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McWilliam HEG, Villadangos JA. MR1 antigen presentation to MAIT cells and other MR1-restricted T cells. Nat Rev Immunol 2024; 24:178-192. [PMID: 37773272 PMCID: PMC11108705 DOI: 10.1038/s41577-023-00934-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2023] [Indexed: 10/01/2023]
Abstract
MHC antigen presentation plays a fundamental role in adaptive and semi-invariant T cell immunity. Distinct MHC molecules bind antigens that differ in chemical structure, origin and location and present them to specialized T cells. MHC class I-related protein 1 (MR1) presents a range of small molecule antigens to MR1-restricted T (MR1T) lymphocytes. The best studied MR1 ligands are derived from microbial metabolism and are recognized by a major class of MR1T cells known as mucosal-associated invariant T (MAIT) cells. Here, we describe the MR1 antigen presentation pathway: the known types of antigens presented by MR1, the location where MR1-antigen complexes form, the route followed by the complexes to the cell surface, the mechanisms involved in termination of MR1 antigen presentation and the accessory cellular proteins that comprise the MR1 antigen presentation machinery. The current road map of the MR1 antigen presentation pathway reveals potential strategies for therapeutic manipulation of MR1T cell function and provides a foundation for further studies that will lead to a deeper understanding of MR1-mediated immunity.
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Affiliation(s)
- Hamish E G McWilliam
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria, Australia.
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.
| | - Jose A Villadangos
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria, Australia.
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.
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2
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Samer C, McWilliam HE, McSharry BP, Velusamy T, Burchfield JG, Stanton RJ, Tscharke DC, Rossjohn J, Villadangos JA, Abendroth A, Slobedman B. Multi-targeted loss of the antigen presentation molecule MR1 during HSV-1 and HSV-2 infection. iScience 2024; 27:108801. [PMID: 38303725 PMCID: PMC10831258 DOI: 10.1016/j.isci.2024.108801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 09/18/2023] [Accepted: 01/02/2024] [Indexed: 02/03/2024] Open
Abstract
The major histocompatibility complex (MHC), Class-I-related (MR1) molecule presents microbiome-synthesized metabolites to Mucosal-associated invariant T (MAIT) cells, present at sites of herpes simplex virus (HSV) infection. During HSV type 1 (HSV-1) infection there is a profound and rapid loss of MR1, in part due to expression of unique short 3 protein. Here we show that virion host shutoff RNase protein downregulates MR1 protein, through loss of MR1 transcripts. Furthermore, a third viral protein, infected cell protein 22, also downregulates MR1, but not classical MHC-I molecules. This occurs early in the MR1 trafficking pathway through proteasomal degradation. Finally, HSV-2 infection results in the loss of MR1 transcripts, and intracellular and surface MR1 protein, comparable to that seen during HSV-1 infection. Thus HSV coordinates a multifaceted attack on the MR1 antigen presentation pathway, potentially protecting infected cells from MAIT cell T cell receptor-mediated detection at sites of primary infection and reactivation.
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Affiliation(s)
- Carolyn Samer
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Hamish E.G. McWilliam
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Brian P. McSharry
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- School of Dentistry and Medical Sciences, Faculty of Science and Health, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Thilaga Velusamy
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - James G. Burchfield
- Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Richard J. Stanton
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, Wales
| | - David C. Tscharke
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Jamie Rossjohn
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, Wales
- Infection and Immunity Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Jose A. Villadangos
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Allison Abendroth
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Barry Slobedman
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
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Corbett AJ, Ussher JE, Hinks TSC. Editorial: MAIT cells come of age. Front Immunol 2023; 14:1281881. [PMID: 37744347 PMCID: PMC10513092 DOI: 10.3389/fimmu.2023.1281881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023] Open
Affiliation(s)
- Alexandra J. Corbett
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - James E. Ussher
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Timothy S. C. Hinks
- Respiratory Medicine Unit and National Institute for Health Research Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
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Sandberg JK, Leeansyah E, Eller MA, Shacklett BL, Paquin-Proulx D. The Emerging Role of MAIT Cell Responses in Viral Infections. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:511-517. [PMID: 37549397 PMCID: PMC10421619 DOI: 10.4049/jimmunol.2300147] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/08/2023] [Indexed: 08/09/2023]
Abstract
Mucosal-associated invariant T (MAIT) cells are unconventional T cells with innate-like antimicrobial responsiveness. MAIT cells are known for MR1 (MHC class I-related protein 1)-restricted recognition of microbial riboflavin metabolites giving them the capacity to respond to a broad range of microbes. However, recent progress has shown that MAIT cells can also respond to several viral infections in humans and in mouse models, ranging from HIV-1 and hepatitis viruses to influenza virus and SARS-CoV-2, in a primarily cognate Ag-independent manner. Depending on the disease context MAIT cells can provide direct or indirect antiviral protection for the host and may help recruit other immune cells, but they may also in some circumstances amplify inflammation and aggravate immunopathology. Furthermore, chronic viral infections are associated with varying degrees of functional and numerical MAIT cell impairment, suggesting secondary consequences for host defense. In this review, we summarize recent progress and highlight outstanding questions regarding the emerging role of MAIT cells in antiviral immunity.
