1
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Wosen JE, Ilstad-Minnihan A, Co JY, Jiang W, Mukhopadhyay D, Fernandez-Becker NQ, Kuo CJ, Amieva MR, Mellins ED. Human Intestinal Enteroids Model MHC-II in the Gut Epithelium. Front Immunol 2019; 10:1970. [PMID: 31481960 PMCID: PMC6710476 DOI: 10.3389/fimmu.2019.01970] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 08/05/2019] [Indexed: 01/14/2023] Open
Abstract
The role of intestinal epithelial cells (IECs) in mucosal tolerance and immunity remains poorly understood. We present a method for inducing MHC class II (MHC-II) in human enteroids, "mini-guts" derived from small intestinal crypt stem cells, and show that the intracellular MHC-II peptide-pathway is intact and functional in IECs. Our approach enables human enteroids to be used for novel in vitro studies into IEC MHC-II regulation and function during health and disease.
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Affiliation(s)
- Jonathan E. Wosen
- Program in Immunology, Department of Pediatrics, Stanford University, Stanford, CA, United States
| | | | - Julia Y. Co
- Division of Infectious Diseases, Department of Pediatrics, Stanford University, Stanford, CA, United States
| | - Wei Jiang
- Program in Immunology, Department of Pediatrics, Stanford University, Stanford, CA, United States
| | - Dhriti Mukhopadhyay
- Program in Immunology, Department of Pediatrics, Stanford University, Stanford, CA, United States
| | - Nielsen Q. Fernandez-Becker
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, CA, United States
| | - Calvin J. Kuo
- Division of Hematology, Department of Medicine, Stanford University, Stanford, CA, United States
| | - Manuel R. Amieva
- Division of Infectious Diseases, Department of Pediatrics, Stanford University, Stanford, CA, United States
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Elizabeth D. Mellins
- Program in Immunology, Department of Pediatrics, Stanford University, Stanford, CA, United States
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2
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Min S, Yang F, Zhou L, Zhang X, Chen H. Identification of MHC-DMA and -DMB alleles in Tibetan macaques (Macaca thibetana). HLA 2019; 94:398-400. [PMID: 31347300 DOI: 10.1111/tan.13643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 07/24/2019] [Indexed: 11/27/2022]
Abstract
Fifteen Math-DMA and 16 Math-DMB novel alleles of Tibetan macaques were identified.
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Affiliation(s)
- Shaokun Min
- Department of Ophthalmology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Fan Yang
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Liang Zhou
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Xinshang Zhang
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Hui Chen
- Department of Ophthalmology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
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3
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Hung SC, Hou T, Jiang W, Wang N, Qiao SW, Chow IT, Liu X, van der Burg SH, Koelle DM, Kwok WW, Sollid LM, Mellins ED. Epitope Selection for HLA-DQ2 Presentation: Implications for Celiac Disease and Viral Defense. THE JOURNAL OF IMMUNOLOGY 2019; 202:2558-2569. [PMID: 30926644 DOI: 10.4049/jimmunol.1801454] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/01/2019] [Indexed: 01/28/2023]
Abstract
We have reported that the major histocompatibility molecule HLA-DQ2 (DQA1*05:01/DQB1*02:01) (DQ2) is relatively resistant to HLA-DM (DM), a peptide exchange catalyst for MHC class II. In this study, we analyzed the role of DQ2/DM interaction in the generation of DQ2-restricted gliadin epitopes, relevant to celiac disease, or DQ2-restricted viral epitopes, relevant to host defense. We used paired human APC, differing in DM expression (DMnull versus DMhigh) or differing by expression of wild-type DQ2, versus a DM-susceptible, DQ2 point mutant DQ2α+53G. The APC pairs were compared for their ability to stimulate human CD4+ T cell clones. Despite higher DQ2 levels, DMhigh APC attenuated T cell responses compared with DMnull APC after intracellular generation of four tested gliadin epitopes. DMhigh APC expressing the DQ2α+53G mutant further suppressed these gliadin-mediated responses. The gliadin epitopes were found to have moderate affinity for DQ2, and even lower affinity for the DQ2 mutant, consistent with DM suppression of their presentation. In contrast, DMhigh APC significantly promoted the presentation of DQ2-restricted epitopes derived intracellularly from inactivated HSV type 2, influenza hemagglutinin, and human papillomavirus E7 protein. When extracellular peptide epitopes were used as Ag, the DQ2 surface levels and peptide affinity were the major regulators of T cell responses. The differential effect of DM on stimulation of the two groups of T cell clones implies differences in DQ2 presentation pathways associated with nonpathogen- and pathogen-derived Ags in vivo.
