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Roberts AD, Taraska JW. B cell receptor (BCR) endocytosis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 194:159-177. [PMID: 36631191 DOI: 10.1016/bs.pmbts.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The B cell receptor (BCR) interacts with foreign antigens to mediate B cell activation and secretion of antibodies. B cell activation begins with initiation of signaling pathways, such as NFAT, NF-κB, and MAPK, and endocytosis of the BCR-antigen complex. Many studies have investigated the signaling pathways associated with BCR activation, and this work has led to significant advances in drug therapies to treat cancer and autoimmune diseases that are linked to aberrant BCR signaling. Less is known, however, about the mechanisms of BCR endocytosis and the role endocytosis plays in B cell pathogenesis. This chapter will review key characteristics of the BCR, including a review of signaling pathways, and endocytic mechanisms associated with the activated BCR. We will also review recent studies investigating the role of BCR endocytosis disease pathogenesis.
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Affiliation(s)
- Aleah D Roberts
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States.
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2
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Gopalakrishnan S, Hansen MD, Skovdahl HK, Roseth IA, van Beelen Granlund A, Østvik AE, Bakke I, Sandvik AK, Bruland T. Tofacitinib Downregulates TNF and Poly(I:C)-Dependent MHC-II Expression in the Colonic Epithelium. Front Immunol 2022; 13:882277. [PMID: 35655783 PMCID: PMC9152176 DOI: 10.3389/fimmu.2022.882277] [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: 02/23/2022] [Accepted: 04/15/2022] [Indexed: 11/13/2022] Open
Abstract
Major Histocompatibility Complex (MHC)-I and -II genes are upregulated in intestinal epithelial cells (IECs) during active inflammatory bowel diseases (IBD), but little is known about how IBD-relevant pro-inflammatory signals and IBD drugs can regulate their expression. We have previously shown that the synthetic analog of double-stranded RNA (dsRNA) Polyinosinic:polycytidylic acid (Poly(I:C)), induces interferon stimulated genes (ISGs) in colon organoids (colonoids). These ISGs may be involved in the induction of antigen presentation. In the present study, we applied colonoids derived from non-IBD controls and ulcerative colitis patients to identify induction and effects of IBD-drugs on antigen presentation in IECs in the context of Tumor Necrosis Factor (TNF)-driven inflammation. By RNA sequencing, we show that a combination of TNF and Poly(I:C) strongly induced antigen-presentation gene signatures in colonoids, including expression of MHC-II genes. MHC-I and -II protein expression was confirmed by immunoblotting and immunofluorescence. TNF+Poly(I:C)-dependent upregulation of MHC-II expression was associated with increased expression of Janus Kinases JAK1/2 as well as increased activation of transcription factor Signal transducer and activator of transcription 1 (STAT1). Accordingly, pre-treatment of colonoids with IBD-approved pan-Janus Kinase (JAK) inhibitor Tofacitinib led to the downregulation of TNF+Poly(I:C)-dependent MHC-II expression associated with the abrogation of STAT1 activation. Pre-treatment with corticosteroid Budesonide, commonly used in IBD, did not alter MHC-II expression. Collectively, our results identify a regulatory role for IBD-relevant pro-inflammatory signals on MHC-II expression that is influenced by Tofacitinib.
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Affiliation(s)
- Shreya Gopalakrishnan
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, Clinic of Medicine, St. Olav's University Hospital, Trondheim, Norway
| | - Marianne Doré Hansen
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, St. Olav's University Hospital, Trondheim, Norway
| | - Helene Kolstad Skovdahl
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Centre of Molecular Inflammation Research (CEMIR), NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Ingrid Aass Roseth
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Atle van Beelen Granlund
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, Clinic of Medicine, St. Olav's University Hospital, Trondheim, Norway.,Centre of Molecular Inflammation Research (CEMIR), NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Ann Elisabet Østvik
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, Clinic of Medicine, St. Olav's University Hospital, Trondheim, Norway
| | - Ingunn Bakke
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, St. Olav's University Hospital, Trondheim, Norway
| | - Arne Kristian Sandvik
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, Clinic of Medicine, St. Olav's University Hospital, Trondheim, Norway.,Centre of Molecular Inflammation Research (CEMIR), NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Torunn Bruland
- Department of Clinical and Molecular Medicine (IKOM), NTNU - Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, Clinic of Medicine, St. Olav's University Hospital, Trondheim, Norway
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3
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Mamedov AE, Filimonova IN, Smirnov IV, Belogurov AA. Peculiarities of the Presentation of the Encephalitogenic MBP Peptide by HLA-DR Complexes Providing Protection and Predisposition to Multiple Sclerosis. Acta Naturae 2021; 13:127-133. [PMID: 33959392 PMCID: PMC8084299 DOI: 10.32607/actanaturae.11008] [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: 05/18/2020] [Accepted: 08/05/2020] [Indexed: 12/02/2022] Open
Abstract
Predisposition to multiple sclerosis (MS), a chronic autoimmune disease of the central nervous system, is due to various factors. The genetic component is considered one of the most important factors. HLA class II genes contribute the most to the development of MS. The HLA-DRB1*15 allele group is considered one of the main genetic risk factors predisposing to MS. The group of HLA-DRB1*01 alleles was shown to have a protective effect against this disease in the Russian population. In this work, we compared the binding of the encephalitogenic fragment of the myelin basic protein (MBP) to two HLA-DR complexes that provide protection against and predisposition to MS: HLA-DR1 (HLA-DRB1*0101) and HLA-DR15 (HLA-DRB1*1501), respectively. We found that the myelin peptide MBP88-100 binds to HLA-DR1 at a rate almost an order of magnitude lower than the viral peptide of hemagglutinin (HA). The same was true for the binding of MBP85-97 to HLA-DR15 in comparison with viral pp65. The structure of the C-terminal part of the peptide plays a key role in the binding to HLA-DR1 for equally high-affinity N-terminal regions of the peptides. The IC50 of the myelin peptide MBP88-100 competing with viral HA for binding to HLA-DR1 is almost an order of magnitude higher than that of HA. As for HA, the same was also true for the binding of MBP85-97 to HLA-DR15 in comparison with viral pp65. Thus, autoantigenic MBP cannot compete with the viral peptide for binding to protective HLA-DR1. However, it is more competitive than viral peptide for HLA-DR15.
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Affiliation(s)
- A. E. Mamedov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Moscow, 117997 Russia
| | - I. N. Filimonova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Moscow, 117997 Russia
| | - I. V. Smirnov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Moscow, 117997 Russia
- Institute of Fundamental Medicine and Biology, Kazan (Volga) Federal University, Kazan, 420008 Russia
| | - A. A. Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Moscow, 117997 Russia
- Lomonosov Moscow State University, Moscow, 119991 Russia
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4
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Antohe I, Tanasa MP, Dăscălescu A, Dănăilă C, Titieanu A, Zlei M, Ivanov I, Sireteanu A, Cianga P. The MHC-II antigen presentation machinery and B7 checkpoint ligands display distinctive patterns correlated with acute myeloid leukaemias blast cells HLA-DR expression. Immunobiology 2020; 226:152049. [PMID: 33352400 DOI: 10.1016/j.imbio.2020.152049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/09/2020] [Accepted: 11/29/2020] [Indexed: 10/22/2022]
Abstract
Acute Myeloid Leukaemia (AML) is a neoplasia characterised by rapid proliferation and an increased rate of relapses. The AML blasts display features of antigen-presenting cells (APC), and thus can directly modulate the anti-tumour T cell responses. The bone marrow of a group consisting of 30 newly diagnosed patients and four healthy donors (HD) was investigated for the expression of HLA-DR, several molecules involved in MHC-II antigen-presentation and MHC-II groove editing, like HLA-DM, CD74 and CLIP, as well as a set of immune checkpoint ligands, like ICOS-L, B7.2, PD-L2 and B7-H3. The patients were further characterised for their genetic anomalies and distributed to favourable, intermediate and adverse ELN risk categories. We were able to show that while 23% of our patients displayed a low level of HLA-DR surface expression, all patients displayed higher HLA-DM and CD74 expression compared to HD. However, a higher CLIP expression was noticed only in the HLA-DR low patients. The co-inhibitory PD-L2 and B7-H3 molecules were increased in the cases with normal HLA-DR expression; oppositely, the co-stimulatory ICOS-L and the dual function B7.2 were significantly increased in the cases with HLA-DR low expression. Furthermore, no favourable ELN risk cases were found within the HLA-DR low group. All in all, these data show that the AML with low versus normal HLA-DR expression display different profiles of MHC class II machinery molecules and B7 ligands, which are correlated with distinct ELN stratification. Furthermore, as our study included healthy individuals, it offers valuable information about the expression levels that should be considered as normal for these markers known to cause differences in peptide repertoires, reflected further in distinct T-cells polarisation pathways.
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Affiliation(s)
- Ion Antohe
- Haematology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania; Haematology Department, Regional Oncology Institute, Iaşi, Romania
| | - Mariana Pavel Tanasa
- Immunology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania
| | - Angela Dăscălescu
- Haematology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania; Haematology Department, Regional Oncology Institute, Iaşi, Romania
| | - Cătălin Dănăilă
- Haematology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania; Haematology Department, Regional Oncology Institute, Iaşi, Romania
| | - Amalia Titieanu
- Haematology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania; Haematology Department, Regional Oncology Institute, Iaşi, Romania
| | - Mihaela Zlei
- Immunophenotyping Department, Regional Oncology Institute, Iaşi, Romania
| | - Iuliu Ivanov
- Molecular Diagnostic Department, Regional Oncology Institute, Iaşi, Romania
| | - Adriana Sireteanu
- Molecular Diagnostic Department, Regional Oncology Institute, Iaşi, Romania
| | - Petru Cianga
- Immunology Department, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, Romania.