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Affiliation(s)
- Johan K. Sandberg
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Edwin Leeansyah
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
- Precision Medicine and Healthcare Research Centre, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China
| | - Michael A. Eller
- Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Barbara L. Shacklett
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA
| | - Dominic Paquin-Proulx
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD
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Rashu R, Ninkov M, Wardell CM, Benoit JM, Wang NI, Meilleur CE, D'Agostino MR, Zhang A, Feng E, Saeedian N, Bell GI, Vahedi F, Hess DA, Barr SD, Troyer RM, Kang CY, Ashkar AA, Miller MS, Haeryfar SMM. Targeting the MR1-MAIT cell axis improves vaccine efficacy and affords protection against viral pathogens. PLoS Pathog 2023; 19:e1011485. [PMID: 37384813 DOI: 10.1371/journal.ppat.1011485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 06/14/2023] [Indexed: 07/01/2023] Open
Abstract
Mucosa-associated invariant T (MAIT) cells are MR1-restricted, innate-like T lymphocytes with tremendous antibacterial and immunomodulatory functions. Additionally, MAIT cells sense and respond to viral infections in an MR1-independent fashion. However, whether they can be directly targeted in immunization strategies against viral pathogens is unclear. We addressed this question in multiple wild-type and genetically altered but clinically relevant mouse strains using several vaccine platforms against influenza viruses, poxviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We demonstrate that 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU), a riboflavin-based MR1 ligand of bacterial origin, can synergize with viral vaccines to expand MAIT cells in multiple tissues, reprogram them towards a pro-inflammatory MAIT1 phenotype, license them to bolster virus-specific CD8+ T cell responses, and potentiate heterosubtypic anti-influenza protection. Repeated 5-OP-RU administration did not render MAIT cells anergic, thus allowing for its inclusion in prime-boost immunization protocols. Mechanistically, tissue MAIT cell accumulation was due to their robust proliferation, as opposed to altered migratory behavior, and required viral vaccine replication competency and Toll-like receptor 3 and type I interferon receptor signaling. The observed phenomenon was reproducible in female and male mice, and in both young and old animals. It could also be recapitulated in a human cell culture system in which peripheral blood mononuclear cells were exposed to replicating virions and 5-OP-RU. In conclusion, although viruses and virus-based vaccines are devoid of the riboflavin biosynthesis machinery that supplies MR1 ligands, targeting MR1 enhances the efficacy of vaccine-elicited antiviral immunity. We propose 5-OP-RU as a non-classic but potent and versatile vaccine adjuvant against respiratory viruses.
