1
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Clement CC, Nanaware PP, Stern LJ, Santambrogio L. A protocol for qualitative and quantitative measurement of endosomal processing using hot spot analysis. STAR Protoc 2021; 2:100648. [PMID: 34278334 PMCID: PMC8264744 DOI: 10.1016/j.xpro.2021.100648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A detailed quantification of antigen processing by endosomal compartments provides important information on the pattern of protein fragmentation. Here, we describe a protocol that combines gradient purified endosomes, incubated with antigens, followed by hot spot analysis of MS/MS-sequenced peptides. The analysis identifies differences in endosomal antigen processing by dendritic cells under diverse experimental conditions. For complete details on the use and execution of this protocol, please refer to Clement et al. (2021).
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Affiliation(s)
- Cristina C. Clement
- Department of Radiation Oncology, Weill Cornell Medicine, New York, NY 10065 USA
| | - Padma P. Nanaware
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Lawrence J. Stern
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Laura Santambrogio
- Department of Radiation Oncology, Weill Cornell Medicine, New York, NY 10065 USA
- Caryl and Israel Englander Institute for Precision Medicine, New York, NY 10065, USA
- Sandra and Edward Meyer Cancer Center, New York, NY 10065, USA
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2
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Cloutier M, Fortin JS, Thibodeau J. The transmembrane domain and luminal C-terminal region independently support invariant chain trimerization and assembly with MHCII into nonamers. BMC Immunol 2021; 22:56. [PMID: 34384367 PMCID: PMC8362237 DOI: 10.1186/s12865-021-00444-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 07/20/2021] [Indexed: 05/31/2023] Open
Abstract
Background Invariant chain (CD74, Ii) is a multifunctional protein expressed in antigen presenting cells. It assists the ER exit of various cargos and serves as a receptor for the macrophage migration inhibitory factor. The newly translated Ii chains trimerize, a structural feature that is not readily understood in the context of its MHCII chaperoning function. Two segments of Ii, the luminal C-terminal region (TRIM) and the transmembrane domain (TM), have been shown to participate in the trimerization process but their relative importance and impact on the assembly with MHCII molecules remains debated. Here, we addressed the requirement of these domains in the trimerization of human Ii as well as in the oligomerization with MHCII molecules. We used site-directed mutagenesis to generate series of Ii and DR mutants. These were transiently transfected in HEK293T cells to test their cell surface expression and analyse their interactions by co-immunoprecipitations. Results Our results showed that the TRIM domain is not essential for Ii trimerization nor for intracellular trafficking with MHCII molecules. We also gathered evidence that in the absence of TM, TRIM allows the formation of multi-subunit complexes with HLA-DR. Similarly, in the absence of TRIM, Ii can assemble into high-order structures with MHCII molecules. Conclusions Altogether, our data show that trimerization of Ii through either TM or TRIM sustains nonameric complex formation with MHCII molecules. Supplementary Information The online version contains supplementary material available at 10.1186/s12865-021-00444-6.
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Affiliation(s)
- Maryse Cloutier
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada
| | - Jean-Simon Fortin
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada
| | - Jacques Thibodeau
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada.
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3
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Partnering for the major histocompatibility complex class II and antigenic determinant requires flexibility and chaperons. Curr Opin Immunol 2021; 70:112-121. [PMID: 34146954 DOI: 10.1016/j.coi.2021.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/12/2021] [Indexed: 11/22/2022]
Abstract
Cytotoxic, or helper T cells recognize antigen via T cell receptors (TCRs) that can see their target antigen as short sequences of peptides bound to the groove of proteins of major histocompatibility complex (MHC) class I, and class II respectively. For MHC class II epitope selection from exogenous pathogens or self-antigens, participation of several accessory proteins, molecular chaperons, processing enzymes within multiple vesicular compartments is necessary. A major contributing factor is the MHC class II structure itself that uniquely offers a dynamic and flexible groove essential for epitope selection. In this review, I have taken a historical perspective focusing on the flexibility of the MHC II molecules as the driving force in determinant selection and interactions with the accessory molecules in antigen processing, HLA-DM and HLA-DO.
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4
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In vitro immunogenicity prediction: bridging between innate and adaptive immunity. Bioanalysis 2021; 13:1071-1081. [PMID: 34124935 DOI: 10.4155/bio-2021-0077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Development of antidrug antibodies (ADAs) is an undesirable potential outcome of administration of biotherapeutics and involves the innate and adaptive immune systems. ADAs can have detrimental clinical consequences: they can reduce biotherapeutic efficacy or produce adverse events. Because animal models are considered poor predictors of immunogenicity in humans, in vitro assays with human innate and adaptive immune cells are commonly used alternatives that can reveal cell-mediated unwanted immune responses. Multiple methods have been developed to assess the immune cell response following exposure to biotherapeutics and estimate the potential immunogenicity of biotherapeutics. This review highlights the role of innate and adaptive immune cells as the drivers of immunogenicity and summarizes the use of these cells in assays to predict clinical ADA.
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5
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Caballero B, Bourdenx M, Luengo E, Diaz A, Sohn PD, Chen X, Wang C, Juste YR, Wegmann S, Patel B, Young ZT, Kuo SY, Rodriguez-Navarro JA, Shao H, Lopez MG, Karch CM, Goate AM, Gestwicki JE, Hyman BT, Gan L, Cuervo AM. Acetylated tau inhibits chaperone-mediated autophagy and promotes tau pathology propagation in mice. Nat Commun 2021; 12:2238. [PMID: 33854069 PMCID: PMC8047017 DOI: 10.1038/s41467-021-22501-9] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/17/2021] [Indexed: 02/06/2023] Open
Abstract
Disrupted homeostasis of the microtubule binding protein tau is a shared feature of a set of neurodegenerative disorders known as tauopathies. Acetylation of soluble tau is an early pathological event in neurodegeneration. In this work, we find that a large fraction of neuronal tau is degraded by chaperone-mediated autophagy (CMA) whereas, upon acetylation, tau is preferentially degraded by macroautophagy and endosomal microautophagy. Rerouting of acetylated tau to these other autophagic pathways originates, in part, from the inhibitory effect that acetylated tau exerts on CMA and results in its extracellular release. In fact, experimental blockage of CMA enhances cell-to-cell propagation of pathogenic tau in a mouse model of tauopathy. Furthermore, analysis of lysosomes isolated from brains of patients with tauopathies demonstrates similar molecular mechanisms leading to CMA dysfunction. This study reveals that CMA failure in tauopathy brains alters tau homeostasis and could contribute to aggravate disease progression. The tau protein has been implicated in neurodegenerative disorders and can propagate from cell to cell. Here, the authors show that tau acetylation reduces its degradation by chaperone-mediated autophagy, causing re-routing to other autophagic pathways and increasing extracellular tau release.
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Affiliation(s)
- Benjamin Caballero
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.,Roche Chile Pharmaceuticals, Las Condes, Region Metropolitana, Chile
| | - Mathieu Bourdenx
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.,Institut des Maladies Neurodégénératives, CNRS, Université de Bordeaux, Bordeaux, France
| | - Enrique Luengo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute Teofilo Hernando for Drug Discovery, Department of Pharmacology, School of Medicine, Universidad Autonoma de Madrid, Madrid, Spain.,Instituto de Investigación Biosanitaria Hospital de la Princesa, Madrid, Spain
| | - Antonio Diaz
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Peter Dongmin Sohn
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Xu Chen
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Chao Wang
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Yves R Juste
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Susanne Wegmann
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Bindi Patel
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Zapporah T Young
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA, USA
| | - Szu Yu Kuo
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA, USA
| | - Jose Antonio Rodriguez-Navarro
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.,Instituto Ramón y Cajal de Investigaciones Sanitarias Hospital Ramón y Cajal, Madrid, Spain
| | - Hao Shao
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA, USA
| | - Manuela G Lopez
- Institute Teofilo Hernando for Drug Discovery, Department of Pharmacology, School of Medicine, Universidad Autonoma de Madrid, Madrid, Spain.,Instituto de Investigación Biosanitaria Hospital de la Princesa, Madrid, Spain
| | - Celeste M Karch
- Department of Psychiatry, Washington University, St. Louis, MO, USA
| | - Alison M Goate
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jason E Gestwicki
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA, USA
| | - Bradley T Hyman
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Li Gan
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.
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6
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Abstract
Endosomal microautophagy (eMI) is a type of autophagy that allows for the selective uptake and degradation of cytosolic proteins in late endosome/multi-vesicular bodies (LE/MVB). This process starts with the recognition of a pentapeptide amino acid KFERQ-like targeting motif in the substrate protein by the hsc70 chaperone, which then enables binding and subsequent uptake of the protein into the LE/MVB compartment. The recognition of a KFERQ-like motif by hsc70 is the same initial step in chaperone-mediated autophagy (CMA), a form of selective autophagy that degrades the hsc70-targeted proteins in lysosomes in a LAMP-2A dependent manner. The shared step of substrate recognition by hsc70, originally identified for CMA, makes it now necessary to differentiate between the two pathways. Here, we detail biochemical and imaging-based methods to track eMI activity in vitro with isolated LE/MVBs and in cells in culture using fluorescent reporters and highlight approaches to distinguish whether a protein is a substrate of eMI or CMA.