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5
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Heuberger C, Pott J, Maloy KJ. Why do intestinal epithelial cells express MHC class II? Immunology 2020; 162:357-367. [PMID: 32966619 PMCID: PMC7968399 DOI: 10.1111/imm.13270] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 12/23/2022] Open
Abstract
Intestinal epithelial cells (IECs) constitute the border between the vast antigen load present in the intestinal lumen and the mucosal immune compartment. Their ability to express antigen processing and presentation machinery evokes the question whether IECs function as non-conventional antigen-presenting cells. Major histocompatibility complex (MHC) class II expression by non-haematopoietic cells, such as IECs, is tightly regulated by the class II transactivator (CIITA) and is classically induced by IFN-γ. As MHC class II expression by IECs is upregulated under inflammatory conditions, it has been proposed to activate effector CD4+ T (Teff) cells. However, other studies have reported contradictory results and instead suggested a suppressive role of antigen presentation by IECs, through regulatory T (Treg)-cell activation. Recent studies investigating the role of MHC class II + exosomes released by IECs also reported conflicting findings of either immune enhancing or immunosuppressive activities. Moreover, in addition to modulating inflammatory responses, recent findings suggest that MHC class II expression by intestinal stem cells may elicit crosstalk that promotes epithelial renewal. A more complete understanding of the different consequences of IEC MHC class II antigen presentation will guide future efforts to modulate this pathway to selectively invoke protective immunity while maintaining tolerance to beneficial antigens.
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Affiliation(s)
- Cornelia Heuberger
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.,Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
| | - Johanna Pott
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.,Hubrecht Organoid Technology, Utrecht, Netherlands
| | - Kevin Joseph Maloy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.,Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
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6
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Szeto C, Bloom JI, Sloane H, Lobos CA, Fodor J, Jayasinghe D, Chatzileontiadou DSM, Grant EJ, Buckle AM, Gras S. Impact of HLA-DR Antigen Binding Cleft Rigidity on T Cell Recognition. Int J Mol Sci 2020; 21:ijms21197081. [PMID: 32992915 PMCID: PMC7582474 DOI: 10.3390/ijms21197081] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 01/22/2023] Open
Abstract
The interaction between T cell receptor (TCR) and peptide (p)-Human Leukocyte Antigen (HLA) complexes is the critical first step in determining T cell responses. X-ray crystallographic studies of pHLA in TCR-bound and free states provide a structural perspective that can help understand T cell activation. These structures represent a static “snapshot”, yet the nature of pHLAs and their interactions with TCRs are highly dynamic. This has been demonstrated for HLA class I molecules with in silico techniques showing that some interactions, thought to stabilise pHLA-I, are only transient and prone to high flexibility. Here, we investigated the dynamics of HLA class II molecules by focusing on three allomorphs (HLA-DR1, -DR11 and -DR15) that are able to present the same epitope and activate CD4+ T cells. A single TCR (F24) has been shown to recognise all three HLA-DR molecules, albeit with different affinities. Using molecular dynamics and crystallographic ensemble refinement, we investigate the molecular basis of these different affinities and uncover hidden roles for HLA polymorphic residues. These polymorphisms were responsible for the widening of the antigen binding cleft and disruption of pHLA-TCR interactions, underpinning the hierarchy of F24 TCR binding affinity, and ultimately T cell activation. We expanded this approach to all available pHLA-DR structures and discovered that all HLA-DR molecules were inherently rigid. Together with in vitro protein stability and peptide affinity measurements, our results suggest that HLA-DR1 possesses inherently high protein stability, and low HLA-DM susceptibility.
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Affiliation(s)
- Christopher Szeto
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Joseph I. Bloom
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Hannah Sloane
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Christian A. Lobos
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - James Fodor
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 0200, Australia
| | - Dhilshan Jayasinghe
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Demetra S. M. Chatzileontiadou
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Emma J. Grant
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Ashley M. Buckle
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Stephanie Gras
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Monash University, Clayton, VIC 3800, Australia
- Correspondence:
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Reyes-Vargas E, Barker AP, Zhou Z, He X, Jensen PE. HLA-DM catalytically enhances peptide dissociation by sensing peptide-MHC class II interactions throughout the peptide-binding cleft. J Biol Chem 2020; 295:2959-2973. [PMID: 31969393 PMCID: PMC7062162 DOI: 10.1074/jbc.ra119.010645] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/13/2020] [Indexed: 11/06/2022] Open
Abstract
Human leukocyte antigen-DM (HLA-DM) is an integral component of the major histocompatibility complex class II (MHCII) antigen-processing and -presentation pathway. HLA-DM shapes the immune system by differentially catalyzing peptide exchange on MHCII molecules, thereby editing the peptide-MHCII (pMHCII) repertoire by imposing a bias on the foreign and self-derived peptide cargos that are presented on the cell surface for immune surveillance and tolerance induction by CD4+ T cells. To better understand DM selectivity, here we developed a real-time fluorescence anisotropy assay to delineate the pMHCII intrinsic stability, DM-binding affinity, and catalytic turnover, independent kinetic parameters of HLA-DM enzymatic activity. We analyzed prominent pMHCII contacts by differentiating the kinetic parameters in pMHCII homologs, observing that peptide interactions throughout the MHCII-binding cleft influence both the rate of peptide dissociation from the DM-pMHCII catalytic complex and the binding affinity of HLA-DM for a pMHCII. We show that the intrinsic stability of a pMHCII linearly correlates with DM catalytic turnover, but is nonlinearly correlated with its binding affinity. Surprisingly, interactions at the peptides N terminus up to and including MHCII position one (P1) anchor affected the catalytic turnover, suggesting that the active DM-pMHCII catalytic complex operates on pMHCII complexes with full peptide occupancy. Furthermore, interactions at the peptide C terminus modulated DM-binding affinity, suggesting distal communication between peptide interactions with the MHCII and the DM-pMHCII binding interface. Our results imply an intimate linkage between the DM-pMHCII interface and peptide-MHCII interactions throughout the peptide-binding cleft.
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Affiliation(s)
- Eduardo Reyes-Vargas
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Adam P Barker
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112; Department of Pathology, ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108
| | - Zemin Zhou
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Xiao He
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112.
| | - Peter E Jensen
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112; Department of Pathology, ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108.
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8
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Mamedov A, Vorobyeva N, Filimonova I, Zakharova M, Kiselev I, Bashinskaya V, Baulina N, Boyko A, Favorov A, Kulakova O, Ziganshin R, Smirnov I, Poroshina A, Shilovskiy I, Khaitov M, Sykulev Y, Favorova O, Vlassov V, Gabibov A, Belogurov A. Protective Allele for Multiple Sclerosis HLA-DRB1*01:01 Provides Kinetic Discrimination of Myelin and Exogenous Antigenic Peptides. Front Immunol 2020; 10:3088. [PMID: 32010139 PMCID: PMC6978714 DOI: 10.3389/fimmu.2019.03088] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 12/17/2019] [Indexed: 12/15/2022] Open
Abstract
Risk of the development of multiple sclerosis (MS) is known to be increased in individuals bearing distinct class II human leukocyte antigen (HLA) variants, whereas some of them may have a protective effect. Here we analyzed distribution of a highly polymorphous HLA-DRB1 locus in more than one thousand relapsing-remitting MS patients and healthy individuals of Russian ethnicity. Carriage of HLA-DRB1*15 and HLA-DRB1*03 alleles was associated with MS risk, whereas carriage of HLA-DRB1*01 and HLA-DRB1*11 was found to be protective. Analysis of genotypes revealed the compensatory effect of risk and resistance alleles in trans. We have identified previously unknown MBP153-161 peptide located at the C-terminus of MBP protein and MBP90-98 peptide that bound to recombinant HLA-DRB1*01:01 protein with affinity comparable to that of classical antigenic peptide 306-318 from the hemagglutinin (HA) of the influenza virus demonstrating the ability of HLA-DRB1*01:01 to present newly identified MBP153-161 and MBP90-98 peptides. Measurements of kinetic parameters of MBP and HA peptides binding to HLA-DRB1*01:01 catalyzed by HLA-DM revealed a significantly lower rate of CLIP exchange for MBP153-161 and MBP90-98 peptides as opposed to HA peptide. Analysis of the binding of chimeric MBP-HA peptides demonstrated that the observed difference between MBP153-161, MBP90-98, and HA peptide epitopes is caused by the lack of anchor residues in the C-terminal part of the MBP peptides resulting in a moderate occupation of P6/7 and P9 pockets of HLA-DRB1*01:01 by MBP153-161 and MBP90-98 peptides in contrast to HA308-316 peptide. This leads to the P1 and P4 docking failure and rapid peptide dissociation and release of empty HLA-DM-HLA-DR complex. We would like to propose that protective properties of the HLA-DRB1*01 allele could be directly linked to the ability of HLA-DRB1*01:01 to kinetically discriminate between antigenic exogenous peptides and endogenous MBP derived peptides.
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Affiliation(s)
- Azad Mamedov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | | | - Ioanna Filimonova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Maria Zakharova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Pirogov Russian National Research Medical University, Moscow, Russia
| | - Ivan Kiselev
- Pirogov Russian National Research Medical University, Moscow, Russia
| | | | - Natalia Baulina
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Alexey Boyko
- Pirogov Russian National Research Medical University, Moscow, Russia.,Neuroimmunological Department of the Federal Center of Cerebrovascular Diseases and Stroke, Moscow, Russia
| | - Alexander Favorov
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University, Baltimore, MD, United States.,Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Olga Kulakova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Rustam Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ivan Smirnov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Institute of Fundamental Medicine and Biology, Kazan (Volga) Federal University, Kazan, Russia
| | - Alina Poroshina
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Igor Shilovskiy
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Musa Khaitov
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Yuri Sykulev
- Department of Microbiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Olga Favorova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Valentin Vlassov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexander Gabibov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Department of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Alexey Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Department of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
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9
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A personal retrospective on the mechanisms of antigen processing. Immunogenetics 2019; 71:141-160. [PMID: 30694344 DOI: 10.1007/s00251-018-01098-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/22/2018] [Indexed: 10/27/2022]
Abstract
My intention here is to describe the history of the molecular aspects of the antigen processing field from a personal perspective, beginning with the early identification of the species that we now know as MHC class I and MHC class II molecules, to the recognition that their stable surface expression and detection by T cells depends on peptide association, and to the unraveling of the biochemical and cell biological mechanisms that regulate peptide binding. One goal is to highlight the role that serendipity or, more colloquially, pure blind luck can play in advancing the research enterprise when it is combined with an appropriately receptive mind. This is not intended to be an overarching review, and because of my own work I focus primarily on studies of the human MHC. This means that I neglect the work of many other individuals who made advances in other species, particularly those who produced the many knockout mouse strains used to demonstrate the importance of the antigen processing machinery for initiating immune responses. I apologize in advance to colleagues around the globe whose contributions I deal with inadequately for these reasons, and to those whose foundational work is now firmly established in text books and therefore not cited. So many individuals have worked to advance the field that giving all of them the credit they deserve is almost impossible. I have attempted, while focusing on work from my own laboratory, to point out contemporaneous or sometimes earlier advances made by others. Much of the success of my own laboratory came because we simultaneously worked on both the MHC class I and class II systems and used the findings in one area to inform the other, but mainly it depended on the extraordinary group of students and fellows who have worked on these projects over the years. To those who worked in other areas who are not mentioned here, rest assured that I appreciate your efforts just as much.