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Affiliation(s)
- Shu-Chen Hung
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305.,Program in Immunology, Stanford University, Stanford, CA 94305
| | - Tieying Hou
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305.,Program in Immunology, Stanford University, Stanford, CA 94305
| | - Wei Jiang
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305.,Program in Immunology, Stanford University, Stanford, CA 94305
| | - Nan Wang
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305.,Program in Immunology, Stanford University, Stanford, CA 94305
| | - Shuo-Wang Qiao
- Centre for Immune Regulation, Department of Immunology, University of Oslo and Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway.,K.G. Jebsen Coeliac Disease Research Centre, University of Oslo, 0424 Oslo, Norway
| | - I-Ting Chow
- Benaroya Research Institute at Virginia Mason, Seattle, WA 98101
| | - Xiaodan Liu
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305.,Program in Immunology, Stanford University, Stanford, CA 94305
| | - Sjoerd H van der Burg
- Department of Medical Oncology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - David M Koelle
- Department of Medicine, University of Washington, Seattle, WA 98195.,Department of Laboratory Medicine, University of Washington, Seattle, WA 98195; and.,Department of Global Health, University of Washington, Seattle, WA 98195
| | - William W Kwok
- Benaroya Research Institute at Virginia Mason, Seattle, WA 98101
| | - Ludvig M Sollid
- Centre for Immune Regulation, Department of Immunology, University of Oslo and Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway.,K.G. Jebsen Coeliac Disease Research Centre, University of Oslo, 0424 Oslo, Norway
| | - Elizabeth D Mellins
- Division of Human Gene Therapy, Department of Pediatrics, Stanford University, Stanford, CA 94305; .,Program in Immunology, Stanford University, Stanford, CA 94305
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4
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Anczurowski M, Yamashita Y, Nakatsugawa M, Ochi T, Kagoya Y, Guo T, Wang CH, Rahman MA, Saso K, Butler MO, Hirano N. Mechanisms underlying the lack of endogenous processing and CLIP-mediated binding of the invariant chain by HLA-DP 84Gly. Sci Rep 2018; 8:4804. [PMID: 29555965 PMCID: PMC5859192 DOI: 10.1038/s41598-018-22931-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 03/05/2018] [Indexed: 12/26/2022] Open
Abstract
While the principles of classical antigen presentation via MHC class II are well-established, the mechanisms for the many routes of cross-presentation by which endogenous antigens become associated with class II molecules are not fully understood. We have recently demonstrated that the single amino acid polymorphism HLA-DPβ84Gly (DP84Gly) is critical to abrogate class II invariant chain associated peptide (CLIP) region-mediated binding of invariant chain (Ii) to DP, allowing endoplasmic reticulum (ER)-resident endogenous antigens to constitutively associate with DP84Gly such as DP4. In this study, we demonstrate that both the CLIP and N-terminal non-CLIP Ii regions cooperatively generate an Ii conformation that cannot associate with DP84Gly via the CLIP region. We also demonstrate the ability of DP4 to efficiently process and present antigens encoded in place of CLIP in a chimeric Ii, regardless of wild type Ii and HLA-DM expression. These data highlight the complex interplay between DP polymorphisms and the multiple Ii regions that cooperatively regulate this association, ultimately controlling the presentation of endogenous antigens on DP molecules. These results may also offer a mechanistic explanation for recent studies identifying the differential effects between DP84Gly and DP84Asp as clinically relevant in human disease.