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Affiliation(s)
- Gregory J Krause
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY, United States; Institute for Aging Studies, Albert Einstein College of Medicine, New York, NY, United States
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY, United States; Institute for Aging Studies, Albert Einstein College of Medicine, New York, NY, United States.
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7
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Iacono A, Pompa A, De Marchis F, Panfili E, Greco FA, Coletti A, Orabona C, Volpi C, Belladonna ML, Mondanelli G, Albini E, Vacca C, Gargaro M, Fallarino F, Bianchi R, De Marcos Lousa C, Mazza EM, Bicciato S, Proietti E, Milano F, Martelli MP, Iamandii IM, Graupera Garcia-Mila M, Llena Sopena J, Hawkins P, Suire S, Okkenhaug K, Stark AK, Grassi F, Bellucci M, Puccetti P, Santambrogio L, Macchiarulo A, Grohmann U, Pallotta MT. Class IA PI3Ks regulate subcellular and functional dynamics of IDO1. EMBO Rep 2020; 21:e49756. [PMID: 33159421 DOI: 10.15252/embr.201949756] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 09/28/2020] [Accepted: 10/05/2020] [Indexed: 12/12/2022] Open
Abstract
Knowledge of a protein's spatial dynamics at the subcellular level is key to understanding its function(s), interactions, and associated intracellular events. Indoleamine 2,3-dioxygenase 1 (IDO1) is a cytosolic enzyme that controls immune responses via tryptophan metabolism, mainly through its enzymic activity. When phosphorylated, however, IDO1 acts as a signaling molecule in plasmacytoid dendritic cells (pDCs), thus activating genomic effects, ultimately leading to long-lasting immunosuppression. Whether the two activities-namely, the catalytic and signaling functions-are spatially segregated has been unclear. We found that, under conditions favoring signaling rather than catabolic events, IDO1 shifts from the cytosol to early endosomes. The event requires interaction with class IA phosphoinositide 3-kinases (PI3Ks), which become activated, resulting in full expression of the immunoregulatory phenotype in vivo in pDCs as resulting from IDO1-dependent signaling events. Thus, IDO1's spatial dynamics meet the needs for short-acting as well as durable mechanisms of immune suppression, both under acute and chronic inflammatory conditions. These data expand the theoretical basis for an IDO1-centered therapy in inflammation and autoimmunity.
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Affiliation(s)
- Alberta Iacono
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Andrea Pompa
- Department of Biomolecular Sciences, University Carlo Bo, Urbino, Italy.,Institute of Biosciences and Bioresources, National Research Council of Italy, Perugia, Italy
| | - Francesca De Marchis
- Institute of Biosciences and Bioresources, National Research Council of Italy, Perugia, Italy
| | - Eleonora Panfili
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Francesco A Greco
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Alice Coletti
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Ciriana Orabona
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Claudia Volpi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Maria L Belladonna
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | - Elisa Albini
- Department of Experimental Medicine, University of Perugia, Perugia, Italy.,Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Carmine Vacca
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Marco Gargaro
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | - Roberta Bianchi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Carine De Marcos Lousa
- Centre for Biomedical Sciences, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK.,Center for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | | | - Silvio Bicciato
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisa Proietti
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | | | - Ioana M Iamandii
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | - Judith Llena Sopena
- Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | | | | | - Klaus Okkenhaug
- Department of Pathology, University of Cambridge, Cambridge, UK
| | | | - Fabio Grassi
- Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - Michele Bellucci
- Institute of Biosciences and Bioresources, National Research Council of Italy, Perugia, Italy
| | - Paolo Puccetti
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Laura Santambrogio
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Antonio Macchiarulo
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Ursula Grohmann
- Department of Experimental Medicine, University of Perugia, Perugia, Italy.,Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Maria T Pallotta
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
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8
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Cho KJ, Ishido S, Eisenlohr LC, Roche PA. Activation of Dendritic Cells Alters the Mechanism of MHC Class II Antigen Presentation to CD4 T Cells. THE JOURNAL OF IMMUNOLOGY 2020; 204:1621-1629. [PMID: 31996461 DOI: 10.4049/jimmunol.1901234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/31/2019] [Indexed: 11/19/2022]
Abstract
Both immature and mature dendritic cells (DCs) can process and present foreign Ags to CD4 T cells; however, the mechanism by which MHC class II (MHC-II) in mature DCs acquires antigenic peptides remains unknown. To address this, we have studied Ag processing and presentation of two distinct CD4 T cell epitopes of the influenza virus hemagglutinin coat protein by both immature and mature mouse DCs. We find that immature DCs almost exclusively use newly synthesized MHC-II targeted to DM+ late endosomes for presentation to influenza virus-specific CD4 T cells. By contrast, mature DCs exclusively use recycling MHC-II that traffics to both early and late endosomes for antigenic peptide binding. Rab11a knockdown partially inhibits recycling of MHC-II in mature DCs and selectively inhibits presentation of an influenza virus hemagglutinin CD4 T cell epitope generated in early endosomes. These studies highlight a "division of labor" in MHC-II peptide binding, in which immature DCs preferentially present Ags acquired in Rab11a- DM+ late endosomes, whereas mature DCs use recycling MHC-II to present antigenic peptides acquired in both Rab11a+ early endosomes and Rab11a- endosomes for CD4 T cell activation.
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Affiliation(s)
- Kyung-Jin Cho
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Satoshi Ishido
- Department of Microbiology, Hyogo College of Medicine, Nishinomiya, 663-8501 Japan
| | - Laurence C Eisenlohr
- The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104; and.,Perelman School of Medicine at The University of Pennsylvania, Philadelphia, PA 19104
| | - Paul A Roche
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892;
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9
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Hernández-Pérez S, Vainio M, Kuokkanen E, Šuštar V, Petrov P, Forstén S, Paavola V, Rajala J, Awoniyi LO, Sarapulov AV, Vihinen H, Jokitalo E, Bruckbauer A, Mattila PK. B cells rapidly target antigen and surface-derived MHCII into peripheral degradative compartments. J Cell Sci 2019; 133:jcs.235192. [PMID: 31780582 DOI: 10.1242/jcs.235192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 11/20/2019] [Indexed: 11/20/2022] Open
Abstract
In order to mount high-affinity antibody responses, B cells internalise specific antigens and process them into peptides loaded onto MHCII for presentation to T helper cells (TH cells). While the biochemical principles of antigen processing and MHCII loading have been well dissected, how the endosomal vesicle system is wired to enable these specific functions remains much less studied. Here, we performed a systematic microscopy-based analysis of antigen trafficking in B cells to reveal its route to the MHCII peptide-loading compartment (MIIC). Surprisingly, we detected fast targeting of internalised antigen into peripheral acidic compartments that possessed the hallmarks of the MIIC and also showed degradative capacity. In these vesicles, internalised antigen converged rapidly with membrane-derived MHCII and partially overlapped with cathepsin-S and H2-M, both required for peptide loading. These early compartments appeared heterogenous and atypical as they contained a mixture of both early and late endosomal markers, indicating a specialized endosomal route. Together, our data suggest that, in addition to in the previously reported perinuclear late endosomal MIICs, antigen processing and peptide loading could have already started in these specialized early peripheral acidic vesicles (eMIIC) to support fast peptide-MHCII presentation.
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Affiliation(s)
- Sara Hernández-Pérez
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Marika Vainio
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Elina Kuokkanen
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland
| | - Vid Šuštar
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland
| | - Petar Petrov
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Sofia Forstén
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Vilma Paavola
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland
| | - Johanna Rajala
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland
| | - Luqman O Awoniyi
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Alexey V Sarapulov
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland.,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Helena Vihinen
- Institute of Biotechnology, Electron Microscopy Unit, 00014 University of Helsinki, Finland
| | - Eija Jokitalo
- Institute of Biotechnology, Electron Microscopy Unit, 00014 University of Helsinki, Finland
| | - Andreas Bruckbauer
- Facility for Imaging by Light Microscopy (FILM), National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Pieta K Mattila
- Institute of Biomedicine, and MediCity Research Laboratories, University of Turku, 20014 Turku, Finland .,Turku Bioscience, University of Turku and Åbo Akademi University, 20520 Turku, Finland
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10
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Graab P, Bock C, Weiss K, Hirth A, Koller N, Braner M, Jung J, Loehr F, Tampé R, Behrends C, Abele R. Lysosomal targeting of the ABC transporter TAPL is determined by membrane-localized charged residues. J Biol Chem 2019; 294:7308-7323. [PMID: 30877195 DOI: 10.1074/jbc.ra118.007071] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/08/2019] [Indexed: 01/16/2023] Open
Abstract
The human lysosomal polypeptide ABC transporter TAPL (ABC subfamily B member 9, ABCB9) transports 6-59-amino-acid-long polypeptides from the cytosol into lysosomes. The subcellular localization of TAPL depends solely on its N-terminal transmembrane domain, TMD0, which lacks conventional targeting sequences. However, the intracellular route and the molecular mechanisms that control TAPL localization remain unclear. Here, we delineated the route of TAPL to lysosomes and investigated the determinants of single trafficking steps. By synchronizing trafficking events by a retention using selective hooks (RUSH) assay and visualizing individual intermediate steps through immunostaining and confocal microscopy, we demonstrate that TAPL takes the direct route to lysosomes. We further identified conserved charged residues within TMD0 transmembrane helices that are essential for individual steps of lysosomal targeting. Substitutions of these residues retained TAPL in the endoplasmic reticulum (ER) or Golgi. We also observed that for release from the ER, a salt bridge between Asp-17 and Arg-57 is essential. An interactome analysis revealed that Yip1-interacting factor homolog B membrane-trafficking protein (YIF1B) interacts with TAPL. We also found that YIF1B is involved in ER-to-Golgi trafficking and interacts with TMD0 of TAPL via its transmembrane domain and that this interaction strongly depends on the newly identified salt bridge within TMD0. These results expand our knowledge about lysosomal trafficking of TAPL and the general function of extra transmembrane domains of ABC transporters.
