the endocytic pathway. In addition, the antibody detects the isolated beta chain on Western blots. Using mutants of the DO(beta) cytoplasmic tail fused to a reporter molecule and expressed in epithelial cells, we showed by flow cytometry that the antibody epitope includes one or both of the leucine residues forming the lysosomal sorting signal. Finally, we have used HKC5 to evaluate the presence of the HLA-DO(beta) chain in HeLa cells expressing the class II transactivator protein CIITA. Our flow cytometry and confocal microscopy analyses showed a marked expression of DO(beta) suggesting that HLA-DO could accumulate under the influence of CIITA in non-B cells.
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Affiliation(s)
- H Khalil
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie et Immunologie, Faculté de Médecine, Université de Montréal, Québec, Canada
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39
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Vogt AB, Spindeldreher S, Kropshofer H. Clustering of MHC-peptide complexes prior to their engagement in the immunological synapse: lipid raft and tetraspan microdomains. Immunol Rev 2002; 189:136-51. [PMID: 12445271 DOI: 10.1034/j.1600-065x.2002.18912.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Protein reorganization at the interface of a T cell and an antigen-presenting cell (APC) plays an important role in T cell activation. Imaging techniques reveal that reorganization of particular receptor-ligand pairs gives rise to an intercellular junction, termed the immunological synapse. In this synapse antigenic peptides associated with major histocompatibility complex (MHC) molecules form multimolecular arrays on the APC side, engaging an equivalent number of clustered T cell receptors (TCRs) on the T cell. The accumulation of MHC molecules carrying cognate peptide in the APC-T cell interface was thought to depend on the specificity and presence of TCRs. Recent evidence, however, suggests that the APC is equipped to preorganize MHC-peptide complexes in the absence of T cells. To this end, MHC molecules become incorporated into two types of membrane microdomains: (i) cholesterol- and glycosphingolipid-enriched domains, denoted lipid rafts, that preconcentrate MHC class II molecules; and (ii) microdomains made up of tetraspan proteins, such as CD9, CD63, CD81 or CD82, that mediate enrichment of MHC class II molecules loaded with a select set of peptides. It follows that the integrity, composition and dynamics of these microdomains are candidate determinants favoring activation or silencing of T cells.
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Affiliation(s)
- Anne B Vogt
- Roche Center for Medical Genomics, F. Hoffmann-La Roche, Ltd, Basel, Switzerland
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40
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Muntasell A, Carrascal M, Serradell L, Veelen Pv PV, Verreck F, Koning F, Raposo G, Abián J, Jaraquemada D. HLA-DR4 molecules in neuroendocrine epithelial cells associate to a heterogeneous repertoire of cytoplasmic and surface self peptides. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:5052-60. [PMID: 12391221 DOI: 10.4049/jimmunol.169.9.5052] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expression of MHC class II genes by epithelial cells is induced in inflammatory conditions such as autoimmunity and organ transplantation. Class II ligands generated by the epithelial cell processing mechanisms are unknown, although some unique epitopes have been described in epithelial cells that B cells could not generate. Epithelial cells are the targets of autoreactive T cell responses in autoimmune diseases and of transplant rejection processes, which may involve recognition of cell type-specific epitopes. In the present report, we have compared the DR4-associated repertoire and the intracellular distribution of class II, invariant chain (Ii), and DM molecules between a human DR4-, Ii-, and DM-transfected rat neuroendocrine epithelial cell line and a homozygous DR4 (DRB1*0401) lymphoblastoid B cell line, by mass spectrometry sequencing techniques, and immunoelectron microscopy. The epithelial cells chosen for transfection, RINm5F, are rat insular cells widely used for human studies of autoimmune diabetes. The results revealed a remarkably heterogeneous pool of self protein-derived peptides from the cell surface and various intracellular compartments, including the cytosol and secretory vesicles in epithelial cells, compared with a very restricted homogeneous repertoire in lymphoblastoid B cell lines, where few epitopes from surface molecules were predominant. The generation of distinct DR4-associated peptide repertoires in these two cell types could be due to the effect of several factors including differences in subcellular location of Ii and DM molecules, differential DO expression, and cell type-specific mechanisms of class II ligand generation. This is specially relevant to processes involving epithelial T cell interactions such as organ-specific autoimmunity and transplant rejection.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigen Presentation/genetics