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10
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Thibodeau J, Moulefera MA, Balthazard R. On the structure–function of MHC class II molecules and how single amino acid polymorphisms could alter intracellular trafficking. Hum Immunol 2019; 80:15-31. [DOI: 10.1016/j.humimm.2018.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 12/01/2022]
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11
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Giles DA, Duncker PC, Wilkinson NM, Washnock-Schmid JM, Segal BM. CNS-resident classical DCs play a critical role in CNS autoimmune disease. J Clin Invest 2018; 128:5322-5334. [PMID: 30226829 DOI: 10.1172/jci123708] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/11/2018] [Indexed: 12/19/2022] Open
Abstract
Experimental autoimmune encephalomyelitis (EAE) is an inflammatory demyelinating disease of the central nervous system (CNS), induced by the adoptive transfer of myelin-reactive CD4+ T cells into naive syngeneic mice. It is widely used as a rodent model of multiple sclerosis (MS). The development of EAE lesions is initiated when transferred CD4+ T cells access the CNS and are reactivated by local antigen-presenting cells (APCs) bearing endogenous myelin peptide/MHC class II complexes. The identity of the CNS-resident, lesion-initiating APCs is widely debated. Here we demonstrate that classical dendritic cells (cDCs) normally reside in the meninges, brain, and spinal cord in the steady state. These cells are unique among candidate CNS APCs in their ability to stimulate naive, as well as effector, myelin-specific T cells to proliferate and produce proinflammatory cytokines directly ex vivo. cDCs expanded in the meninges and CNS parenchyma in association with disease progression. Selective depletion of cDCs led to a decrease in the number of myelin-primed donor T cells in the CNS and reduced the incidence of clinical EAE by half. Based on our findings, we propose that cDCs, and the factors that regulate them, be further investigated as potential therapeutic targets in MS.
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Affiliation(s)
- David A Giles
- Holtom-Garrett Program in Neuroimmunology, Department of Neurology.,Graduate Program in Immunology, and.,Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick C Duncker
- Holtom-Garrett Program in Neuroimmunology, Department of Neurology.,Graduate Program in Immunology, and
| | | | | | - Benjamin M Segal
- Holtom-Garrett Program in Neuroimmunology, Department of Neurology.,Graduate Program in Immunology, and.,Neurology Service, VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
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12
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Adler LN, Jiang W, Bhamidipati K, Millican M, Macaubas C, Hung SC, Mellins ED. The Other Function: Class II-Restricted Antigen Presentation by B Cells. Front Immunol 2017; 8:319. [PMID: 28386257 PMCID: PMC5362600 DOI: 10.3389/fimmu.2017.00319] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/07/2017] [Indexed: 12/31/2022] Open
Abstract
Mature B lymphocytes (B cells) recognize antigens using their B cell receptor (BCR) and are activated to become antibody-producing cells. In addition, and integral to the development of a high-affinity antibodies, B cells utilize the specialized major histocompatibility complex class II (MHCII) antigen presentation pathway to process BCR-bound and internalized protein antigens and present selected peptides in complex with MHCII to CD4+ T cells. This interaction influences the fate of both types of lymphocytes and shapes immune outcomes. Specific, effective, and optimally timed antigen presentation by B cells requires well-controlled intracellular machinery, often regulated by the combined effects of several molecular events. Here, we delineate and summarize these events in four steps along the antigen presentation pathway: (1) antigen capture and uptake by B cells; (2) intersection of internalized antigen/BCRs complexes with MHCII in peptide-loading compartments; (3) generation and regulation of MHCII/peptide complexes; and (4) exocytic transport for presentation of MHCII/peptide complexes at the surface of B cells. Finally, we discuss modulation of the MHCII presentation pathway across B cell development and maturation to effector cells, with an emphasis on the shaping of the MHCII/peptide repertoire by two key antigen presentation regulators in B cells: HLA-DM and HLA-DO.
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Affiliation(s)
- Lital N Adler
- Department of Pediatrics, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA
| | - Wei Jiang
- Department of Pediatrics, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA
| | | | | | - Claudia Macaubas
- Department of Pediatrics, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA
| | - Shu-Chen Hung
- Department of Pediatrics, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA
| | - Elizabeth D Mellins
- Department of Pediatrics, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA
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13
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Thomas C, Tampé R. Proofreading of Peptide-MHC Complexes through Dynamic Multivalent Interactions. Front Immunol 2017; 8:65. [PMID: 28228754 PMCID: PMC5296336 DOI: 10.3389/fimmu.2017.00065] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/16/2017] [Indexed: 11/18/2022] Open
Abstract
The adaptive immune system is able to detect and destroy cells that are malignantly transformed or infected by intracellular pathogens. Specific immune responses against these cells are elicited by antigenic peptides that are presented on major histocompatibility complex class I (MHC I) molecules and recognized by cytotoxic T lymphocytes at the cell surface. Since these MHC I-presented peptides are generated in the cytosol by proteasomal protein degradation, they can be metaphorically described as a window providing immune cells with insights into the state of the cellular proteome. A crucial element of MHC I antigen presentation is the peptide-loading complex (PLC), a multisubunit machinery, which contains as key constituents the transporter associated with antigen processing (TAP) and the MHC I-specific chaperone tapasin (Tsn). While TAP recognizes and shuttles the cytosolic antigenic peptides into the endoplasmic reticulum (ER), Tsn samples peptides in the ER for their ability to form stable complexes with MHC I, a process called peptide proofreading or peptide editing. Through its selection of peptides that improve MHC I stability, Tsn contributes to the hierarchy of immunodominant peptide epitopes. Despite the fact that it concerns a key event in adaptive immunity, insights into the catalytic mechanism of peptide proofreading carried out by Tsn have only lately been gained via biochemical, biophysical, and structural studies. Furthermore, a Tsn homolog called TAP-binding protein-related (TAPBPR) has only recently been demonstrated to function as a second MHC I-specific chaperone and peptide proofreader. Although TAPBPR is PLC-independent and has a distinct allomorph specificity, it is likely to share a common catalytic mechanism with Tsn. This review focuses on the current knowledge of the multivalent protein–protein interactions and the concomitant dynamic molecular processes underlying peptide-proofreading catalysis. We do not only derive a model that highlights the common mechanistic principles shared by the MHC I editors Tsn and TAPBPR, and the MHC II editor HLA-DM, but also illustrate the distinct quality control strategies employed by these chaperones to sample epitopes. Unraveling the mechanistic underpinnings of catalyzed peptide proofreading will be crucial for a thorough understanding of many aspects of immune recognition, from infection control and tumor immunity to autoimmune diseases and transplant rejection.
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Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
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14
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Veerappan Ganesan AP, Eisenlohr LC. The elucidation of non-classical MHC class II antigen processing through the study of viral antigens. Curr Opin Virol 2017; 22:71-76. [PMID: 28081485 PMCID: PMC5346044 DOI: 10.1016/j.coviro.2016.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 11/22/2016] [Indexed: 11/22/2022]
Abstract
By convention, CD4+ T cells are activated predominantly by Major Histocompatibility Complex class II-bound peptides derived from extracellular (exogenous) antigens. It has been known for decades that alternative sources of antigen, particularly those synthesized within the antigen-presenting cell, can also supply peptides but the impact on TCD4+ responses, sometimes considerable, has only recently become appreciated. This review focuses on the contributions that studies of viral antigen have made to this shift in perspective, concluding with discussions of relevance to rational vaccine design, autoimmunity and cancer immunotherapy.
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Affiliation(s)
- Asha Purnima Veerappan Ganesan
- Department of Pathology and Laboratory Medicine at the Children's Hospital of Philadelphia Research Institute and the Perelman School of Medicine at The University of Pennsylvania, Philadelphia, PA, United States
| | - Laurence C Eisenlohr
- Department of Pathology and Laboratory Medicine at the Children's Hospital of Philadelphia Research Institute and the Perelman School of Medicine at The University of Pennsylvania, Philadelphia, PA, United States.
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15
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Zhou Z, Reyes-Vargas E, Escobar H, Chang KY, Barker AP, Rockwood AL, Delgado JC, He X, Jensen PE. Peptidomic analysis of type 1 diabetes associated HLA-DQ molecules and the impact of HLA-DM on peptide repertoire editing. Eur J Immunol 2016; 47:314-326. [PMID: 27861808 DOI: 10.1002/eji.201646656] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/21/2016] [Accepted: 11/10/2016] [Indexed: 11/08/2022]
Abstract
HLA-DM and class II associated invariant chain (Ii) are key cofactors in the MHC class II (MHCII) antigen processing pathway. We used tandem mass spectrometry sequencing to directly interrogate the global impact of DM and Ii on the repertoire of MHCII-bound peptides in human embryonic kidney 293T cells expressing HLA-DQ molecules in the absence or presence of these cofactors. We found that Ii and DM have a major impact on the repertoire of peptides presented by DQ1 and DQ6, with the caveat that this technology is not quantitative. The peptide repertoires of type 1 diabetes (T1D) associated DQ8, DQ2, and DQ8/2 are altered to a lesser degree by DM expression, and these molecules share overlapping features in their peptide binding motifs that are distinct from control DQ1 and DQ6 molecules. Peptides were categorized into DM-resistant, DM-dependent, or DM-sensitive groups based on the mass spectrometry data, and representative peptides were tested in competitive binding assays and peptide dissociation rate experiments with soluble DQ6. Our data support the conclusion that high intrinsic stability of DQ-peptide complexes is necessary but not sufficient to confer resistance to DM editing, and provide candidate parameters that may be useful in predicting the sensitivity of T-cell epitopes to DM editing.