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Affiliation(s)
- Mark Anczurowski
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Yuki Yamashita
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Munehide Nakatsugawa
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Toshiki Ochi
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Yuki Kagoya
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Tingxi Guo
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Chung-Hsi Wang
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Muhammed A Rahman
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Kayoko Saso
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada
| | - Marcus O Butler
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Naoto Hirano
- Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 2M9, Canada. .,Department of Immunology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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5
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Alvaro-Benito M, Morrison E, Wieczorek M, Sticht J, Freund C. Human leukocyte Antigen-DM polymorphisms in autoimmune diseases. Open Biol 2017; 6:rsob.160165. [PMID: 27534821 PMCID: PMC5008016 DOI: 10.1098/rsob.160165] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 07/19/2016] [Indexed: 12/20/2022] Open
Abstract
Classical MHC class II (MHCII) proteins present peptides for CD4+ T-cell surveillance and are by far the most prominent risk factor for a number of autoimmune disorders. To date, many studies have shown that this link between particular MHCII alleles and disease depends on the MHCII's particular ability to bind and present certain peptides in specific physiological contexts. However, less attention has been paid to the non-classical MHCII molecule human leucocyte antigen-DM, which catalyses peptide exchange on classical MHCII proteins acting as a peptide editor. DM function impacts the presentation of both antigenic peptides in the periphery and key self-peptides during T-cell development in the thymus. In this way, DM activity directly influences the response to pathogens, as well as mechanisms of self-tolerance acquisition. While decreased DM editing of particular MHCII proteins has been proposed to be related to autoimmune disorders, no experimental evidence for different DM catalytic properties had been reported until recently. Biochemical and structural investigations, together with new animal models of loss of DM activity, have provided an attractive foundation for identifying different catalytic efficiencies for DM allotypes. Here, we revisit the current knowledge of DM function and discuss how DM function may impart autoimmunity at the organism level.
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Affiliation(s)
- Miguel Alvaro-Benito
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Eliot Morrison
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Marek Wieczorek
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
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6
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Jiang W, Strohman MJ, Somasundaram S, Ayyangar S, Hou T, Wang N, Mellins ED. pH-susceptibility of HLA-DO tunes DO/DM ratios to regulate HLA-DM catalytic activity. Sci Rep 2015; 5:17333. [PMID: 26610428 PMCID: PMC4661524 DOI: 10.1038/srep17333] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/28/2015] [Indexed: 11/14/2022] Open
Abstract
The peptide-exchange catalyst, HLA-DM, and its inhibitor, HLA-DO control endosomal generation of peptide/class II major histocompatibility protein (MHC-II) complexes; these complexes traffic to the cell surface for inspection by CD4+ T cells. Some evidence suggests that pH influences DO regulation of DM function, but pH also affects the stability of polymorphic MHC-II proteins, spontaneous peptide loading, DM/MHC-II interactions and DM catalytic activity, imposing challenges on approaches to determine pH effects on DM-DO function and their mechanistic basis. Using optimized biochemical methods, we dissected pH-dependence of spontaneous and DM-DO-mediated class II peptide exchange and identified an MHC-II allele-independent relationship between pH, DO/DM ratio and efficient peptide exchange. We demonstrate that active, free DM is generated from DM-DO complexes at late endosomal/lysosomal pH due to irreversible, acid-promoted DO destruction rather than DO/DM molecular dissociation. Any soluble DM that remains in complex with DO stays inert. pH-exposure of DM-DO in cell lysates corroborates such a pH-regulated mechanism, suggesting acid-activated generation of functional DM in DO-expressing cells.
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Affiliation(s)
- Wei Jiang
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA.,Stanford Program in Immunology, Stanford University, Stanford, CA 94305, USA
| | - Michael J Strohman
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA.,Stanford Program in Immunology, Stanford University, Stanford, CA 94305, USA
| | | | - Sashi Ayyangar
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Tieying Hou
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Nan Wang
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Elizabeth D Mellins
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA.,Stanford Program in Immunology, Stanford University, Stanford, CA 94305, USA
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7
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Sadegh-Nasseri S, Kim A. Exogenous antigens bind MHC class II first, and are processed by cathepsins later. Mol Immunol 2015; 68:81-4. [PMID: 26254987 DOI: 10.1016/j.molimm.2015.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 11/18/2022]
Abstract
The field of antigen processing and presentation is likely one of the most well defined areas in immunology based on decades of intense molecular and structural studies. Many molecules contributing to antigen processing and presentation have been discovered and their mechanisms of action been largely defined, yet a major question, which lies at the very core of the field has remained hard to pin down. The question is what determines immunodominance? Immunodominance is defined as a few specific epitopes being selected to represent an antigen to the immune system and provide targets for T cells. Many studies have aimed at understanding how epitopes are selected. A range of hypotheses related to the structural features of antigens, sensitivity to proteases, epitope affinity for MHC II, T cell precursor frequency, and T cell receptor affinity for peptide/MHC II have been considered. However, because of the variety of proteins and factors involved in antigen processing and enormous complexity, finding an answer has been challenging. Here we make an effort to tease out the sequence of events in antigen processing that promote selection of immunodominant epitopes for exogenous antigens.