- Antigens, Differentiation, B-Lymphocyte/biosynthesis
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Autoantigens/genetics
- Autoantigens/immunology
- Autoantigens/isolation & purification
- Autoantigens/metabolism
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- Cattle
- Cell Line, Transformed/immunology
- Cell Line, Transformed/metabolism
- Cell Membrane/genetics
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Cytoplasm/genetics
- Cytoplasm/immunology
- Cytoplasm/metabolism
- Epithelial Cells/immunology
- Epithelial Cells/metabolism
- HLA-D Antigens/biosynthesis
- HLA-D Antigens/genetics
- HLA-D Antigens/metabolism
- HLA-DR Antigens/biosynthesis
- HLA-DR Antigens/isolation & purification
- HLA-DR4 Antigen/biosynthesis
- HLA-DR4 Antigen/genetics
- HLA-DR4 Antigen/metabolism
- HLA-DRB1 Chains
- Histocompatibility Antigens Class II/biosynthesis
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/metabolism
- Humans
- Insulinoma/immunology
- Insulinoma/metabolism
- Ligands
- Molecular Sequence Data
- Peptide Fragments/genetics
- Peptide Fragments/immunology
- Peptide Fragments/isolation & purification
- Peptide Fragments/metabolism
- Rats
- Transfection
- Tumor Cells, Cultured/immunology
- Tumor Cells, Cultured/metabolism
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Affiliation(s)
- Aura Muntasell
- Immunology Unit and Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Spain
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41
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Guermonprez P, Valladeau J, Zitvogel L, Théry C, Amigorena S. Antigen presentation and T cell stimulation by dendritic cells. Annu Rev Immunol 2002; 20:621-67. [PMID: 11861614 DOI: 10.1146/annurev.immunol.20.100301.064828] [Citation(s) in RCA: 1238] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dendritic cells take up antigens in peripheral tissues, process them into proteolytic peptides, and load these peptides onto major histocompatibility complex (MHC) class I and II molecules. Dendritic cells then migrate to secondary lymphoid organs and become competent to present antigens to T lymphocytes, thus initiating antigen-specific immune responses, or immunological tolerance. Antigen presentation in dendritic cells is finely regulated: antigen uptake, intracellular transport and degradation, and the traffic of MHC molecules are different in dendritic cells as compared to other antigen-presenting cells. These specializations account for dendritic cells' unique role in the initiation of immune responses and the induction of tolerance.
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42
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Abstract
The presentation of peptides to T cells by MHC class II molecules is of critical importance in specific recognition by the immune system. Expression of class II molecules is exquisitely controlled at the transcriptional level. A large set of proteins interact with the promoters of class II genes. The most important of these is CIITA, a master controller that orchestrates expression but does not bind directly to the promoter. The transcriptosome complex formed at class II promoters is a model for induction of gene expression.
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Affiliation(s)
- Jenny Pan-Yun Ting
- Department of Microbiology and Immunology and The Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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43
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Abstract
Processing exogenous and endogenous proteins for presentation by major histocompatibility complex (MHC) molecules to T cells is the defining function of antigen-presenting cells (APC) as major regulatory cells in the acquired immune response. MHC class II-restricted antigen presentation to CD4 T cells is achieved by an essentially common pathway that is subject to variation with regard to the location and extent of degradation of protein antigens and the site of peptide binding to MHC class II molecules. These subtle variations reveal a surprising flexibility in the ways a diverse peptide repertoire is displayed on the APC surface. This diversity may have profound consequences for the induction of immunity to infection and tumours, as well as autoimmunity and tolerance.
