1
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Shi Y, Strasser A, Green DR, Latz E, Mantovani A, Melino G. Legacy of the discovery of the T-cell receptor: 40 years of shaping basic immunology and translational work to develop novel therapies. Cell Mol Immunol 2024:10.1038/s41423-024-01168-4. [PMID: 38822079 DOI: 10.1038/s41423-024-01168-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Accepted: 04/18/2024] [Indexed: 06/02/2024] Open
Affiliation(s)
- Yufang Shi
- The Fourth Affiliated Hospital of Soochow University, Institutes for Translational Medicine, State Key Laboratory of Radiation Medicine and Protection, Medical College of Soochow University, Soochow University, Suzhou, 215000, China.
| | - Andreas Strasser
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Eicke Latz
- Institute of Innate Immunity, University of Bonn, Bonn, 53127, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, 53175, Germany
| | | | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, 00133, Rome, Italy.
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2
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Querol Cano L, Dunlock VME, Schwerdtfeger F, van Spriel AB. Membrane organization by tetraspanins and galectins shapes lymphocyte function. Nat Rev Immunol 2024; 24:193-212. [PMID: 37758850 DOI: 10.1038/s41577-023-00935-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2023] [Indexed: 09/29/2023]
Abstract
Immune receptors are not randomly distributed at the plasma membrane of lymphocytes but are segregated into specialized domains that function as platforms to initiate signalling, as exemplified by the B cell or T cell receptor complex and the immunological synapse. 'Membrane-organizing proteins' and, in particular, tetraspanins and galectins, are crucial for controlling the spatiotemporal organization of immune receptors and other signalling proteins. Deficiencies in specific tetraspanins and galectins result in impaired immune synapse formation, lymphocyte proliferation, antibody production and migration, which can lead to impaired immunity, tumour development and autoimmunity. In contrast to conventional ligand-receptor interactions, membrane organizers interact in cis (on the same cell) and modulate receptor clustering, receptor dynamics and intracellular signalling. New findings have uncovered their complex and dynamic nature, revealing shared binding partners and collaborative activity in determining the composition of membrane domains. Therefore, immune receptors should not be envisaged as independent entities and instead should be studied in the context of their spatial organization in the lymphocyte membrane. We advocate for a novel approach to study lymphocyte function by globally analysing the role of membrane organizers in the assembly of different membrane complexes and discuss opportunities to develop therapeutic approaches that act via the modulation of membrane organization.
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Affiliation(s)
- Laia Querol Cano
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Vera-Marie E Dunlock
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Fabian Schwerdtfeger
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Annemiek B van Spriel
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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3
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van Weijsten MJ, Venrooij KR, Lelieveldt L, Kissel T, van Buijtenen E, van Dalen FJ, Verdoes M, Toes R, Bonger KM. Effect of Antigen Valency on Autoreactive B-Cell Targeting. Mol Pharm 2024; 21:481-490. [PMID: 37862070 PMCID: PMC10848265 DOI: 10.1021/acs.molpharmaceut.3c00527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/21/2023]
Abstract
Many autoimmune diseases are characterized by B cells that mistakenly recognize autoantigens and produce antibodies toward self-proteins. Current therapies aim to suppress the immune system, which is associated with adverse effects. An attractive and more specific approach is to target the autoreactive B cells selectively through their unique B-cell receptor (BCR) using an autoantigen coupled to an effector molecule able to modulate the B-cell activity. The cellular response upon antigen binding, such as receptor internalization, impacts the choice of effector molecule. In this study, we systematically investigated how a panel of well-defined mono-, di-, tetra-, and octavalent peptide antigens affects the binding, activation, and internalization of the BCR. To test our constructs, we used a B-cell line expressing a BCR against citrullinated antigens, the main autoimmune epitope in rheumatoid arthritis. We found that the dimeric antigen construct has superior targeting properties compared to those of its monomeric and multimeric counterparts, indicating that it can serve as a basis for future antigen-specific targeting studies for the treatment of RA.
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Affiliation(s)
- M. J. van Weijsten
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
| | - K. R. Venrooij
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
| | - L.P.W.M. Lelieveldt
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
| | - T. Kissel
- Department
of Rheumatology, Leiden University Medical
Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - E. van Buijtenen
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - F. J. van Dalen
- Department
of Medical BioSciences, Radboudumc, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
| | - M. Verdoes
- Department
of Medical BioSciences, Radboudumc, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
| | - R.E.M. Toes
- Department
of Rheumatology, Leiden University Medical
Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - K. M. Bonger
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen, The Netherlands
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4
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Isomursu A, Alanko J, Hernández-Pérez S, Saukkonen K, Saari M, Mattila PK, Ivaska J. Dynamic Micropatterning Reveals Substrate-Dependent Differences in the Geometric Control of Cell Polarization and Migration. SMALL METHODS 2024; 8:e2300719. [PMID: 37926786 DOI: 10.1002/smtd.202300719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/03/2023] [Indexed: 11/07/2023]
Abstract
Cells are highly dynamic and adopt variable shapes and sizes. These variations are biologically important but challenging to investigate in a spatiotemporally controlled manner. Micropatterning, confining cells on microfabricated substrates with defined geometries and molecular compositions, is a powerful tool for controlling cell shape and interactions. However, conventional binary micropatterns are static and fail to address dynamic changes in cell polarity, spreading, and migration. Here, a method for dynamic micropatterning is reported, where the non-adhesive surface surrounding adhesive micropatterns is rapidly converted to support specific cell-matrix interactions while allowing simultaneous imaging of the cells. The technique is based on ultraviolet photopatterning of biotinylated polyethylene glycol-grafted poly-L-lysine, and it is simple, inexpensive, and compatible with a wide range of streptavidin-conjugated ligands. Experiments using biotinylation-based dynamic micropatterns reveal that distinct extracellular matrix ligands and bivalent integrin-clustering antibodies support different degrees of front-rear polarity in human glioblastoma cells, which correlates to altered directionality and persistence upon release and migration on fibronectin. Unexpectedly, however, neither an asymmetric cell shape nor centrosome orientation can fully predict the future direction of migration. Taken together, biotinylation-based dynamic micropatterns allow easily accessible and highly customizable control over cell morphology and motility.