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Affiliation(s)
| | | | | | | | | | | | - Jennifer Jung
- the Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, and
| | - Frank Loehr
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - Robert Tampé
- From the Institute of Biochemistry, Biocenter, and
| | - Christian Behrends
- the Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, and.,the Munich Cluster for Systems Neurology, Ludwig Maximilians University Munich, Feodor-Lynen-Strasse 17, 81377 Munich, Germany
| | - Rupert Abele
- From the Institute of Biochemistry, Biocenter, and
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11
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Baranov MV, Bianchi F, Schirmacher A, van Aart MAC, Maassen S, Muntjewerff EM, Dingjan I, Ter Beest M, Verdoes M, Keyser SGL, Bertozzi CR, Diederichsen U, van den Bogaart G. The Phosphoinositide Kinase PIKfyve Promotes Cathepsin-S-Mediated Major Histocompatibility Complex Class II Antigen Presentation. iScience 2018; 11:160-177. [PMID: 30612035 PMCID: PMC6319320 DOI: 10.1016/j.isci.2018.12.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/28/2018] [Accepted: 12/14/2018] [Indexed: 02/07/2023] Open
Abstract
Antigen presentation to T cells in major histocompatibility complex class II (MHC class II) requires the conversion of early endo/phagosomes into lysosomes by a process called maturation. Maturation is driven by the phosphoinositide kinase PIKfyve. Blocking PIKfyve activity by small molecule inhibitors caused a delay in the conversion of phagosomes into lysosomes and in phagosomal acidification, whereas production of reactive oxygen species (ROS) increased. Elevated ROS resulted in reduced activity of cathepsin S and B, but not X, causing a proteolytic defect of MHC class II chaperone invariant chain Ii processing. We developed a novel universal MHC class II presentation assay based on a bio-orthogonal "clickable" antigen and showed that MHC class II presentation was disrupted by the inhibition of PIKfyve, which in turn resulted in reduced activation of CD4+ T cells. Our results demonstrate a key role of PIKfyve in the processing and presentation of antigens, which should be taken into consideration when targeting PIKfyve in autoimmune disease and cancer.
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Affiliation(s)
- Maksim V Baranov
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Frans Bianchi
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands
| | - Anastasiya Schirmacher
- Institute of Organic and Biomolecular Chemistry, Georg-August-University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
| | - Melissa A C van Aart
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Sjors Maassen
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands
| | - Elke M Muntjewerff
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Ilse Dingjan
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Martijn Verdoes
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | | | - Carolyn R Bertozzi
- Department of Chemistry and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Ulf Diederichsen
- Institute of Organic and Biomolecular Chemistry, Georg-August-University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands.
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12
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Caballero B, Wang Y, Diaz A, Tasset I, Juste YR, Stiller B, Mandelkow EM, Mandelkow E, Cuervo AM. Interplay of pathogenic forms of human tau with different autophagic pathways. Aging Cell 2018; 17. [PMID: 29024336 PMCID: PMC5770880 DOI: 10.1111/acel.12692] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2017] [Indexed: 12/15/2022] Open
Abstract
Loss of neuronal proteostasis, a common feature of the aging brain, is accelerated in neurodegenerative disorders, including different types of tauopathies. Aberrant turnover of tau, a microtubule-stabilizing protein, contributes to its accumulation and subsequent toxicity in tauopathy patients' brains. A direct toxic effect of pathogenic forms of tau on the proteolytic systems that normally contribute to their turnover has been proposed. In this study, we analyzed the contribution of three different types of autophagy, macroautophagy, chaperone-mediated autophagy, and endosomal microautophagy to the degradation of tau protein variants and tau mutations associated with this age-related disease. We have found that the pathogenic P301L mutation inhibits degradation of tau by any of the three autophagic pathways, whereas the risk-associated tau mutation A152T reroutes tau for degradation through a different autophagy pathway. We also found defective autophagic degradation of tau when using mutations that mimic common posttranslational modifications in tau or known to promote its aggregation. Interestingly, although most mutations markedly reduced degradation of tau through autophagy, the step of this process preferentially affected varies depending on the type of tau mutation. Overall, our studies unveil a complex interplay between the multiple modifications of tau and selective forms of autophagy that may determine its physiological degradation and its faulty clearance in the disease context.
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Affiliation(s)
- Benjamin Caballero
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
| | - Yipeng Wang
- German Center for Neurodegenerative Diseases (DZNE); 53175 Bonn Germany
- CAESAR Research Center; 53175 Bonn Germany
| | - Antonio Diaz
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
| | - Inmaculada Tasset
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
| | - Yves Robert Juste
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
| | - Barbara Stiller
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE); 53175 Bonn Germany
- CAESAR Research Center; 53175 Bonn Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE); 53175 Bonn Germany
- CAESAR Research Center; 53175 Bonn Germany
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; Bronx NY 10461 USA
- Institute for Aging Studies; Albert Einstein College of Medicine; Bronx NY 10461 USA
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13
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Lee C, Lee M, Rhee I. Distinct features of dendritic cell-based immunotherapy as cancer vaccines. Clin Exp Vaccine Res 2018; 7:16-23. [PMID: 29399576 PMCID: PMC5795041 DOI: 10.7774/cevr.2018.7.1.16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 12/22/2017] [Accepted: 12/28/2017] [Indexed: 01/07/2023] Open
Abstract
Dendritic cells (DCs) are the most professional antigen presenting cells that play important roles in connection between innate and adaptive immune responses. Numerous studies revealed that the functions of DCs are related with the capture and processing of antigen as well as the migration to lymphoid tissues for the presenting antigens to T cells. These unique features of DCs allow them to be considered as therapeutic vaccines that can induce immune responses and anti-tumor activity. Here, we discuss and understand the immunological basis of DCs and presume the possibilities of DC-based vaccines for the promising cancer therapy.
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Affiliation(s)
- Chaelin Lee
- Department of Bioscience & Biotechnology, Sejong University, Seoul, Korea
| | - Myungmi Lee
- Department of Bioscience & Biotechnology, Sejong University, Seoul, Korea
| | - Inmoo Rhee
- Department of Bioscience & Biotechnology, Sejong University, Seoul, Korea
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14
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Veselits M, Tanaka A, Chen Y, Hamel K, Mandal M, Kandasamy M, Manicassamy B, O'Neill SK, Wilson P, Sciammas R, Clark MR. Igβ ubiquitination activates PI3K signals required for endosomal sorting. J Exp Med 2017; 214:3775-3790. [PMID: 29141870 PMCID: PMC5716028 DOI: 10.1084/jem.20161868] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 07/20/2017] [Accepted: 09/12/2017] [Indexed: 12/26/2022] Open
Abstract
Veselits et al. show that Igβ ubiquitination activates PI3K and the accumulation of PIP3 on BCR-associated endosomal membranes, which is necessary and sufficient for sorting into classical antigen-processing compartments. Surprisingly, proper BCR sorting is critical for endosomal TLR activation yet dispensable for T-dependent humoral immunity. A wealth of in vitro data has demonstrated a central role for receptor ubiquitination in endocytic sorting. However, how receptor ubiquitination functions in vivo is poorly understood. Herein, we report that ablation of B cell antigen receptor ubiquitination in vivo uncouples the receptor from CD19 phosphorylation and phosphatidylinositol 3-kinase (PI3K) signals. These signals are necessary and sufficient for accumulating phosphatidylinositol (3,4,5)-trisphosphate (PIP3) on B cell receptor–containing early endosomes and proper sorting into the MHC class II antigen-presenting compartment (MIIC). Surprisingly, MIIC targeting is dispensable for T cell–dependent immunity. Rather, it is critical for activating endosomal toll-like receptors and antiviral humoral immunity. These findings demonstrate a novel mechanism of receptor endosomal signaling required for specific peripheral immune responses.
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Affiliation(s)
- Margaret Veselits
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Azusa Tanaka
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Yaoqing Chen
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Keith Hamel
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Malay Mandal
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | | | | | | | - Patrick Wilson
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Roger Sciammas
- Center for Comparative Medicine, University of California, Davis, Davis, CA
| | - Marcus R Clark
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
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15
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Abstract
Unlike B cells, CD8-positive and CD4-positive T cells of the adaptive immune system do not recognize intact foreign proteins but instead recognize polypeptide fragments of potential antigens. These antigenic peptides are expressed on the surface of antigen presenting cells bound to MHC class I and MHC class II proteins. Here, we review the basics of antigen acquisition by antigen presenting cells, antigen proteolysis into polypeptide fragments, antigenic peptide binding to MHC proteins, and surface display of both MHC class I-peptide and MHC class II-peptide complexes.