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Affiliation(s)
- Zemin Zhou
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | | | | | - Kuan Y Chang
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Adam P Barker
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Alan L Rockwood
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Julio C Delgado
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Xiao He
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | - Peter E Jensen
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
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16
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Oh J, Shin JS. Molecular mechanism and cellular function of MHCII ubiquitination. Immunol Rev 2016; 266:134-44. [PMID: 26085212 DOI: 10.1111/imr.12303] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The major histocompatibility complex class II (MHCII) is ubiquitinated via the evolutionarily conserved lysine in the cytoplasmic tail of the β chain in dendritic cells (DCs) and B cells. The ubiquitination is mediated by the membrane-associated RING-CH1 (MARCH1) ubiquitin ligase although it can be also mediated by the homologous ligase MARCH8 in model cell lines. The ubiquitination promotes MHCII endocytosis and lysosomal sorting that results in a reduction in the level of MHCII at cell surface. Functionally, MHCII ubiquitination serves as a means by which DCs suppress MHCII expression and reduce antigen presentation in response to the immune regulatory cytokine interleukin-10 (IL-10) and regulatory T cells. Recently, additional roles of MHCII ubiquitination have emerged. MHCII ubiquitination promoted DC production of inflammatory cytokines in response to the Toll-like receptor ligands. It also potentiated DC ability to activate antigen-specific naive CD4(+) T cells while limiting the amount of antigens presented at cell surface. Similarly, MHCII ubiquitination promoted DC activation of CD4(+) thymocytes supporting regulatory T-cell development independent of its effect of limiting antigen presentation. Thus, ubiquitination appears to confer MHCII a function independent of presenting antigens by a mechanism yet to be identified.
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Affiliation(s)
- Jaehak Oh
- Department of Microbiology and Immunology, Sandler Asthma Basic Research Center, University of California San Francisco, San Francisco, CA, USA
| | - Jeoung-Sook Shin
- Department of Microbiology and Immunology, Sandler Asthma Basic Research Center, University of California San Francisco, San Francisco, CA, USA
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17
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Heterodimer HLA-DM Fused with Constant Fragment of the Heavy Chain of the Human Immunoglobulin Accelerates Influenza Hemagglutinin HA306-318 Loading to HLA-DR1. Bull Exp Biol Med 2016; 161:92-5. [PMID: 27265131 DOI: 10.1007/s10517-016-3353-y] [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: 04/26/2015] [Indexed: 10/21/2022]
Abstract
Major histocompatibility complex class II (MHC II) plays an important role not only in the adaptive immune responses to foreign pathogens, but also in the development of some autoimmune diseases. Non-classical MHC, HLA-DM is directly involved in MHC II loading with the peptide. To study this process, we synthesized recombinant proteins HLA-DR1 and HLA-DM. α/β-Chains of DR1 heterodimer contained C-terminal leucine domains of the fos and jun factors, respectively. Each DM chain contained constant fragment of human antibody heavy chain fused via a long linker domain. In addition, DM α-chain carried N165D substitution suppressing potential glycosylation at this site. We observed significant acceleration of DR1 peptide loading with influenza HA306-318 hemagglutinin in the presence of DM, which indicates functionality of recombinant DR1-DM protein couple. Our results can be used to study the presentation of other viral and self-antigens and can become the basis for the development of new drug modeling.
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18
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Unanue ER, Turk V, Neefjes J. Variations in MHC Class II Antigen Processing and Presentation in Health and Disease. Annu Rev Immunol 2016; 34:265-97. [PMID: 26907214 DOI: 10.1146/annurev-immunol-041015-055420] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
MHC class II (MHC-II) molecules are critical in the control of many immune responses. They are also involved in most autoimmune diseases and other pathologies. Here, we describe the biology of MHC-II and MHC-II variations that affect immune responses. We discuss the classic cell biology of MHC-II and various perturbations. Proteolysis is a major process in the biology of MHC-II, and we describe the various components forming and controlling this endosomal proteolytic machinery. This process ultimately determines the MHC-II-presented peptidome, including cryptic peptides, modified peptides, and other peptides that are relevant in autoimmune responses. MHC-II also variable in expression, glycosylation, and turnover. We illustrate that MHC-II is variable not only in amino acids (polymorphic) but also in its biology, with consequences for both health and disease.
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Affiliation(s)
- Emil R Unanue
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110;
| | - Vito Turk
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, SI-1000 Ljubljana, Slovenia;
| | - Jacques Neefjes
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands; .,Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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19
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Ferrante A, Templeton M, Hoffman M, Castellini MJ. The Thermodynamic Mechanism of Peptide-MHC Class II Complex Formation Is a Determinant of Susceptibility to HLA-DM. THE JOURNAL OF IMMUNOLOGY 2015; 195:1251-61. [PMID: 26116504 DOI: 10.4049/jimmunol.1402367] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 05/28/2015] [Indexed: 11/19/2022]
Abstract
Peptides bind MHC class II molecules through a thermodynamically nonadditive process consequent to the flexibility of the reactants. Currently, how the specific outcome of this binding process affects the ensuing epitope selection needs resolution. Calorimetric assessment of binding thermodynamics for hemagglutinin 306-319 peptide variants to the human MHC class II HLA-DR1 (DR1) and a mutant DR1 reveals that peptide/DR1 complexes can be formed with different enthalpic and entropic contributions. Complexes formed with a smaller entropic penalty feature circular dichroism spectra consistent with a non-compact form, and molecular dynamics simulation shows a more flexible structure. The opposite binding mode, compact and less flexible, is associated with greater entropic penalty. These structural variations are associated with rearrangements of residues known to be involved in HLA-DR (DM) binding, affinity of DM for the complex, and complex susceptibility to DM-mediated peptide exchange. Thus, the thermodynamic mechanism of peptide binding to DR1 correlates with the structural rigidity of the complex, and DM mediates peptide exchange by "sensing" flexible complexes in which the aforementioned residues are rearranged at a higher frequency than in more rigid ones.
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Affiliation(s)
- Andrea Ferrante
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775;
| | - Megan Templeton
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775; Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775; and
| | - Megan Hoffman
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775
| | - Margaret J Castellini
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775
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20
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Baker K, Rath T, Pyzik M, Blumberg RS. The Role of FcRn in Antigen Presentation. Front Immunol 2014; 5:408. [PMID: 25221553 PMCID: PMC4145246 DOI: 10.3389/fimmu.2014.00408] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/12/2014] [Indexed: 01/06/2023] Open
Abstract
Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors that bind IgG at the cell surface, the neonatal Fc receptor (FcRn) is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC). Cross-linking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells initiates specific mechanisms that result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both major histocompatibility complex class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and cancer.
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Affiliation(s)
- Kristi Baker
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA
| | - Timo Rath
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA ; Division of Gastroenterology, Department of Medicine, Erlangen University Hospital, Friedrich Alexander University Erlangen-Nueremberg , Erlangen , Germany
| | - Michal Pyzik
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA
| | - Richard S Blumberg
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA ; Harvard Digestive Diseases Center , Boston, MA , USA
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21
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The human-specific invariant chain isoform Iip35 modulates Iip33 trafficking and function. Immunol Cell Biol 2014; 92:791-8. [PMID: 24983457 DOI: 10.1038/icb.2014.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 05/12/2014] [Accepted: 05/31/2014] [Indexed: 12/24/2022]
Abstract
The invariant chain (Ii) is a multifunctional protein, which has an essential role in the assembly and transport of major histocompatibility complex class II (MHC II) molecules. From a single gene, Ii is synthesized as four different isoforms: Iip33, Iip35, Iip41 and Iip43. Iip35 and Iip43 are specific to humans, and are formed due to an upstream alternative translation site, resulting in an N-terminal extension of 16 amino acids. This extension harbors a strong endoplasmic reticulum (ER) retention motif. Consequently, Iip35 or Iip43 expressed alone are retained in the ER, whereas Iip33 and Iip41 rapidly traffic to the endosomal pathway. Endogenously expressed, the four isoforms form mixed heterotrimers in the ER; however, mainly due to the absence of the Iip35/p43 isoforms in mice, little is known about how they influence general Ii function. In this study, we have co-expressed Iip33 and Iip35 in human cells with and without MHC II to gain a better understanding of how Iip35 isoform influences the cellular properties of Iip33. We find that Iip35 significantly affects the properties of Iip33. In the presence of Iip35, the transport of Iip33 out of the ER is delayed, its half-life is dramatically prolonged and its ability to induce enlarged endosomes and delayed endosomal maturation is abrogated.
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22
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Sant AJ, Chaves FA, Krafcik FR, Lazarski CA, Menges P, Richards K, Weaver JM. Immunodominance in CD4 T-cell responses: implications for immune responses to influenza virus and for vaccine design. Expert Rev Vaccines 2014; 6:357-68. [PMID: 17542751 DOI: 10.1586/14760584.6.3.357] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CD4 T cells play a primary role in regulating immune responses to pathogenic organisms and to vaccines. Antigen-specific CD4 T cells provide cognate help to B cells, a requisite event for immunoglobulin switch and affinity maturation of B cells that produce neutralizing antibodies and also provide help to cytotoxic CD8 T cells, critical for their expansion and persistence as memory cells. Finally, CD4 T cells may participate directly in pathogen clearance via cell-mediated cytotoxicity or through production of cytokines. Understanding the role of CD4 T-cell immunity to viruses and other pathogens, as well as evaluation of the efficacy of vaccines, requires insight into the specificity of CD4 T cells. This review focuses on the events within antigen-presenting cells that focus CD4 T cells toward a limited number of peptide antigens within the pathogen or vaccine. The molecular events are discussed in light of the special challenges that the influenza virus poses, owing to the high degree of genetic variability, unpredictable pathogenicity and the repeated encounters that human populations face with this highly infectious pathogenic organism.