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Affiliation(s)
- Aleksi Isomursu
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
| | - Jonna Alanko
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
| | - Sara Hernández-Pérez
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, 20014, Finland
- Department of Life Technologies, University of Turku, Turku, 20520, Finland
| | - Karla Saukkonen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
| | - Markku Saari
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
| | - Pieta K Mattila
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, 20014, Finland
- Department of Life Technologies, University of Turku, Turku, 20520, Finland
| | - Johanna Ivaska
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, 20520, Finland
- Department of Life Technologies, University of Turku, Turku, 20520, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, 20520, Finland
- Western Finnish Cancer Center (FICAN West), University of Turku, Turku, 20520, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, 00014, Finland
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5
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Sam G, Stenos J, Graves SR, Rehm BHA. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines 2023; 8:133. [PMID: 37679410 PMCID: PMC10484952 DOI: 10.1038/s41541-023-00727-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Q fever is an infectious zoonotic disease, caused by the Gram-negative bacterium Coxiella burnetii. Transmission occurs from livestock to humans through inhalation of a survival form of the bacterium, the Small Cell Variant, often via handling of animal parturition products. Q fever manifests as an acute self-limiting febrile illness or as a chronic disease with complications such as vasculitis and endocarditis. The current preventative human Q fever vaccine Q-VAX poses limitations on its worldwide implementation due to reactogenic responses in pre-sensitized individuals. Many strategies have been undertaken to develop a universal Q fever vaccine but with little success to date. The mechanisms of the underlying reactogenic responses remain only partially understood and are important factors in the development of a safe Q fever vaccine. This review provides an overview of previous and current experimental vaccines developed for use against Q fever and proposes approaches to develop a vaccine that establishes immunological memory while eliminating harmful reactogenic responses.
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Affiliation(s)
- Gayathri Sam
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia
| | - John Stenos
- Australian Rickettsial Reference Laboratory, University Hospital, Geelong, VIC, 3220, Australia
| | - Stephen R Graves
- Australian Rickettsial Reference Laboratory, University Hospital, Geelong, VIC, 3220, Australia
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW, 2567, Australia
| | - Bernd H A Rehm
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia.
- Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, 4222, Australia.
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6
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Rinaldi DA, Kanagy WK, Kaye HC, Grattan RM, Lucero SR, Pérez MP, Wester MJ, Lidke KA, Wilson BS, Lidke DS. Antigen Geometry Tunes Mast Cell Signaling Through Distinct FcεRI Aggregation and Structural Changes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552060. [PMID: 37609336 PMCID: PMC10441289 DOI: 10.1101/2023.08.04.552060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Immunoreceptor tyrosine-based activation motif (ITAM)-containing Fc receptors are critical components of the innate and adaptive immune systems. FcεRI mediates the allergic response via crosslinking of IgE-bound receptors by multivalent antigens. Yet, the underlying molecular mechanisms that govern the response of FcεRI to specific antigens remain poorly understood. We compared responses induced by two antigens with distinct geometries, high valency DNP-BSA and trivalent DF3, and found unique secretion and receptor phosphorylation profiles that are due to differential recruitment of Lyn and SHIP1. To understand how these two antigens can cause such markedly different outcomes, we used direct stochastic optical reconstruction microscopy (dSTORM) super-resolution imaging combined with Bayesian Grouping of Localizations (BaGoL) analysis to compare the nanoscale characteristics of FcεRI aggregates. DF3 aggregates were found to be smaller and more densely packed than DNP-BSA aggregates. Using lifetime-based Förster resonance energy transfer (FRET) measurements, we discovered that FcεRI subunits undergo structural rearrangements upon crosslinking with either antigen, and in response to interaction with monovalent antigen presented on a supported lipid bilayer. The extent of conformational change is positively correlated with signaling efficiency. Finally, we provide evidence for forces in optimizing FcεRI signaling, such that immobilizing DF3 on a rigid surface promoted degranulation while increasing DNP-BSA flexibility lowered degranulation. These results provide a link between the physical attributes of allergens, including size, shape, valency, and flexibility, and FcεRI signaling strength. Thus, the antigen modulates mast cell outcomes by creating unique aggregate geometries that tune FcεRI conformation, phosphorylation and signaling partner recruitment.
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Affiliation(s)
- Derek A. Rinaldi
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | - William K. Kanagy
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
- Present address: Department of Immunology, University of Minnesota, Minneapolis, MN 55455
| | - Hannah C. Kaye
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | - Rachel M. Grattan
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | - Shayna R. Lucero
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | | | - Michael J. Wester
- Department Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131
| | - Keith A. Lidke
- Department Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131
- Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
| | - Bridget S. Wilson
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
- Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
| | - Diane S. Lidke
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
- Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
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7
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Ferapontov A, Omer M, Baudrexel I, Nielsen JS, Dupont DM, Juul-Madsen K, Steen P, Eklund AS, Thiel S, Vorup-Jensen T, Jungmann R, Kjems J, Degn SE. Antigen footprint governs activation of the B cell receptor. Nat Commun 2023; 14:976. [PMID: 36813795 PMCID: PMC9947222 DOI: 10.1038/s41467-023-36672-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/10/2023] [Indexed: 02/24/2023] Open
Abstract
Antigen binding by B cell receptors (BCR) on cognate B cells elicits a response that eventually leads to production of antibodies. However, it is unclear what the distribution of BCRs is on the naïve B cell and how antigen binding triggers the first step in BCR signaling. Using DNA-PAINT super-resolution microscopy, we find that most BCRs are present as monomers, dimers, or loosely associated clusters on resting B cells, with a nearest-neighbor inter-Fab distance of 20-30 nm. We leverage a Holliday junction nanoscaffold to engineer monodisperse model antigens with precision-controlled affinity and valency, and find that the antigen exerts agonistic effects on the BCR as a function of increasing affinity and avidity. Monovalent macromolecular antigens can activate the BCR at high concentrations, whereas micromolecular antigens cannot, demonstrating that antigen binding does not directly drive activation. Based on this, we propose a BCR activation model determined by the antigen footprint.
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Affiliation(s)
- Alexey Ferapontov
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark
| | - Marjan Omer
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Isabelle Baudrexel
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jesper Sejrup Nielsen
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Daniel Miotto Dupont
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | | | - Philipp Steen
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Munich, Germany
| | - Alexandra S Eklund
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark
| | | | - Ralf Jungmann
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany.,Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Munich, Germany
| | - Jørgen Kjems
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Søren Egedal Degn
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark. .,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.