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16
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Sadegh-Nasseri S. A step-by-step overview of the dynamic process of epitope selection by major histocompatibility complex class II for presentation to helper T cells. F1000Res 2016; 5. [PMID: 27347387 PMCID: PMC4902097 DOI: 10.12688/f1000research.7664.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/27/2016] [Indexed: 11/25/2022] Open
Abstract
T cell antigen receptors (TCRs) expressed on cytotoxic or helper T cells can only see their specific target antigen as short sequences of peptides bound to the groove of proteins of major histocompatibility complex (MHC) class I, and class II respectively. In addition to the many steps, several participating proteins, and multiple cellular compartments involved in the processing of antigens, the MHC structure, with its dynamic and flexible groove, has perfectly evolved as the underlying instrument for epitope selection. In this review, I have taken a step-by-step, and rather historical, view to describe antigen processing and determinant selection, as we understand it today, all based on decades of intense research by hundreds of laboratories.
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17
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α-Synuclein-independent histopathological and motor deficits in mice lacking the endolysosomal Parkinsonism protein Atp13a2. J Neurosci 2015; 35:5724-42. [PMID: 25855184 DOI: 10.1523/jneurosci.0632-14.2015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Accumulating evidence from genetic and biochemical studies implicates dysfunction of the autophagic-lysosomal pathway as a key feature in the pathogenesis of Parkinson's disease (PD). Most studies have focused on accumulation of neurotoxic α-synuclein secondary to defects in autophagy as the cause of neurodegeneration, but abnormalities of the autophagic-lysosomal system likely mediate toxicity through multiple mechanisms. To further explore how endolysosomal dysfunction causes PD-related neurodegeneration, we generated a murine model of Kufor-Rakeb syndrome (KRS), characterized by early-onset Parkinsonism with additional neurological features. KRS is caused by recessive loss-of-function mutations in the ATP13A2 gene encoding the endolysosomal ATPase ATP13A2. We show that loss of ATP13A2 causes a specific protein trafficking defect, and that Atp13a2 null mice develop age-related motor dysfunction that is preceded by neuropathological changes, including gliosis, accumulation of ubiquitinated protein aggregates, lipofuscinosis, and endolysosomal abnormalities. Contrary to predictions from in vitro data, in vivo mouse genetic studies demonstrate that these phenotypes are α-synuclein independent. Our findings indicate that endolysosomal dysfunction and abnormalities of α-synuclein homeostasis are not synonymous, even in the context of an endolysosomal genetic defect linked to Parkinsonism, and highlight the presence of α-synuclein-independent neurotoxicity consequent to endolysosomal dysfunction.
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18
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Hennies CM, Lehn MA, Janssen EM. Quantitating MHC class II trafficking in primary dendritic cells using imaging flow cytometry. J Immunol Methods 2015; 423:18-28. [PMID: 25967952 DOI: 10.1016/j.jim.2015.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 04/24/2015] [Accepted: 04/30/2015] [Indexed: 01/24/2023]
Abstract
Presentation of antigenic peptides in MHC class II (MHCII) on dendritic cells (DCs) is the first step in the activation of antigen-specific CD4(+)T cells. The expression of surface MHCII-peptide complexes is tightly regulated as the frequency of MHCII-peptide complexes can affect the magnitude, as well as the phenotype of the ensuing CD4(+)T cell response. The surface MHCII-peptide levels are determined by the balance between expression of newly generated complexes, complex internalization, and their subsequent re-emergence or degradation. However, the molecular mechanisms that underpin these processes are still poorly understood. Here we describe a multispectral imaging flow cytometry assay to visualize MHCII trafficking that can be used as a tool to dissect the molecular mechanisms that regulate MHCII homeostasis in primary mouse and human DCs.
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Affiliation(s)
- Cassandra M Hennies
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Maria A Lehn
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Edith M Janssen
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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19
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Xu F, Ye H, Liu X, Chen F, Ding X, Chen X, Li L. The intracellular localization and association of porcine Ia-associated invariant chain with the MHC class I-related porcine neonatal Fc receptor for IgG. Gene 2015; 559:9-15. [PMID: 25592816 DOI: 10.1016/j.gene.2015.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 01/05/2015] [Indexed: 10/24/2022]
Abstract
The neonatal Fc receptor (FcRn) transports IgG from mother to young and is involved in antigen presentation. FcRn is structurally similar to MHC class I, but its intracellular trafficking pathway is much more analogous to that of MHC class II. Ia-associated invariant chain (Ii) molecules play an additional role in directing MHC class II trafficking within the endocytic compartments by physical association with MHC class II. This study addresses the question of whether pig Ii chain plays this important role in FcRn trafficking to the endoplasmic reticulum. Red or green fluorescent protein-fused Ii or FcRn was constructed, and the intracellular localization of pig Ii with FcRn was detected using confocal microscopy. Immunoprecipitation and western blotting were used to test for their association. The results indicate that pig Ii chain specifically interacts with both FcRn H chain alone and FcRn-β2m complex, and the CLIP in Ii was required for FcRn-Ii association. A truncated FcRn deletion in the cytoplasmic tail changed the intracellular localization of FcRn. However, the truncated FcRn can still combine Ii. This indicated that the cytoplasmic tail of FcRn fails to affect FcRn association with Ii. These results suggest that association of FcRn with Ii chain is relevant, and appreciation of this process is important to the understanding of how IgG is transported.
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Affiliation(s)
- Fazhi Xu
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
| | - Hong Ye
- AnHui Academy of Medical Sciences, Hefei 230061, China.
| | - Xuelan Liu
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
| | - Fangfang Chen
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
| | - Xiaoling Ding
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
| | - Xingyong Chen
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
| | - Lvmu Li
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China.
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20
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The ins and outs of MHC class II-mediated antigen processing and presentation. Nat Rev Immunol 2015; 15:203-16. [PMID: 25720354 DOI: 10.1038/nri3818] [Citation(s) in RCA: 617] [Impact Index Per Article: 68.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Antigenic peptide-loaded MHC class II molecules (peptide-MHC class II) are constitutively expressed on the surface of professional antigen-presenting cells (APCs), including dendritic cells, B cells, macrophages and thymic epithelial cells, and are presented to antigen-specific CD4(+) T cells. The mechanisms of antigen uptake, the nature of the antigen processing compartments and the lifetime of cell surface peptide-MHC class II complexes can vary depending on the type of APC. It is likely that these differences are important for the function of each distinct APC subset in the generation of effective adaptive immune responses. In this Review, we describe our current knowledge of the mechanisms of uptake and processing of antigens, the intracellular formation of peptide-MHC class II complexes, the intracellular trafficking of peptide-MHC class II complexes to the APC plasma membrane and their ultimate degradation.
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21
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Bejarano E, Yuste A, Patel B, Stout RF, Spray DC, Cuervo AM. Connexins modulate autophagosome biogenesis. Nat Cell Biol 2014; 16:401-14. [PMID: 24705551 PMCID: PMC4008708 DOI: 10.1038/ncb2934] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 02/14/2014] [Indexed: 12/17/2022]
Abstract
The plasma membrane contributes to the formation of autophagosomes, the double-membrane vesicles that sequester cytosolic cargo and deliver it to lysosomes for degradation during autophagy. In this study, we have identified a regulatory role for connexins (Cx), the main components of plasma membrane gap junctions, in autophagosome formation. We have found that plasma-membrane-localized Cx proteins constitutively downregulate autophagy through a direct interaction with several autophagy-related proteins involved in the initial steps of autophagosome formation, such as Atg16 and components of the PI(3)K autophagy initiation complex (Vps34, Beclin-1 and Vps15). On nutrient starvation, this inhibitory effect is released by the arrival of Atg14 to the Cx-Atg complex. This promotes the internalization of Cx-Atg along with Atg9, which is also recruited to the plasma membrane in response to starvation. Maturation of the Cx-containing pre-autophagosomes into autophagosomes leads to degradation of these endogenous inhibitors, allowing for sustained activation of autophagy.
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Affiliation(s)
- Eloy Bejarano
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andrea Yuste
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Bindi Patel
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Randy F. Stout
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David C. Spray
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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22
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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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23
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ten Broeke T, Wubbolts R, Stoorvogel W. MHC class II antigen presentation by dendritic cells regulated through endosomal sorting. Cold Spring Harb Perspect Biol 2013; 5:a016873. [PMID: 24296169 DOI: 10.1101/cshperspect.a016873] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
For the initiation of adaptive immune responses, dendritic cells present antigenic peptides in association with major histocompatibility complex class II (MHCII) to naïve CD4(+) T lymphocytes. In this review, we discuss how antigen presentation is regulated through intracellular processing and trafficking of MHCII. Newly synthesized MHCII is chaperoned by the invariant chain to endosomes, where peptides from endocytosed pathogens can bind. In nonactivated dendritic cells, peptide-loaded MHCII is ubiquitinated and consequently sorted by the ESCRT machinery to intraluminal vesicles of multivesicular bodies, ultimately leading to lysosomal degradation. Ubiquitination of newly synthesized MHCII is blocked when dendritic cells are activated, now allowing its transfer to the cell surface. This mode of regulation for MHCII is a prime example of how molecular processing and sorting at multivesicular bodies can determine the expression of signaling receptors at the plasma membrane.
