1
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Aguilar OA, Fong LK, Lanier LL. ITAM-based receptors in natural killer cells. Immunol Rev 2024; 323:40-53. [PMID: 38411263 PMCID: PMC11102329 DOI: 10.1111/imr.13313] [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: 10/31/2023] [Accepted: 02/15/2024] [Indexed: 02/28/2024]
Abstract
The ability of cells of the immune system to acquire features such as increased longevity and enhanced secondary responses was long thought to be restricted to cells of the adaptive immune system. Natural killer (NK) cells have challenged this notion by demonstrating that they can also gain adaptive features. This has been observed in both humans and mice during infection with cytomegalovirus (CMV). The generation of adaptive NK cells requires antigen-specific recognition of virally infected cells through stimulatory NK receptors. These receptors lack the ability to signal on their own and rather rely on adaptor molecules that contain ITAMs for driving signals. Here, we highlight our understanding of how these receptors influence the production of adaptive NK cells and propose areas in the field that merit further investigation.
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Affiliation(s)
- Oscar A. Aguilar
- Dept. of Microbiology and Immunology, University of California - San Francisco, San Francisco, CA, USA
- Parker Institute for Cancer Immunotherapy, University of California - San Francisco, San Francisco, CA, USA
| | - Lam-Kiu Fong
- Dept. of Pharmaceutical Chemistry, University of California – San Francisco, San Francisco, CA
| | - Lewis L. Lanier
- Dept. of Microbiology and Immunology, University of California - San Francisco, San Francisco, CA, USA
- Parker Institute for Cancer Immunotherapy, University of California - San Francisco, San Francisco, CA, USA
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2
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Piersma SJ. Tissue-specific features of innate lymphoid cells in antiviral defense. Cell Mol Immunol 2024:10.1038/s41423-024-01161-x. [PMID: 38684766 DOI: 10.1038/s41423-024-01161-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Accepted: 04/01/2024] [Indexed: 05/02/2024] Open
Abstract
Innate lymphocytes (ILCs) rapidly respond to and protect against invading pathogens and cancer. ILCs include natural killer (NK) cells, ILC1s, ILC2s, ILC3s, and lymphoid tissue inducer (LTi) cells and include type I, type II, and type III immune cells. While NK cells have been well recognized for their role in antiviral immunity, other ILC subtypes are emerging as players in antiviral defense. Each ILC subset has specialized functions that uniquely impact the antiviral immunity and health of the host depending on the tissue microenvironment. This review focuses on the specialized functions of each ILC subtype and their roles in antiviral immune responses across tissues. Several viruses within infection-prone tissues will be highlighted to provide an overview of the extent of the ILC immunity within tissues and emphasize common versus virus-specific responses.
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Affiliation(s)
- Sytse J Piersma
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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3
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Gbedande K, Ibitokou SA, Ong ML, Degli-Esposti MA, Brown MG, Stephens R. Boosting Live Malaria Vaccine with Cytomegalovirus Vector Can Prolong Immunity through Innate and Adaptive Mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539025. [PMID: 37205446 PMCID: PMC10187235 DOI: 10.1101/2023.05.02.539025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Vaccines to persistent parasite infections have been challenging, and current iterations lack long-term protection. Cytomegalovirus (CMV) chronic vaccine vectors drive protection against SIV, tuberculosis and liver-stage malaria correlated with antigen-specific CD8 T cells with a Tem phenotype. This phenotype is likely driven by a combination of antigen-specific and innate adjuvanting effects of the vector, though these mechanisms are less well understood. Sterilizing immunity from live Plasmodium chabaudi vaccination lasts less than 200 days. While P. chabaudi-specific antibody levels remain stable after vaccination, the decay of parasite-specific T cells correlates with loss of challenge protection. Therefore, we enlisted murine CMV as a booster strategy to prolong T cell responses against malaria. To study induced T cell responses, we included P. chabaudi MSP-1 epitope B5 (MCMV-B5). We found that MCMV vector alone significantly protected against a challenge P. chabaudi infection 40-60 days later, and that MCMV-B5 was able to make B5-specific Teff, in addition to previously-reported Tem, that survive to the challenge timepoint. Used as a booster, MCMV-B5 prolonged protection from heterologous infection beyond day 200, and increased B5 TCR Tg T cell numbers, including both a highly-differentiated Tem phenotype and Teff, both previously reported to protect. B5 epitope expression was responsible for maintenance of Th1 and Tfh B5 T cells. In addition, the MCMV vector had adjuvant properties, contributing non-specifically through prolonged stimulation of IFN-γ. In vivo neutralization of IFN-γ, but not IL-12 and IL-18, late in the course of MCMV, led to loss of the adjuvant effect. Mechanistically, sustained IFN-γ from MCMV increased CD8α+ dendritic cell numbers, and led to increased IL-12 production upon Plasmodium challenge. In addition, neutralization of IFN-γ before challenge reduced the polyclonal Teff response to challenge. Our findings suggest that, as protective epitopes are defined, an MCMV vectored booster can prolong protection through the innate effects of IFN-γ.
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Affiliation(s)
- Komi Gbedande
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-0435
- Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Cancer Center, 205 S. Orange Avenue, Newark, NJ 07103
| | - Samad A Ibitokou
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-0435
| | - Monique L Ong
- Centre for Experimental Immunology, Lions Eye Institute; Nedlands, Western Australia, Australia
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University; Clayton, Victoria, Australia
| | - Mariapia A Degli-Esposti
- Centre for Experimental Immunology, Lions Eye Institute; Nedlands, Western Australia, Australia
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University; Clayton, Victoria, Australia
| | - Michael G Brown
- Department of Medicine, Division of Nephrology, and the Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA
| | - Robin Stephens
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-0435
- Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Cancer Center, 205 S. Orange Avenue, Newark, NJ 07103
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX
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4
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López-Botet M, De Maria A, Muntasell A, Della Chiesa M, Vilches C. Adaptive NK cell response to human cytomegalovirus: Facts and open issues. Semin Immunol 2023; 65:101706. [PMID: 36542944 DOI: 10.1016/j.smim.2022.101706] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022]
Abstract
Human cytomegalovirus (HCMV) infection exerts broad effects on the immune system. These include the differentiation and persistent expansion of a mature NK cell subset which displays a characteristic phenotypic and functional profile hallmarked by expression of the HLA-E-specific CD94/NKG2C activating receptor. Based on our experience and recent advances in the field, we overview the adaptive features of the NKG2C+ NK cell response, discussing observations and open questions on: (a) the mechanisms and influence of viral and host factors; (b) the existence of other NKG2C- NK cell subsets sharing adaptive features; (c) the development and role of adaptive NKG2C+ NK cells in the response to HCMV in hematopoietic and solid organ transplant patients; (d) their relation with other viral infections, mainly HIV-1; and (e) current perspectives for their use in adoptive immunotherapy of cancer.
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Affiliation(s)
- Miguel López-Botet
- Hospital del Mar Medical Research Institute (IMIM). Barcelona, Spain; Department of Medicine and Life Sciences. Univ. Pompeu Fabra. Barcelona, Spain.
| | - Andrea De Maria
- Division of Infectious Diseases, IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Health Sciences, University of Genoa, Genoa, Italy.
| | - Aura Muntasell
- Hospital del Mar Medical Research Institute (IMIM). Barcelona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERonc), Spain; Universitat Autònoma de Barcelona, Barcelona, Spain.
| | | | - Carlos Vilches
- Immunogenetics & Histocompatibility Lab, Instituto de Investigación Sanitaria Puerta de Hierro - Segovia de Arana, Majadahonda, Madrid, Spain.
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5
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Cronk JM, Dziewulska KH, Puchalski P, Crittenden RB, Hammarskjöld ML, Brown MG. Altered-Self MHC Class I Sensing via Functionally Disparate Paired NK Cell Receptors Counters Murine Cytomegalovirus gp34-Mediated Immune Evasion. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:1545-1554. [PMID: 36165178 PMCID: PMC9529956 DOI: 10.4049/jimmunol.2200441] [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: 06/22/2022] [Accepted: 08/01/2022] [Indexed: 01/04/2023]
Abstract
The murine CMV (MCMV) immunoevasin m04/gp34 escorts MHC class I (MHC I) molecules to the surface of infected cells where these complexes bind Ly49 inhibitory receptors (IRs) and prevent NK cell attack. Nonetheless, certain self-MHC I-binding Ly49 activating and inhibitory receptors are able to promote robust NK cell expansion and antiviral immunity during MCMV infection. A basis for MHC I-dependent NK cell sensing of MCMV-infected targets and control of MCMV infection however remains unclear. In this study, we discovered that the Ly49R activation receptor is selectively triggered during MCMV infection on antiviral NK cells licensed by the Ly49G2 IR. Ly49R activating receptor recognition of MCMV-infected targets is dependent on MHC I Dk and MCMV gp34 expression. Remarkably, although Ly49R is critical for Ly49G2-dependent antiviral immunity, blockade of the activation receptor in Ly49G2-deficient mice has no impact on virus control, suggesting that paired Ly49G2 MCMV sensing might enable Ly49R+ NK cells to better engage viral targets. Indeed, MCMV gp34 facilitates Ly49G2 binding to infected cells, and the IR is required to counter gp34-mediated immune evasion. A specific requirement for Ly49G2 in antiviral immunity is further explained by its capacity to license cytokine receptor signaling pathways and enhance Ly49R+ NK cell proliferation during infection. These findings advance our understanding of the molecular basis for functionally disparate self-receptor enhancement of antiviral NK cell immunity.
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Affiliation(s)
- John M Cronk
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia, USA
| | - Karolina H Dziewulska
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Pathology, University of Virginia, Charlottesville, VA
| | - Patryk Puchalski
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia, USA
- Division of Nephrology, Department of Medicine, University of Virginia, Charlottesville, VA; and
| | - Rowena B Crittenden
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia, USA
- Division of Nephrology, Department of Medicine, University of Virginia, Charlottesville, VA; and
| | - Marie-Louise Hammarskjöld
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA
| | - Michael G Brown
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA;
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia, USA
- Division of Nephrology, Department of Medicine, University of Virginia, Charlottesville, VA; and
- Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia, Charlottesville, VA
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6
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Weaver GC, Arya R, Schneider CL, Hudson AW, Stern LJ. Structural Models for Roseolovirus U20 And U21: Non-Classical MHC-I Like Proteins From HHV-6A, HHV-6B, and HHV-7. Front Immunol 2022; 13:864898. [PMID: 35444636 PMCID: PMC9013968 DOI: 10.3389/fimmu.2022.864898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/08/2022] [Indexed: 01/08/2023] Open
Abstract
Human roseolovirus U20 and U21 are type I membrane glycoproteins that have been implicated in immune evasion by interfering with recognition of classical and non-classical MHC proteins. U20 and U21 are predicted to be type I glycoproteins with extracytosolic immunoglobulin-like domains, but detailed structural information is lacking. AlphaFold and RoseTTAfold are next generation machine-learning-based prediction engines that recently have revolutionized the field of computational three-dimensional protein structure prediction. Here, we review the structural biology of viral immunoevasins and the current status of computational structure prediction algorithms. We use these computational tools to generate structural models for U20 and U21 proteins, which are predicted to adopt MHC-Ia-like folds with closed MHC platforms and immunoglobulin-like domains. We evaluate these structural models and place them within current understanding of the structural basis for viral immune evasion of T cell and natural killer cell recognition.