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Affiliation(s)
| | - AeRyon Kim
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21205, United States
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8
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Macmillan H, Strohman MJ, Ayyangar S, Jiang W, Rajasekaran N, Spura A, Hessell AJ, Madec AM, Mellins ED. The MHC class II cofactor HLA-DM interacts with Ig in B cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 193:2641-2650. [PMID: 25098292 PMCID: PMC4157100 DOI: 10.4049/jimmunol.1400075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
B cells internalize extracellular Ag into endosomes using the Ig component of the BCR. In endosomes, Ag-derived peptides are loaded onto MHC class II proteins. How these pathways intersect remains unclear. We find that HLA-DM (DM), a catalyst for MHC class II peptide loading, coprecipitates with Ig in lysates from human tonsillar B cells and B cell lines. The molecules in the Ig/DM complexes have mature glycans, and the complexes colocalize with endosomal markers in intact cells. A larger fraction of Ig precipitates with DM after BCR crosslinking, implying that complexes can form when DM meets endocytosed Ig. In vitro, in the endosomal pH range, soluble DM directly binds the Ig Fab domain and increases levels of free Ag released from immune complexes. Taken together, these results argue that DM and Ig intersect in the endocytic pathway of B cells with potential functional consequences.
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Affiliation(s)
- Henriette Macmillan
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael J. Strohman
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sashi Ayyangar
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wei Jiang
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Narendiran Rajasekaran
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Armin Spura
- Life Technologies, South San Francisco, CA 94080, USA
| | - Ann J. Hessell
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | | | - Elizabeth D. Mellins
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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9
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Parra-López CA, Bernal-Estévez D, Vargas LE, Pulido-Calixto C, Salazar LM, Calvo-Calle JM, Stern LJ. An unstable Th epitope of P. falciparum fosters central memory T cells and anti-CS antibody responses. PLoS One 2014; 9:e100639. [PMID: 24983460 PMCID: PMC4077652 DOI: 10.1371/journal.pone.0100639] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 05/29/2014] [Indexed: 11/19/2022] Open
Abstract
Malaria is transmitted by Plasmodium-infected anopheles mosquitoes. Widespread resistance of mosquitoes to insecticides and resistance of parasites to drugs highlight the urgent need for malaria vaccines. The most advanced malaria vaccines target sporozoites, the infective form of the parasite. A major target of the antibody response to sporozoites are the repeat epitopes of the circumsporozoite (CS) protein, which span almost one half of the protein. Antibodies to these repeats can neutralize sporozoite infectivity. Generation of protective antibody responses to the CS protein (anti-CS Ab) requires help by CD4 T cells. A CD4 T cell epitope from the CS protein designated T* was previously identified by screening T cells from volunteers immunized with irradiated P. falciparum sporozoites. The T* sequence spans twenty amino acids that contains multiple T cell epitopes restricted by various HLA alleles. Subunit malaria vaccines including T* are highly immunogenic in rodents, non-human primates and humans. In this study we characterized a highly conserved HLA-DRβ1*04:01 (DR4) restricted T cell epitope (QNT-5) located at the C-terminus of T*. We found that a peptide containing QNT-5 was able to elicit long-term anti-CS Ab responses and prime CD4 T cells in HLA-DR4 transgenic mice despite forming relatively unstable MHC-peptide complexes highly susceptible to HLA-DM editing. We attempted to improve the immunogenicity of QNT-5 by replacing the P1 anchor position with an optimal tyrosine residue. The modified peptide QNT-Y formed stable MHC-peptide complexes highly resistant to HLA-DM editing. Contrary to expectations, a linear peptide containing QNT-Y elicited almost 10-fold lower long-term antibody and IFN-γ responses compared to the linear peptide containing the wild type QNT-5 sequence. Some possibilities regarding why QNT-5 is more effective than QNT-Y in inducing long-term T cell and anti-CS Ab when used as vaccine are discussed.