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Affiliation(s)
- Toine ten Broeke
- Utrecht University, Faculty of Veterinary Medicine, Department of Biochemistry and Cell Biology, Yalelaan 2, 3584 CM, Utrecht, The Netherlands
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24
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Microautophagy of cytosolic proteins by late endosomes. Dev Cell 2011; 20:131-9. [PMID: 21238931 DOI: 10.1016/j.devcel.2010.12.003] [Citation(s) in RCA: 620] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/26/2010] [Accepted: 12/04/2010] [Indexed: 02/06/2023]
Abstract
Autophagy delivers cytosolic components to lysosomes for their degradation. The delivery of autophagic cargo to late endosomes for complete or partial degradation has also been described. In this report we present evidence that distinct autophagic mechanisms control cytosolic protein delivery to late endosomes and identify a microautophagy-like process that delivers soluble cytosolic proteins to the vesicles of late endosomes/multivesicular bodies (MVBs). This microautophagy-like process has selectivity and is distinct from chaperone-mediated autophagy that occurs in lysosomes. Endosomal microautophagy occurs during MVB formation, relying on the ESCRT I and III systems for formation of the vesicles in which the cytosolic cargo is internalized. Protein cargo selection is mediated by the chaperone hsc70 and requires the cationic domain of hsc70 for electrostatic interactions with the endosomal membrane. Therefore, we propose that endosomal microautophagy shares molecular components with both the endocytic and autophagic pathways.
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25
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Ye L, Liu X, Rout SN, Li Z, Yan Y, Lu L, Kamala T, Nanda NK, Song W, Samal SK, Zhu X. The MHC class II-associated invariant chain interacts with the neonatal Fc gamma receptor and modulates its trafficking to endosomal/lysosomal compartments. THE JOURNAL OF IMMUNOLOGY 2008; 181:2572-85. [PMID: 18684948 DOI: 10.4049/jimmunol.181.4.2572] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The neonatal Fc receptor for IgG (FcRn) transfers maternal IgG to the offspring and protects IgG from degradation. The FcRn resides in an acidic intracellular compartment, allowing it to bind IgG. In this study, we found the association of FcRn and invariant chain (Ii). The interaction was initiated within the endoplasmic reticulum by Ii binding to either the FcRn H chain alone or FcRn H chain-beta(2)-microglobulin complex and appeared to be maintained throughout the endocytic pathway. The CLIP in Ii was not required for FcRn-Ii association. The interaction was also detected in IFN-gamma-treated THP-1, epithelial and endothelial cells, and immature mouse DCs. A truncated FcRn without the cytoplasmic tail was unable to traffic to early endosomes; however, its location in early endosomes was restored by Ii expression. FcRn was also detected in the late endosome/lysosome only in the presence of Ii or on exposure to IFN-gamma. In immature human or mouse DCs, FcRn was barely detected in the late endosome/lysosome in the absence of Ii. Furthermore, the cytoplasmic tail of Ii conferred tailless FcRn to route to both the early endosome and late endosome/lysosome in a hybrid molecule. Because the FcRn is expressed in macrophages and DCs or epithelial and endothelial cells where Ii is induced under inflammation and infection, these results reveal the complexity of FcRn trafficking in which Ii is capable of expanding the boundary of FcRn trafficking. Taken together, the intracellular trafficking of FcRn is regulated by its intrinsic sorting information and/or an interaction with Ii chain.
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Affiliation(s)
- Lilin Ye
- Laboratory of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD 20742, USA
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Tallóczy Z, Martinez J, Joset D, Ray Y, Gácser A, Toussi S, Mizushima N, Nosanchuk JD, Goldstein H, Loike J, Sulzer D, Santambrogio L. Methamphetamine inhibits antigen processing, presentation, and phagocytosis. PLoS Pathog 2008; 4:e28. [PMID: 18282092 PMCID: PMC2242831 DOI: 10.1371/journal.ppat.0040028] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 12/28/2007] [Indexed: 12/04/2022] Open
Abstract
Methamphetamine (Meth) is abused by over 35 million people worldwide. Chronic Meth abuse may be particularly devastating in individuals who engage in unprotected sex with multiple partners because it is associated with a 2-fold higher risk for obtaining HIV and associated secondary infections. We report the first specific evidence that Meth at pharmacological concentrations exerts a direct immunosuppressive effect on dendritic cells and macrophages. As a weak base, Meth collapses the pH gradient across acidic organelles, including lysosomes and associated autophagic organelles. This in turn inhibits receptor-mediated phagocytosis of antibody-coated particles, MHC class II antigen processing by the endosomal–lysosomal pathway, and antigen presentation to splenic T cells by dendritic cells. More importantly Meth facilitates intracellular replication and inhibits intracellular killing of Candida albicans and Cryptococcus neoformans, two major AIDS-related pathogens. Meth exerts previously unreported direct immunosuppressive effects that contribute to increased risk of infection and exacerbate AIDS pathology. There is a new population of HIV+ men who are developing AIDS over months instead of years as typical. It has recently become popular among gay and bisexual men to consume very high levels of Meth. Unsafe sex together with Meth abuse has been suspected to lead to rapid disease progression. While studies show exacerbated AIDS symptoms and disease progression in HIV+ Meth abusers, the molecular mechanism is yet unknown. It was postulated, yet unproven, that the rapid disease progression might be due to a mutant “superstrain” of HIV that was extremely virulent. It was also assumed that the effects of the drug on behavior may lead to unsafe sex, although this would not explain the more rapid time course of the disease. We now demonstrate the first direct evidence that Meth is an immunosuppressive agent, and that the molecular mechanism of this immunosuppression is due to the collapse of acidic organelle pH in cells of the immune system, inhibiting the functions of antigen presentation, as well as phagocytosis. These effects compromise the immune response to opportunistic infections and HIV. These findings could have a major impact on public health, as there are over 35 million Meth abusers worldwide
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Affiliation(s)
- Zsolt Tallóczy
- Department of Neurology, Columbia University, New York, New York, United States of America
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McCormick PJ, Martina JA, Bonifacino JS. Involvement of clathrin and AP-2 in the trafficking of MHC class II molecules to antigen-processing compartments. Proc Natl Acad Sci U S A 2005; 102:7910-5. [PMID: 15911768 PMCID: PMC1138261 DOI: 10.1073/pnas.0502206102] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Indexed: 11/18/2022] Open
Abstract
Major histocompatibility complex class II (MHC-II) molecules are composed of two polymorphic chains, alpha and beta, which assemble with an invariant chain, Ii, in the endoplasmic reticulum. The assembled MHC-II complexes are transported to the Golgi complex and then to late endosomes/lysosomes, where Ii is degraded and alphabeta dimers bind peptides derived from exogenous antigens. Targeting of MHC-II molecules to these compartments is mediated by two dileucine-based signals in the cytoplasmic domain of Ii. These signals bind in vitro to two adaptor protein (AP) complexes, AP-1 and AP-2, which are components of clathrin coats involved in vesicle formation and cargo sorting. The physiological roles of these proteins in MHC-II molecule trafficking, however, remain to be addressed. Here, we report the use of RNA interference to examine the involvement of clathrin and four AP complexes (AP-1, AP-2, AP-3, and AP-4) in MHC-II molecule trafficking in vivo. We found that depletion of clathrin or AP-2 caused >10-fold increases in Ii expression on the cell surface and a concomitant decrease in Ii localization to endosomal/lysosomal vesicles. In addition, depletion of clathrin or AP-2 delayed the degradation of Ii and reduced the surface expression of peptide-loaded alphabeta dimers. In contrast, depletion of AP-1, AP-3, or AP-4 had little or no effect. These findings demonstrate that clathrin and AP-2 participate in MHC-II molecule trafficking in vivo. Because AP-2 is only associated with the plasma membrane, these results also indicate that a significant pool of MHC-II molecules traffic to the endosomal-lysosomal system by means of the cell surface.
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Affiliation(s)
- Peter J McCormick
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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28
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Dugast M, Toussaint H, Dousset C, Benaroch P. AP2 clathrin adaptor complex, but not AP1, controls the access of the major histocompatibility complex (MHC) class II to endosomes. J Biol Chem 2005; 280:19656-64. [PMID: 15749704 DOI: 10.1074/jbc.m501357200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Newly synthesized MHC II alpha- and beta-chains associated with the invariant chain chaperone (Ii) enter the endocytic pathway for Ii degradation and loading with peptides before transport to the cell surface. It is unclear how alphabetaIi complexes are sorted from the Golgi apparatus and directed to endosomes. However, indirect evidence tends to support direct transport involving the AP1 clathrin adaptor complex. Surprisingly, we show here that knocking down the production of AP1 by RNA interference did not affect the trafficking of alphabetaIi complexes. In contrast, AP2 depletion led to a large increase in surface levels of alphabetaIi complexes, inhibited their rapid internalization, and strongly delayed the appearance of mature MHC II in intracellular compartments. Thus, in the cell systems studied here, rapid internalization of alphabetaIi complexes via an AP2-dependent pathway represents a key step for MHC II delivery to endosomes and lysosomes.