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8
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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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9
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Hinke DM, Andersen TK, Gopalakrishnan RP, Skullerud LM, Werninghaus IC, Grødeland G, Fossum E, Braathen R, Bogen B. Antigen bivalency of antigen-presenting cell-targeted vaccines increases B cell responses. Cell Rep 2022; 39:110901. [PMID: 35649357 DOI: 10.1016/j.celrep.2022.110901] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 04/09/2022] [Accepted: 05/10/2022] [Indexed: 11/25/2022] Open
Abstract
Antibodies are important for vaccine efficacy. Targeting antigens to antigen-presenting cells (APCs) increases antibody levels. Here, we explore the role of antigen valency in MHC class II (MHCII)-targeted vaccines delivered as DNA. We design heterodimeric proteins that carry either two identical (bivalent vaccines), or two different antigens (monovalent vaccines). Bivalent vaccines with two identical influenza hemagglutinins (HA) elicit higher amounts of anti-HA antibodies in mice than monovalent versions with two different HAs. Bivalent vaccines increase the levels of germinal center (GC) B cells and long-lived plasma cells. Only HA-bivalent vaccines completely protect mice against challenge with homologous influenza virus. Similar results are obtained with other antigens by targeting CD11c and Xcr1 on dendritic cells (DCs) or when administering the vaccine as protein with adjuvant. Bivalency probably increases B cell responses by cross-linking BCRs in readily observable DC-B cell synapses. These results are important for generating potent APC-targeted vaccines.
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Affiliation(s)
- Daniëla Maria Hinke
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway
| | - Tor Kristian Andersen
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway
| | | | - Lise Madelene Skullerud
- Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway
| | | | - Gunnveig Grødeland
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway
| | - Even Fossum
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway
| | - Ranveig Braathen
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway.
| | - Bjarne Bogen
- K.G. Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo 0372, Norway; Department of Immunology (IMM), University of Oslo and Oslo University Hospital, Oslo 0372, Norway.
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10
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Udoye CC, Rau CN, Freye SM, Almeida LN, Vera-Cruz S, Othmer K, Korkmaz RÜ, Clauder AK, Lindemann T, Niebuhr M, Ott F, Kalies K, Recke A, Busch H, Fähnrich A, Finkelman FD, Manz RA. B-cell receptor physical properties affect relative IgG1 and IgE responses in mouse egg allergy. Mucosal Immunol 2022; 15:1375-1388. [PMID: 36114245 PMCID: PMC9705252 DOI: 10.1038/s41385-022-00567-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/10/2022] [Accepted: 09/01/2022] [Indexed: 02/04/2023]
Abstract
Mutated and unmutated IgE and IgG play different and partly opposing roles in allergy development, but the mechanisms controlling their relative production are incompletely understood. Here, we analyzed the IgE-response in murine food allergy. Deep sequencing of the complementary-determining region (CDR) repertoires indicated that an ongoing unmutated extrafollicular IgE response coexists with a germinal center response, even after long-lasting allergen challenges. Despite overall IgG1-dominance, a significant proportion of clonotypes contained several-fold more IgE than IgG1. Clonotypes with differential bias to either IgE or IgG1 showed distinct hypermutation and clonal expansion. Hypermutation rates were associated with different physiochemical binding properties of individual B-cell receptors (BCR). Increasing BCR signaling strength inhibited class switching from IgG1 to IgE in vitro, preferentially constraining IgE formation. These data indicate that antigen-binding properties of individual BCRs determine differential IgE hypermutation and IgE versus IgG1 production on the level of single B-cell clones.
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Affiliation(s)
- Christopher C. Udoye
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Christina N. Rau
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Sarah M. Freye
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Larissa N. Almeida
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Sarah Vera-Cruz
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Kai Othmer
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Rabia Ü. Korkmaz
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Ann-Katrin Clauder
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Timo Lindemann
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Markus Niebuhr
- grid.4562.50000 0001 0057 2672Institute for Anatomy, University of Lübeck, Lübeck, Germany
| | - Fabian Ott
- grid.4562.50000 0001 0057 2672Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Kathrin Kalies
- grid.4562.50000 0001 0057 2672Institute for Anatomy, University of Lübeck, Lübeck, Germany
| | - Andreas Recke
- Department of Dermatology, Allergology and Venereology, University off Lübeck, Lübeck, Germany
| | - Hauke Busch
- grid.4562.50000 0001 0057 2672Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Anke Fähnrich
- grid.4562.50000 0001 0057 2672Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Fred D. Finkelman
- grid.239573.90000 0000 9025 8099Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati College of Medicine and the Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA
| | - Rudolf A. Manz
- grid.4562.50000 0001 0057 2672Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
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11
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Johanson TM, Keenan CR, Allan RS. Shedding Structured Light on Molecular Immunity: The Past, Present and Future of Immune Cell Super Resolution Microscopy. Front Immunol 2021; 12:754200. [PMID: 34975842 PMCID: PMC8715013 DOI: 10.3389/fimmu.2021.754200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/23/2021] [Indexed: 12/16/2022] Open
Abstract
In the two decades since the invention of laser-based super resolution microscopy this family of technologies has revolutionised the way life is viewed and understood. Its unparalleled resolution, speed, and accessibility makes super resolution imaging particularly useful in examining the highly complex and dynamic immune system. Here we introduce the super resolution technologies and studies that have already fundamentally changed our understanding of a number of central immunological processes and highlight other immunological puzzles only addressable in super resolution.
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Affiliation(s)
- Timothy M. Johanson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Christine R. Keenan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Rhys S. Allan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
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12
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Deretic N, Bolger-Munro M, Choi K, Abraham L, Gold MR. The Actin-Disassembly Protein Glia Maturation Factor γ Enhances Actin Remodeling and B Cell Antigen Receptor Signaling at the Immune Synapse. Front Cell Dev Biol 2021; 9:647063. [PMID: 34336818 PMCID: PMC8318000 DOI: 10.3389/fcell.2021.647063] [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: 12/29/2020] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
Signaling by the B cell antigen receptor (BCR) initiates actin remodeling. The assembly of branched actin networks that are nucleated by the Arp2/3 complex exert outward force on the plasma membrane, allowing B cells to form membrane protrusions that can scan the surface of antigen-presenting cells (APCs). The resulting Arp2/3 complex-dependent actin retrograde flow promotes the centripetal movement and progressive coalescence of BCR microclusters, which amplifies BCR signaling. Glia maturation factor γ (GMFγ) is an actin disassembly-protein that releases Arp2/3 complex-nucleated actin filaments from actin networks. By doing so, GMFγ could either oppose the actions of the Arp2/3 complex or support Arp2/3 complex-nucleated actin polymerization by contributing to the recycling of actin monomers and Arp2/3 complexes. We now show that reducing the levels of GMFγ in human B cell lines via transfection with a specific siRNA impairs the ability of B cells to spread on antigen-coated surfaces, decreases the velocity of actin retrograde flow, diminishes the coalescence of BCR microclusters into a central cluster at the B cell-APC contact site, and decreases APC-induced BCR signaling. These effects of depleting GMFγ are similar to what occurs when the Arp2/3 complex is inhibited. This suggests that GMFγ cooperates with the Arp2/3 complex to support BCR-induced actin remodeling and amplify BCR signaling at the immune synapse.