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Affiliation(s)
- John H Robinson
- Department of Microbiology and Immunology, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
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44
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Brocke P, Garbi N, Momburg F, Hämmerling GJ. HLA-DM, HLA-DO and tapasin: functional similarities and differences. Curr Opin Immunol 2002; 14:22-9. [PMID: 11790529 DOI: 10.1016/s0952-7915(01)00294-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In both the MHC class II and class I pathways of antigen presentation, accessory molecules influence formation of MHC-peptide complexes. In the MHC class II pathway, DM functions in the loading and editing of peptides; recent work demonstrated that it is acting not only in late endosomal compartments but also in recycling compartments and on the surface of B cells and immature dendritic cells. DM activity is modulated by another accessory molecule, DO, but this modulation is mainly operative in B cells, where it may lead to preferential activation of B cells producing high-affinity antibodies. In the MHC class I pathway of antigen presentation, recent in vivo experiments with knockout mice confirmed the role of tapasin in antigen presentation and indicate that it acts as a peptide editor and as a chaperone for TAP and the MHC class I heavy chain. In the class I loading complex, calreticulin and the thiol-dependent oxidoreductase ER60/ERp57 appear to support the function of tapasin in an as-yet-unknown fashion. The picture emerges that DM and tapasin have analogous functions in shaping the peptide repertoire presented by the respective MHC class II and class I molecules.
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Affiliation(s)
- Pascale Brocke
- DKFZ Deutsches Krebsforschungszentrum, German Cancer Research Center, Molecular Immunology, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany
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45
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Bryant PW, Lennon-Duménil AM, Fiebiger E, Lagaudrière-Gesbert C, Ploegh HL. Proteolysis and antigen presentation by MHC class II molecules. Adv Immunol 2002; 80:71-114. [PMID: 12078484 PMCID: PMC7130937 DOI: 10.1016/s0065-2776(02)80013-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Proteolysis is the primary mechanism used by all cells not only to dispose of unwanted proteins but also to regulate protein function and maintain cellular homeostasis. Proteases that reside in the endocytic pathway are the principal actors of terminal protein degradation. The proteases contained in the endocytic pathway are classified into four major groups based on the active-site amino acid used by the enzyme to hydrolyze amide bonds of proteins: cysteine, aspartyl, serine, and metalloproteases. The presentation of peptide antigens by major histocompatibility complex (MHC) class II molecules is strictly dependent on the action of proteases. Class II molecules scour the endocytic pathway for antigenic peptides to bind and present at the cell surface for recognition by CD4+ T cells. The specialized cell types that support antigen presentation by class II molecules are commonly referred to as professional antigen presenting cells (APCs), which include bone marrow-derived B lymphocytes, dendritic cells (DCs), and macrophages. In addition, the expression of certain endocytic proteases is regulated either at the level of gene transcription or enzyme maturation and their activity is controlled by the presence of endogenous protease inhibitors.
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Affiliation(s)
- Paula Wolf Bryant
- Department of Microbiology, Ohio State University, Columbus, Ohio 43210, USA
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46
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Affiliation(s)
- C Watts
- Department of Biochemistry, University of Dundee, Dundee, DD1 5EH, UK
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47
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Kleijmeer M, Ramm G, Schuurhuis D, Griffith J, Rescigno M, Ricciardi-Castagnoli P, Rudensky AY, Ossendorp F, Melief CJ, Stoorvogel W, Geuze HJ. Reorganization of multivesicular bodies regulates MHC class II antigen presentation by dendritic cells. J Cell Biol 2001; 155:53-63. [PMID: 11581285 PMCID: PMC2150788 DOI: 10.1083/jcb.200103071] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Immature dendritic cells (DCs) sample their environment for antigens and after stimulation present peptide associated with major histocompatibility complex class II (MHC II) to naive T cells. We have studied the intracellular trafficking of MHC II in cultured DCs. In immature cells, the majority of MHC II was stored intracellularly at the internal vesicles of multivesicular bodies (MVBs). In contrast, DM, an accessory molecule required for peptide loading, was located predominantly at the limiting membrane of MVBs. After stimulation, the internal vesicles carrying MHC II were transferred to the limiting membrane of the MVB, bringing MHC II and DM to the same membrane domain. Concomitantly, the MVBs transformed into long tubular organelles that extended into the periphery of the cells. Vesicles that were formed at the tips of these tubules nonselectively incorporated MHC II and DM and presumably mediated transport to the plasma membrane. We propose that in maturing DCs, the reorganization of MVBs is fundamental for the timing of MHC II antigen loading and transport to the plasma membrane.