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Affiliation(s)
- Marc Dugast
- INSERM U520 Institut Curie, Section de Recherche, Paris, France
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29
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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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30
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Perrin-Cocon LA, Villiers CL, Salamero J, Gabert F, Marche PN. B cell receptors and complement receptors target the antigen to distinct intracellular compartments. THE JOURNAL OF IMMUNOLOGY 2004; 172:3564-72. [PMID: 15004157 DOI: 10.4049/jimmunol.172.6.3564] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The processing of exogenous Ags is an essential step for the generation of immunogenic peptides that will be presented to T cells. This processing relies on the efficient intracellular targeting of Ags, because it depends on the content of the compartments in which Ags are delivered in APCs. Opsonization of Ags by the complement component C3 strongly enhances their presentation by B cells and increases their immunogenicity in vivo. To investigate the role of C3 in the targeting of Ags, we compared the intracellular traffic of proteins internalized by complement receptor (CR) and B cell receptor (BCR) in B lymphocytes. Whereas both receptors are able to induce efficient Ag presentation, their intracellular pathways are different. CR ligand is delivered to compartments containing MHC class II molecules (MHC-II) but devoid of transferrin receptor and Lamp-2, whereas BCR rapidly targets its ligand toward Lamp-2-positive, late endosomal MHC-II-enriched compartments through intracellular vesicles containing transferrin receptor. CR and BCR are delivered to distinct endocytic pathways, and the kinetic evolution of the protein content of these pathways is very different. Both types of compartments contain MHC-II, but CR-targeted compartments receive less neosynthesized MHC-II than do BCR-targeted compartments. The targeting induced by CR toward compartments that are distinct from BCR-targeted compartments probably participates in C3 modulation of Ag presentation.
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Affiliation(s)
- Laure A Perrin-Cocon
- Laboratoire d'Immunochimie, Département de Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, Unité 548, Université Joseph Fourier, Grenoble, France
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31
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Pu Z, Lovitch SB, Bikoff EK, Unanue ER. T Cells Distinguish MHC-Peptide Complexes Formed in Separate Vesicles and Edited by H2-DM. Immunity 2004; 20:467-76. [PMID: 15084275 DOI: 10.1016/s1074-7613(04)00073-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 02/04/2004] [Accepted: 03/01/2004] [Indexed: 11/24/2022]
Abstract
The peptide spanning residues 48-61 of hen egg white lysozyme (HEL) presented by I-A(k) gives rise to two T cell populations, referred to as type A and B, that distinguish the complex generated intracellularly upon processing of HEL from that formed with exogenous peptide. Here, we ascribe this difference to recognition of distinct conformers of the complex and show that formation of the two complexes results from antigen processing in different intracellular compartments and is dependent upon H2-DM. While the type A complex preferentially formed in a lysosome-like late vesicle, the type B complex failed to form in this compartment; this distinction was abolished in antigen-presenting cells lacking DM. Experiments in vitro indicated that H2-DM acts directly on the complex to eliminate the type B conformation. We conclude that different antigen-processing pathways generate distinct MHC-peptide conformers, priming T cells with distinct specificity that may play unique roles in immunity.
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Affiliation(s)
- Zheng Pu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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32
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Lautwein A, Kraus M, Reich M, Burster T, Brandenburg J, Overkleeft HS, Schwarz G, Kammer W, Weber E, Kalbacher H, Nordheim A, Driessen C. Human B lymphoblastoid cells contain distinct patterns of cathepsin activity in endocytic compartments and regulate MHC class II transport in a cathepsin S-independent manner. J Leukoc Biol 2004; 75:844-55. [PMID: 14966190 DOI: 10.1189/jlb.0803367] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Endocytic proteolysis represents a major functional component of the major histocompatibility complex class II antigen-presentation machinery. Although transport and assembly of class II molecules in the endocytic compartment are well characterized, we lack information about the pattern of endocytic protease activity along this pathway. Here, we used chemical tools that visualize endocytic proteases in an activity-dependent manner in combination with subcellular fractionation to dissect the subcellular distribution of the major cathepsins (Cat) CatS, CatB, CatH, CatD, CatC, and CatZ as well as the asparagine-specific endoprotease (AEP) in human B-lymphoblastoid cells (BLC). Endocytic proteases were distributed in two distinct patterns: CatB and CatZ were most prominent in early and late endosomes but absent from lysosomes, and CatH, CatS, CatD, CatC, and AEP distributed between late endosomes and lysosomes, suggesting that CatB and CatZ might be involved in the initial proteolytic attack on a given antigen. The entire spectrum of protease activity colocalized with human leukocyte antigen-DM and the C-terminal and N-terminal processing of invariant chain (Ii) in late endosomes. CatS was active in all endocytic compartments. Surprisingly and in contrast with results from dendritic cells, inhibition of CatS activity by leucine-homophenylalanine-vinylsulfone-phenol prevented N-terminal processing of Ii but did not alter the subcellular trafficking or surface delivery of class II complexes, as deferred from pulse-chase analysis in combination with subcellular fractionation and biotinylation of cell-surface protein. Thus, BLC contain distinct activity patterns of proteases in endocytic compartments and regulate the intracellular transport and surface-delivery of class II in a CatS-independent manner.
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Affiliation(s)
- Alfred Lautwein
- Department of Medicine II, Medical and Natural Sciences Research Centre, Germany
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33
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Neumann J, Eis-Hübinger AM, Koch N. Herpes simplex virus type 1 targets the MHC class II processing pathway for immune evasion. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:3075-83. [PMID: 12960333 DOI: 10.4049/jimmunol.171.6.3075] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
HSV type 1 (HSV-1) has evolved numerous strategies for modifying immune responses that protect against infection. Important targets of HSV-1 infection are the MHC-encoded peptide receptors. Previous studies have shown that a helper T cell response and Ab production play important roles in controlling HSV-1 infection. The reduced capacity of infected B cells to stimulate CD4(+) T cells is beneficial for HSV-1 to evade immune defenses. We investigated the impact of HSV-1 infection on the MHCII processing pathway, which is critical to generate CD4(+) T cell help. HSV-1 infection targets the molecular coplayers of MHC class II processing, HLA-DR (DR), HLA-DM (DM), and invariant chain (Ii). HSV-1 infection strongly reduces expression of Ii, which impairs formation of SDS-resistant DR-peptide complexes. Residual activity of the MHC class II processing pathway is diminished by viral envelope glycoprotein B (gB). Binding of gB to DR competes with binding to Ii. In addition, we found gB associated with DM molecules. Both, gB-associated DR and DM heterodimers are exported from the endoplasmic reticulum, as indicated by carbohydrate maturation. Evaluation of DR, DM, and gB subcellular localization revealed abundant changes in intracellular distribution. DR-gB complexes are localized in subcellular vesicles and restrained from cell surface expression.
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Affiliation(s)
- Jürgen Neumann
- Section of Immunobiology, Institute for Molecular Physiology, University of Bonn, Bonn, Germany
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34
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Arudchelvan Y, Nishimura Y, Tokuda N, Sawada T, Ueyama Y, Fukumoto T. Identification and characterization of major histocompatibility complex class II compartments in cortical thymic epithelial cells. THE ANATOMICAL RECORD. PART A, DISCOVERIES IN MOLECULAR, CELLULAR, AND EVOLUTIONARY BIOLOGY 2003; 274:798-806. [PMID: 12923890 DOI: 10.1002/ar.a.10081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Previous studies have concentrated on elucidating the subcellular localization of major histocompatibility (MHC) class II molecules mainly in B cells, macrophages, and dendritic cells. Despite very rich cell-surface expression of MHC class II molecules by cortical thymic epithelial cells (cTECs), little is known regarding the expression of these molecules by cTECs at the subcellular level. In the present study we focused on the identification and characterization of MHC class II compartments (MIICs) in cTECs in situ by immunogold electron microscopy (IEM). We found that MHC class II molecules were located exclusively in the cytoplasmic vacuoles, and we identified these MHC class II molecule-containing cytoplasmic vacuoles as MIICs in cTECs. These MIICs were immunopositive for early endosomal, late endosomal, and lysosomal markers. Moreover, in these MIICs, MHC class II molecules were colocalized with cathepsin L, H2-DM, class II-associated invariant chain (Ii), and class II-associated invariant chain peptide (CLIP). Similarly, Ii molecules were colocalized with endosomal and lysosomal markers, cathepsin L, and H2-DM in the vacuoles. Taken together, these results suggest that MIICs in cTECs represent conventional endocytic compartments. The colocalization of MHC class II molecule or Ii with cathepsin L and H2-DM in the MIICs suggests that MIICs in cTECs may be sites of Ii degradation and peptide loading.
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Affiliation(s)
- Yamini Arudchelvan
- Department of Oral and Maxillofacial Surgery, Yamaguchi University School of Medicine, Ube, Japan.