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Affiliation(s)
- Andrea J Sant
- David H Smith Center for Vaccine Biology and Immunology, Aab Institute and Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA.
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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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Dijkstra JM, Grimholt U, Leong J, Koop BF, Hashimoto K. Comprehensive analysis of MHC class II genes in teleost fish genomes reveals dispensability of the peptide-loading DM system in a large part of vertebrates. BMC Evol Biol 2013; 13:260. [PMID: 24279922 PMCID: PMC4219347 DOI: 10.1186/1471-2148-13-260] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 11/04/2013] [Indexed: 12/18/2022] Open
Abstract
Background Classical major histocompatibility complex (MHC) class II molecules play an essential role in presenting peptide antigens to CD4+ T lymphocytes in the acquired immune system. The non-classical class II DM molecule, HLA-DM in the case of humans, possesses critical function in assisting the classical MHC class II molecules for proper peptide loading and is highly conserved in tetrapod species. Although the absence of DM-like genes in teleost fish has been speculated based on the results of homology searches, it has not been definitively clear whether the DM system is truly specific for tetrapods or not. To obtain a clear answer, we comprehensively searched class II genes in representative teleost fish genomes and analyzed those genes regarding the critical functional features required for the DM system. Results We discovered a novel ancient class II group (DE) in teleost fish and classified teleost fish class II genes into three major groups (DA, DB and DE). Based on several criteria, we investigated the classical/non-classical nature of various class II genes and showed that only one of three groups (DA) exhibits classical-type characteristics. Analyses of predicted class II molecules revealed that the critical tryptophan residue required for a classical class II molecule in the DM system could be found only in some non-classical but not in classical-type class II molecules of teleost fish. Conclusions Teleost fish, a major group of vertebrates, do not possess the DM system for the classical class II peptide-loading and this sophisticated system has specially evolved in the tetrapod lineage.
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Affiliation(s)
- Johannes M Dijkstra
- Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
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Sant AJ, Chaves FA, Leddon SA, Tung J. The control of the specificity of CD4 T cell responses: thresholds, breakpoints, and ceilings. Front Immunol 2013; 4:340. [PMID: 24167504 PMCID: PMC3805957 DOI: 10.3389/fimmu.2013.00340] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 10/04/2013] [Indexed: 12/31/2022] Open
Abstract
It has been known for over 25 years that CD4 T cell responses are restricted to a finite number of peptide epitopes within pathogens or protein vaccines. These selected peptide epitopes are termed "immunodominant." Other peptides within the antigen that can bind to host MHC molecules and recruit CD4 T cells as single peptides are termed "cryptic" because they fail to induce responses when expressed in complex proteins or when in competition with other peptides during the immune response. In the last decade, our laboratory has evaluated the mechanisms that underlie the preferential specificity of CD4 T cells and have discovered that both intracellular events within antigen presenting cells, particular selective DM editing, and intercellular regulatory pathways, involving IFN-γ, indoleamine 2,3-dioxygenase, and regulatory T cells, play a role in selecting the final peptide specificity of CD4 T cells. In this review, we summarize our findings, discuss the implications of this work on responses to pathogens and vaccines and speculate on the logic of these regulatory events.
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Affiliation(s)
- Andrea J. Sant
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
| | - Francisco A. Chaves
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
| | - Scott A. Leddon
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jacqueline Tung
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
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Schulze MSED, Anders AK, Sethi DK, Call MJ. Disruption of hydrogen bonds between major histocompatibility complex class II and the peptide N-terminus is not sufficient to form a human leukocyte antigen-DM receptive state of major histocompatibility complex class II. PLoS One 2013; 8:e69228. [PMID: 23976922 PMCID: PMC3743349 DOI: 10.1371/journal.pone.0069228] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 06/06/2013] [Indexed: 01/17/2023] Open
Abstract
Peptide presentation by MHC class II is of critical importance to the function of CD4+ T cells. HLA-DM resides in the endosomal pathway and edits the peptide repertoire of newly synthesized MHC class II molecules before they are exported to the cell surface. HLA-DM ensures MHC class II molecules bind high affinity peptides by targeting unstable MHC class II:peptide complexes for peptide exchange. Research over the past decade has implicated the peptide N-terminus in modulating the ability of HLA-DM to target a given MHC class II:peptide combination. In particular, attention has been focused on both the hydrogen bonds between MHC class II and peptide, and the occupancy of the P1 anchor pocket. We sought to solve the crystal structure of a HLA-DR1 molecule containing a truncated hemagglutinin peptide missing three N-terminal residues compared to the full-length sequence (residues 306-318) to determine the nature of the MHC class II:peptide species that binds HLA-DM. Here we present structural evidence that HLA-DR1 that is loaded with a peptide truncated to the P1 anchor residue such that it cannot make select hydrogen bonds with the peptide N-terminus, adopts the same conformation as molecules loaded with full-length peptide. HLA-DR1:peptide combinations that were unable to engage up to four key hydrogen bonds were also unable to bind HLA-DM, while those truncated to the P2 residue bound well. These results indicate that the conformational changes in MHC class II molecules that are recognized by HLA-DM occur after disengagement of the P1 anchor residue.
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Affiliation(s)
- Monika-Sarah E. D. Schulze
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Anne-Kathrin Anders
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Program in Immunology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dhruv K. Sethi
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Melissa J. Call
- Structural Biology Division, the Walter and Eliza Hall Institute of Medical Research, the University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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Pos W, Sethi DK, Call MJ, Schulze MSED, Anders AK, Pyrdol J, Wucherpfennig KW. Crystal structure of the HLA-DM-HLA-DR1 complex defines mechanisms for rapid peptide selection. Cell 2013; 151:1557-68. [PMID: 23260142 DOI: 10.1016/j.cell.2012.11.025] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/15/2012] [Accepted: 11/14/2012] [Indexed: 12/18/2022]
Abstract
HLA-DR molecules bind microbial peptides in an endosomal compartment and present them on the cell surface for CD4 T cell surveillance. HLA-DM plays a critical role in the endosomal peptide selection process. The structure of the HLA-DM-HLA-DR complex shows major rearrangements of the HLA-DR peptide-binding groove. Flipping of a tryptophan away from the HLA-DR1 P1 pocket enables major conformational changes that position hydrophobic HLA-DR residues into the P1 pocket. These conformational changes accelerate peptide dissociation and stabilize the empty HLA-DR peptide-binding groove. Initially, incoming peptides have access to only part of the HLA-DR groove and need to compete with HLA-DR residues for access to the P2 site and the hydrophobic P1 pocket. This energetic barrier creates a rapid and stringent selection process for the highest-affinity binders. Insertion of peptide residues into the P2 and P1 sites reverses the conformational changes, terminating selection through DM dissociation.
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Affiliation(s)
- Wouter Pos
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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28
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Painter CA, Stern LJ. Conformational variation in structures of classical and non-classical MHCII proteins and functional implications. Immunol Rev 2013; 250:144-57. [PMID: 23046127 DOI: 10.1111/imr.12003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent structural characterizations of classical and non-classical major histocompatibility complex class II (MHCII) proteins have provided a view into the dynamic nature of the MHCII-peptide binding groove and the role that structural changes play in peptide loading processes. Although there have been numerous reports of crystal structures for MHCII-peptide complexes, a detailed analysis comparing all the structures has not been reported, and subtle conformational variations present in these structures may not have been fully appreciated. We compared the 91 MHCII crystal structures reported in the PDB to date, including an HLA-DR mutant particularly susceptible to DM-mediated peptide exchange, and reviewed experimental and computational studies of the effect of peptide binding on MHCII structure. These studies provide evidence for conformational lability in and around the α-subunit 3-10 helix at residues α48-51, a region known to be critical for HLA-DM-mediated peptide exchange. A biophysical study of MHC-peptide hydrogen bond strengths and a recent structure of the non-classical MHCII protein HLA-DO reveal changes in the same region. Conformational variability was observed also in the vicinity of a kink in the β-subunit helical region near residue β66 and in the orientation and loop conformation in the β2 Ig domain. Here, we provide an overview of the regions within classical and non-classical MHCII proteins that display conformational changes and the potential role that these changes may have in the peptide loading/exchange process.
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Affiliation(s)
- Corrie A Painter
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, USA
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Abstract
T cell recognition of antigen-presenting cells depends on their expression of a spectrum of peptides bound to major histocompatibility complex class I (MHC-I) and class II (MHC-II) molecules. Conversion of antigens from pathogens or transformed cells into MHC-I- and MHC-II-bound peptides is critical for mounting protective T cell responses, and similar processing of self proteins is necessary to establish and maintain tolerance. Cells use a variety of mechanisms to acquire protein antigens, from translation in the cytosol to variations on the theme of endocytosis, and to degrade them once acquired. In this review, we highlight the aspects of MHC-I and MHC-II biosynthesis and assembly that have evolved to intersect these pathways and sample the peptides that are produced.
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Affiliation(s)
- Janice S Blum
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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30
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Pulse-chase analysis for studies of MHC class II biosynthesis, maturation, and peptide loading. Methods Mol Biol 2013; 960:411-432. [PMID: 23329504 DOI: 10.1007/978-1-62703-218-6_31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pulse-chase analysis is a commonly used technique for studying the synthesis, processing and transport of proteins. Cultured cells expressing proteins of interest are allowed to take up radioactively labeled amino acids for a brief interval ("pulse"), during which all newly synthesized proteins incorporate the label. The cells are then returned to nonradioactive culture medium for various times ("chase"), during which proteins may undergo conformational changes, trafficking, or degradation. Proteins of interest are isolated (usually by immunoprecipitation) and resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the fate of radiolabeled molecules is examined by autoradiography. This chapter describes a pulse-chase protocol suitable for studies of major histocompatibility complex (MHC) class II biosynthesis and maturation. We discuss how results are affected by the recognition by certain anti-class II antibodies of distinct class II conformations associated with particular biosynthetic states. Our protocol can be adapted to follow the fate of many other endogenously synthesized proteins, including viral or transfected gene products, in cultured cells.