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Affiliation(s)
- Grant C. Weaver
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | - Richa Arya
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | | | - Amy W. Hudson
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Lawrence J. Stern
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
- Department of Biochemistry and Molecular Biotechnology, UMass Chan Medical School, Worcester, MA, United States
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7
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Abstract
CD4+ T cells are key to controlling cytomegalovirus infections. Salivary gland infection by murine cytomegalovirus (MCMV) provides a way to identify mechanisms. CD11c+ dendritic cells (DC) disseminate MCMV to the salivary glands, where they transfer infection to acinar cells. Antiviral CD4+ T cells are often considered to be directly cytotoxic for cells expressing major histocompatibility complex class II (MHCII). However, persistently infected salivary gland acinar cells are MHCII- and are presumably inaccessible to direct CD4 T cell recognition. Here, we show that CD4+ T cell depletion amplified infection of MHCII- acinar cells but not MHCII+ cells. MCMV-infected mice with disrupted MHCII on CD11c+ cells showed increased MHCII- acinar infection; antiviral CD4+ T cells were still primed, but their recruitment to the salivary glands was reduced, suggesting that engagement with local MHCII+ DC is important for antiviral protection. As MCMV downregulates MHCII on infected DC, the DC participating in CD4 protection may thus be uninfected. NK cells and gamma interferon (IFN-γ) may also contribute to CD4+ T cell-dependent virus control: CD4 T cell depletion reduced NK cell recruitment to the salivary glands, and both NK cell and IFN-γ depletion equalized infection between MHCII-disrupted and control mice. Taken together, these results suggest that CD4+ T cells protect indirectly against infected acinar cells in the salivary gland via DC engagement, requiring the recruitment of NK cells and the action of IFN-γ. Congruence of these results with an established CD4+ T cell/NK cell axis of gammaherpesvirus infection control suggests a common mode of defense against evasive viruses. IMPORTANCE Cytomegalovirus infections commonly cause problems in immunocompromised patients and in pregnancy. We lack effective vaccines. CD4+ T cells play an important role in normal infection control, yet how they act has been unknown. Using murine cytomegalovirus as an accessible model, we show that CD4+ T cells are unlikely to recognize infected cells directly. We propose that CD4+ T cells interact with uninfected cells that present viral antigens and recruit other immune cells to attack infected targets. These data present a new outlook on understanding how CD4+ T cell-directed control protects against persistent cytomegalovirus infection.
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8
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Olfactory Entry Promotes Herpesvirus Recombination. J Virol 2021; 95:e0155521. [PMID: 34523965 DOI: 10.1128/jvi.01555-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Herpesvirus genomes show abundant evidence of past recombination. Its functional importance is unknown. A key question is whether recombinant viruses can outpace the immunity induced by their parents to reach higher loads. We tested this by coinfecting mice with attenuated mutants of murid herpesvirus 4 (MuHV-4). Infection by the natural olfactory route routinely allowed mutant viruses to reconstitute wild-type genotypes and reach normal viral loads. Lung coinfections rescued much less well. Attenuated murine cytomegalovirus mutants similarly showed recombinational rescue via the nose but not the lungs. These infections spread similarly, so route-specific rescue implied that recombination occurred close to the olfactory entry site. Rescue of replication-deficient MuHV-4 confirmed this, showing that coinfection occurred in the first encountered olfactory cells. This worked even with asynchronous inoculation, implying that a defective virus can wait here for later rescue. Virions entering the nose get caught on respiratory mucus, which the respiratory epithelial cilia push back toward the olfactory surface. Early infection was correspondingly focused on the anterior olfactory edge. Thus, by concentrating incoming infection into a small area, olfactory entry seems to promote functionally significant recombination. IMPORTANCE All organisms depend on genetic diversity to cope with environmental change. Small viruses rely on frequent point mutations. This is harder for herpesviruses because they have larger genomes. Recombination provides another means of genetic optimization. Human herpesviruses often coinfect, and they show evidence of past recombination, but whether this is rare and incidental or functionally important is unknown. We showed that herpesviruses entering mice via the natural olfactory route meet reliably enough for recombination routinely to repair crippling mutations and restore normal viral loads. It appeared to occur in the first encountered olfactory cells and reflected a concentration of infection at the anterior olfactory edge. Thus, natural host entry incorporates a significant capacity for herpesvirus recombination.
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9
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Chan B, Arapović M, Masters LL, Rwandamuiye F, Jonjić S, Smith LM, Redwood AJ. The m15 Locus of Murine Cytomegalovirus Modulates Natural Killer Cell Responses to Promote Dissemination to the Salivary Glands and Viral Shedding. Pathogens 2021; 10:pathogens10070866. [PMID: 34358016 PMCID: PMC8308470 DOI: 10.3390/pathogens10070866] [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: 06/16/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022] Open
Abstract
As the largest herpesviruses, the 230 kb genomes of cytomegaloviruses (CMVs) have increased our understanding of host immunity and viral escape mechanisms, although many of the annotated genes remain as yet uncharacterised. Here we identify the m15 locus of murine CMV (MCMV) as a viral modulator of natural killer (NK) cell immunity. We show that, rather than discrete transcripts from the m14, m15 and m16 genes as annotated, there are five 3′-coterminal transcripts expressed over this region, all utilising a consensus polyA tail at the end of the m16 gene. Functional inactivation of any one of these genes had no measurable impact on viral replication. However, disruption of all five transcripts led to significantly attenuated dissemination to, and replication in, the salivary glands of multiple strains of mice, but normal growth during acute infection. Disruption of the m15 locus was associated with heightened NK cell responses, including enhanced proliferation and IFNγ production. Depletion of NK cells, but not T cells, rescued salivary gland replication and viral shedding. These data demonstrate the identification of multiple transcripts expressed by a single locus which modulate, perhaps in a concerted fashion, the function of anti-viral NK cells.
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Affiliation(s)
- Baca Chan
- School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (B.C.); (L.L.M.); (F.R.); (L.M.S.)
- Institute of Respiratory Health, University of Western Australia, Nedlands, WA 6009, Australia
| | - Maja Arapović
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (M.A.); (S.J.)
| | - Laura L. Masters
- School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (B.C.); (L.L.M.); (F.R.); (L.M.S.)
| | - Francois Rwandamuiye
- School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (B.C.); (L.L.M.); (F.R.); (L.M.S.)
| | - Stipan Jonjić
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (M.A.); (S.J.)
| | - Lee M. Smith
- School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (B.C.); (L.L.M.); (F.R.); (L.M.S.)
| | - Alec J. Redwood
- School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (B.C.); (L.L.M.); (F.R.); (L.M.S.)
- Institute of Respiratory Health, University of Western Australia, Nedlands, WA 6009, Australia
- Correspondence: ; Tel.: +61-8-6151-0895
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10
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Parikh BA, Bern MD, Piersma SJ, Yang L, Beckman DL, Poursine-Laurent J, Plougastel-Douglas B, Yokoyama WM. Control of Viral Infection by Natural Killer Cell Inhibitory Receptors. Cell Rep 2021; 32:107969. [PMID: 32726632 PMCID: PMC7458139 DOI: 10.1016/j.celrep.2020.107969] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/27/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Major histocompatibility complex class I (MHC-I)-restricted immune responses are largely attributed to cytotoxic T lymphocytes (CTLs). However, natural killer (NK) cells, as predicted by the missing-self hypothesis, have opposing requirements for MHC-I, suggesting that they may also demonstrate MHC-I-restricted effects. In mice, the Ly49 inhibitory receptors prevent NK cell killing of missing-self targets in effector responses, and they have a proposed second function in licensing or educating NK cells via self-MHC-I in vivo. Here we show MHC-I-restricted control of murine cytomegalovirus (MCMV) infection in vivo that is NK cell dependent. Using mice lacking specific Ly49 receptors, we show that control of MCMV requires inhibitory Ly49 receptors and an inhibitory signaling motif and the capacity for MCMV to downregulate MHC-I. Taken together, these data provide definitive evidence that the inhibitory receptors are required for missing-self rejection and are relevant to MHC-I-restricted NK cell control of a viral infection in vivo. Parikh et al. show that major histocompatibility complex class I (MHC-I)-restricted control of viral infection is due to natural killer (NK) cells rather than cytotoxic T cells. Inhibitory NK cell receptors are essential for protection, requiring NK cell licensing (education) by self-MHC-I and missing-self recognition due to virus-induced MHC-I downregulation.
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Affiliation(s)
- Bijal A Parikh
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Michael D Bern
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sytse J Piersma
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Liping Yang
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Diana L Beckman
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jennifer Poursine-Laurent
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Béatrice Plougastel-Douglas
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Wayne M Yokoyama
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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11
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Abstract
Natural killer (NK) cells are innate lymphocytes that provide critical host defense against pathogens and cancer. Originally heralded for their early and rapid effector activity, NK cells have been recognized over the last decade for their ability to undergo adaptive immune processes, including antigen-driven clonal expansion and generation of long-lived memory. This review presents an overview of how NK cells lithely partake in both innate and adaptive responses and how this versatility is manifest in human NK cell-mediated immunity.