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Affiliation(s)
- Carlos A. Parra-López
- Department of Microbiology, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
- Graduate School in Biomedical Sciences, Universidad Nacional de Colombia, Bogotá, Colombia
- * E-mail: (CAP-L); (LJS)
| | - David Bernal-Estévez
- Department of Microbiology, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
- Graduate School in Biomedical Sciences, Universidad Nacional de Colombia, Bogotá, Colombia
- Fundación Salud de los Andes, Research Group of Immunology and Clinical Oncology - GIIOC, Bogotá, Colombia
| | - Luis Eduardo Vargas
- Department of Microbiology, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Carolina Pulido-Calixto
- Department of Microbiology, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Luz Mary Salazar
- Faculty of Sciences, Universidad Nacional de Colombia, Bogotá, Colombia
| | - J. Mauricio Calvo-Calle
- University of Massachusetts Medical School, Department of Pathology and Biochemistry and the Department of Molecular Pharmacology, Worcester, Massachusetts, United States of America
| | - Lawrence J. Stern
- University of Massachusetts Medical School, Department of Pathology and Biochemistry and the Department of Molecular Pharmacology, Worcester, Massachusetts, United States of America
- * E-mail: (CAP-L); (LJS)
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10
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Fortin JS, Cloutier M, Thibodeau J. Exposing the Specific Roles of the Invariant Chain Isoforms in Shaping the MHC Class II Peptidome. Front Immunol 2013; 4:443. [PMID: 24379812 PMCID: PMC3861868 DOI: 10.3389/fimmu.2013.00443] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/26/2013] [Indexed: 11/26/2022] Open
Abstract
The peptide repertoire (peptidome) associated with MHC class II molecules (MHCIIs) is influenced by the polymorphic nature of the peptide binding groove but also by cell-intrinsic factors. The invariant chain (Ii) chaperones MHCIIs, affecting their folding and trafficking. Recent discoveries relating to Ii functions have provided insights as to how it edits the MHCII peptidome. In humans, the Ii gene encodes four different isoforms for which structure-function analyses have highlighted common properties but also some non-redundant roles. Another layer of complexity arises from the fact that Ii heterotrimerizes, a characteristic that has the potential to affect the maturation of associated MHCIIs in many different ways, depending on the isoform combinations. Here, we emphasize the peptide editing properties of Ii and discuss the impact of the various isoforms on the MHCII peptidome.
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Affiliation(s)
- Jean-Simon Fortin
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal , Montréal, QC , Canada
| | - Maryse Cloutier
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal , Montréal, QC , Canada
| | - Jacques Thibodeau
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal , Montréal, QC , Canada
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11
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De Riva A, Busch R. MHC Class II Protein Turnover In vivo and Its Relevance for Autoimmunity in Non-Obese Diabetic Mice. Front Immunol 2013; 4:399. [PMID: 24324466 PMCID: PMC3839011 DOI: 10.3389/fimmu.2013.00399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 11/08/2013] [Indexed: 11/19/2022] Open
Abstract
Major histocompatibility complex class II (MHCII) proteins are loaded with endosomal peptides and reside at the surface of antigen-presenting cells (APCs) for a time before being degraded. In vitro, MHCII protein levels and turnover are affected by peptide loading and by rates of ubiquitin-dependent internalization from the cell surface, which is in turn affected by APC type and activation state. Prior work suggested that fast turnover of disease-associated MHCII alleles may contribute to autoimmunity. We recently developed novel stable isotope tracer techniques to test this hypothesis in vivo. In non-obese diabetic (NOD) mice, a model of type 1 diabetes (T1D), MHCII turnover was affected by APC type, but unaffected by disease-associated structural polymorphism. Differences in MHCII turnover were observed between NOD colonies with high and low T1D incidence, but fast turnover was dispensable for autoimmunity. Moreover, NOD mice with gene knockouts of peptide loading cofactors do not develop T1D. Thus, fast turnover does not appear pathogenic, and conventional antigen presentation is critical for autoimmunity in NOD mice. However, shared environmental factors may underpin colony differences in MHCII protein turnover, immune regulation, and pathogenesis.