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Affiliation(s)
- Nikola Deretic
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Madison Bolger-Munro
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kate Choi
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Libin Abraham
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Gold
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
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13
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Src Family Protein Kinase Controls the Fate of B Cells in Autoimmune Diseases. Inflammation 2020; 44:423-433. [PMID: 33037966 DOI: 10.1007/s10753-020-01355-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/07/2020] [Accepted: 09/30/2020] [Indexed: 02/07/2023]
Abstract
There are more than 80 kinds of autoimmune diseases known at present, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), inflammatory bowel disease (IBD), as well as other disorders. Autoimmune diseases have a characteristic of immune responses directly attacking own tissues, leading to systematic inflammation and subsequent tissue damage. B cells play a vital role in the development of autoimmune diseases and differentiate into plasma cells or memory B cells to secrete high-affinity antibody or provide long-lasting function. Drugs targeting B cells show good therapeutic effects for the treatment of autoimmune diseases, such as rituximab (anti-CD20 antibody). Src family protein kinases (SFKs) are believed to play important roles in a variety of cellular functions such as growth, proliferation, and differentiation of B cell via B cell antigen receptor (BCR). Lck/Yes-related novel protein tyrosine kinase (LYN), BLK (B lymphocyte kinase), and Fyn are three different kinds of SFKs mainly expressed in B cells. LYN has a dual role in the BCR signal. On the one hand, positive signals are beneficial to the development and maturation of B cells. On the other hand, LYN can also inhibit excessively activated B cells. BLK is involved in the proliferation, differentiation, and immune tolerance of B lymphocytes, and further affects the function of B cells, which may lead to autoreactive or regulatory cellular responses, increasing the risk of autoimmune diseases. Fyn may affect the development of autoimmune disorders via the differentiation of B cells in the early stage of B cell development. This article reviews the recent advances of SFKs in B lymphocytes in autoimmune diseases.
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14
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Seco BMS, Xu FF, Grafmüller A, Kottari N, Pereira CL, Seeberger PH. Sequential Linkage of Carbohydrate Antigens to Mimic Capsular Polysaccharides: Toward Semisynthetic Glycoconjugate Vaccine Candidates against Streptococcus pneumoniae Serotype 14. ACS Chem Biol 2020; 15:2395-2405. [PMID: 32835479 PMCID: PMC7506939 DOI: 10.1021/acschembio.0c00360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Vaccines
based on isolated polysaccharides successfully protect
humans from bacterial pathogens such as Streptococcus pneumoniae. Because polysaccharide production and isolation can be technically
challenging, glycoconjugates containing synthetic antigens are an
attractive alternative. Typically, the shortest possible oligosaccharide
antigen is preferable as syntheses of longer structures are more difficult
and time-consuming. Combining several protective epitopes or polysaccharide
repeating units as blocks by bonds other than glycosidic linkages
would greatly reduce the synthetic effort if the immunological response
to the polysaccharide could be retained. To explore this concept,
we bridged the well-understood and immunologically potent RU of S. pneumoniae serotype 14 (ST14) with an aliphatic spacer
and conjugated it to the carrier protein CRM197. Mice immunized with
the spacer-bridged glycan conjugates produced high levels of specific
antibodies after just one or two vaccine doses, while the tetrasaccharide
repeating unit alone required three doses. The antibodies recognized
specifically ST14 CPS, while no significant antibody levels were raised
against the spacer or unrelated CPS. Synthetic vaccines generated
antibodies with opsonic activity. Mimicking polysaccharides by coupling
repeating unit antigens via an aliphatic spacer may prove useful also
for the development of other glycoconjugate vaccine candidates, thereby
reducing the synthetic complexity while enhancing a faster immune
response.
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Affiliation(s)
- Bruna M. S. Seco
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Fei-Fei Xu
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Andrea Grafmüller
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Naresh Kottari
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Claney L. Pereira
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Peter H. Seeberger
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
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15
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Kim J, Oh J, Kang CS, Choi YS. Virus-like Particle (VLP) Mediated Antigen Delivery as a Sensitization Tool of Experimental Allergy Mouse Models. Immune Netw 2020; 20:e35. [PMID: 32895622 PMCID: PMC7458801 DOI: 10.4110/in.2020.20.e35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 12/31/2022] Open
Abstract
Antigen delivery systems play critical roles in determining the quality and quantity of Ab responses in vivo. Induction of protective antibodies by B cells is essential in the development of vaccines against infectious pathogens, whereas production of IgE antibodies is prerequisite for investigation of allergic responses, or type 1 hypersensitivity reactions. Virus-like particles (VLPs) are efficient platforms for expression of proteins of interest in highly repetitive manners, which grants strong Ab responses to target antigens. Here, we report that delivery of hen egg lysozyme (HEL), a model allergen, through VLP could provoke strong HEL specific IgE Ab responses in mice. Moreover, acute allergic responses were robustly induced in the mice sensitized with VLPs that express HEL, when challenged with recombinant HEL protein. Our data show that antigen delivery in the context of VLPs could function as a platform for sensitization of mice and for subsequent examination of allergic reactions to molecules of interest.
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Affiliation(s)
- Juhyung Kim
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jeein Oh
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Chon-Sik Kang
- National Institute of Crop Science, Rural Development Administration (RDA), Wanju 55365, Korea
| | - Youn Soo Choi
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Medicine, Seoul National University College of Medicine, Seoul 03080, Korea.,Transplant Research Institute, Seoul National University Hospital, Seoul 03080, Korea
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16
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Núñez MF, Wisser K, Veatch SL. Synergistic factors control kinase-phosphatase organization in B-cells engaged with supported bilayers. Mol Biol Cell 2019; 31:667-682. [PMID: 31877064 PMCID: PMC7202075 DOI: 10.1091/mbc.e19-09-0507] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
B-cells become activated by ligands with varying valency and mode of presentation to the B-cell receptor (BCR). We previously demonstrated that clustering the immunoglobulin M (IgM) isotype of BCR with an artificial soluble cross-linker stabilized an ordered phase-like domain that enriched kinases and depleted phosphatases to promote receptor tyrosine phosphorylation. BCR is also activated by ligands presented at surfaces, and here we activate B-cells via supported bilayers of phosphatidylcholine lipids, a natural ligand for the IgM BCR expressed in the CH27 cells used. Using superresolution fluorescence localization microscopy, along with a quantitative cross-correlation analysis, we find that BRCs engaged with bilayers sort minimal peptide markers of liquid-ordered and liquid-disordered phases, indicating that ordered-domain stabilization is a general feature of BCR clustering. The phosphatase CD45 is more strongly excluded from bilayer-engaged BRCs than a transmembrane peptide, indicating that mechanisms other than domain partitioning contribute to its organization. Experimental observations are assembled into a minimal model of receptor activation that incorporates both ordered domains and direct phosphatase exclusion mechanisms to produce a more sensitive response.