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Affiliation(s)
- Adriana M Mujal
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Rebecca B Delconte
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Joseph C Sun
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; .,Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY 10065, USA
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12
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Repair of an Attenuated Low-Passage Murine Cytomegalovirus Bacterial Artificial Chromosome Identifies a Novel Spliced Gene Essential for Salivary Gland Tropism. J Virol 2020; 94:JVI.01456-20. [PMID: 32847854 DOI: 10.1128/jvi.01456-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/23/2020] [Indexed: 01/22/2023] Open
Abstract
The cloning of herpesviruses as bacterial artificial chromosomes (BACs) has revolutionized the study of herpesvirus biology, allowing rapid and precise manipulation of viral genomes. Several clinical strains of human cytomegalovirus (HCMV) have been cloned as BACs; however, no low-passage strains of murine CMV (MCMV), which provide a model mimicking these isolates, have been cloned. Here, the low-passage G4 strain of was BAC cloned. G4 carries an m157 gene that does not ligate the natural killer (NK) cell-activating receptor, Ly49H, meaning that unlike laboratory strains of MCMV, this virus replicates well in C57BL/6 mice. This BAC clone exhibited normal replication during acute infection in the spleen and liver but was attenuated for salivary gland tropism. Next-generation sequencing revealed a C-to-A mutation at nucleotide position 188422, located in the 3' untranslated region of sgg1, a spliced gene critical for salivary gland tropism. Repair of this mutation restored tropism for the salivary glands. Transcriptional analysis revealed a novel spliced gene within the sgg1 locus. This small open reading frame (ORF), sgg1.1, starts at the 3' end of the first exon of sgg1 and extends exon 2 of sgg1. This shorter spliced gene is prematurely terminated by the nonsense mutation at nt 188422. Sequence analysis of tissue culture-passaged virus demonstrated that sgg1.1 was stable, although other mutational hot spots were identified. The G4 BAC will allow in vivo studies in a broader range of mice, avoiding the strong NK cell responses seen in B6 mice with other MCMV BAC-derived MCMVs.IMPORTANCE Murine cytomegalovirus (MCMV) is widely used as a model of human CMV (HCMV) infection. However, this model relies on strains of MCMV that have been serially passaged in the laboratory for over four decades. These laboratory strains have been cloned as bacterial artificial chromosomes (BACs), which permits rapid and precise manipulation. Low-passage strains of MCMV add to the utility of the mouse model of HCMV infection but do not exist as cloned BACs. This study describes the first such low-passage MCMV BAC. This BAC-derived G4 was initially attenuated in vivo, with subsequent full genomic sequencing revealing a novel spliced transcript required for salivary gland tropism. These data suggest that MCMV, like HCMV, undergoes tissue culture adaptation that can limit in vivo growth and supports the use of BAC clones as a way of standardizing viral strains and minimizing interlaboratory strain variation.
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13
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Abstract
The continuous interactions between host and pathogens during their coevolution have shaped both the immune system and the countermeasures used by pathogens. Natural killer (NK) cells are innate lymphocytes that are considered central players in the antiviral response. Not only do they express a variety of inhibitory and activating receptors to discriminate and eliminate target cells but they can also produce immunoregulatory cytokines to alert the immune system. Reciprocally, several unrelated viruses including cytomegalovirus, human immunodeficiency virus, influenza virus, and dengue virus have evolved a multitude of mechanisms to evade NK cell function, such as the targeting of pathways for NK cell receptors and their ligands, apoptosis, and cytokine-mediated signaling. The studies discussed in this article provide further insights into the antiviral function of NK cells and the pathways involved, their constituent proteins, and ways in which they could be manipulated for host benefit.
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Affiliation(s)
- Mathieu Mancini
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 0C7, Canada;,
- McGill University Research Centre on Complex Traits, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Silvia M. Vidal
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 0C7, Canada;,
- McGill University Research Centre on Complex Traits, McGill University, Montreal, Quebec H3G 0B1, Canada
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
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14
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A CD4 + T Cell-NK Cell Axis of Gammaherpesvirus Control. J Virol 2020; 94:JVI.01545-19. [PMID: 31694958 DOI: 10.1128/jvi.01545-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 10/31/2019] [Indexed: 01/27/2023] Open
Abstract
CD4+ T cells are essential to control herpesviruses. Murid herpesvirus 4 (MuHV-4)-driven lung disease in CD4+ T-cell-deficient mice provides a well-studied example. Protective CD4+ T cells have been hypothesized to kill infected cells directly. However, removing major histocompatibility complex class II (MHCII) from LysM+ or CD11c+ cells increased MuHV-4 replication not in those cells but in type 1 alveolar epithelial cells, which lack MHCII, LysM, or CD11c. Disruption of MHCII in infected cells had no effect. Therefore, CD4+ T cells engaged uninfected presenting cells and protected indirectly. Mice lacking MHCII in LysM+ or CD11c+ cells maintained systemic antiviral CD4+ T cell responses, but recruited fewer CD4+ T cells into infected lungs. NK cell infiltration was also reduced, and NK cell depletion normalized infection between MHCII-deficient and control mice. Therefore, NK cell recruitment seemed to be an important component of CD4+ T-cell-dependent protection. Disruption of viral CD8+ T cell evasion made this defense redundant, suggesting that it is important mainly to control CD8-evasive pathogens.IMPORTANCE Gammaherpesviruses are widespread and cause cancers. CD4+ T cells are a key defense. We found that they defend indirectly, engaging uninfected presenting cells and recruiting innate immune cells to attack infected targets. This segregation of CD4+ T cells from immediate contact with infection helps the immune system to cope with viral evasion. Priming this defense by vaccination offers a way to protect against gammaherpesvirus-induced cancers.
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15
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Berry R, Watson GM, Jonjic S, Degli-Esposti MA, Rossjohn J. Modulation of innate and adaptive immunity by cytomegaloviruses. Nat Rev Immunol 2019; 20:113-127. [PMID: 31666730 DOI: 10.1038/s41577-019-0225-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 02/07/2023]
Abstract
The coordinated activities of innate and adaptive immunity are critical for effective protection against viruses. To counter this, some viruses have evolved sophisticated strategies to circumvent immune cell recognition. In particular, cytomegaloviruses encode large arsenals of molecules that seek to subvert T cell and natural killer cell function via a remarkable array of mechanisms. Consequently, these 'immunoevasins' play a fundamental role in shaping the nature of the immune system by driving the evolution of new immune receptors and recognition mechanisms. Here, we review the diverse strategies adopted by cytomegaloviruses to target immune pathways and outline the host's response.
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Affiliation(s)
- Richard Berry
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia. .,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia. .,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia.
| | - Gabrielle M Watson
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia
| | - Stipan Jonjic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Mariapia A Degli-Esposti
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Centre for Experimental Immunology, Lions Eye Institute, Perth, Western Australia, Australia
| | - Jamie Rossjohn
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia.,Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
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16
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Farrell HE, Bruce K, Redwood AJ, Stevenson PG. Murine cytomegalovirus disseminates independently of CX3CR1, CCL2 or its m131/m129 chemokine homologue. J Gen Virol 2019; 100:1695-1700. [PMID: 31609196 DOI: 10.1099/jgv.0.001333] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cytomegaloviruses (CMVs) use myeloid cells to move within their hosts. Murine CMV (MCMV) colonizes the salivary glands for long-term shedding, and reaches them via CD11c+ infected cells. A need to recruit patrolling monocytes for systemic spread has been proposed, based on poor salivary gland infection in fractalkine receptor (CX3CR1)-deficient mice. We found no significant CX3CR1 dependence of salivary gland infection. CCL2 and the viral m131/m129 chemokine homologue were also redundant for acute MCMV spread, arguing against a need for inflammation or infection to recruit additional monocytes to the entry site. M131/m129 promoted salivary gland infection, but only after the initial seeding of infected cells to this site. Our data support the idea that MCMV disseminates by infecting and mobilizing tissue-resident dendritic cells.
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Affiliation(s)
- Helen E Farrell
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Kimberley Bruce
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Alec J Redwood
- The Institute for Respiratory Health, University of Western Australia, Crawley WA 6009, Australia
| | - Philip G Stevenson
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
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17
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Železnjak J, Lisnić VJ, Popović B, Lisnić B, Babić M, Halenius A, L'Hernault A, Roviš TL, Hengel H, Erhard F, Redwood AJ, Vidal SM, Dölken L, Krmpotić A, Jonjić S. The complex of MCMV proteins and MHC class I evades NK cell control and drives the evolution of virus-specific activating Ly49 receptors. J Exp Med 2019; 216:1809-1827. [PMID: 31142589 PMCID: PMC6683999 DOI: 10.1084/jem.20182213] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/04/2019] [Accepted: 05/07/2019] [Indexed: 11/05/2022] Open
Abstract
Železnjak et al. demonstrate that two MCMV-encoded proteins interact with MHC I molecules, forming an altered-self complex that prevents missing self recognition by increasing specificity for inhibitory Ly49 receptors. This led to the evolution of CMV-specific activating Ly49s. CMVs efficiently target MHC I molecules to avoid recognition by cytotoxic T cells. However, the lack of MHC I on the cell surface renders the infected cell susceptible to NK cell killing upon missing self recognition. To counter this, mouse CMV (MCMV) rescues some MHC I molecules to engage inhibitory Ly49 receptors. Here we identify a new viral protein, MATp1, that is essential for MHC I surface rescue. Rescued altered-self MHC I molecules show increased affinity to inhibitory Ly49 receptors, resulting in inhibition of NK cells despite substantially reduced MHC I surface levels. This enables the virus to evade recognition by licensed NK cells. During evolution, this novel viral immune evasion mechanism could have prompted the development of activating NK cell receptors that are specific for MATp1-modified altered-self MHC I molecules. Our study solves a long-standing conundrum of how MCMV avoids recognition by NK cells, unravels a fundamental new viral immune evasion mechanism, and demonstrates how this forced the evolution of virus-specific activating MHC I–restricted Ly49 receptors.