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31
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Endogenous HLA class II epitopes that are immunogenic in vivo show distinct behavior toward HLA-DM and its natural inhibitor HLA-DO. Blood 2012; 120:3246-55. [DOI: 10.1182/blood-2011-12-399311] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
CD4+ T cells play a central role in adaptive immunity. The acknowledgment of their cytolytic effector function and the finding that endogenous antigens can enter the HLA class II processing pathway make CD4+ T cells promising tools for immunotherapy. Expression of HLA class II and endogenous antigen, however, does not always correlate with T-cell recognition. We therefore investigated processing and presentation of endogenous HLA class II epitopes that induced CD4+ T cells during in vivo immune responses. We demonstrate that the peptide editor HLA-DM allowed antigen presentation of some (DM-resistant antigens) but abolished surface expression of other natural HLA class II epitopes (DM-sensitive antigens). DM sensitivity was shown to be epitope specific, mediated via interaction between HLA-DM and the HLA-DR restriction molecule, and reversible by HLA-DO. Because of the restricted expression of HLA-DO, presentation of DM-sensitive antigens was limited to professional antigen-presenting cells, whereas DM-resistant epitopes were expressed on all HLA class II–expressing cells. In conclusion, our data provide novel insights into the presentation of endogenous HLA class II epitopes and identify intracellular antigen processing and presentation as a critical factor for CD4+ T-cell recognition. This opens perspectives to exploit selective processing capacities as a new approach for targeted immunotherapy.
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32
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Jahnke M, Trowsdale J, Kelly AP. Structural requirements for recognition of major histocompatibility complex class II by membrane-associated RING-CH (MARCH) protein E3 ligases. J Biol Chem 2012; 287:28779-89. [PMID: 22761441 PMCID: PMC3436574 DOI: 10.1074/jbc.m112.381541] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 06/26/2012] [Indexed: 01/12/2023] Open
Abstract
MARCH E3 ligases play a key role in controlling MHC class II surface expression by regulated ubiquitination of a lysine residue in the β-chain. Little is known concerning how these enzymes target their specific substrates. Here we show that recognition of HLA-DR by MARCH proteins is complex. Several features associated with the transmembrane domain and bordering regions influence the overall efficiency of receptor internalization. A cluster of residues at the interface of the lipid bilayer and the cytosol plays the most important role in MARCH8 recognition of HLA-DRβ. Variation in this sequence also determines specificity of MARCH9 for HLA-DQ. Residues located in helical face four of HLA-DRβ together with a charged residue at the boundary with the stalk region also contribute significantly to recognition. Truncation analysis suggested that a dileucine-like motif in the DRβ cytoplasmic tail influences the efficiency of co-localization of HLA-DR with MARCH8. The DRβ-encoded acceptor lysine functioned optimally when placed in its natural location relative to the bilayer. In the DRα/DRβ dimer most other amino acids in the cytoplasmic tail could be substituted for alanine with minimal influence on function. Our data support a model whereby multiple features of HLA-DR are involved in substrate recognition by MARCH8. The single most important region is located at the interface between the transmembrane domain and the cytosol. Variation in sequence in this location between different class II isotypes controls efficiency of recognition by different MARCH E3 ligases.
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Affiliation(s)
- Martin Jahnke
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - John Trowsdale
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - Adrian P. Kelly
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
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33
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On the perils of poor editing: regulation of peptide loading by HLA-DQ and H2-A molecules associated with celiac disease and type 1 diabetes. Expert Rev Mol Med 2012; 14:e15. [PMID: 22805744 DOI: 10.1017/erm.2012.9] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This review discusses mechanisms that link allelic variants of major histocompatibility complex (MHC) class II molecules (MHCII) to immune pathology. We focus on HLA (human leukocyte antigen)-DQ (DQ) alleles associated with celiac disease (CD) and type 1 diabetes (T1D) and the role of the murine DQ-like allele, H2-Ag7 (I-Ag7 or Ag7), in murine T1D. MHCII molecules bind peptides, and alleles vary in their peptide-binding specificity. Disease-associated alleles permit binding of disease-inducing peptides, such as gluten-derived, Glu-/Pro-rich gliadin peptides in CD and peptides from islet autoantigens, including insulin, in T1D. In addition, the CD-associated DQ2.5 and DQ8 alleles are unusual in their interactions with factors that regulate their peptide loading, invariant chain (Ii) and HLA-DM (DM). The same alleles, as well as other T1D DQ risk alleles (and Ag7), share nonpolar residues in place of Asp at β57 and prefer peptides that place acidic side chains in a pocket in the MHCII groove (P9). Antigen-presenting cells from T1D-susceptible mice and humans retain CLIP because of poor DM editing, although underlying mechanisms differ between species. We propose that these effects on peptide presentation make key contributions to CD and T1D pathogenesis.
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34
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Regulation of cathepsins S and L by cystatin F during maturation of dendritic cells. Eur J Cell Biol 2012; 91:391-401. [DOI: 10.1016/j.ejcb.2012.01.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/20/2011] [Accepted: 01/01/2012] [Indexed: 11/18/2022] Open
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35
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Jahnke M, Trowsdale J, Kelly AP. Ubiquitination of human leukocyte antigen (HLA)-DM by different membrane-associated RING-CH (MARCH) protein family E3 ligases targets different endocytic pathways. J Biol Chem 2012; 287:7256-64. [PMID: 22247549 PMCID: PMC3293585 DOI: 10.1074/jbc.m111.305961] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 01/12/2012] [Indexed: 01/24/2023] Open
Abstract
HLA-DM plays an essential role in the peptide loading of classical class II molecules and is present both at the cell surface and in late endosomal peptide-loading compartments. Trafficking of DM within antigen-presenting cells is complex and is, in part, controlled by a tyrosine-based targeting signal present in the cytoplasmic tail of DMβ. Here, we show that DM also undergoes post-translational modification through ubiquitination of a single lysine residue present in the cytoplasmic tail of the α chain, DMα. Ubiquitination of DM by MARCH1 and MARCH9 induced loss of DM molecules from the cell surface by a mechanism that cumulatively involved both direct attachment of ubiquitin chains to DMα and a functional tyrosine-based signal on DMβ. In contrast, MARCH8-induced loss of surface DM was entirely dependent upon the tyrosine signal on DMβ. In the absence of this tyrosine residue, levels of DM remained unchanged irrespective of whether DMα was ubiquitinated by MARCH8. The influence of MARCH8 was indirect and may have resulted from modification of components of the endocytic machinery by ubiquitination.
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Affiliation(s)
- Martin Jahnke
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - John Trowsdale
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - Adrian P. Kelly
- From the Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
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36
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Watts C. The endosome-lysosome pathway and information generation in the immune system. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1824:14-21. [PMID: 21782984 PMCID: PMC3476823 DOI: 10.1016/j.bbapap.2011.07.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 07/06/2011] [Accepted: 07/07/2011] [Indexed: 12/04/2022]
Abstract
For a long time the lysosomal pathway was thought to be exclusively one for catabolism and recycling of material taken up by endocytosis from the external milieu or from the cytosol by autophagy. At least in the immune system it is clear now that endo/lysosomal proteolysis generates crucially important information, in particular peptides that bind class II MHC molecules to create ligands for survey by the diverse antigen receptors of the T lymphocyte system. This process of antigen processing and presentation is used to display not only foreign but also self peptides and therefore is important for 'self' tolerance as well as immunity to pathogens. Some cells, macrophages and particularly dendritic cells can load peptides on class I MHC molecules in the endosome system through the important, though still not fully characterised, pathway of cross-presentation. Here I try to provide a brief review of how this area developed focussing to some extent our own contributions to understanding the class II MHC pathway. I also mention briefly recent work of others showing that proteolysis along this pathway turns out to regulate immune signalling events in the innate immune system such as the activation of some members of the Toll-like receptor family. Finally, our recent work on the endo/lysosome targeted protease inhibitor cystatin F, suggests that auto-regulation of protease activity in some immune cells occurs. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.
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Affiliation(s)
- Colin Watts
- Division of Cell Signaling & Immunology, College of Life Sciences, University of Dundee, Dundee, UK.
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37
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Porter GW, Yi W, Denzin LK. TLR agonists downregulate H2-O in CD8alpha- dendritic cells. THE JOURNAL OF IMMUNOLOGY 2011; 187:4151-60. [PMID: 21918198 DOI: 10.4049/jimmunol.1003137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptide loading of MHC class II (MHCII) molecules is catalyzed by the nonclassical MHCII-related molecule H2-M. H2-O, another MHCII-like molecule, associates with H2-M and modulates H2-M function. The MHCII presentation pathway is tightly regulated in dendritic cells (DCs), yet how the key modulators of MHCII presentation, H2-M and H2-O, are affected in different DC subsets in response to maturation is unknown. In this study, we show that H2-O is markedly downregulated in vivo in mouse CD8α(-) DCs in response to a broad array of TLR agonists. In contrast, CD8α(+) DCs only modestly downregulated H2-O in response to TLR agonists. H2-M levels were slightly downmodulated in both CD8α(-) and CD8α(+) DCs. As a consequence, H2-M/H2-O ratios significantly increased for CD8α(-) but not for CD8α(+) DCs. The TLR-mediated downregulation was DC specific, as B cells did not show significant H2-O and H2-M downregulation. TLR4 signaling was required to mediate DC H2-O downregulation in response to LPS. Finally, our studies showed that the mechanism of H2-O downregulation was likely due to direct protein degradation of H2-O as well as downregulation of H2-O mRNA levels. The differential H2-O and H2-M modulation after DC maturation supports the proposed roles of CD8α(-) DCs in initiating CD4-restricted immune responses by optimal MHCII presentation and of CD8α(+) DCs in promoting immune tolerance via presentation of low levels of MHCII-peptide.