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35
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Abstract
Ever since the emergence of models for the processing and presentation of antigenic determinants by MHC class II molecules, the main view has been that proteins are unfolded, enzymatically cleaved into peptide lengths of about 12-25 amino acids and then loaded onto MHC class II molecules. There is, however, an alternative model stating that partially intact unfolding antigens are first bound by MHC class II molecules and then trimmed to fragments of a smaller size while remaining bound to the MHC class II molecule. In this analysis, we make the case that a considerable portion of the elutable peptide cargo belongs to this latter class.
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Affiliation(s)
- Eli E Sercarz
- Torrey Pines Institute for Molecular Studies, San Diego, California 92121, USA.
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36
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Clark MR, Massenburg D, Zhang M, Siemasko K. Molecular mechanisms of B cell antigen receptor trafficking. Ann N Y Acad Sci 2003; 987:26-37. [PMID: 12727621 DOI: 10.1111/j.1749-6632.2003.tb06030.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
B lymphocytes are among the most efficient cells of the immune system in capturing, processing, and presenting MHC class II restricted peptides to T cells. Antigen capture is essentially restricted by the specificity of the clonotypic antigen receptor expressed on each B lymphocyte. However, receptor recognition is only one factor determining whether an antigen is processed and presented. The context of antigen encounter is crucial. In particular, polyvalent arrays of repetitive epitopes, indicative of infection, accelerate the delivery of antigen to specialized processing compartments, and up-regulate the surface expression of MHC class II and co-stimulatory molecules such as B7. Recent studies have demonstrated that receptor-mediated signaling and receptor-facilitated peptide presentation to T cells are intimately related. For example, rapid sorting of endocytosed receptor complexes through early endosomes requires the activation of the tyrosine Syk. This proximal kinase initiates all BCR-dependent signaling pathways. Subsequent entry into the antigen-processing compartment requires the tyrosine phosphorylation of the BCR constituent Igalpha and direct recruitment of the linker protein BLNK. Signals from the BCR also regulate the biophysical and biochemical properties of the targeted antigen-processing compartments. These observations indicate that the activation and recruitment of signaling molecules by the BCR orchestrate a complex series of cellular responses that favor the presentation of even rare or low-affinity antigens if encountered in contexts indicative of infection. The requirement for BCR signaling provides possible mechanisms by which cognate B:T cell interactions can be controlled by the milieu in which antigen engagement occurs.
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Affiliation(s)
- Marcus R Clark
- University of Chicago, Section of Rheumatology, 5841 South Maryland Avenue, Chicago, Illinois 60637, USA.
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37
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Greiner A, Lautwein A, Overkleeft HS, Weber E, Driessen C. Activity and subcellular distribution of cathepsins in primary human monocytes. J Leukoc Biol 2003; 73:235-42. [PMID: 12554800 DOI: 10.1189/jlb.0802398] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cathepsins (Cat) in antigen presenting cells (APC) control antigen processing as well as major histocompatibility complex class II transport and function. The set of active Cat and the subcellular architecture of the class II antigen presentation compartment are largely unknown in primary human APC, including peripheral blood monocytes. We used novel chemical tools to visualize Cat in an activity-dependent manner. Primary human monocytes contained active CatS, -B, and -H, while CatL was absent. Expression and activity patterns of Cat in human myelo-monocytoid cell lines were distinct from those found in primary cells. On a subcellular scale, the bulk of active Cat was concentrated in lysosomes in primary monocytes. In late endosomes, only active CatS was found in sizable amounts, colocalizing with C-terminal processing of the class II invariant chain and with cystatin C, the major endogenous Cat inhibitor. Late endosomes of human peripheral blood monocytes contain a well-controlled proteolytic machinery distinct from lysosomes, which is likely to play a key role in class II function.
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Affiliation(s)
- Andrea Greiner
- Department of Medicine II, University of Tübingen, Ob dem Himmelreich 7, 72074 Tübingen, Germany
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38
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Lautwein A, Burster T, Lennon-Duménil AM, Overkleeft HS, Weber E, Kalbacher H, Driessen C. Inflammatory stimuli recruit cathepsin activity to late endosomal compartments in human dendritic cells. Eur J Immunol 2002; 32:3348-57. [PMID: 12432565 DOI: 10.1002/1521-4141(200212)32:12<3348::aid-immu3348>3.0.co;2-s] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Proteolysis by endocytic cysteine proteases is a central element of the antigen-presentation machinery in dendritic cells (DC). It controls the generation of immunogenic peptides, guides the transit of both MHC class II and MHC-like molecules through the endocytic compartment and converts class II into a peptide-receptive state - features closely linked to DC maturation. Differential activity of endocytic proteases, in particular cathepsins, in subcellular compartments has been implicated as a key regulatory element in controlling this machinery in murine DC. We analyzed the expression and subcellular distribution of the major endocytic cysteine proteases (cathepsins S, B, L and H) along with their major endogenous inhibitor, Cystatin C, in resting and stimulated human DC. Although the majority of cathepsin activity was restricted to lysosomes in resting DC, cathepsins selectively accumulated in late endosomes after LPS-induced stimulation. Surprisingly, expression and distribution of Cystatin C was unaffected by DC maturation. Thus, late endosomes represent a specialized compartment where proteolytic activity is developmentally regulated in DC. This could facilitate the conversion of exogenous protein into MHC class II-peptide complexes.
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Affiliation(s)
- Alfred Lautwein
- Medical and Natural Sciences Research Center, University of Tübingen, Tübingen, Germany
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39
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Felbor U, Kessler B, Mothes W, Goebel HH, Ploegh HL, Bronson RT, Olsen BR. Neuronal loss and brain atrophy in mice lacking cathepsins B and L. Proc Natl Acad Sci U S A 2002; 99:7883-8. [PMID: 12048238 PMCID: PMC122989 DOI: 10.1073/pnas.112632299] [Citation(s) in RCA: 238] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cathepsins B and L are widely expressed cysteine proteases implicated in both intracellular proteolysis and extracellular matrix remodeling. However, specific roles remain to be validated in vivo. Here we show that combined deficiency of cathepsins B and L in mice is lethal during the second to fourth week of life. Cathepsin B(-/-)/L(-/-) mice reveal a degree of brain atrophy not previously seen in mice. This is because of massive apoptosis of select neurons in the cerebral cortex and the cerebellar Purkinje and granule cell layers. Neurodegeneration is accompanied by pronounced reactive astrocytosis and is preceded by an accumulation of ultrastructurally and biochemically unique lysosomal bodies in large cortical neurons and by axonal enlargements. Our data demonstrate a pivotal role for cathepsins B and L in maintenance of the central nervous system.
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Affiliation(s)
- Ute Felbor
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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40
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Siemasko K, Skaggs BJ, Kabak S, Williamson E, Brown BK, Song W, Clark MR. Receptor-facilitated antigen presentation requires the recruitment of B cell linker protein to Igalpha. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:2127-38. [PMID: 11859098 DOI: 10.4049/jimmunol.168.5.2127] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Ags that cross-link the B cell Ag receptor are preferentially and rapidly delivered to the MHC class II-enriched compartment for processing into peptides and subsequent loading onto MHC class II. Proper sorting of Ag/receptor complexes requires the recruitment of Syk to the phosphorylated immunoreceptor tyrosine-based activation motif tyrosines of the B cell Ag receptor constituent Igalpha. We postulated that the Igalpha nonimmunoreceptor tyrosine-based activation motif tyrosines, Y(176) and Y(204), contributed to receptor trafficking. Igalpha(YDeltaF(176,204))/Igbeta receptors were targeted to late endosomes, but were excluded from the vesicle lumen and could not facilitate the presentation of Ag to T cells. Subsequent analysis demonstrated that phosphorylation of Y(176)/Y(204) recruited the B cell linker protein, Vav, and Grb2. Reconstitution of Igalpha(YDeltaF(176,204))/Igbeta with the B cell linker protein rescued both receptor-facilitated Ag presentation and entry into the MHC class II-enriched compartment. Thus, aggregation accelerates receptor trafficking by recruiting two separate signaling modules required for transit through sequential checkpoints.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Motifs
- Animals
- Antigen Presentation
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/metabolism
- B-Lymphocytes/immunology
- B-Lymphocytes/ultrastructure
- CD79 Antigens
- Carrier Proteins/physiology
- Cell Cycle Proteins
- Endocytosis
- Endosomes/metabolism
- GRB2 Adaptor Protein
- Mice
- Microscopy, Immunoelectron
- Models, Immunological
- Models, Molecular
- Phosphoproteins/physiology
- Phosphorylation
- Phosphotyrosine/physiology
- Proteins/metabolism
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-vav
- Receptors, Antigen, B-Cell/chemistry
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Antigen, B-Cell/physiology
- Recombinant Fusion Proteins/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- Karyn Siemasko
- Department of Medicine, Section of Rheumatology, University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA
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41
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Abstract
Antigen presenting cells (APCs) alert the immune system to attack by extracellular organisms; APCs achieve this via internalization, degradation, and display of antigenic fragments on the cell surface by MHC class II molecules. These class II molecules bind to an accessory protein, termed the invariant chain, that ensures proper folding of the molecules. Invariant-chain binding also directs class II molecules to lysosomes, which are probably the most important sites for antigen loading. Endosomes are intermediates in the transport of class-II-invariant chain complexes to antigen-processing compartments, whereas trafficking of class II-peptide complexes to the membrane (and beyond) is less-well understood. Unlike other APCs, dendritic cells alter their capacity to present peptides via MHC class II molecules during differentiation, revealing a complex level of regulated antigen-presentation by this APC subtype.