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Affiliation(s)
| | - Kathleen Wisser
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48105
| | - Sarah L Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48105
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17
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Zheng S, Sieder M, Mitterer M, Reth M, Cavallari M, Yang J. A new branched proximity hybridization assay for the quantification of nanoscale protein-protein proximity. PLoS Biol 2019; 17:e3000569. [PMID: 31825964 PMCID: PMC6905527 DOI: 10.1371/journal.pbio.3000569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/14/2019] [Indexed: 01/15/2023] Open
Abstract
Membrane proteins are organized in nanoscale compartments. Their reorganization plays a crucial role in receptor activation and cell signaling. To monitor the organization and reorganization of membrane proteins, we developed a new branched proximity hybridization assay (bPHA) allowing better quantification of the nanoscale protein-protein proximity. In this assay, oligo-coupled binding probes, such as aptamer, nanobody, and antibodies, are used to translate the proximity of target proteins to the proximity of oligos. The closely positioned oligos then serve as a template for a maximum of 400-fold branched DNA (bDNA) signal amplification. The amplified bPHA signal is recorded by flow cytometer, thus enabling proximity studies with high throughput, multiplexing, and single-cell resolution. To demonstrate the potential of the bPHA method, we measured the reorganization of the immunoglobulin M (IgM)- and immunoglobulin D (IgD)-class B cell antigen receptor (BCR) on the plasma membrane and the recruitment of spleen tyrosine kinase (Syk) to the BCR upon B lymphocyte activation.
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Affiliation(s)
- Shuangshuang Zheng
- BIOSS Centre For Biological Signaling Studies and Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Melanie Sieder
- BIOSS Centre For Biological Signaling Studies and Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School for Biology and Medicine (SGBM), Freiburg, Germany
| | - Michael Mitterer
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Michael Reth
- BIOSS Centre For Biological Signaling Studies and Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Marco Cavallari
- BIOSS Centre For Biological Signaling Studies and Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Jianying Yang
- BIOSS Centre For Biological Signaling Studies and Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- * E-mail:
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18
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Membrane Organization and Physical Regulation of Lymphocyte Antigen Receptors: A Biophysicist's Perspective. J Membr Biol 2019; 252:397-412. [PMID: 31352492 DOI: 10.1007/s00232-019-00085-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/18/2019] [Indexed: 12/19/2022]
Abstract
Receptors at the membrane of immune cells are the central players of innate and adaptative immunity, providing effective defence mechanisms against pathogens or cancer cells. Their function is intimately linked to their position at and within the membrane which provides accessibility, mobility as well as membrane proximal cytoskeleton anchoring, all of these elements playing important roles in the final function and links to cellular actions. Understanding how immune cells integrate the specific signals received at their membrane to take a decision remains an immense challenge and a very active field of fundamental and applied research. Recent progress in imaging and micromanipulation techniques have led to an unprecedented refinement in the description of molecular structures and supramolecular assemblies at the immune cell membrane, and provided a glimpse into their dynamics and regulation by force. Several key elements have been scrutinized such as the roles of relative sizes of molecules, lateral organisation, motion in the membrane of the receptors, but also physical cues such as forces, mediated by cellular substrates of different rigidities or applied by the cell itself, in conjunction with its partner cell. We review here these recent discoveries associated with a description of the biophysical methods used. While a conclusive picture integrating all of these components is still lacking, mainly due to the implication of diverse and different mechanisms and spatio-temporal scales involved, the amount of quantitative data available opens the way for physical modelling and numerical simulations and new avenues for experimental research.
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19
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A symmetric geometry of transmembrane domains inside the B cell antigen receptor complex. Proc Natl Acad Sci U S A 2019; 116:13468-13473. [PMID: 31209055 PMCID: PMC6613136 DOI: 10.1073/pnas.1907481116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The specific activation of B lymphocytes via the binding of antigen to their B cell antigen receptor (BCR) is of central importance for the establishment of humoral immunity and a successful vaccination. A better understanding of the antigen sensing process of B cells requires insight into the structure of the BCR comprising the mIg molecule and the Igα/Igβ heterodimer in a 1:1 complex. How a symmetric molecule such as the mIg molecule is asymmetrically associated with only one Igα/Igβ heterodimer has been a puzzle. We suggest that inside the lipid bilayer the BCR forms a symmetric Igα-mHC:mHC-Igβ complex. Our results give insight into the BCR structure and the B cell activation mechanism. B lymphocytes have the ability to sense thousands of structurally different antigens and produce cognate antibodies against these molecules. For this they carry on their surface multiple copies of the B cell antigen receptor (BCR) comprising the membrane-bound Ig (mIg) molecule and the Igα/Igβ heterodimer functioning as antigen binding and signal transducing components, respectively. The mIg is a symmetric complex of 2 identical membrane-bound heavy chains (mHC) and 2 identical light chains. How the symmetric mIg molecule is asymmetrically associated with only one Igα/Igβ heterodimer has been a puzzle. Here we describe that Igα and Igβ both carry on one side of their α-helical transmembrane domain a conserved amino acid motif. By a mutational analysis in combination with a BCR rebuilding approach, we show that this motif is required for the retention of unassembled Igα or Igβ molecules inside the endoplasmic reticulum and the binding of the Igα/Igβ heterodimer to the mIg molecule. We suggest that the BCR forms within the lipid bilayer of the membrane a symmetric Igα-mHC:mHC-Igβ complex that is stabilized by an aromatic proline-tyrosine interaction. Outside the membrane this symmetry is broken by the disulfide-bridged dimerization of the extracellular Ig domains of Igα and Igβ. However, symmetry of the receptor can be regained by a dimerization of 2 BCR complexes as suggested by the dissociation activation model.
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20
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Gold MR, Reth MG. Antigen Receptor Function in the Context of the Nanoscale Organization of the B Cell Membrane. Annu Rev Immunol 2019; 37:97-123. [DOI: 10.1146/annurev-immunol-042718-041704] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The B cell antigen receptor (BCR) plays a central role in the self/nonself selection of B lymphocytes and in their activation by cognate antigen during the clonal selection process. It was long thought that most cell surface receptors, including the BCR, were freely diffusing and randomly distributed. Since the advent of superresolution techniques, it has become clear that the plasma membrane is compartmentalized and highly organized at the nanometer scale. Hence, a complete understanding of the precise conformation and activation mechanism of the BCR must take into account the organization of the B cell plasma membrane. We review here the recent literature on the nanoscale organization of the lymphocyte membrane and discuss how this new information influences our view of the conformational changes that the BCR undergoes during activation.