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Affiliation(s)
- Rasheduzzaman Rashu
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Marina Ninkov
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Christine M Wardell
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Jenna M Benoit
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Nicole I Wang
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Courtney E Meilleur
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Michael R D'Agostino
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
| | - Ali Zhang
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
| | - Emily Feng
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
| | - Nasrin Saeedian
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Gillian I Bell
- Krembil Centre for Stem Cell Biology, Molecular Medicine Research Laboratories, Robarts Research Institute, London, Ontario, Canada
| | - Fatemeh Vahedi
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
| | - David A Hess
- Krembil Centre for Stem Cell Biology, Molecular Medicine Research Laboratories, Robarts Research Institute, London, Ontario, Canada
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Stephen D Barr
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Ryan M Troyer
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Chil-Yong Kang
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Ali A Ashkar
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Matthew S Miller
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - S M Mansour Haeryfar
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Division of Clinical Immunology and Allergy, Department of Medicine, Western University, London, Ontario, Canada
- Division of General Surgery, Department of Surgery, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
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Purohit SK, Corbett AJ, Slobedman B, Abendroth A. Varicella Zoster Virus infects mucosal associated Invariant T cells. Front Immunol 2023; 14:1121714. [PMID: 37006246 PMCID: PMC10063790 DOI: 10.3389/fimmu.2023.1121714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/06/2023] [Indexed: 03/19/2023] Open
Abstract
IntroductionMucosal Associated Invariant T (MAIT) cells are innate-like T cells that respond to conserved pathogen-derived vitamin B metabolites presented by the MHC class I related-1 molecule (MR1) antigen presentation pathway. Whilst viruses do not synthesize these metabolites, we have reported that varicella zoster virus (VZV) profoundly suppresses MR1 expression, implicating this virus in manipulation of the MR1:MAIT cell axis. During primary infection, the lymphotropism of VZV is likely to be instrumental in hematogenous dissemination of virus to gain access to cutaneous sites where it clinically manifests as varicella (chickenpox). However, MAIT cells, which are found in the blood and at mucosal and other organ sites, have yet to be examined in the context of VZV infection. The goal of this study was to examine any direct impact of VZV on MAIT cells.MethodsUsing flow cytometry, we interrogated whether primary blood derived MAIT cells are permissive to infection by VZV whilst further analysing differential levels of infection between various MAIT cell subpopulations. Changes in cell surface extravasation, skin homing, activation and proliferation markers after VZV infection of MAIT cells was also assessed via flow cytometry. Finally the capacity of MAIT cells to transfer infectious virus was tested through an infectious center assay and imaged via fluorescence microscopy.ResultsWe identify primary blood-derived MAIT cells as being permissive to VZV infection. A consequence of VZV infection of MAIT cells was their capacity to transfer infectious virus to other permissive cells, consistent with MAIT cells supporting productive infection. When subgrouping MAIT cells by their co- expression of a variety cell surface markers, there was a higher proportion of VZV infected MAIT cells co-expressing CD4+ and CD4+/CD8+ MAIT cells compared to the more phenotypically dominant CD8+ MAIT cells, whereas infection was not associated with differences in co-expression of CD56 (MAIT cell subset with enhanced responsiveness to innate cytokine stimulation), CD27 (co-stimulatory) or PD-1 (immune checkpoint). Infected MAIT cells retained high expression of CCR2, CCR5, CCR6, CLA and CCR4, indicating a potentially intact capacity for transendothelial migration, extravasation and trafficking to skin sites. Infected MAIT cells also displayed increased expression of CD69 (early activation) and CD71 (proliferation) markers.DiscussionThese data identify MAIT cells as being permissive to VZV infection and identify impacts of such infection on co- expressed functional markers.