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Affiliation(s)
- Jelena Železnjak
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.,Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Vanda Juranić Lisnić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.,Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Branka Popović
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Berislav Lisnić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.,Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Marina Babić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.,Innate Immunity, German Rheumatism Research Centre, a Leibniz Institute, Berlin, Germany
| | - Anne Halenius
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anne L'Hernault
- Precision Medicine and Genomics, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Cambridge, UK
| | - Tihana Lenac Roviš
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.,Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Hartmut Hengel
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Florian Erhard
- Institute of Virology and Immunobiology, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Alec J Redwood
- Institute for Respiratory Health, University of Western Australia, Western Australia, Australia
| | - Silvia M Vidal
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,McGill Center for Complex Traits, McGill University, Montreal, Quebec, Canada
| | - Lars Dölken
- Institute of Virology and Immunobiology, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Astrid Krmpotić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Stipan Jonjić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia .,Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
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18
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Brown MG, Gamache A, Nash WT, Cronk J. Natural selection for killer receptors and their MHC class I ligands: In pursuit of gene pairs that fit well in tandem. J Leukoc Biol 2018; 105:489-495. [PMID: 30500089 DOI: 10.1002/jlb.2ri0818-315r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 08/13/2018] [Accepted: 09/13/2018] [Indexed: 11/11/2022] Open
Abstract
Our understanding of the genetic basis of host resistance to viral infection and disease has progressed significantly over the last century. Numerous genes coding for modifiers of immune functions have been identified, which impact a variety of critical cellular processes, including signaling via lymphocyte receptors and their ligands, signal transduction, cytokine signaling, production and release of cytotoxic effectors, transcriptional regulation, and proliferation. Genome-wide association studies implicate an important role for both highly polymorphic NK cell receptors and their MHC class I ligands in modifying host resistance. These findings indicate NK cells are critical mediators of viral control with considerable potential to affect morbidity and mortality outcomes. They further suggest that both stimulatory and inhibitory NK receptor polymorphisms alter NK cell sensing of MHC I ligands on viral targets, which influences how NK cells respond to infection. In many cases, however, the underlying causes associated with host outcomes remain elusive. Herein, we discuss several modes of NK cell sensing of MHC I and MHC I-like molecules on viral targets, and the role of genetic diversity in this evolutionarily dynamic process. We further suggest that natural selection for paired NK receptors with opposing function, but shared MHC I ligands may give rise to rare, but highly effective MHC I-dependent modes of NK cell sensing of viral targets.
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Affiliation(s)
- Michael G Brown
- Department of Medicine, Division of Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Awndre Gamache
- Department of Medicine, Division of Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - William T Nash
- Department of Medicine, Division of Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - John Cronk
- Department of Medicine, Division of Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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19
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Hammer Q, Rückert T, Romagnani C. Natural killer cell specificity for viral infections. Nat Immunol 2018; 19:800-808. [PMID: 30026479 DOI: 10.1038/s41590-018-0163-6] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/05/2018] [Indexed: 12/12/2022]
Abstract
Natural killer (NK) cells are lymphocytes that contribute to the early immune responses to viruses. NK cells are innate immune cells that do not express rearranged antigen receptors but sense their environment via receptors for pro-inflammatory cytokines, as well as via germline-encoded activating receptors specific for danger or pathogen signals. A group of such activating receptors is stochastically expressed by certain subsets within the NK cell compartment. After engagement of the cognate viral ligand, these receptors contribute to the specific activation and 'preferential' population expansion of defined NK cell subsets, which partially recapitulate some features of adaptive lymphocytes. In this Review, we discuss the numerous modes for the specific recognition of viral antigens and peptides by NK cells and the implications of this for the composition of the NK cell repertoire as well as for the the selection of viral variants.
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Affiliation(s)
- Quirin Hammer
- Innate Immunity, German Rheumatism Research Center, Leibniz Association, Berlin, Germany.,Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Timo Rückert
- Innate Immunity, German Rheumatism Research Center, Leibniz Association, Berlin, Germany
| | - Chiara Romagnani
- Innate Immunity, German Rheumatism Research Center, Leibniz Association, Berlin, Germany. .,Medical Department I, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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20
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Holder KA, Comeau EM, Grant MD. Origins of natural killer cell memory: special creation or adaptive evolution. Immunology 2018; 154:38-49. [PMID: 29355919 DOI: 10.1111/imm.12898] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/09/2018] [Accepted: 01/14/2018] [Indexed: 12/13/2022] Open
Abstract
The few initial formative studies describing non-specific and apparently spontaneous activity of natural killer (NK) cells have since multiplied into thousands of scientific reports defining their unique capacities and means of regulation. Characterization of the array of receptors that govern NK cell education and activation revealed an unexpected relationship with the major histocompatibility molecules that NK cells originally became well known for ignoring. Proceeding true to form, NK cells continue to up-end archetypal understanding of their ever-expanding capabilities. Discovery that the NK cell repertoire is extremely diverse and can be reshaped by particular viruses into unique subsets of adaptive NK cells challenges, or at least broadens, the definition of immunological memory. This review provides an overview of studies identifying adaptive NK cells, addressing the origins of NK cell memory and introducing the heretical concept of NK cells with extensive antigenic specificity. Whether these newly apparent properties reflect adaptive utilization of known NK cell attributes and receptors or a specially creative allocation from an undefined receptor array remains to be fully determined.
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Affiliation(s)
- Kayla A Holder
- Immunology and Infectious Diseases Programme, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL, Canada
| | - Emilie M Comeau
- Immunology and Infectious Diseases Programme, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL, Canada
| | - Michael D Grant
- Immunology and Infectious Diseases Programme, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL, Canada
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21
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Goodier MR, Jonjić S, Riley EM, Juranić Lisnić V. CMV and natural killer cells: shaping the response to vaccination. Eur J Immunol 2017; 48:50-65. [PMID: 28960320 DOI: 10.1002/eji.201646762] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/14/2017] [Accepted: 09/22/2017] [Indexed: 12/14/2022]
Abstract
Cytomegaloviruses (CMVs) are highly prevalent, persistent human pathogens that not only evade but also shape our immune responses. Natural killer (NK) cells play an important role in the control of CMV and CMVs have in turn developed a plethora of immunoevasion mechanisms targeting NK cells. This complex interplay can leave a long-lasting imprint on the immune system in general and affect responses toward other pathogens and vaccines. This review aims to provide an overview of NK cell biology and development, the manipulation of NK cells by CMVs and the potential impact of these evasion strategies on responses to vaccination.
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Affiliation(s)
- Martin R Goodier
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Stipan Jonjić
- Department for Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Croatia
| | - Eleanor M Riley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Vanda Juranić Lisnić
- Department for Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Croatia
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22
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Use of C57BL/6N mice on the variety of immunological researches. Lab Anim Res 2017; 33:119-123. [PMID: 28747977 PMCID: PMC5527137 DOI: 10.5625/lar.2017.33.2.119] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/09/2017] [Accepted: 06/09/2017] [Indexed: 12/11/2022] Open
Abstract
Inbred mice are an essential animal strain for research as they can improve the reproducibility and reliability of study results. The establishment of new inbred lines is continuing, and new inbred lines are being used in many research fields. C57BL/6 is a mouse laboratory animal that has been developed and used as an inbred strain since early stage of mouse strain development, and, in the 1950s, C57BL/6 was separated into substrains by the Jackson Laboratory (C57BL/6J) and the National Institutes of Health (C57BL/6N). C57BL/6 mice have been used in immunology and antitumor activity studies since the early strain development stage. After the mouse genome was fully described, C57BL/6 mice use in many areas of research has expanded. In particular, immunological characteristics such as those related to cell-mediated immunity and NK cell activity are relatively higher in C57BL/6 mice than in other mice. The C57BL/6NKorl is a stock of C57BL/6N established as part of a localization of experimental animal strategy of the Korean Food and Drug Administration. Based on analysis of single nucleotide polymorphisms (SNPs), C57BL/6NKorl is considered a genetically distinct inbred stock from other C57BL/6N. Various research efforts have been made to describe the characteristics and increase knowledge of the characteristics of C57BL/6Nkorl. The results obtained through these efforts are expected to increase the utilization of C57BL/6Nkorl as a domestic laboratory animal resource and to enhance the reliability of mouse based studies.
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23
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Zeleznjak J, Popovic B, Krmpotic A, Jonjic S, Lisnic VJ. Mouse cytomegalovirus encoded immunoevasins and evolution of Ly49 receptors - Sidekicks or enemies? Immunol Lett 2017; 189:40-47. [PMID: 28414184 DOI: 10.1016/j.imlet.2017.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 12/26/2022]
Abstract
Cytomegaloviruses (CMVs) have dedicated a large portion of their genome towards immune evasion targeting many aspects of the host immune system, particularly NK cells. However, the host managed to cope with the infection by developing multiple mechanisms to recognize viral threat and counterattack it, thus illustrating never-ending evolutionary interplay between CMV and its host. In this review, we will focus on several mechanisms of NK cell evasion by mouse CMV (MCMV), the role of host inhibitory and activating Ly49 receptors involved in the virus control and acquisition of adaptive features by NK cells as a consequence of MCMV infection.
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Affiliation(s)
- Jelena Zeleznjak
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia
| | - Branka Popovic
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia
| | - Astrid Krmpotic
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia
| | - Stipan Jonjic
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia; Center for Proteomics, Faculty of Medicine, University of Rijeka, Croatia
| | - Vanda Juranic Lisnic
- Department for Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia; Center for Proteomics, Faculty of Medicine, University of Rijeka, Croatia.
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24
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Kinetic and thermodynamic studies of the interaction between activating and inhibitory Ly49 natural killer receptors and MHC class I molecules. Biochem J 2017; 474:179-194. [PMID: 27831490 DOI: 10.1042/bcj20160876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/01/2016] [Accepted: 11/09/2016] [Indexed: 11/17/2022]
Abstract
Natural killer (NK) cells are lymphocytes of the innate immune system that eliminate virally infected or malignantly transformed cells. NK cell function is regulated by diverse surface receptors that are both activating and inhibitory. Among them, the homodimeric Ly49 receptors control NK cell cytotoxicity by sensing major histocompatibility complex class I molecules (MHC-I) on target cells. Although crystal structures have been reported for Ly49/MHC-I complexes, the underlying binding mechanism has not been elucidated. Accordingly, we carried out thermodynamic and kinetic experiments on the interaction of four NK Ly49 receptors (Ly49G, Ly49H, Ly49I and Ly49P) with two MHC-I ligands (H-2Dd and H-2Dk). These Ly49s embrace the structural and functional diversity of the highly polymorphic Ly49 family. Combining surface plasmon resonance, fluorescence anisotropy and far-UV circular dichroism (CD), we determined that the best model to describe both inhibitory and activating Ly49/MHC-I interactions is one in which the two MHC-I binding sites of the Ly49 homodimer present similar binding constants for the two sites (∼106 M-1) with a slightly positive co-operativity in some cases, and without far-UV CD observable conformational changes. Furthermore, Ly49/MHC-I interactions are diffusion-controlled and enthalpy-driven. These features stand in marked contrast with the activation-controlled and entropy-driven interaction of Ly49s with the viral immunoevasin m157, which is characterized by strong positive co-operativity and conformational selection. These differences are explained by the distinct structures of Ly49/MHC-I and Ly49/m157 complexes. Moreover, they reflect the opposing roles of NK cells to rapidly scan for virally infected cells and of viruses to escape detection using immunoevasins such as m157.