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Affiliation(s)
- Michael R. Gold
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael G. Reth
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, 79104 Freiburg, Germany
- Department of Molecular Immunology, Institute of Biology III, Faculty of Biology, University of Freiburg, 79108 Freiburg, Germany
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21
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Wilhelm I, Levit-Zerdoun E, Jakob J, Villringer S, Frensch M, Übelhart R, Landi A, Müller P, Imberty A, Thuenauer R, Claudinon J, Jumaa H, Reth M, Eibel H, Hobeika E, Römer W. Carbohydrate-dependent B cell activation by fucose-binding bacterial lectins. Sci Signal 2019; 12:12/571/eaao7194. [PMID: 30837305 DOI: 10.1126/scisignal.aao7194] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Bacterial lectins are typically multivalent and bind noncovalently to specific carbohydrates on host tissues to facilitate bacterial adhesion. Here, we analyzed the effects of two fucose-binding lectins, BambL from Burkholderia ambifaria and LecB from Pseudomonas aeruginosa, on specific signaling pathways in B cells. We found that these bacterial lectins induced B cell activation, which, in vitro, was dependent on the cell surface expression of the B cell antigen receptor (BCR) and its co-receptor CD19, as well as on spleen tyrosine kinase (Syk) activity. The resulting release of intracellular Ca2+ was followed by an increase in the cell surface abundance of the activation marker CD86, augmented cytokine secretion, and subsequent cell death, replicating all of the events that are observed in vitro upon canonical and antigen-mediated B cell activation. Moreover, injection of BambL in mice resulted in a substantial, BCR-independent loss of B cells in the bone marrow with simultaneous, transient enlargement of the spleen (splenomegaly), as well as an increase in the numbers of splenic B cells and myeloid cells. Together, these data suggest that bacterial lectins can initiate polyclonal activation of B cells through their sole capacity to bind to fucose.
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Affiliation(s)
- Isabel Wilhelm
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Ella Levit-Zerdoun
- Max Planck Institute of Immunology and Epigenetics Freiburg, 79108 Freiburg, Germany.,International Max Planck Research School (IMPRS), Max Planck Institute of Immunobiology and Epigenetics Freiburg, 79108 Freiburg, Germany.,German Cancer Consortium (DKTK) partner site Freiburg, German Cancer Center (DKFZ), Heidelberg, Institute of Molecular Medicine and Cell Research, 79104 Freiburg, Germany
| | - Johanna Jakob
- Institute for Immunology, University Medical Centre Ulm, 89081 Ulm, Germany
| | - Sarah Villringer
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Marco Frensch
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany.,International Max Planck Research School (IMPRS), Max Planck Institute of Immunobiology and Epigenetics Freiburg, 79108 Freiburg, Germany
| | - Rudolf Übelhart
- Institute for Immunology, University Medical Centre Ulm, 89081 Ulm, Germany
| | - Alessia Landi
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Peter Müller
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Anne Imberty
- Univ. Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France
| | - Roland Thuenauer
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Julie Claudinon
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Hassan Jumaa
- Institute for Immunology, University Medical Centre Ulm, 89081 Ulm, Germany
| | - Michael Reth
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany.,Max Planck Institute of Immunology and Epigenetics Freiburg, 79108 Freiburg, Germany
| | - Hermann Eibel
- CCI-Center for Chronic Immunodeficiency (CCI), University Medical Centre, 79106 Freiburg, Germany.,Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Elias Hobeika
- Institute for Immunology, University Medical Centre Ulm, 89081 Ulm, Germany.
| | - Winfried Römer
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany. .,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
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22
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Li J, Yin W, Jing Y, Kang D, Yang L, Cheng J, Yu Z, Peng Z, Li X, Wen Y, Sun X, Ren B, Liu C. The Coordination Between B Cell Receptor Signaling and the Actin Cytoskeleton During B Cell Activation. Front Immunol 2019; 9:3096. [PMID: 30687315 PMCID: PMC6333714 DOI: 10.3389/fimmu.2018.03096] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 12/13/2018] [Indexed: 01/27/2023] Open
Abstract
B-cell activation plays a crucial part in the immune system and is initiated via interaction between the B cell receptor (BCR) and specific antigens. In recent years with the help of modern imaging techniques, it was found that the cortical actin cytoskeleton changes dramatically during B-cell activation. In this review, we discuss how actin-cytoskeleton reorganization regulates BCR signaling in different stages of B-cell activation, specifically when stimulated by antigens, and also how this reorganization is mediated by BCR signaling molecules. Abnormal BCR signaling is associated with the progression of lymphoma and immunological diseases including autoimmune disorders, and recent studies have proved that impaired actin cytoskeleton can devastate the normal activation of B cells. Therefore, to figure out the coordination between the actin cytoskeleton and BCR signaling may reveal an underlying mechanism of B-cell activation, which has potential for new treatments for B-cell associated diseases.
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Affiliation(s)
- Jingwen Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Yin
- Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yukai Jing
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Danqing Kang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Yang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiali Cheng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ze Yu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zican Peng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingbo Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Wen
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xizi Sun
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Boxu Ren
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
- Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, China
| | - Chaohong Liu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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23
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Felce JH, Sezgin E, Wane M, Brouwer H, Dustin ML, Eggeling C, Davis SJ. CD45 exclusion- and cross-linking-based receptor signaling together broaden FcεRI reactivity. Sci Signal 2018; 11:11/561/eaat0756. [PMID: 30563863 DOI: 10.1126/scisignal.aat0756] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
For many years, the high-affinity receptor for immunoglobulin E (IgE) FcεRI, which is expressed by mast cells and basophils, has been widely held to be the exemplar of cross-linking (that is, aggregation dependent) signaling receptors. We found, however, that FcεRI signaling could occur in the presence or absence of receptor cross-linking. Using both cell and cell-free systems, we showed that FcεRI signaling was stimulated by surface-associated monovalent ligands through the passive, size-dependent exclusion of the receptor-type tyrosine phosphatase CD45 from plasma membrane regions of FcεRI-ligand engagement. Similarly to the T cell receptor, FcεRI signaling could also be initiated in a ligand-independent manner. These data suggest that a simple mechanism of CD45 exclusion-based receptor triggering could function together with cross-linking-based FcεRI signaling, broadening mast cell and basophil reactivity by enabling these cells to respond to both multivalent and surface-presented monovalent antigens. These findings also strengthen the case that a size-dependent, phosphatase exclusion-based receptor triggering mechanism might serve generally to facilitate signaling by noncatalytic immune receptors.