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Affiliation(s)
- Gavin W Porter
- Immunology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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38
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Call MJ. Small molecule modulators of MHC class II antigen presentation: Mechanistic insights and implications for therapeutic application. Mol Immunol 2011; 48:1735-43. [DOI: 10.1016/j.molimm.2011.05.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 05/23/2011] [Accepted: 05/24/2011] [Indexed: 02/02/2023]
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Hou T, Macmillan H, Chen Z, Keech CL, Jin X, Sidney J, Strohman M, Yoon T, Mellins ED. An insertion mutant in DQA1*0501 restores susceptibility to HLA-DM: implications for disease associations. THE JOURNAL OF IMMUNOLOGY 2011; 187:2442-52. [PMID: 21775680 DOI: 10.4049/jimmunol.1100255] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
HLA-DM (DM) catalyzes CLIP release, stabilizes MHC class II molecules, and edits the peptide repertoire presented by class II. Impaired DM function may have profound effects on Ag presentation events in the thymus and periphery that are critical for maintenance of self-tolerance. The associations of the HLA-DQ2 (DQ2) allele with celiac disease and type 1 diabetes mellitus have been appreciated for a long time. The explanation for these associations, however, remains unknown. We previously found that DQ2 is a poor substrate for DM. In this study, to further characterize DQ2-DM interaction, we introduced point mutations into DQ2 on the proposed DQ2-DM interface to restore the sensitivity of DQ2 to DM. The effects of mutations were investigated by measuring the peptide dissociation and exchange rate in vitro, CLIP and DQ2 expression on the cell surface, and the presentation of α-II-gliadin epitope (residues 62-70) to murine, DQ2-restricted T cell hybridomas. We found that the three α-chain mutations (α+53G, α+53R, or αY22F) decreased the intrinsic stability of peptide-class II complex. More interestingly, the α+53G mutant restored DQ2 sensitivity to DM, likely due to improved interaction with DM. Our data also suggest that α-II-gliadin 62-70 is a DM-suppressed epitope. The DQ2 resistance to DM changes the fate of this peptide from a cryptic to an immunodominant epitope. Our findings elucidate the structural basis for reduced DQ2-DM interaction and have implications for mechanisms underlying disease associations of DQ2.
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Affiliation(s)
- Tieying Hou
- Department of Pediatrics, Program in Immunology, Stanford University, Stanford, CA 94305, USA
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40
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van Luijn MM, van den Ancker W, Chamuleau MED, Zevenbergen A, Westers TM, Ossenkoppele GJ, van Ham SM, van de Loosdrecht AA. Absence of class II-associated invariant chain peptide on leukemic blasts of patients promotes activation of autologous leukemia-reactive CD4+ T cells. Cancer Res 2011; 71:2507-17. [PMID: 21310823 DOI: 10.1158/0008-5472.can-10-3689] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Immune escape in cancer poses a substantial obstacle to successful cancer immunotherapy. Multiple defects in HLA class I antigen presentation exist in cancer that may contribute to immune escape, but less is known about roles for HLA class II antigen presentation. On class II(+) leukemic blasts, the presence of class II-associated invariant chain peptide (CLIP) is known to be correlated with poor survival in acute myeloid leukemia (AML). In this study, we evaluated the functional significance of CLIP expression on leukemic blasts of AML patients. CD4(+) T cells from patients were cocultured with autologous CLIP(-) and CLIP(+) primary leukemic blasts and analyzed for several functional parameters by flow cytometry. Increased HLA-DR and IFN-γ expression was observed for CD4(+) T cells stimulated with CLIP(-) leukemic blasts, in contrast to CLIP(+) leukemic blasts, which indicated an activation and polarization of the CD4(+) T cells toward T-helper 1 cells. In addition, CLIP(-) leukemic blasts induced greater outgrowth of effector memory CD4(+) T cells (with HLA-DR-restricted T-cell receptor Vβ repertoires) that were associated with better leukemia-specific reactivity than with CLIP(+) leukemic blasts. Our findings offer a clinical rationale to downmodulate CLIP on leukemic blasts as a strategy to degrade immune escape and improve leukemia-specific T-cell immunity in AML patients.
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Affiliation(s)
- Marvin M van Luijn
- Department of Hematology, Cancer Center Amsterdam and VU Institute for Cancer and Immunology, VU University Medical Center, The Netherlands.
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41
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Crotzer VL, Glosson N, Zhou D, Nishino I, Blum JS. LAMP-2-deficient human B cells exhibit altered MHC class II presentation of exogenous antigens. Immunology 2011; 131:318-30. [PMID: 20518820 DOI: 10.1111/j.1365-2567.2010.03309.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Major histocompatibility complex (MHC) class II molecules present antigenic peptides derived from engulfed exogenous proteins to CD4(+) T cells. Exogenous antigens are processed in mature endosomes and lysosomes where acidic proteases reside and peptide-binding to class II alleles is favoured. Hence, maintenance of the microenvironment within these organelles is probably central to efficient MHC class II-mediated antigen presentation. Lysosome-associated membrane proteins such as LAMP-2 reside in mature endosomes and lysosomes, yet their role in exogenous antigen presentation pathways remains untested. In this study, human B cells lacking LAMP-2 were examined for changes in MHC class II-restricted antigen presentation. MHC class II presentation of exogenous antigen and peptides to CD4(+) T cells was impaired in the LAMP-2-deficient B cells. Peptide-binding to MHC class II on LAMP-2-deficient B cells was reduced at physiological pH compared with wild-type cells. However, peptide-binding and class II-restricted antigen presentation were restored by incubation of LAMP-2-negative B cells at acidic pH, suggesting that efficient loading of exogenous epitopes by MHC class II molecules is dependent upon LAMP-2 expression in B cells. Interestingly, class II presentation of an epitope derived from an endogenous transmembrane protein was detected using LAMP-2-deficient B cells. Consequently, LAMP-2 may control the repertoire of peptides displayed by MHC class II molecules on B cells and influence the balance between endogenous and exogenous antigen presentation.
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Affiliation(s)
- Victoria L Crotzer
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202-5120, USA
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Anders AK, Call MJ, Schulze MSED, Fowler KD, Schubert DA, Seth NP, Sundberg EJ, Wucherpfennig KW. HLA-DM captures partially empty HLA-DR molecules for catalyzed removal of peptide. Nat Immunol 2010; 12:54-61. [PMID: 21131964 PMCID: PMC3018327 DOI: 10.1038/ni.1967] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 11/09/2010] [Indexed: 11/20/2022]
Abstract
The mechanisms of HLA-DM catalyzed peptide exchange remain uncertain. We found that all stages of the interaction of DM with HLA-DR were dependent on the occupancy state of the peptide binding groove. High-affinity peptides were protected from removal by DM through two mechanisms: peptide binding induced dissociation of a long-lived complex of empty DR and DM, and high-affinity DR-peptide complexes bound DM only very slowly. Non-binding covalent DR-peptide complexes were converted to efficient DM binders upon truncation of an N-terminal peptide segment that emptied the P1 pocket and disrupted conserved hydrogen bonds to MHC. DM thus only binds to DR conformers in which a critical part of the binding site is vacant, due to spontaneous peptide motion.
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Affiliation(s)
- Anne-Kathrin Anders
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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Generation of MHC class II-peptide ligands for CD4 T-cell allorecognition of MHC class II molecules. Curr Opin Organ Transplant 2010; 15:505-11. [PMID: 20616724 DOI: 10.1097/mot.0b013e32833bfc5c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The molecular and cellular mechanisms that underlie allorecognition of MHC class II molecules have been the subject of much debate and experimentation in recent decades. In this review, we discuss several aspects of MHC class II structure, peptide acquisition and TcR-MHC-peptide interactions that have particular relevance to recognition of cells bearing allogeneic class II molecules. RECENT FINDINGS First, MHC polymorphism is heavily biased toward those amino acids that influence stable peptide binding by MHC class II. Second, the peptide repertoire presented by class II molecules is highly diverse and can be edited substantially by the molecular catalyst HLA-DM and by tissue-specific expression of HLA-DO, stress and cytokines. Third, T-cell receptor docking onto MHC peptide consistently involves substantial contacts with the bound peptide in the MHC class II molecule. Finally, there is increasing evidence that T-cell recognition of MHC is, in part, germline encoded through T-cell-receptor V region contacts with MHC class II alpha helices. SUMMARY Together, these conclusions support the view that allorecognition of MHC class II molecules is likely to parallel key aspects of conventional CD4 T-cell recognition, with allele-dependent variation in peptide representation accounting in large part for the high precursor frequency of alloreactive CD4 T cells.
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H2-O, a MHC class II-like protein, sets a threshold for B-cell entry into germinal centers. Proc Natl Acad Sci U S A 2010; 107:16607-12. [PMID: 20807742 DOI: 10.1073/pnas.1004664107] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Upon antigen (Ag) encounter, B cells require T-cell help to enter the germinal center (GC). They obtain this help by presenting Ag-derived peptides on MHC class II (MHCII) for recognition by the T-cell receptor (TCR) of CD4(+) T cells. Peptides are loaded onto MHCII in endosomal compartments in a process catalyzed by the MHCII-like protein H2-M (HLA-DM in humans). This process is modulated by another MHCII-like protein, H2-O (HLA-DO in humans). H2-O is a biochemical inhibitor of peptide loading onto MHCII; however, on the cellular level, it has been shown to have varying effects on Ag presentation. Thus, the function of H2-O in the adaptive immune response remains unclear. Here, we examine the effect of H2-O expression on the ability of Ag-specific B cells to enter the GC. We show that when Ag specific WT and H2-O(-/-) B cells are placed in direct competition, H2-O(-/-) B cells preferentially populate the GC. This advantage is confined to Ag-specific B cells and is due to their superior ability to obtain Ag-specific T-cell help when T-cell help is limiting. Overall, our work shows that H2-O expression reduces the ability of B cells to gain T-cell help and participate in the GC reaction.