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25
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Farrell HE, Bruce K, Lawler C, Cardin RD, Davis-Poynter NJ, Stevenson PG. Type 1 Interferons and NK Cells Limit Murine Cytomegalovirus Escape from the Lymph Node Subcapsular Sinus. PLoS Pathog 2016; 12:e1006069. [PMID: 27926941 PMCID: PMC5142805 DOI: 10.1371/journal.ppat.1006069] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/16/2016] [Indexed: 12/26/2022] Open
Abstract
Cytomegaloviruses (CMVs) establish chronic, systemic infections. Peripheral infection spreads via lymph nodes, which are also a focus of host defence. Thus, this is a point at which systemic infection spread might be restricted. Subcapsular sinus macrophages (SSM) captured murine CMV (MCMV) from the afferent lymph and poorly supported its replication. Blocking the type I interferon (IFN-I) receptor (IFNAR) increased MCMV infection of SSM and of the fibroblastic reticular cells (FRC) lining the subcapsular sinus, and accelerated viral spread to the spleen. Little splenic virus derived from SSM, arguing that they mainly induce an anti-viral state in the otherwise susceptible FRC. NK cells also limited infection, killing infected FRC and causing tissue damage. They acted independently of IFN-I, as IFNAR blockade increased NK cell recruitment, and NK cell depletion increased infection in IFNAR-blocked mice. Thus SSM restricted MCMV infection primarily though IFN-I, with NK cells providing a second line of defence. The capacity of innate immunity to restrict MCMV escape from the subcapsular sinus suggested that enhancing its recruitment might improve infection control. Cytomegaloviruses (CMVs) infect most people and are a common cause of fetal damage. We lack an effective vaccine. Our knowledge of human CMV is largely limited to chronic infection, which is hard to treat. Vaccination must target early infection. Related animal viruses therefore provide a vital source of information. Lymph nodes are a bottleneck in murine CMV spread from local to systemic infection. We show that viral passage through lymph nodes is restricted by interferons and NK cells. These defences alone cannot contain infection, but boosting their recruitment by vaccination has the potential to keep infection locally contained.
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Affiliation(s)
- Helen E. Farrell
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
- * E-mail:
| | - Kimberley Bruce
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Clara Lawler
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Rhonda D. Cardin
- Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | | | - Philip G. Stevenson
- School of Chemistry and Molecular Biosciences and Child Health Research Centre, University of Queensland, Brisbane, Australia
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26
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Abstract
Viral infections continuously challenge and shape our immune system. Due to their fine antigen recognition ability, adaptive lymphocytes protect against pathogen reencounter by generating specific immunological memory. Innate cells such as macrophages also adapt to pathogen challenge and mount resistance to reinfection, a phenomenon termed trained immunity. As part of the innate immunity, natural killer (NK) cells can display rapid effector functions and play a crucial role in the control of viral infections, especially by the β-herpesvirus cytomegalovirus (CMV). CMV activates the NK-cell pool by inducing proinflammatory signals, which prime NK cells, paralleling macrophage training. In addition, CMV dramatically shapes the NK-cell repertoire due to its ability to trigger specific NK cell-activating receptors, and enables the expansion and persistence of a specific NK-cell subset displaying adaptive and memory features. In this chapter, we will discuss how different signals during CMV infection contribute to NK-cell training and acquisition of classical memory properties and how these events can impact on reinfection and cross-resistance.
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27
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Rahim MMA, Wight A, Mahmoud AB, Aguilar OA, Lee SH, Vidal SM, Carlyle JR, Makrigiannis AP. Expansion and Protection by a Virus-Specific NK Cell Subset Lacking Expression of the Inhibitory NKR-P1B Receptor during Murine Cytomegalovirus Infection. THE JOURNAL OF IMMUNOLOGY 2016; 197:2325-37. [PMID: 27511735 DOI: 10.4049/jimmunol.1600776] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/08/2016] [Indexed: 11/19/2022]
Abstract
NK cells play a major role in immune defense against human and murine CMV (MCMV) infection. Although the MCMV genome encodes for MHC class I-homologous decoy ligands for inhibitory NK cell receptors to evade detection, some mouse strains have evolved activating receptors, such as Ly49H, to recognize these ligands and initiate an immune response. In this study, we demonstrate that approximately half of the Ly49H-expressing (Ly49H(+)) NK cells in the spleen and liver of C57BL/6 mice also express the inhibitory NKR-P1B receptor. During MCMV infection, the NKR-P1B(-)Ly49H(+) NK cell subset proliferates to constitute the bulk of the NK cell population. This NK cell subset also confers better protection against MCMV infection compared with the NKR-P1B(+)Ly49H(+) subset. The two populations are composed of cells that differ in their surface expression of receptors such as Ly49C/I and NKG2A/C/E, as well as developmental markers, CD27 and CD11b, and the high-affinity IL-2R (CD25) following infection. Although the NKR-P1B(+) NK cells can produce effector molecules such as IFNs and granzymes, their proliferation is inhibited during infection. A similar phenotype in MCMV-infected Clr-b-deficient mice, which lack the ligand for NKR-P1B, suggests the involvement of ligands other than the host Clr-b. Most interestingly, genetic deficiency of the NKR-P1B, but not Clr-b, results in accelerated virus clearance and recovery from MCMV infection. This study is particularly significant because the mouse NKR-P1B:Clr-b receptor:ligand system represents the closest homolog of the human NKR-P1A:LLT1 system and may have a direct relevance to human CMV infection.
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Affiliation(s)
- Mir Munir A Rahim
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada;
| | - Andrew Wight
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Ahmad Bakur Mahmoud
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; College of Applied Medical Sciences, Taibah University, 30001 Madinah Munawwarah, Saudi Arabia
| | - Oscar A Aguilar
- Department of Immunology, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada; and
| | - Seung-Hwan Lee
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Silvia M Vidal
- Department of Human Genetics, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - James R Carlyle
- Department of Immunology, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada; and
| | - Andrew P Makrigiannis
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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Rahim MMA, Makrigiannis AP. Ly49 receptors: evolution, genetic diversity, and impact on immunity. Immunol Rev 2016; 267:137-47. [PMID: 26284475 DOI: 10.1111/imr.12318] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Natural killer (NK) cells express cell surface receptors that recognize class I major histocompatibility complex (MHC-I) molecules to distinguish between healthy and unhealthy cells. The multigenic and polymorphic nature of the MHC-I genes has influenced the convergent evolution of similarly polymorphic and diversified NK cell receptor families: the C-type lectin-like Ly49 receptors in mice, and the killer cell immunoglobulin-like receptors (KIRs) in humans. Although structurally distinct, both receptor families have similar functions in terms of MHC-I recognition and downstream signal transduction, and they regulate multiple aspects of NK cell biology during development and after maturation as fully differentiated and functionally competent cells. The Ly49 gene locus has undergone rapid, lineage-specific expansions and contractions resulting in multiple distinct haplotypes of variable gene number, allelic diversity, and MHC-I ligand specificity. This in turn has influenced the type and degree of Ly49 receptor expression on NK cells, and their contribution to immunity in different mouse strains. In this review, we have attempted to describe the evolutionary processes that have shaped strain-specific Ly49 receptor repertoires, and their impact on NK cell functions during health and disease.
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Affiliation(s)
- Mir Munir A Rahim
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Andrew P Makrigiannis
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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Tu MM, Mahmoud AB, Makrigiannis AP. Licensed and Unlicensed NK Cells: Differential Roles in Cancer and Viral Control. Front Immunol 2016; 7:166. [PMID: 27199990 PMCID: PMC4852173 DOI: 10.3389/fimmu.2016.00166] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 04/18/2016] [Indexed: 11/25/2022] Open
Abstract
Natural killer (NK) cells are known for their well characterized ability to control viral infections and eliminate tumor cells. Through their repertoire of activating and inhibitory receptors, NK cells are able to survey different potential target cells for various surface markers, such as MHC-I – which signals to the NK cell that the target is healthy – as well as stress ligands or viral proteins, which alert the NK cell to the aberrant state of the target and initiate a response. According to the “licensing” hypothesis, interactions between self-specific MHC-I receptors – Ly49 in mice and KIR in humans – and self-MHC-I molecules during NK cell development is crucial for NK cell functionality. However, there also exists a large proportion of NK cells in mice and humans, which lack self-specific MHC-I receptors and are consequentially “unlicensed.” While the licensed NK cell subset plays a major role in the control of MHC-I-deficient tumors, this review will go on to highlight the important role of the unlicensed NK cell subset in the control of MHC-I-expressing tumors, as well as in viral control. Unlike the licensed NK cells, unlicensed NK cells seem to benefit from the lack of self-specific inhibitory receptors, which could otherwise be exploited by some aberrant cells for immunoevasion by upregulating the expression of ligands or mimic ligands for these receptors.
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Affiliation(s)
- Megan M Tu
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa , Ottawa, ON , Canada
| | - Ahmad Bakur Mahmoud
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada; College of Applied Medical Sciences, Taibah University, Madinah Munawwarah, Saudi Arabia
| | - Andrew P Makrigiannis
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa , Ottawa, ON , Canada
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Brisse E, Imbrechts M, Put K, Avau A, Mitera T, Berghmans N, Rutgeerts O, Waer M, Ninivaggi M, Kelchtermans H, Boon L, Snoeck R, Wouters CH, Andrei G, Matthys P. Mouse Cytomegalovirus Infection in BALB/c Mice Resembles Virus-Associated Secondary Hemophagocytic Lymphohistiocytosis and Shows a Pathogenesis Distinct from Primary Hemophagocytic Lymphohistiocytosis. THE JOURNAL OF IMMUNOLOGY 2016; 196:3124-34. [PMID: 26903481 DOI: 10.4049/jimmunol.1501035] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 01/22/2016] [Indexed: 01/04/2023]
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immunological disorder that is characterized by systemic inflammation, widespread organ damage, and hypercytokinemia. Primary HLH is caused by mutations in granule-mediated cytotoxicity, whereas secondary HLH occurs, without a known genetic background, in a context of infections, malignancies, or autoimmune and autoinflammatory disorders. Clinical manifestations of both HLH subtypes are often precipitated by a viral infection, predominantly with Herpesviridae. Exploiting this knowledge, we established an animal model of virus-associated secondary HLH by infecting immunocompetent wild-type mice with the β-herpesvirus murine CMV. C57BL/6 mice developed a mild inflammatory phenotype, whereas BALB/c mice displayed the clinicopathologic features of HLH, as set forth in the Histiocyte Society diagnostic guidelines: fever, cytopenia, hemophagocytosis, hyperferritinemia, and elevated serum levels of soluble CD25. BALB/c mice also developed lymphadenopathy, liver dysfunction, and decreased NK cell numbers. Lymphoid and myeloid cells were in a hyperactivated state. Nonetheless, depletion of CD8(+) T cells could not inhibit or cure the HLH-like syndrome, highlighting a first dissimilarity from mouse models of primary HLH. Immune cell hyperactivation in BALB/c mice was accompanied by a cytokine storm. Notably, plasma levels of IFN-γ, a key pathogenic cytokine in models of primary HLH, were the highest. Nevertheless, murine CMV-infected IFN-γ-deficient mice still developed the aforementioned HLH-like symptoms. In fact, IFN-γ-deficient mice displayed a more complete spectrum of HLH, including splenomegaly, coagulopathy, and decreased NK cell cytotoxicity, indicating a regulatory role for IFN-γ in the pathogenesis of virus-associated secondary HLH as opposed to its central pathogenic role in primary HLH.