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Affiliation(s)
- James H Felce
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.,Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Erdinc Sezgin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Madina Wane
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Heather Brouwer
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK.
| | - Christian Eggeling
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Simon J Davis
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK. .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
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24
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Kläsener K, Yang J, Reth M. Study B Cell Antigen Receptor Nano-Scale Organization by In Situ Fab Proximity Ligation Assay. Methods Mol Biol 2018; 1707:171-181. [PMID: 29388107 DOI: 10.1007/978-1-4939-7474-0_12] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The B cell antigen receptor (BCR) is found to be non-randomly organized at nano-scale distances on the B cell surface. Studying the organization and relocalization of the BCR is thus likely to provide new clues to understand the activation of the BCR. Indeed, with the in situ Fab proximity ligation assay (Fab-PLA), we now obtain proofs for the dissociation activation of BCRs and start to gain insight into how the relocalization of B cell surface signaling molecules could activate the cells. This chapter describes our methods to study the nano-scale organization of B cell surface receptors and co-receptors with Fab-PLA.
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Affiliation(s)
- Kathrin Kläsener
- Department of Molecular Immunology, BIOSS Centre for Biological Signaling Studies, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Jianying Yang
- Department of Molecular Immunology, BIOSS Centre for Biological Signaling Studies, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany. .,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
| | - Michael Reth
- Department of Molecular Immunology, BIOSS Centre for Biological Signaling Studies, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany. .,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
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25
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Noviski M, Zikherman J. Control of autoreactive B cells by IgM and IgD B cell receptors: maintaining a fine balance. Curr Opin Immunol 2018; 55:67-74. [PMID: 30292928 DOI: 10.1016/j.coi.2018.09.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 12/11/2022]
Abstract
A substantial fraction of mature naïve B cells recognize endogenous antigens, and this autoreactivity must be controlled to prevent autoantibody secretion. Selective downregulation of the IgM BCR on autoreactive B cells has long been appreciated, and recent findings illustrate how this might impose tolerance. The BCR isotype maintained on autoreactive B cells, IgD, is less sensitive to endogenous antigens than IgM. This reduced sensitivity may be conferred by structural properties of IgD and/or differential association with activating and inhibitory co-receptors. Once activated, autoreactive B cells are normally excluded from rapid plasma cell responses, but they can enter the germinal center and lose their autoreactivity through a mutation-selection process termed clonal redemption.
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Affiliation(s)
- Mark Noviski
- Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, CA, 94143, USA
| | - Julie Zikherman
- Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, CA, 94143, USA.
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26
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Hobeika E, Dautzenberg M, Levit-Zerdoun E, Pelanda R, Reth M. Conditional Selection of B Cells in Mice With an Inducible B Cell Development. Front Immunol 2018; 9:1806. [PMID: 30127788 PMCID: PMC6087743 DOI: 10.3389/fimmu.2018.01806] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/23/2018] [Indexed: 11/13/2022] Open
Abstract
Developing B cells undergo defined maturation steps in the bone marrow and in the spleen. The timing and the factors that control these differentiation steps are not fully understood. By targeting the B cell-restricted mb-1 locus to generate an mb-1 allele that expresses a tamoxifen inducible Cre and another allele in which mb-1 expression can be controlled by Cre, we have established a mouse model with an inducible B cell compartment. With these mice, we studied in detail the kinetics of B cell development and the consequence of BCR activation at a defined B cell maturation stage. Contrary to expectations, transitional 1-B cells exposed to anti-IgM reagents in vivo did not die but instead developed into transitional 2 (T2)-B cells with upregulated Bcl-2 expression. We show, however, that these T2-B cells had an increased dependency on the B cell survival factor B cell activating factor when compared to non-stimulated B cells. Overall, our findings indicate that the inducible mb-1 mouse strain represents a useful model, which allows studying the signals that control the selection of B cells in greater detail.
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Affiliation(s)
- Elias Hobeika
- Centre for Biological Signaling Studies (BIOSS), Biology III, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Marcel Dautzenberg
- Centre for Biological Signaling Studies (BIOSS), Biology III, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Ella Levit-Zerdoun
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,International Max Planck Research School for Molecular and Cellular Biology, Freiburg, Germany
| | - Roberta Pelanda
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Michael Reth
- Centre for Biological Signaling Studies (BIOSS), Biology III, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
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27
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Immuno-receptors: from recognition to signaling and function. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:363-371. [PMID: 29600443 DOI: 10.1007/s00249-018-1294-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 03/06/2018] [Accepted: 03/13/2018] [Indexed: 01/20/2023]
Abstract
The vertebrate adaptive immune response is initiated by specific recognition of antigens. This is carried out by molecules, soluble or cell surface receptors that are members of the Multichain Immune Recognition Receptors (MIRR) group of proteins. The soluble arm of the response is based on antibodies. Kinetic analysis of antibody-antigenic epitope interactions pioneered insights into the complexity underlying the capacity of relatively limited repertoires of antibodies to recognize an essentially unlimited range of epitopes by employing conformational diversity of a given single sequence. The arm responsible for recognition of cellular targets involves a considerably more elaborate process, predominantly of antigen-derived peptides presented bound to molecules encoded by the major histocompatibility complex (MHC). This remarkable cellular recognition process performed by T-cell receptors requires earlier steps of peptide presentation and involves interactions of the receptor sites with the array of its MHC-peptide composite ligand. In both cases, antigen recognition needs to be followed by its coupling, by biochemical cascades, to different specific responses, namely activation of effector functions. The parameters required for coupling to functional responses are still a focus of intense research. In solution, antigen-antibody aggregation is one established activation process. Those required for coupling antigen recognition to cell activation, whether by Fc receptor bound antibodies or by the B-cell antigen receptor, are also still subject to active research efforts. Though activation by immune-receptors requires antigen recognition, considerable differences could exist among the requirements set by distinct cell types. Moreover, antigen binding requiring intercellular interactions introduces additional complexity.
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28
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Westbroek ML, Geahlen RL. Modulation of BCR Signaling by the Induced Dimerization of Receptor-Associated SYK. Antibodies (Basel) 2017; 6:antib6040023. [PMID: 31548538 PMCID: PMC6698873 DOI: 10.3390/antib6040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/27/2017] [Accepted: 12/02/2017] [Indexed: 01/14/2023] Open
Abstract
Clustering of the B cell antigen receptor (BCR) by polyvalent antigens is transmitted through the SYK tyrosine kinase to the activation of multiple intracellular pathways that determine the physiological consequences of receptor engagement. To explore factors that modulate the quantity and quality of signals sent by the crosslinked BCR, we developed a novel chemical mediator of dimerization to induce clustering of receptor-associated SYK. To accomplish this, we fused SYK with E. coli dihydrofolate reductase (eDHFR), which binds the small molecule trimethoprim (TMP) with high affinity and selectivity and synthesized a dimer of TMP with a flexible linker. The TMP dimer is able to induce the aggregation of eDHFR-linked SYK in live cells. The induced dimerization of SYK bound to the BCR differentially regulates the activation of downstream transcription factors, promoting the activation of Nuclear Factor of Activated T cells (NFAT) without affecting the activation of NFκB. The dimerization of SYK enhances the duration but not the amplitude of calcium mobilization by enhancing the extent and duration of its interaction with the crosslinked BCR at the plasma membrane.
