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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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Wang Y, Tibbetts SA, Krug LT. Conquering the Host: Determinants of Pathogenesis Learned from Murine Gammaherpesvirus 68. Annu Rev Virol 2021; 8:349-371. [PMID: 34586873 PMCID: PMC9153731 DOI: 10.1146/annurev-virology-011921-082615] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Gammaherpesviruses are an important class of oncogenic pathogens that are exquisitely evolved to their respective hosts. As such, the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV) do not naturally infect nonhuman primates or rodents. There is a clear need to fully explore mechanisms of gammaherpesvirus pathogenesis, host control, and immune evasion in the host. A gammaherpesvirus pathogen isolated from murid rodents was first reported in 1980; 40 years later, murine gammaherpesvirus 68 (MHV68, MuHV-4, γHV68) infection of laboratory mice is a well-established pathogenesis system recognized for its utility in applying state-of-the-art approaches to investigate virus-host interactions ranging from the whole host to the individual cell. Here, we highlight recent advancements in our understanding of the processes by which MHV68 colonizes the host and drives disease. Lessons that inform KSHV and EBV pathogenesis and provide future avenues for novel interventions against infection and virus-associated cancers are emphasized.
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Affiliation(s)
- Yiping Wang
- Department of Molecular Genetics and Microbiology, UF Health Cancer Center, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Scott A Tibbetts
- Department of Molecular Genetics and Microbiology, UF Health Cancer Center, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Laurie T Krug
- HIV and AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA;
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Nguyen-Robertson C, Haque A, Mintern J, La Flamme AC. COVID-19: searching for clues among other respiratory viruses. Immunol Cell Biol 2020; 98:247-250. [PMID: 32319148 DOI: 10.1111/imcb.12336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 03/30/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Catriona Nguyen-Robertson
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Ashraful Haque
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Justine Mintern
- Department of Biochemistry and Molecular Biology, The University of Melbourne, VIC, Melbourne, Australia
| | - Anne C La Flamme
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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Yunis J, Redwood AJ, Belz GT, Stevenson PG. Membrane association of a model CD4 + T-cell vaccine antigen confers enhanced yet incomplete protection against murid herpesvirus-4 infection. Immunol Cell Biol 2020; 98:332-343. [PMID: 31997396 DOI: 10.1111/imcb.12319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/20/2020] [Accepted: 01/27/2020] [Indexed: 12/14/2022]
Abstract
Vaccination against γ-herpesviruses has proved difficult. CD4+ T cells are essential to contain infection, but how best to prime them and whether this can reduce viral loads remain unclear. To address these questions, we used ovalbumin (OVA) as a model antigen, delivering it with murine cytomegalovirus (MCMV) to protect mice against OVA-expressing murine herpesvirus-4 (MuHV-4). Membrane-associated OVA (mOVA) was more effective than soluble OVA, both to prime CD4+ T cells and as an effector target. It was also a better target than an OVA epitope limited to infected cells, suggesting that protective CD4+ T cells recognize infected cell debris rather than infected cells themselves. While MCMV-mOVA protected acutely against MuHV-4-mOVA, long-term protection was incomplete, even when OVA-specific CD8+ T cells and B cells were also primed. Thus, even optimized single-target vaccines may poorly reduce long-term γ-herpesvirus infections.
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Affiliation(s)
- Joseph Yunis
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Alec J Redwood
- Faculty of Health and Medical Sciences, University of Western Australia, Perth, WA, Australia
| | - Gabrielle T Belz
- Molecular Immunology, Walter and Eliza Hall Institute, Melbourne, VIC, Australia
| | - Philip G Stevenson
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
- Royal Children's Hospital, Brisbane, QLD, Australia
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Lawler C, Stevenson PG. Limited protection against γ-herpesvirus infection by replication-deficient virus particles. J Gen Virol 2020; 101:420-425. [PMID: 31985394 DOI: 10.1099/jgv.0.001391] [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] [Indexed: 12/13/2022] Open
Abstract
The γ-herpesviruses have proved hard to vaccination against, with no convincing protection against long-term latent infection by recombinant viral subunits. In experimental settings, whole-virus vaccines have proved more effective, even when the vaccine virus itself establishes latent infection poorly. The main alternative is replication-deficient virus particles. Here high-dose, replication-deficient murid herpesvirus-4 only protected mice partially against wild-type infection. By contrast, latency-deficient but replication-competent vaccine protected mice strongly, even when delivered non-invasively to the olfactory epithelium. Thus, this approach seems to provide the best chance of a safe and effective γ-herpesvirus vaccine.
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Affiliation(s)
- Clara Lawler
- Present address: School of Biochemistry and Immunology, Trinity College, Dublin, Ireland.,School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Philip G Stevenson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia.,Child Health Research Center, University of Queensland, South Brisbane, Australia
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Samreen B, Tao S, Tischer K, Adler H, Drexler I. ORF6 and ORF61 Expressing MVA Vaccines Impair Early but Not Late Latency in Murine Gammaherpesvirus MHV-68 Infection. Front Immunol 2019; 10:2984. [PMID: 31921215 PMCID: PMC6930802 DOI: 10.3389/fimmu.2019.02984] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/05/2019] [Indexed: 01/02/2023] Open
Abstract
Gammaherpesviruses (γHV) are important pathogens causing persistent infections which lead to several malignancies in immunocompromised patients. Murine γHV 68 (MHV-68), a homolog to human EBV and KSHV, has been employed as a classical pathogen to investigate the molecular pathogenicity of γHV infections. γHV express distinct antigens during lytic or latent infection and antigen-specific T cells have a significant role in controlling the acute and latent viral infection, although the quality of anti-viral T cell responses required for protective immunity is not well-understood. We have generated recombinant modified vaccinia virus Ankara (recMVA) vaccines via MVA-BAC homologous recombination technology expressing MHV-68 ORF6 and ORF61 antigens encoding both MHC class I and II-restricted epitopes. After vaccination, we examined T cell responses before and after MHV-68 infection to determine their involvement in latent virus control. We show recognition of recMVA- and MHV-68-infected APC by ORF6 and ORF61 epitope-specific T cell lines in vitro. The recMVA vaccines efficiently induced MHV-68-specific CD8+ and CD4+ T cell responses after a single immunization and more pronounced after homologous prime/boost vaccination in mice. Moreover, we exhibit protective capacity of prophylactic recMVA vaccination during early latency at day 17 after intranasal challenge with MHV-68, but failed to protect from latency at day 45. Further T cell analysis indicated that T cell exhaustion was not responsible for the lack of protection by recMVA vaccination in long-term latency at day 45. The data support further efforts aiming at improved vaccine development against γHV infections with special focus on targeting protective CD4+ T cell responses.
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Affiliation(s)
- Baila Samreen
- Institute for Virology, Düsseldorf University Hospital, Heinrich-Heine-University, Düsseldorf, Germany.,Department of Oncology-Pathology, Science for Life Laboratory, Karolinska University Hospital, Stockholm, Sweden
| | - Sha Tao
- Institute for Virology, Düsseldorf University Hospital, Heinrich-Heine-University, Düsseldorf, Germany
| | - Karsten Tischer
- Fachbereich Veterinärmedizin, Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Heiko Adler
- Comprehensive Pneumology Center, Research Unit Lung Repair and Regeneration, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Member of the German Center of Lung Research (DZL), Munich, Germany
| | - Ingo Drexler
- Institute for Virology, Düsseldorf University Hospital, Heinrich-Heine-University, Düsseldorf, Germany
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