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Affiliation(s)
- Ellen Brisse
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Maya Imbrechts
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Karen Put
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Anneleen Avau
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Tania Mitera
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Nele Berghmans
- Laboratory of Molecular Immunology, Rega Institute, University of Leuven, 3000 Leuven, Belgium
| | - Omer Rutgeerts
- Laboratory of Experimental Transplantation, University of Leuven, 3000 Leuven, Belgium
| | - Mark Waer
- Laboratory of Experimental Transplantation, University of Leuven, 3000 Leuven, Belgium
| | - Marisa Ninivaggi
- Synapse BV, Cardiovascular Research Institute Maastricht School for Cardiovascular Diseases, Maastricht University, 6229 Maastricht, the Netherlands
| | - Hilde Kelchtermans
- Synapse BV, Cardiovascular Research Institute Maastricht School for Cardiovascular Diseases, Maastricht University, 6229 Maastricht, the Netherlands
| | - Louis Boon
- Epirus Biopharmaceuticals Netherlands, 3584 Utrecht, the Netherlands
| | - Robert Snoeck
- Laboratory of Virology and Chemotherapy, Rega Institute, University of Leuven, 3000 Leuven, Belgium; and
| | - Carine H Wouters
- Laboratory of Pediatric Immunology, University Hospital Gasthuisberg, University of Leuven, 3000 Leuven, Belgium
| | - Graciela Andrei
- Laboratory of Virology and Chemotherapy, Rega Institute, University of Leuven, 3000 Leuven, Belgium; and
| | - Patrick Matthys
- Laboratory of Immunobiology, Rega Institute, University of Leuven, 3000 Leuven, Belgium;
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Abstract
Natural killer (NK) cells are immune cells that play a crucial role against viral infections and tumors. To be tolerant against healthy tissue and simultaneously attack infected cells, the activity of NK cells is tightly regulated by a sophisticated array of germline-encoded activating and inhibiting receptors. The best characterized mechanism of NK cell activation is “missing self” detection, i.e., the recognition of virally infected or transformed cells that reduce their MHC expression to evade cytotoxic T cells. To monitor the expression of MHC-I on target cells, NK cells have monomorphic inhibitory receptors which interact with conserved MHC molecules. However, there are other NK cell receptors (NKRs) encoded by gene families showing a remarkable genetic diversity. Thus, NKR haplotypes contain several genes encoding for receptors with activating and inhibiting signaling, and that vary in gene content and allelic polymorphism. But if missing-self detection can be achieved by a monomorphic NKR system why have these polygenic and polymorphic receptors evolved? Here, we review the expansion of NKR receptor families in different mammal species, and we discuss several hypotheses that possibly underlie the diversification of the NK cell receptor complex, including the evolution of viral decoys, peptide sensitivity, and selective MHC-downregulation.
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33
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Forbes CA, Coudert JD. Mechanisms regulating NK cell activation during viral infection. Future Virol 2015. [DOI: 10.2217/fvl.14.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT NK cells constitute a population of lymphocytes involved in innate immune functions. They play a critical role in antiviral immune surveillance. Viruses have evolved with their host species for millions of years, each exerting a selective pressure upon the other. As a corollary, the pathways used by the immune system that are critical to control viral infection can be revealed by defining the role of viral gene products that are nonessential for virus replication. We relate here the battery of resources available to NK cells to recognize and eliminate viruses and reciprocally the immune evasion mechanisms developed by viruses to prevent NK cell activation.
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Affiliation(s)
- Catherine A Forbes
- Centre for Experimental Immunology, Lions Eye Institute, 2 Verdun St, Nedlands, WA 6009, Australia
| | - Jerome D Coudert
- Centre for Experimental Immunology, Lions Eye Institute, 2 Verdun St, Nedlands, WA 6009, Australia
- Centre for Ophthalmology & Vision Science, M517, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
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A natural genetic variant of granzyme B confers lethality to a common viral infection. PLoS Pathog 2014; 10:e1004526. [PMID: 25502180 PMCID: PMC4263754 DOI: 10.1371/journal.ppat.1004526] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 10/16/2014] [Indexed: 01/02/2023] Open
Abstract
Many immune response genes are highly polymorphic, consistent with the selective pressure imposed by pathogens over evolutionary time, and the need to balance infection control with the risk of auto-immunity. Epidemiological and genomic studies have identified many genetic variants that confer susceptibility or resistance to pathogenic micro-organisms. While extensive polymorphism has been reported for the granzyme B (GzmB) gene, its relevance to pathogen immunity is unexplored. Here, we describe the biochemical and cytotoxic functions of a common allele of GzmB (GzmBW) common in wild mouse. While retaining ‘Asp-ase’ activity, GzmBW has substrate preferences that differ considerably from GzmBP, which is common to all inbred strains. In vitro, GzmBW preferentially cleaves recombinant Bid, whereas GzmBP activates pro-caspases directly. Recombinant GzmBW and GzmBP induced equivalent apoptosis of uninfected targets cells when delivered with perforin in vitro. Nonetheless, mice homozygous for GzmBW were unable to control murine cytomegalovirus (MCMV) infection, and succumbed as a result of excessive liver damage. Although similar numbers of anti-viral CD8 T cells were generated in both mouse strains, GzmBW-expressing CD8 T cells isolated from infected mice were unable to kill MCMV-infected targets in vitro. Our results suggest that known virally-encoded inhibitors of the intrinsic (mitochondrial) apoptotic pathway account for the increased susceptibility of GzmBW mice to MCMV. We conclude that different natural variants of GzmB have a profound impact on the immune response to a common and authentic viral pathogen. Granzymes (Gzm) are serine proteases expressed by cytotoxic T cells and natural killer cells, and are important for the destruction of virally infected cells. To date, the function of these molecules has been assessed exclusively in common laboratory mouse strains that express identical granzyme proteins. In wild mouse populations, variants of granzyme B have been identified, but how these function, especially in the context of infections, is unknown. We have generated a novel mouse strain expressing a granzyme B variant found in wild mice (GzmBW), and exposed these mice to viral infections. The substrates cleaved by GzmBW were found to differ significantly from those cleaved by the GzmBP protein, which is normally expressed by laboratory mice. Alterations in substrate specificity resulted in GzmBW mice being significantly more susceptible to infection with murine cytomegalovirus, a common mouse pathogen. Our findings demonstrate that polymorphisms in granzyme B can profoundly affect the outcome of infections with some viral pathogens.
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35
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Pyzik M, Dumaine AA, Charbonneau B, Fodil-Cornu N, Jonjic S, Vidal SM. Viral MHC Class I–like Molecule Allows Evasion of NK Cell Effector Responses In Vivo. THE JOURNAL OF IMMUNOLOGY 2014; 193:6061-9. [DOI: 10.4049/jimmunol.1401386] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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36
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Brizić I, Lenac Roviš T, Krmpotić A, Jonjić S. MCMV avoidance of recognition and control by NK cells. Semin Immunopathol 2014; 36:641-50. [DOI: 10.1007/s00281-014-0441-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 07/15/2014] [Indexed: 01/27/2023]
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Verma S, Loewendorf A, Wang Q, McDonald B, Redwood A, Benedict CA. Inhibition of the TRAIL death receptor by CMV reveals its importance in NK cell-mediated antiviral defense. PLoS Pathog 2014; 10:e1004268. [PMID: 25122141 PMCID: PMC4133390 DOI: 10.1371/journal.ppat.1004268] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 06/08/2014] [Indexed: 11/19/2022] Open
Abstract
TNF-related apoptosis inducing ligand (TRAIL) death receptors (DR) regulate apoptosis and inflammation, but their role in antiviral defense is poorly understood. Cytomegaloviruses (CMV) encode many immune-modulatory genes that shape host immunity, and they utilize multiple strategies to target the TNF-family cytokines. Here we show that the m166 open reading frame (orf) of mouse CMV (MCMV) is strictly required to inhibit expression of TRAIL-DR in infected cells. An MCMV mutant lacking m166 expression (m166stop) is severely compromised for replication in vivo, most notably in the liver, and depleting natural killer (NK) cells, or infecting TRAIL-DR-/- mice, restored MCMV-m166stop replication completely. These results highlight the critical importance for CMV to have evolved a strategy to inhibit TRAIL-DR signaling to thwart NK-mediated defenses.