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Affiliation(s)
- Elizabeth M Hiltbold
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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42
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Stumptner-Cuvelette P, Benaroch P. Multiple roles of the invariant chain in MHC class II function. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1542:1-13. [PMID: 11853874 DOI: 10.1016/s0167-4889(01)00166-5] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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43
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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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44
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Abstract
Dendritic cells (DCs) are bone marrow-derived cells of both lymphoid and myeloid stem cell origin that populate all lymphoid organs including the thymus, spleen, and lymph nodes, as well as nearly all nonlymphoid tissues and organs. Although DCs are a moderately diverse set of cells, they all have potent antigen-presenting capacity for stimulating naive, memory, and effector T cells. DCs are members of the innate immune system in that they can respond to dangers in the host environment by immediately generating protective cytokines. Most important, immature DCs respond to danger signals in the microenvironment by maturing, i.e., differentiating, and acquiring the capacity to direct the development of primary immune responses appropriate to the type of danger perceived. The powerful adjuvant activity that DCs possess in stimulating specific CD4 and CD8 T cell responses has made them targets in vaccine development strategies for the prevention and treatment of infections, allograft reactions, allergic and autoimmune diseases, and cancer. This review addresses the origins and migration of DCs to their sites of activity, their basic biology as antigen-presenting cells, their roles in important human diseases and, finally, selected strategies being pursued to harness their potent antigen-stimulating activity.
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Affiliation(s)
- Mary F Lipscomb
- Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131-5301, USA.
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45
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Jayawardena-Wolf J, Benlagha K, Chiu YH, Mehr R, Bendelac A. CD1d endosomal trafficking is independently regulated by an intrinsic CD1d-encoded tyrosine motif and by the invariant chain. Immunity 2001; 15:897-908. [PMID: 11754812 DOI: 10.1016/s1074-7613(01)00240-0] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Endosomal trafficking is an essential component of the CD1 pathway of lipid antigen presentation to T cells. We demonstrate that CD1d access to endosomal compartments is under dual regulation by an intrinsic tyrosine-based motif, which governs intense recycling between the plasma membrane and the endosome, and by the invariant chain, with which CD1d associates in the endoplasmic reticulum. Both pathways independently enhance antigen presentation to V(alpha)14(+) NKT cells, the main subset of CD1d-restricted T cells. These results reveal the complexity of CD1d trafficking and suggest that the invariant chain was a component of ancestral antigen presentation pathways prior to the evolution of MHC and CD1.
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MESH Headings
- Amino Acid Motifs
- Animals
- Antigen Presentation/physiology
- Antigens, CD1/chemistry
- Antigens, CD1/genetics
- Antigens, CD1/metabolism
- Antigens, CD1d
- Antigens, Differentiation, B-Lymphocyte/physiology
- Antigens, Surface/metabolism
- B-Lymphocytes/metabolism
- Biotinylation
- Cell Membrane/metabolism
- Cells, Cultured/metabolism
- Dendritic Cells/metabolism
- Endoplasmic Reticulum/metabolism
- Endosomes/metabolism
- Evolution, Molecular
- Fibroblasts/metabolism
- Glycosylation
- Histocompatibility Antigens Class II/physiology
- Hybridomas/metabolism
- Kinetics
- Lymphoma, B-Cell/pathology
- Lysosomes/metabolism
- Mice
- Microscopy, Fluorescence
- Protein Binding
- Protein Processing, Post-Translational
- Protein Transport
- Recombinant Fusion Proteins/metabolism
- Subcellular Fractions/metabolism
- Transfection
- Tumor Cells, Cultured/metabolism
- Tyrosine/chemistry
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Affiliation(s)
- J Jayawardena-Wolf
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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46
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Fortin A, Lagacé J, Thérien HM. Trafficking of surface-linked and encapsulated liposomal antigens in macrophages: an immunocytochemical study. J Histochem Cytochem 2001; 49:1407-20. [PMID: 11668194 DOI: 10.1177/002215540104901109] [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: 01/02/2023] Open
Abstract
Liposomal antigens are potent adjuvants of humoral and cell-mediated immunity. Although this property requires as an essential condition a physical association between the antigen and the phospholipid vehicle, the nature of the association, i.e., encapsulation or surface linkage, markedly influences the outcome of the elicited response. Available evidence suggests that macrophages are involved in this fine tuning of the immune response in a manner that is not yet clearly established. It is postulated that this might be related to their capacity to interact differently with surface-linked and encapsulated formulations. Using conalbumin as a model antigen, we address the question by analyzing the movements of encapsulated and surface-linked antigen as well as those of MHC-II molecules in macrophages in a pulse-chase immunoelectron microscopic study carried out over a 24-hr period. The antigen was followed using a polyclonal serum specifically raised against fragmented conalbumin (fCA) that allows the detection of processed antigen and of some MHC-peptide complexes. The results indicate that, in macrophages, the two liposomal formulations affect macrophage morphology in distinct ways and circulate through the various subcellular compartments with different kinetics. On the basis of the overall results, we conclude that surface-linked antigen gains access less readily to the endogenous presentation pathway than encapsulated antigen but can favor a more sustained activation of the immune system through its production of exosome-like structures and its more thorough utilization of the MHC-II pathway.
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Affiliation(s)
- A Fortin
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, Ste-Foy, Qc, Canada
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47
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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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48
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Lennon-Duménil AM, Roberts RA, Valentijn K, Driessen C, Overkleeft HS, Erickson A, Peters PJ, Bikoff E, Ploegh HL, Wolf Bryant P. The p41 isoform of invariant chain is a chaperone for cathepsin L. EMBO J 2001; 20:4055-64. [PMID: 11483509 PMCID: PMC149174 DOI: 10.1093/emboj/20.15.4055] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The p41 splice variant of major histocompatibility complex (MHC) class II-associated invariant chain (Ii) contains a 65 aa segment that binds to the active site of cathepsin L (CatL), a lysosomal cysteine protease involved in MHC class II-restricted antigen presentation. This segment is absent from the predominant form of Ii, p31. Here we document the in vivo significance of the p41-CatL interaction. By biochemical means and electron microscopy, we demonstrate that the levels of active CatL are strongly reduced in bone marrow-derived antigen-presenting cells that lack p41. This defect mainly concerns the mature two-chain forms of CatL, which depend on p41 to be expressed at wild-type levels. Indeed, pulse-chase analysis suggests that these mature forms of CatL are degraded by endocytic proteases when p41 is absent. We conclude that p41 is required for activity of CatL by stabilizing the mature forms of the enzyme. This suggests that p41 is not merely an inhibitor of CatL enzymatic activity, but serves as a chaperone to help maintain a pool of mature enzyme in late-endocytic compartments of antigen-presenting cells.
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Affiliation(s)
- Ana-Maria Lennon-Duménil
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Rebecca A. Roberts
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Karine Valentijn
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Christoph Driessen
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Herman S. Overkleeft
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Ann Erickson
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Peter J. Peters
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Elizabeth Bikoff
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Hidde L. Ploegh
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
| | - Paula Wolf Bryant
- Department of Pathology, Harvard Medical School, Boston, MA 02115, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, Department of Microbiology, Ohio State University, Columbus, OH 43210, USA and Netherlands Cancer Institute, Amsterdam, The Netherlands Corresponding author e-mail:
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49
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van Lith M, van Ham M, Griekspoor A, Tjin E, Verwoerd D, Calafat J, Janssen H, Reits E, Pastoors L, Neefjes J. Regulation of MHC class II antigen presentation by sorting of recycling HLA-DM/DO and class II within the multivesicular body. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:884-92. [PMID: 11441095 DOI: 10.4049/jimmunol.167.2.884] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
MHC class II molecules bind antigenic peptides in the late endosomal/lysosomal MHC class II compartments (MIIC) before cell surface presentation. The class II modulatory molecules HLA-DM and HLA-DO mainly localize to the MIICs. Here we show that DM/DO complexes continuously recycle between the plasma membrane and the lysosomal MIICs. Like DMbeta and the class II-associated invariant chain, the DObeta cytoplasmic tail contains potential lysosomal targeting signals. The DObeta signals, however, are not essential for internalization of the DM/DO complex from the plasma membrane or targeting to the MIICs. Instead, the DObeta tail determines the distribution of both DM/DO and class II within the multivesicular MIIC by preferentially localizing them to the limiting membrane and, in lesser amounts, to the internal membranes. This distribution augments the efficiency of class II antigenic peptide loading by affecting the efficacy of lateral interaction between DM/DO and class II molecules. Sorting of DM/DO and class II molecules to specific localizations within the MIIC represents a novel way of regulating MHC class II Ag presentation.
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Affiliation(s)
- M van Lith
- Division of Tumor Biology, Netherlands Cancer Institute, Amsterdam, The Netherlands
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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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