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Affiliation(s)
- Shivam K. Purohit
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
| | - Alexandra J. Corbett
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Barry Slobedman
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
- *Correspondence: Allison Abendroth, ; Barry Slobedman,
| | - Allison Abendroth
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
- *Correspondence: Allison Abendroth, ; Barry Slobedman,
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Ashley CL, McSharry BP, McWilliam HEG, Stanton RJ, Fielding CA, Mathias RA, Fairlie DP, McCluskey J, Villadangos JA, Rossjohn J, Abendroth A, Slobedman B. Suppression of MR1 by human cytomegalovirus inhibits MAIT cell activation. Front Immunol 2023; 14:1107497. [PMID: 36845106 PMCID: PMC9950634 DOI: 10.3389/fimmu.2023.1107497] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/25/2023] [Indexed: 02/12/2023] Open
Abstract
Introduction The antigen presentation molecule MHC class I related protein-1 (MR1) is best characterized by its ability to present bacterially derived metabolites of vitamin B2 biosynthesis to mucosal-associated invariant T-cells (MAIT cells). Methods Through in vitro human cytomegalovirus (HCMV) infection in the presence of MR1 ligand we investigate the modulation of MR1 expression. Using coimmunoprecipitation, mass spectrometry, expression by recombinant adenovirus and HCMV deletion mutants we investigate HCMV gpUS9 and its family members as potential regulators of MR1 expression. The functional consequences of MR1 modulation by HCMV infection are explored in coculture activation assays with either Jurkat cells engineered to express the MAIT cell TCR or primary MAIT cells. MR1 dependence in these activation assays is established by addition of MR1 neutralizing antibody and CRISPR/Cas-9 mediated MR1 knockout. Results Here we demonstrate that HCMV infection efficiently suppresses MR1 surface expression and reduces total MR1 protein levels. Expression of the viral glycoprotein gpUS9 in isolation could reduce both cell surface and total MR1 levels, with analysis of a specific US9 HCMV deletion mutant suggesting that the virus can target MR1 using multiple mechanisms. Functional assays with primary MAIT cells demonstrated the ability of HCMV infection to inhibit bacterially driven, MR1-dependent activation using both neutralizing antibodies and engineered MR1 knockout cells. Discussion This study identifies a strategy encoded by HCMV to disrupt the MR1:MAIT cell axis. This immune axis is less well characterized in the context of viral infection. HCMV encodes hundreds of proteins, some of which regulate the expression of antigen presentation molecules. However the ability of this virus to regulate the MR1:MAIT TCR axis has not been studied in detail.
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Affiliation(s)
- Caroline L. Ashley
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Brian P. McSharry
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
- School of Dentistry and Medical Sciences, Faculty of Science and Health, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Hamish E. G. McWilliam
- Department of Microbiology and Immunology, The Peter Doherty Institute of Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
- Department of Biochemistry and Pharmacology, Institute of Molecular Science and Biotechnology (Bio21), The University of Melbourne, Melbourne, VIC, Australia
| | - Richard J. Stanton
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Ceri A. Fielding
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Rommel A. Mathias
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
- Infection and Immunity Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - David P. Fairlie
- ARC Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
| | - James McCluskey
- Department of Microbiology and Immunology, The Peter Doherty Institute of Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
| | - Jose A. Villadangos
- Department of Microbiology and Immunology, The Peter Doherty Institute of Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
- Department of Biochemistry and Pharmacology, Institute of Molecular Science and Biotechnology (Bio21), The University of Melbourne, Melbourne, VIC, Australia
| | - Jamie Rossjohn
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
- Infection and Immunity Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Allison Abendroth
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Barry Slobedman
- Infection, Immunity and Inflammation, School of Medical Sciences, Faculty of Medicine and Health, and the Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
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Abstract
Mucosal Associated Invariant T cells (MAIT) exert potent antimicrobial activity through direct recognition of metabolite-MR1 complexes and indirect activation by inflammatory cytokines. Additionally, via licensing of antigen presenting cells, MAIT cells orchestrate humoral and cellular adaptive immunity. Our recent understanding of molecular mechanisms of MAIT cell activation, and of the signals required to differentiate them in polarised subsets, pave the way for harnessing their functionality through small molecules or adoptive cell therapy.
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Affiliation(s)
- Mariolina Salio
- Immunocore LTD, 92 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, United Kingdom.
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Abstract
Viruses are essentially, obligate intracellular parasites. They require a host to replicate their genetic material, spread to other cells, and eventually to other hosts. For humans, most viral infections are not considered lethal, regardless if at the cellular level, the virus can obliterate individual cells. Constant genomic mutations, (which can alter the antigenic content of viruses such as influenza or coronaviruses), zoonosis or immunosuppression/immunocompromisation, is when viruses achieve higher host mortality. Frequent examples of the severe consequenses of viral infection can be seen in children and the elderly. In most instances, the immune system will take a multifaceted approach in defending the host against viruses. Depending on the virus, the individual, and the point of entry, the immune system will initiate a robust response which involves multiple components. In this chapter, we expand on the total immune system, breaking it down to the two principal types: Innate and Adaptive Immunity, their different roles in viral recognition and clearance. Finally, how different viruses activate and evade different arms of the immune system.
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