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Affiliation(s)
- Shilpi Verma
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America
| | - Andrea Loewendorf
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America
| | - Qiao Wang
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America
| | - Bryan McDonald
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America
| | - Alec Redwood
- Microbiology and Immunology, School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Chris A. Benedict
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America
- * E-mail:
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38
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Jost NH, Abel S, Hutzler M, Sparwasser T, Zimmermann A, Roers A, Müller W, Klopfleisch R, Hengel H, Westendorf AM, Buer J, Hansen W. Regulatory T cells and T‐cell‐derived IL‐10 interfere with effective anti‐cytomegalovirus immune response. Immunol Cell Biol 2014; 92:860-71. [DOI: 10.1038/icb.2014.62] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 06/25/2014] [Accepted: 06/26/2014] [Indexed: 02/07/2023]
Affiliation(s)
- Nils H Jost
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
| | - Simone Abel
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
| | - Marina Hutzler
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCOREHannoverGermany
| | | | - Axel Roers
- Institute for Immunology, TU DresdenDresdenGermany
| | - Werner Müller
- Faculty of Life Sciences, University of ManchesterManchesterUK
| | | | - Hartmut Hengel
- Institute for Virology, University Medical Center Freiburg, Albert‐Ludwigs UniversityFreiburgGermany
| | - Astrid M Westendorf
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
| | - Jan Buer
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
| | - Wiebke Hansen
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg‐EssenEssenGermany
- Institute for Virology, University Medical Center Freiburg, Albert‐Ludwigs UniversityFreiburgGermany
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39
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Berry R, Vivian JP, Deuss FA, Balaji GR, Saunders PM, Lin J, Littler DR, Brooks AG, Rossjohn J. The structure of the cytomegalovirus-encoded m04 glycoprotein, a prototypical member of the m02 family of immunoevasins. J Biol Chem 2014; 289:23753-63. [PMID: 24982419 DOI: 10.1074/jbc.m114.584128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ability of CMVs to evade the immune system of the host is dependent on the expression of a wide array of glycoproteins, many of which interfere with natural killer cell function. In murine CMV, two large protein families mediate this immune-evasive function. Although it is established that the m145 family members mimic the structure of MHC-I molecules, the structure of the m02 family remains unknown. The most extensively studied m02 family member is m04, a glycoprotein that escorts newly assembled MHC-I molecules to the cell surface, presumably to avoid "missing self" recognition. Here we report the crystal structure of the m04 ectodomain, thereby providing insight into this large immunoevasin family. m04 adopted a β-sandwich immunoglobulin variable (Ig-V)-like fold, despite sharing very little sequence identity with the Ig-V superfamily. In addition to the Ig-V core, m04 possesses several unique structural features that included an unusual β-strand topology, a number of extended loops and a prominent α-helix. The m04 interior was packed by a myriad of hydrophobic residues that form distinct clusters around two conserved tryptophan residues. This hydrophobic core was well conserved throughout the m02 family, thereby indicating that murine CMV encodes a number of Ig-V-like molecules. We show that m04 binds a range of MHC-I molecules with low affinity in a peptide-independent manner. Accordingly, the structure of m04, which represents the first example of an murine CMV encoded Ig-V fold, provides a basis for understanding the structure and function of this enigmatic and large family of immunoevasins.
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Affiliation(s)
- Richard Berry
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and
| | - Julian P Vivian
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and
| | - Felix A Deuss
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and
| | - Gautham R Balaji
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and
| | - Philippa M Saunders
- the Department of Microbiology & Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria 3010, Australia, and
| | - Jie Lin
- the Department of Microbiology & Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria 3010, Australia, and
| | - Dene R Littler
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and
| | - Andrew G Brooks
- the Department of Microbiology & Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria 3010, Australia, and
| | - Jamie Rossjohn
- From the Department of Biochemistry and Molecular Biology, School of Biomedical Sciences and the Institute of Infection and Immunity, Cardiff University, School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom the Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia,
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40
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Forbes CA, Scalzo AA, Degli-Esposti MA, Coudert JD. Ly49C-dependent control of MCMV Infection by NK cells is cis-regulated by MHC Class I molecules. PLoS Pathog 2014; 10:e1004161. [PMID: 24873973 PMCID: PMC4038614 DOI: 10.1371/journal.ppat.1004161] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/20/2014] [Indexed: 11/18/2022] Open
Abstract
Natural Killer (NK) cells are crucial in early resistance to murine cytomegalovirus (MCMV) infection. In B6 mice, the activating Ly49H receptor recognizes the viral m157 glycoprotein on infected cells. We previously identified a mutant strain (MCMVG1F) whose variant m157 also binds the inhibitory Ly49C receptor. Here we show that simultaneous binding of m157 to the two receptors hampers Ly49H-dependent NK cell activation as Ly49C-mediated inhibition destabilizes NK cell conjugation with their targets and prevents the cytoskeleton reorganization that precedes killing. In B6 mice, as most Ly49H+ NK cells do not co-express Ly49C, the overall NK cell response remains able to control MCMVm157G1F infection. However, in B6 Ly49C transgenic mice where all NK cells express the inhibitory receptor, MCMV infection results in altered NK cell activation associated with increased viral replication. Ly49C-mediated inhibition also regulates Ly49H-independent NK cell activation. Most interestingly, MHC class I regulates Ly49C function through cis-interactions that mask the receptor and restricts m157 binding. B6 Ly49C Tg, β2m ko mice, whose Ly49C receptors are unmasked due to MHC class I deficient expression, are highly susceptible to MCMVm157G1F and are unable to control a low-dose infection. Our study provides novel insights into the mechanisms that regulate NK cell activation during viral infection.
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Affiliation(s)
- Catherine A. Forbes
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Anthony A. Scalzo
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Mariapia A. Degli-Esposti
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Vision Science, M517, University of Western Australia, Crawley, Western Australia, Australia
| | - Jerome D. Coudert
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Vision Science, M517, University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
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41
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Nash WT, Teoh J, Wei H, Gamache A, Brown MG. Know Thyself: NK-Cell Inhibitory Receptors Prompt Self-Tolerance, Education, and Viral Control. Front Immunol 2014; 5:175. [PMID: 24795719 PMCID: PMC3997006 DOI: 10.3389/fimmu.2014.00175] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/03/2014] [Indexed: 01/05/2023] Open
Abstract
Natural killer (NK) cells provide essential protection against viral infections. One of the defining features of this lymphocyte population is the expression of a wide array of variable cell surface stimulatory and inhibitory NK receptors (sNKR and iNKR, respectively). The iNKR are particularly important in terms of NK-cell education. As receptors specific for MHC class I (MHC I) molecules, they are responsible for self-tolerance and adjusting NK-cell reactivity based on the expression level of self-MHC I. The end result of this education is twofold: (1) inhibitory signaling tunes the functional capacity of the NK cell, endowing greater potency with greater education, and (2) education on self allows the NK cell to detect aberrations in MHC I expression, a common occurrence during many viral infections. Many studies have indicated an important role for iNKR and MHC I in disease, making these receptors attractive targets for manipulating NK-cell reactivity in the clinic. A greater understanding of iNKR and their ability to regulate NK cells will provide a basis for future attempts at translating their potential utility into benefits for human health.
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Affiliation(s)
- William T Nash
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Jeffrey Teoh
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Hairong Wei
- Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Division of Nephrology, Department of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Awndre Gamache
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Michael G Brown
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Division of Nephrology, Department of Medicine, University of Virginia , Charlottesville, VA , USA
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42
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Li Y, Mariuzza RA. Structural basis for recognition of cellular and viral ligands by NK cell receptors. Front Immunol 2014; 5:123. [PMID: 24723923 PMCID: PMC3972465 DOI: 10.3389/fimmu.2014.00123] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 03/10/2014] [Indexed: 11/13/2022] Open
Abstract
Natural killer (NK) cells are key components of innate immune responses to tumors and viral infections. NK cell function is regulated by NK cell receptors that recognize both cellular and viral ligands, including major histocompatibility complex (MHC), MHC-like, and non-MHC molecules. These receptors include Ly49s, killer immunoglobulin-like receptors, leukocyte immunoglobulin-like receptors, and NKG2A/CD94, which bind MHC class I (MHC-I) molecules, and NKG2D, which binds MHC-I paralogs such as the stress-induced proteins MICA and ULBP. In addition, certain viruses have evolved MHC-like immunoevasins, such as UL18 and m157 from cytomegalovirus, that act as decoy ligands for NK receptors. A growing number of NK receptor–ligand interaction pairs involving non-MHC molecules have also been identified, including NKp30–B7-H6, killer cell lectin-like receptor G1–cadherin, and NKp80–AICL. Here, we describe crystal structures determined to date of NK cell receptors bound to MHC, MHC-related, and non-MHC ligands. Collectively, these structures reveal the diverse solutions that NK receptors have developed to recognize these molecules, thereby enabling the regulation of NK cytolytic activity by both host and viral ligands.
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Affiliation(s)
- Yili Li
- W. M. Keck Laboratory for Structural Biology, Institute for Bioscience and Biotechnology Research, University of Maryland , Rockville, MD , USA ; Department of Cell Biology and Molecular Genetics, University of Maryland , College Park, MD , USA
| | - Roy A Mariuzza
- W. M. Keck Laboratory for Structural Biology, Institute for Bioscience and Biotechnology Research, University of Maryland , Rockville, MD , USA ; Department of Cell Biology and Molecular Genetics, University of Maryland , College Park, MD , USA
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43
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Berry R, Rossjohn J, Brooks AG. The Ly49 natural killer cell receptors: a versatile tool for viral self‐discrimination. Immunol Cell Biol 2014; 92:214-20. [DOI: 10.1038/icb.2013.100] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/10/2013] [Indexed: 12/16/2022]
Affiliation(s)
- Richard Berry
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash UniversityClaytonVictoriaAustralia
| | - Jamie Rossjohn
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash UniversityClaytonVictoriaAustralia
- Institute of Infection and Immunity, School of Medicine, Cardiff UniversityCardiffUK
| | - Andrew G Brooks
- Department of Microbiology and Immunology, University of MelbourneParkvilleVictoriaAustralia
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Mickiewicz KM, Gays F, Lewis RJ, Brooks CG. Mutagenesis of Ly49B reveals key structural elements required for promiscuous binding to MHC class I molecules and new insights into the molecular evolution of Ly49s. THE JOURNAL OF IMMUNOLOGY 2014; 192:1558-69. [PMID: 24403531 DOI: 10.4049/jimmunol.1301643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ly49B is a potentially important immunoregulator expressed on mouse myeloid cells, and it is thus an unusual member of the wider Ly49 family whose members are ordinarily found on NK cells. Ly49B displays substantial sequence divergence from other Ly49s and in particular shares virtually no amino acid sequence identity with the residues that have been reported to bind to MHC class I (cI) ligands in other Ly49s. Despite this, we show in this study that the BALB/c, but not the C57, isoform of Ly49B displays promiscuous cI binding. Binding was not significantly affected by inactivation of any of the four predicted N-linked glycosylation sites of Ly49B, nor was it affected by removal of the unique 20-aa C-terminal extension found in Ly49B. However, transfer of these C-terminal 20 aa to Ly49A inhibited cI binding, as did the addition of a hemagglutinin tag to the C terminus of Ly49B, demonstrating unexpectedly that the C-terminal region of Ly49s can play a significant role in ligand binding. Systematic exchange of BALB/c and C57 residues revealed that Trp(166), Asn(167), and Cys(251) are of major importance for cI binding in Ly49B. These residues are highly conserved in the Ly49 family. Remarkably, however, Ly49B(BALB) variants that have C57 residues at positions 166 or 167, and are unable to bind cI multimers, regain substantial cI binding when amino acid changes are made at distal positions, providing an explanation of how highly divergent Ly49s that retain the ability to bind cI molecules might have evolved.