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Affiliation(s)
- Mark L Westbroek
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
| | - Robert L Geahlen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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29
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Reth M, Gold MR. What goes up must come down: A tripartite Dok-3/Grb2/SHIP1 inhibitory module limits BCR signaling. Eur J Immunol 2017; 46:2507-2511. [PMID: 27813071 DOI: 10.1002/eji.201646705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 09/20/2016] [Accepted: 09/27/2016] [Indexed: 01/30/2023]
Abstract
Properly regulated immunity requires precise integration of activating and inhibitory signals. As for other lymphocytes, B cells express an antigen-specific activating receptor, the B-cell antigen receptor (BCR), and inhibitory receptors (e.g. FcγRIIb) that exercise checkpoint control on B-cell activation. Moreover, following BCR engagement, CD19 recruits proteins that amplify BCR signaling, while CD22 initiates a negative feedback loop by recruiting proteins that inhibit BCR signaling. Initial BCR signaling is mediated by protein tyrosine kinases and lipid kinases; inhibitory receptors directly antagonize the actions of these enzymes by recruiting protein tyrosine phosphatases and lipid phosphatases and positioning them close to actively signaling BCRs. Previously it was thought that inhibitory receptors such as FcγRIIb and CD22 were essential for bringing these phosphatases near the BCR. In this issue of the European Journal of Immunology, Manno et al. show that a tripartite inhibitory module consisting of the adaptor proteins Dok-3 and Grb2 and the lipid phosphatase SHIP1 binds directly to activated BCRs and limits the Ca2+ mobilization that is required for B lymphocyte activation. This reveals that the BCR can be both an activating and inhibitory receptor, one that activates signaling enzymes while initiating a negative feedback loop that prevents excessive signaling.
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Affiliation(s)
- Michael Reth
- BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany
| | - Michael R Gold
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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30
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Fasbender F, Claus M, Wingert S, Sandusky M, Watzl C. Differential Requirements for Src-Family Kinases in SYK or ZAP70-Mediated SLP-76 Phosphorylation in Lymphocytes. Front Immunol 2017; 8:789. [PMID: 28736554 PMCID: PMC5500614 DOI: 10.3389/fimmu.2017.00789] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/22/2017] [Indexed: 01/10/2023] Open
Abstract
In a synthetic biology approach using Schneider (S2) cells, we show that SLP-76 is directly phosphorylated at tyrosines Y113 and Y128 by SYK in the presence of ITAM-containing adapters such as CD3ζ, DAP12, or FcεRγ. This phosphorylation was dependent on at least one functional ITAM and a functional SH2 domain within SYK. Inhibition of Src-kinases by inhibitors PP1 and PP2 did not reduce SLP-76 phosphorylation in S2 cells, suggesting an ITAM and SYK dependent, but Src-kinase independent signaling pathway. This direct ITAM/SYK/SLP-76 signaling pathway therefore differs from previously described ITAM signaling. However, the SYK-family kinase ZAP70 required the additional co-expression of the Src-family kinases Fyn or Lck to efficiently phosphorylate SLP-76 in S2 cells. This difference in Src-family kinase dependency of SYK versus ZAP70-mediated ITAM-based signaling was further demonstrated in human lymphocytes. ITAM signaling in ZAP70-expressing T cells was dependent on the activity of Src-family kinases. In contrast, Src-family kinases were partially dispensable for ITAM signaling in SYK-expressing B cells or in natural killer cells, which express SYK and ZAP70. This demonstrates that SYK can signal using a Src-kinase independent ITAM-based signaling pathway, which may be involved in calibrating the threshold for lymphocyte activation.
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Affiliation(s)
- Frank Fasbender
- Leibniz Research Centre for Working Environment and Human Factors, IfADo, TU-Dortmund, Dortmund, Germany
| | - Maren Claus
- Leibniz Research Centre for Working Environment and Human Factors, IfADo, TU-Dortmund, Dortmund, Germany
| | - Sabine Wingert
- Leibniz Research Centre for Working Environment and Human Factors, IfADo, TU-Dortmund, Dortmund, Germany
| | - Mina Sandusky
- Leibniz Research Centre for Working Environment and Human Factors, IfADo, TU-Dortmund, Dortmund, Germany
| | - Carsten Watzl
- Leibniz Research Centre for Working Environment and Human Factors, IfADo, TU-Dortmund, Dortmund, Germany
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31
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Volkmann C, Brings N, Becker M, Hobeika E, Yang J, Reth M. Molecular requirements of the B-cell antigen receptor for sensing monovalent antigens. EMBO J 2016; 35:2371-2381. [PMID: 27634959 PMCID: PMC5090217 DOI: 10.15252/embj.201694177] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 08/16/2016] [Indexed: 11/22/2022] Open
Abstract
How the B‐cell antigen receptor (BCR) is activated upon interaction with its cognate antigen or with anti‐BCR antibodies is not fully understood. We have recently shown that B‐cell activation is accompanied by the opening of the pre‐organized BCR oligomers, an observation that strengthens the role of receptor reorganization in signalling. We have now analysed the BCR oligomer opening and signalling upon treatment with different monovalent stimuli. Our results indicate that monovalent antigens are able to disturb and open the BCR oligomer, but that this requires the presence and activity of the Src family kinase (SFK) Lyn. We have also shown that monovalent Fab fragments of anti‐BCR antibodies can open the BCR oligomers as long as they directly interact with the antigen‐binding site. We found that monovalent antigen binding opens both the IgM‐BCR and IgD‐BCR, but calcium signalling is only seen in cells expressing IgM‐BCR; this provides a molecular basis for IgM‐ and IgD‐BCR functional segregation.
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Affiliation(s)
- Christoph Volkmann
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Naema Brings
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Martin Becker
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Elias Hobeika
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Institute of Immunology University Hospital Ulm, Ulm, Germany
| | - Jianying Yang
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany .,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Freiburg Institute for Advanced Studies (FRIAS) University of Freiburg, Freiburg, Germany.,University of Strasbourg Institute for Advanced Study (USIAS) University of Strasbourg, Strasbourg, France
| | - Michael Reth
- BIOSS Centre for Biological Signalling Studies, Department of Molecular Immunology, Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany .,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
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