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Affiliation(s)
| | - Robert Busch
- Department of Medicine, University of Cambridge, Cambridge, UK
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12
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De Riva A, Varley MC, Bluck LJ, Cooke A, Deery MJ, Busch R. Accelerated turnover of MHC class II molecules in nonobese diabetic mice is developmentally and environmentally regulated in vivo and dispensable for autoimmunity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2013; 190:5961-71. [PMID: 23677470 PMCID: PMC3785126 DOI: 10.4049/jimmunol.1300551] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The H2-A(g7) (A(g7)) MHC class II (MHCII) allele is required for type 1 diabetes (T1D) in NOD mice. A(g7) not only has a unique peptide-binding profile, it was reported to exhibit biochemical defects, including accelerated protein turnover. Such defects were proposed to impair Ag presentation and, thus, self-tolerance. Here, we report measurements of MHCII protein synthesis and turnover in vivo. NOD mice and BALB/c controls were labeled continuously with heavy water, and splenic B cells and dendritic cells were isolated. MHCII molecules were immunoprecipitated and digested with trypsin. Digests were analyzed by liquid chromatography/mass spectrometry to quantify the fraction of newly synthesized MHCII molecules and, thus, turnover. MHCII turnover was faster in dendritic cells than in B cells, varying slightly between mouse strains. Some A(g7) molecules exhibited accelerated turnover in B cells from young, but not older, prediabetic female NOD mice. This acceleration was not detected in a second NOD colony with a high incidence of T1D. Turnover rates of A(g7) and H2-A(d) were indistinguishable in (NOD × BALB/c) F1 mice. In conclusion, accelerated MHCII turnover may occur in NOD mice, but it reflects environmental and developmental regulation, rather than a structural deficit of the A(g7) allele. Moreover, this phenotype wanes before the onset of overt T1D and is dispensable for the development of autoimmune diabetes. Our observations highlight the importance of in vivo studies in understanding the role of protein turnover in genotype/phenotype relationships and offer a novel approach for addressing this fundamental research challenge.
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Affiliation(s)
| | - Mark C. Varley
- Department of Medicine, University of Cambridge, Cambridge, UK
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Leslie J. Bluck
- Elsie Widdowson Laboratories, Medical Research Council Human Nutrition Research, Fulbourn, Cambridge, UK
| | - Anne Cooke
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Michael J. Deery
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK
| | - Robert Busch
- Department of Medicine, University of Cambridge, Cambridge, UK
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Pulse-chase analysis for studies of MHC class II biosynthesis, maturation, and peptide loading. Methods Mol Biol 2013; 960:411-432. [PMID: 23329504 DOI: 10.1007/978-1-62703-218-6_31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pulse-chase analysis is a commonly used technique for studying the synthesis, processing and transport of proteins. Cultured cells expressing proteins of interest are allowed to take up radioactively labeled amino acids for a brief interval ("pulse"), during which all newly synthesized proteins incorporate the label. The cells are then returned to nonradioactive culture medium for various times ("chase"), during which proteins may undergo conformational changes, trafficking, or degradation. Proteins of interest are isolated (usually by immunoprecipitation) and resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the fate of radiolabeled molecules is examined by autoradiography. This chapter describes a pulse-chase protocol suitable for studies of major histocompatibility complex (MHC) class II biosynthesis and maturation. We discuss how results are affected by the recognition by certain anti-class II antibodies of distinct class II conformations associated with particular biosynthetic states. Our protocol can be adapted to follow the fate of many other endogenously synthesized proteins, including viral or transfected gene products, in cultured cells.