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Affiliation(s)
- Katarzyna M Mickiewicz
- Institute of Cell and Molecular Biosciences, University of Newcastle, Newcastle NE2 4HH, United Kingdom
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45
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Romasanta PN, Curto LM, Urtasun N, Sarratea MB, Chiappini S, Miranda MV, Delfino JM, Mariuzza RA, Fernández MM, Malchiodi EL. A positive cooperativity binding model between Ly49 natural killer cell receptors and the viral immunoevasin m157: kinetic and thermodynamic studies. J Biol Chem 2013; 289:5083-96. [PMID: 24379405 DOI: 10.1074/jbc.m113.532929] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Natural killer (NK) cells discriminate between healthy and virally infected or transformed cells using diverse surface receptors that are both activating and inhibitory. Among them, the homodimeric Ly49 NK receptors, which can adopt two distinct conformations (backfolded and extended), are of particular importance for detecting cells infected with mouse cytomegalovirus (CMV) via recognition of the viral immunoevasin m157. The interaction of m157 with activating (Ly49H) and inhibitory (Ly49I) receptors governs the spread of mouse CMV. We carried out kinetic and thermodynamic experiments to elucidate the Ly49/m157 binding mechanism. Combining surface plasmon resonance, fluorescence anisotropy, and circular dichroism (CD), we determined that the best model to describe both the Ly49H/m157 and Ly49I/m157 interactions is a conformational selection mechanism where only the extended conformation of Ly49 (Ly49*) is able to bind the first m157 ligand followed by binding of the Ly49*/m157 complex to the second m157. The interaction is characterized by strong positive cooperativity such that the second m157 binds the Ly49 homodimer with a 1000-fold higher sequential constant than the first m157 (∼10(8) versus ∼10(5) M(-1)). Using far-UV CD, we obtained evidence for a conformational change in Ly49 upon binding m157 that could explain the positive cooperativity. The rate-limiting step of the overall mechanism is a conformational transition in Ly49 from its backfolded to extended form. The global thermodynamic parameters from the initial state (backfolded Ly49 and m157) to the final state (Ly49*/(m157)2) are characterized by an unfavorable enthalpy that is compensated by a favorable entropy, making the interaction spontaneous.
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Affiliation(s)
- Pablo N Romasanta
- From the Cátedra de Inmunología and Instituto de Estudios de la Inmunidad Humoral (IDEHU), Consejo Nacional de Investigaciones Científicas y técnicas - Universidad de Buenos Aires (CONICET-UBA) and
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46
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Carlin LE, Guseva NV, Shey MR, Ballas ZK, Heusel JW. The Glycophosphatidylinositol Anchor of the MCMV Evasin, m157, Facilitates Optimal Cell Surface Expression and Ly49 Receptor Recognition. PLoS One 2013; 8:e67295. [PMID: 23840655 PMCID: PMC3686720 DOI: 10.1371/journal.pone.0067295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 05/17/2013] [Indexed: 11/18/2022] Open
Abstract
The murine cytomegalovirus-encoded protein m157 is a cognate ligand for both inhibitory and activating receptors expressed by natural killer cells. Additionally, m157 is expressed on the surface of infected cells by a glycophosphatidylinositol (GPI) anchor. Although endogenous GPI-anchored proteins are known to be ligands for the NK cell receptor, NKG2D, the contribution of the GPI anchor for viral m157 ligand function is unknown. To determine whether the GPI anchor for m157 is dispensable for m157 function, we generated m157 variants expressed as transmembrane fusion proteins and tested cells expressing transmembrane m157 for the capacity to activate cognate Ly49 receptors. We found that the GPI anchor is required for high-level cell surface expression of m157, and that the transmembrane m157 ligand retains the capacity to activate reporter cells and NK cells expressing Ly49H, as well as Ly49I(129) reporter cells, but with reduced potency. Importantly, target cells expressing the transmembrane form of m157 were killed less efficiently and failed to mediate Ly49H receptor downregulation on fresh NK cells compared to targets expressing GPI-anchored m157. Taken together, these results show that the GPI anchor for m157 facilitates robust cell surface expression, and that NK cells are sensitive to the altered cell surface expression of this potent viral evasin.
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Affiliation(s)
- Lindsey E. Carlin
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, Iowa, United States of America
- The Department of Pathology, University of Iowa, Iowa City, Iowa, United States of America
| | - Natalya V. Guseva
- The Department of Pathology, University of Iowa, Iowa City, Iowa, United States of America
| | - Michael R. Shey
- The Iowa City VA Medical Center, University of Iowa, Iowa City, Iowa, United States of America
| | - Zuhair K. Ballas
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, Iowa, United States of America
- The Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States of America
- The Iowa City VA Medical Center, University of Iowa, Iowa City, Iowa, United States of America
| | - Jonathan W. Heusel
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, Iowa, United States of America
- The Department of Pathology, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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47
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Targeting of a natural killer cell receptor family by a viral immunoevasin. Nat Immunol 2013; 14:699-705. [DOI: 10.1038/ni.2605] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 04/03/2013] [Indexed: 02/01/2023]
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Schenkel AR, Kingry LC, Slayden RA. The ly49 gene family. A brief guide to the nomenclature, genetics, and role in intracellular infection. Front Immunol 2013; 4:90. [PMID: 23596445 PMCID: PMC3627126 DOI: 10.3389/fimmu.2013.00090] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 04/04/2013] [Indexed: 12/19/2022] Open
Abstract
Understanding the Ly49 gene family can be challenging in terms of nomenclature and genetic organization. The Ly49 gene family has two major gene nomenclature systems, Ly49 and Killer Cell Lectin-like Receptor subfamily A (klra). Mice from different strains have varying numbers of these genes with strain specific allelic variants, duplications, deletions, and pseudogene sequences. Some members activate NK lymphocytes, invariant NKT (iNKT) lymphocytes and γδ T lymphocytes while others inhibit killing activity. One family member, Ly49Q, is expressed only on myeloid cells and is not found on NK, iNKT, or γδ T cells. There is growing evidence that these receptors may regulate not just the immune response to viruses, but other intracellular pathogens as well. Thus, this review’s primary goal is to provide a guide for researchers first encountering the Ly49 gene family and a foundation for future studies on the role that these gene products play in the immune response, particularly the response to intracellular viral and bacterial pathogens.
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Affiliation(s)
- Alan Rowe Schenkel
- Department of Microbiology, Immunology and Pathology, Colorado State University Fort Collins, CO, USA
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49
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Natural killer cell dependent within-host competition arises during multiple MCMV infection: consequences for viral transmission and evolution. PLoS Pathog 2013; 9:e1003111. [PMID: 23300458 PMCID: PMC3536701 DOI: 10.1371/journal.ppat.1003111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 11/18/2012] [Indexed: 11/18/2022] Open
Abstract
It is becoming increasingly clear that many diseases are the result of infection from multiple genetically distinct strains of a pathogen. Such multi-strain infections have the capacity to alter both disease and pathogen dynamics. Infection with multiple strains of human cytomegalovirus (HCMV) is common and has been linked to enhanced disease. Suggestions that disease enhancement in multi-strain infected patients is due to complementation have been supported by trans-complementation studies in mice during co-infection of wild type and gene knockout strains of murine CMV (MCMV). Complementation between naturally circulating strains of CMV has, however, not been assessed. In addition, many models of multi-strain infection predict that co-infecting strains will compete with each other and that this competition may contribute to selective transmission of more virulent pathogen strains. To assess the outcome of multi-strain infection, C57BL/6 mice were infected with up to four naturally circulating strains of MCMV. In this study, profound within-host competition was observed between co-infecting strains of MCMV. This competition was MCMV strain specific and resulted in the complete exclusion of certain strains of MCMV from the salivary glands of multi-strain infected mice. Competition was dependent on Ly49H+ natural killer (NK) cells as well as the expression of the ligand for Ly49H, the MCMV encoded product, m157. Strains of MCMV which expressed an m157 gene product capable of ligating Ly49H were outcompeted by strains of MCMV expressing variant m157 genes. Importantly, within-host competition prevented the shedding of the less virulent strains of MCMV, those recognized by Ly49H, into the saliva of multi-strain infected mice. These data demonstrate that NK cells have the strain specific recognition capacity required to meditate within-host competition between strains of MCMV. Furthermore, this within-host competition has the capacity to shape the dynamics of viral shedding and potentially select for the transmission of more virulent virus strains. Infection of the host with multiple strains of a pathogen is common and occurs with the herpesvirus, human cytomegalovirus (HCMV). However the effects of multi-strain infection on the host and the pathogen remain poorly studied. Here we show, in a mouse model, that infection of C57BL/6 mice with multiple strains of murine CMV (MCMV) results in profound within-host competition. Competition between the strains of MCMV is dependent on Ly49H+ natural killer (NK) cells. The NK cell activation receptor Ly49H receptor targets certain genotypes of the viral protein, m157. During multi-strain infection, strains of MCMV encoding an m157 capable of binding Ly49H are excluded from the salivary gland and the saliva of C57BL/6 mice, allowing for the shedding of only non-Ly49H binding strains of MCMV in the saliva. This within-host competition could therefore have significant impacts on the circulation of MCMV strains, as only the most virulent MCMV strains were present in the saliva.
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50
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Smith LM, McWhorter AR, Shellam GR, Redwood AJ. The genome of murine cytomegalovirus is shaped by purifying selection and extensive recombination. Virology 2012; 435:258-68. [PMID: 23107009 DOI: 10.1016/j.virol.2012.08.041] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 08/02/2012] [Accepted: 08/24/2012] [Indexed: 11/19/2022]
Abstract
The herpesvirus lifestyle results in a long-term interaction between host and invading pathogen, resulting in exquisite adaptation of virus to host. We have sequenced the genomes of nine strains of murine cytomegalovirus (a betaherpesvirus), isolated from free-living mice trapped at locations separated geographically and temporally. Despite this separation these genomes were found to have low levels of nucleotide variation. Of the more than 160 open reading frames, almost 90% had a dN/dS ratio of amino acid substitutions of less than 0.6, indicating the level of purifying selection on the coding potential of MCMV. Examination of selection acting on individual genes at the codon level however indicates some level of positive selection, with 0.03% of codons showing strong evidence for positive selection. Conversely, 1.3% of codons show strong evidence of purifying selection. Alignments of both genome sequences and coding regions suggested that high levels of recombination have shaped the MCMV genome.
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Affiliation(s)
- L M Smith
- School of Pathology and Laboratory Medicine, University of Western Australia, Australia
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