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Zhou Z, Callaway KA, Weber DA, Jensen PE. Cutting edge: HLA-DM functions through a mechanism that does not require specific conserved hydrogen bonds in class II MHC-peptide complexes. THE JOURNAL OF IMMUNOLOGY 2009; 183:4187-91. [PMID: 19767569 DOI: 10.4049/jimmunol.0901663] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
HLA-DM catalyzes peptide dissociation and exchange in class II MHC molecules through a mechanism that has been proposed to involve the disruption of specific components of the conserved hydrogen bond network in MHC-peptide complexes. HLA-DR1 molecules with alanine substitutions at each of the six conserved H- bonding positions were expressed in cells, and susceptibility to DM catalytic activity was evaluated by measuring the release of CLIP. The mutants alphaN62A, alphaN69A, alphaR76A, and betaH81A DR1 were fully susceptible to DM-mediated CLIP release, and betaN82A resulted in spontaneous release of CLIP. Using recombinant soluble DR1 molecules, the amino acid betaN82 was observed to contribute disproportionately in stabilizing peptide complexes. Remarkably, the catalytic potency of DM with each beta-chain mutant was equal to or greater than that observed with wild-type DR1. Our results support the conclusion that no individual component of the conserved hydrogen bond network plays an essential role in the DM catalytic mechanism.
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Affiliation(s)
- Zemin Zhou
- Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
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Crotzer VL, Blum JS. Autophagy and its role in MHC-mediated antigen presentation. THE JOURNAL OF IMMUNOLOGY 2009; 182:3335-41. [PMID: 19265109 DOI: 10.4049/jimmunol.0803458] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Intracellular degradation by autophagy plays a role in the maintenance of cellular homeostasis under normal conditions and during periods of cellular stress. Autophagy has also been implicated in several other cellular processes including immune recognition and responsiveness. More specifically, autophagy has been identified as a route by which cytoplasmic and nuclear Ag are delivered to MHC class II molecules for presentation to CD4(+) T cells. Autophagy has also recently been implicated in MHC class I cross-presentation of tumor Ag and the activation of CD8(+) T cells. This review discusses the role of autophagy in modulating MHC class I and class II Ag presentation as well as its implication in regulating autoimmunity and tolerance, tumor immunity, and host defense against intracellular pathogens.
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Affiliation(s)
- Victoria L Crotzer
- Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine and the Walther Cancer Institute, Indianapolis, IN 46202, USA
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47
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Kambayashi T, Allenspach EJ, Chang JT, Zou T, Shoag JE, Reiner SL, Caton AJ, Koretzky GA. Inducible MHC class II expression by mast cells supports effector and regulatory T cell activation. THE JOURNAL OF IMMUNOLOGY 2009; 182:4686-95. [PMID: 19342644 DOI: 10.4049/jimmunol.0803180] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In addition to their well-established role as regulators of allergic response, recent evidence supports a role for mast cells in influencing the outcome of physiologic and pathologic T cell responses. One mechanism by which mast cells (MCs) influence T cell function is indirectly through secretion of various cytokines. It remains unclear, however, whether MCs can directly activate T cells through Ag presentation, as the expression of MHC class II by MCs has been controversial. In this report, we demonstrate that in vitro stimulation of mouse MCs with LPS and IFN-gamma induces the expression of MHC class II and costimulatory molecules. Although freshly isolated peritoneal MCs do not express MHC class II, an in vivo inflammatory stimulus increases the number of MHC class II-positive MCs in situ. Expression of MHC class II granted MCs the ability to process and present Ags directly to T cells with preferential expansion of Ag-specific regulatory T cells over naive T cells. These data support the notion that, in the appropriate setting, MCs may regulate T cell responses through the direct presentation of Ag.
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Affiliation(s)
- Taku Kambayashi
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
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Souwer Y, Chamuleau MED, van de Loosdrecht AA, Tolosa E, Jorritsma T, Muris JJF, Dinnissen-van Poppel MJ, Snel SN, van de Corput L, Ossenkoppele GJ, Meijer CJLM, Neefjes JJ, Marieke van Ham S. Detection of aberrant transcription of major histocompatibility complex class II antigen presentation genes in chronic lymphocytic leukaemia identifies HLA-DOA mRNA as a prognostic factor for survival. Br J Haematol 2009; 145:334-43. [PMID: 19245431 DOI: 10.1111/j.1365-2141.2009.07625.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In human B cells, effective major histocompatibility complex (MHC) class II-antigen presentation depends not only on MHC class II, but also on the invariant chain (CD74 or Ii), HLA-DM (DM) and HLA-DO (DO), the chaperones regulating the antigen loading process of MHC class II molecules. We analysed immediate ex vivo expression of HLA-DR (DR), CD74, DM and DO in B cell chronic lymphocytic leukaemia (B-CLL). Real-time reverse transcription polymerase chain reaction demonstrated a highly significant upregulation of DRA, CD74, DMB, DOA and DOB mRNA in purified malignant cells compared to B cells from healthy donors. The increased mRNA levels were not translated into enhanced protein levels but could reflect aberrant transcriptional regulation. Indeed, upregulation of DRA, DMB, DOA and DOB mRNA correlated with enhanced expression of class II transactivator (CIITA). In-depth analysis of the various CIITA transcripts demonstrated a significant increased activity of the interferon-gamma-inducible promoter CIITA-PIV in B-CLL. Comparison of the aberrant mRNA levels with clinical outcome identified DOA mRNA as a prognostic indicator for survival. Multivariate analysis revealed that the prognostic value of DOA mRNA was independent of the mutational status of the IGHV genes. Thus, aberrant transcription of DOA forms a novel and additional prognostic indicator for survival in B-CLL.
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Affiliation(s)
- Yuri Souwer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academical Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
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Abstract
The delivery of intracellular substrates such as misfolded proteins and damaged organelles from the cytosol to the lysosome for degradation is crucial for cell survival. Multiple transport pathways including bulk autophagy (microautophagy and macroautophagy) and chaperone‐mediated autophagy (CMA) have been identified to efficiently facilitate this transit of macromolecules from the cytoplasm to acidic vacuolar organelles. While autophagy plays a role in the general housekeeping of cells, it also functions in more specialized processes such as development and differentiation, responses to physiological stress and immunity. The presentation of both exogenous and endogenous antigens (Ag) by major histocompatibility complex (MHC) class II molecules to CD4+ T lymphocytes is critical for the induction of tolerance to self Ag as well as the development of immunity against intracellular pathogens and tumors. Here, we discuss the class II‐mediated presentation of several endogenous Ag, dependent on either macroautophagy or CMA for their transport from the cytosol to endosomal/lysosomal compartments. Thus, the various pathways of autophagy as routes of cytoplasmic Ag delivery to lysosomes have significant implications for the MHC class II‐mediated immune response to intracellular pathogens and cancer.
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Affiliation(s)
- Victoria L Crotzer
- Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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50
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Stephen TL, Fabri M, Groneck L, Röhn TA, Hafke H, Robinson N, Rietdorf J, Schrama D, Becker JC, Plum G, Krönke M, Kropshofer H, Kalka-Moll WM. Transport of Streptococcus pneumoniae capsular polysaccharide in MHC Class II tubules. PLoS Pathog 2007; 3:e32. [PMID: 17367207 PMCID: PMC1828696 DOI: 10.1371/journal.ppat.0030032] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 01/19/2007] [Indexed: 11/23/2022] Open
Abstract
Bacterial capsular polysaccharides are virulence factors and are considered T cell–independent antigens. However, the capsular polysaccharide Sp1 from Streptococcus pneumoniae serotype 1 has been shown to activate CD4+ T cells in a major histocompatibility complex (MHC) class II–dependent manner. The mechanism of carbohydrate presentation to CD4+ T cells is unknown. We show in live murine dendritic cells (DCs) that Sp1 translocates from lysosomal compartments to the plasma membrane in MHCII-positive tubules. Sp1 cell surface presentation results in reduction of self-peptide presentation without alteration of the MHCII self peptide repertoire. In DM-deficient mice, retrograde transport of Sp1/MHCII complexes resulting in T cell–dependent immune responses to the polysaccharide in vitro and in vivo is significantly reduced. The results demonstrate the capacity of a bacterial capsular polysaccharide antigen to use DC tubules as a vehicle for its transport as an MHCII/saccharide complex to the cell surface for the induction of T cell activation. Furthermore, retrograde transport requires the functional role of DM in self peptide–carbohydrate exchange. These observations open new opportunities for the design of vaccines against microbial encapsulated pathogens. Microorganisms are comprised of proteins, carbohydrates, lipids, and nucleic acids. Current immunologic paradigms state that activation of T lymphocytes required for humoral and cellular immune responses resulting in immunologic memory to the pathogens is solely brought about by proteinaceous antigens, processed and degraded to small peptides, loaded onto major histocompatibility complex (MHC) molecules, and transported as MHC/peptide complexes to the cell surface, where the MHC/peptide complex is recognized by the T cell antigen receptor. The findings of the present study elucidate the mechanism of MHC class II (MHCII)–dependent presentation of the bacterial capsular polysaccharide of Streptococcus pneumoniae serotype 1 (Sp1) that results in effective T cell activation. Sp1 is transported in MHCII-positive tubules from lysosomal compartments to the plasma membrane for presentation. In the absence of the DM molecule, known as an editor and catalyst of self and foreign peptide exchange, retrograde transport of carbohydrate/MHCII complexes resulting in dendritic cell engagement with T cells in vitro and T cell–dependent immune responses to the polysaccharide in vivo fail. The results suggest a fundamental shift in the immunologic paradigm, offering previously unrecognized opportunities for the design of new classes of vaccines against infectious diseases.
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Affiliation(s)
- Tom Li Stephen
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Mario Fabri
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Laura Groneck
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Till A Röhn
- Pharmaceutical Research, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Helena Hafke
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Nirmal Robinson
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Jens Rietdorf
- Advanced Light Microscopy Facility, European Molecular Biology Laboratories, Heidelberg, Germany
| | - David Schrama
- Department of Dermatology, Julius-Maximilians-University of Wuerzburg, Wuerzburg, Germany
| | - Jürgen C Becker
- Department of Dermatology, Julius-Maximilians-University of Wuerzburg, Wuerzburg, Germany
| | - Georg Plum
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Martin Krönke
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
| | - Harald Kropshofer
- Pharmaceutical Research, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Wiltrud M Kalka-Moll
- Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Cologne, Germany
- * To whom correspondence should be addressed. E-mail:
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