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Affiliation(s)
- M Kleijmeer
- Department of Cell Biology, University Medical Center, Institute of Biomembranes and Center for Biomedical Genetics, 3584 CX Utrecht, Netherlands
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48
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Mukherjee P, Dani A, Bhatia S, Singh N, Rudensky AY, George A, Bal V, Mayor S, Rath S. Efficient presentation of both cytosolic and endogenous transmembrane protein antigens on MHC class II is dependent on cytoplasmic proteolysis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2632-41. [PMID: 11509605 DOI: 10.4049/jimmunol.167.5.2632] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptides from extracellular proteins presented on MHC class II are mostly generated and loaded in endolysosomal compartments, but the major pathways responsible for loading peptides from APC-endogenous sources on MHC class II are as yet unclear. In this study, we show that MHC class II molecules present peptides from proteins such as OVA or conalbumin introduced into the cytoplasm by hyperosmotic pinosome lysis, with efficiencies comparable to their presentation via extracellular fluid-phase endocytosis. This cytosolic presentation pathway is sensitive to proteasomal inhibitors, whereas the presentation of exogenous Ags taken up by endocytosis is not. Inhibitors of nonproteasomal cytosolic proteases can also inhibit MHC class II-restricted presentation of cytosolically delivered protein, without inhibiting MHC class I-restricted presentation from the same protein. Cytosolic processing of a soluble fusion protein containing the peptide epitope I-Ealpha(52-68) yields an epitope that is similar to the one generated during constitutive presentation of I-Ealpha as an endogenous transmembrane protein, but is subtly different from the one generated in the exogenous pathway. Constitutive MHC class II-mediated presentation of the endogenous transmembrane protein I-Ealpha is also specifically inhibited over time by inhibitors of cytosolic proteolysis. Thus, Ag processing in the cytoplasm appears to be essential for the efficient presentation of endogenous proteins, even transmembrane ones, on MHC class II, and the proteolytic pathways involved may differ from those used for MHC class I-mediated presentation.
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Affiliation(s)
- P Mukherjee
- National Institute of Immunology, New Delhi, India
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49
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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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50
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Sevilla LM, Richter SS, Miller J. Intracellular transport of MHC class II and associated invariant chain in antigen presenting cells from AP-3-deficient mocha mice. Cell Immunol 2001; 210:143-53. [PMID: 11520080 DOI: 10.1006/cimm.2001.1817] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
MHC class II-restricted antigen presentation requires trafficking of newly synthesized class II-invariant chain complexes from the trans-Golgi network to endosomal, peptide-loading compartments. This transport is mediated by dileucine-like motifs within the cytosolic tail of the invariant chain. Although these signals have been well characterized, the cytosolic proteins that interact with these dileucine signals and mediate Golgi sorting and endosomal transport have not been identified. Recently, an adaptor complex, AP-3, has been identified that interacts with dileucine motifs and mediates endosomal/lysosomal transport in yeast, Drosophila, and mammals. In this report, we have assessed class II-invariant chain trafficking in a strain of mice (mocha) which lacks expression of AP-3. Our studies demonstrate that the lack of AP-3 does not affect the kinetics of invariant chain degradation, the route of class II-invariant chain transport, or the rate and extent of class II-peptide binding as assessed by the generation of SDS-stable dimers. The possible role of other known or unknown adaptor complexes in class II-invariant chain transport is discussed.
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Affiliation(s)
- L M Sevilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA
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