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14
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HLA-DO acts as a substrate mimic to inhibit HLA-DM by a competitive mechanism. Nat Struct Mol Biol 2012; 20:90-8. [PMID: 23222639 PMCID: PMC3537886 DOI: 10.1038/nsmb.2460] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 10/25/2012] [Indexed: 12/03/2022]
Abstract
MHCII proteins bind peptide antigens in endosomal compartments of antigen-presenting cells. The non-classical MHCII protein HLA-DM chaperones peptide-free MHCII against inactivation and catalyzes peptide exchange on loaded MHCII. Another non-classical MHCII protein, HLA-DO, binds HLA-DM and influences the repertoire of peptides presented by MHCII proteins. However, the mechanism by which HLA-DO functions is unclear. Here we use x-ray crystallography, enzyme kinetics and mutagenesis approaches to investigate human HLA-DO structure and function. In complex with HLA-DM, HLA-DO adopts a classical MHCII structure, with alterations near the alpha subunit 310 helix. HLA-DO binds to HLA-DM at the same sites implicated in MHCII interaction, and kinetic analysis demonstrates that HLA-DO acts as a competitive inhibitor. These results show that HLA-DO inhibits HLA-DM function by acting as a substrate mimic and place constraints on possible functional roles for HLA-DO in antigen presentation.
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15
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Hou T, Macmillan H, Chen Z, Keech CL, Jin X, Sidney J, Strohman M, Yoon T, Mellins ED. An insertion mutant in DQA1*0501 restores susceptibility to HLA-DM: implications for disease associations. THE JOURNAL OF IMMUNOLOGY 2011; 187:2442-52. [PMID: 21775680 DOI: 10.4049/jimmunol.1100255] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
HLA-DM (DM) catalyzes CLIP release, stabilizes MHC class II molecules, and edits the peptide repertoire presented by class II. Impaired DM function may have profound effects on Ag presentation events in the thymus and periphery that are critical for maintenance of self-tolerance. The associations of the HLA-DQ2 (DQ2) allele with celiac disease and type 1 diabetes mellitus have been appreciated for a long time. The explanation for these associations, however, remains unknown. We previously found that DQ2 is a poor substrate for DM. In this study, to further characterize DQ2-DM interaction, we introduced point mutations into DQ2 on the proposed DQ2-DM interface to restore the sensitivity of DQ2 to DM. The effects of mutations were investigated by measuring the peptide dissociation and exchange rate in vitro, CLIP and DQ2 expression on the cell surface, and the presentation of α-II-gliadin epitope (residues 62-70) to murine, DQ2-restricted T cell hybridomas. We found that the three α-chain mutations (α+53G, α+53R, or αY22F) decreased the intrinsic stability of peptide-class II complex. More interestingly, the α+53G mutant restored DQ2 sensitivity to DM, likely due to improved interaction with DM. Our data also suggest that α-II-gliadin 62-70 is a DM-suppressed epitope. The DQ2 resistance to DM changes the fate of this peptide from a cryptic to an immunodominant epitope. Our findings elucidate the structural basis for reduced DQ2-DM interaction and have implications for mechanisms underlying disease associations of DQ2.
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Affiliation(s)
- Tieying Hou
- Department of Pediatrics, Program in Immunology, Stanford University, Stanford, CA 94305, USA
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Rinderknecht CH, Lu N, Crespo O, Truong P, Hou T, Wang N, Rajasekaran N, Mellins ED. I-Ag7 is subject to post-translational chaperoning by CLIP. Int Immunol 2010; 22:705-16. [PMID: 20547545 DOI: 10.1093/intimm/dxq056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Several MHC class II alleles linked with autoimmune diseases form unusually low-stability complexes with class II-associated invariant chain peptides (CLIP), leading us to hypothesize that this is an important feature contributing to autoimmune pathogenesis. We recently demonstrated a novel post-endoplasmic reticulum (ER) chaperoning role of the CLIP peptides for the murine class II allele I-E(d). In the current study, we tested the generality of this CLIP chaperone function using a series of invariant chain (Ii) mutants designed to have varying CLIP affinity for I-A(g7). In cells expressing these Ii CLIP mutants, I-A(g7) abundance, turnover and antigen presentation are all subject to regulation by CLIP affinity, similar to I-E(d). However, I-A(g7) undergoes much greater quantitative changes than observed for I-E(d). In addition, we find that Ii with a CLIP region optimized for I-A(g7) binding may be preferentially assembled with I-A(g7) even in the presence of higher levels of wild-type Ii. This finding indicates that, although other regions of Ii interact with class II, CLIP binding to the groove is likely to be a dominant event in assembly of nascent class II molecules with Ii in the ER.
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