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Xie W, Bruce K, Belz GT, Farrell HE, Stevenson PG. Indirect CD4 + T cell protection against mouse gamma-herpesvirus infection via interferon gamma. J Virol 2024; 98:e0049324. [PMID: 38578092 PMCID: PMC11092340 DOI: 10.1128/jvi.00493-24] [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: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 04/06/2024] Open
Abstract
CD4+ T cells play a key role in γ-herpesvirus infection control. However, the mechanisms involved are unclear. Murine herpesvirus type 4 (MuHV-4) allows relevant immune pathways to be dissected experimentally in mice. In the lungs, it colonizes myeloid cells, which can express MHC class II (MHCII), and type 1 alveolar epithelial cells (AEC1), which lack it. Nevertheless, CD4+ T cells can control AEC1 infection, and this control depends on MHCII expression in myeloid cells. Interferon-gamma (IFNγ) is a major component of CD4+ T cell-dependent MuHV-4 control. Here, we show that the action of IFNγ is also indirect, as CD4+ T cell-mediated control of AEC1 infection depended on IFNγ receptor (IFNγR1) expression in CD11c+ cells. Indirect control also depended on natural killer (NK) cells. Together, the data suggest that the activation of MHCII+ CD11c+ antigen-presenting cells is key to the CD4+ T cell/NK cell protection axis. By contrast, CD8+ T cell control of AEC1 infection appeared to operate independently. IMPORTANCE CD4+ T cells are critical for the control of gamma-herpesvirus infection; they act indirectly, by recruiting natural killer (NK) cells to attack infected target cells. Here, we report that the CD4+ T cell/NK cell axis of gamma-herpesvirus control requires interferon-γ engagement of CD11c+ dendritic cells. This mechanism of CD4+ T cell control releases the need for the direct engagement of CD4+ T cells with virus-infected cells and may be a common strategy for host control of immune-evasive pathogens.
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Affiliation(s)
- Wanxiaojie Xie
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Kimberley Bruce
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Gabrielle T. Belz
- The University of Queensland Frazer Institute, Brisbane, Queensland, Australia
| | - Helen E. Farrell
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Philip G. Stevenson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
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Vragel G, Gomez BD, Kostelecky RE, Noell KS, Tseng A, Cohen S, Dalwadi M, Medina EM, Nail EA, Goodspeed A, Clambey ET, van Dyk LF. Murine Gammaherpesvirus 68 Efficiently Infects Myeloid Cells Resulting In An Atypical, Restricted Form Of Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.21.545948. [PMID: 37425871 PMCID: PMC10327065 DOI: 10.1101/2023.06.21.545948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The gammaherpesviruses (γHVs) establish a lifelong infection in their hosts, with the cellular outcome of infection intimately regulated by target cell type. Murine gammaherpesvirus 68 (MHV68), a small animal model of γHV infection, infects macrophages in vivo, resulting in a range of outcomes, from lytic replication to latent infection. Here, we have further investigated the nature of MHV68 macrophage infection using reductionist and primary in vivo infection studies. While MHV68 readily infected the J774 macrophage cell line, viral gene expression and replication were significantly impaired relative to a fully permissive fibroblast cell line. Lytic replication only occurred in a small subset of MHV68-infected J774 cells, despite the fact that these cells were fully competent to support lytic replication following pre-treatment with interleukin-4, a known potentiator of replication in macrophages. In parallel, we harvested virally-infected macrophages at 16 hours after MHV68 infection in vivo and analyzed gene expression by single cell RNA-sequencing. Among virally infected macrophages, only rare (0.25%) cells had lytic cycle gene expression, characterized by detection of multiple lytic cycle RNAs. In contrast, ~50% of virally-infected macrophages were characterized by expression of ORF75A, ORF75B and/or ORF75C, in the absence of other detectable viral RNAs. Selective transcription of the ORF75 locus also occurred in MHV68-infected J774 cells. In total, these studies indicate that MHV68 efficiently infects macrophages, with the majority of cells characterized by an atypical state of restricted viral transcription, and only rare cells undergoing lytic replication.
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Affiliation(s)
- Gabrielle Vragel
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Brittany D. Gomez
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Rachael E. Kostelecky
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Kyra S. Noell
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
- Department of Anesthesiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Ashley Tseng
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
- Department of Anesthesiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Shirli Cohen
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Manaal Dalwadi
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Eva M. Medina
- Department of Neurology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Elizabeth A. Nail
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Andrew Goodspeed
- Department of Pharmacology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
- University of Colorado Cancer Center, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Eric T. Clambey
- Department of Anesthesiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
| | - Linda F. van Dyk
- Department of Immunology and Microbiology, University of Colorado Denver | Anschutz Medical Campus, School of Medicine, Aurora, CO, 80045, USA
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Rex V, Zargari R, Stempel M, Halle S, Brinkmann MM. The innate and T-cell mediated immune response during acute and chronic gammaherpesvirus infection. Front Cell Infect Microbiol 2023; 13:1146381. [PMID: 37065193 PMCID: PMC10102517 DOI: 10.3389/fcimb.2023.1146381] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Immediately after entry into host cells, viruses are sensed by the innate immune system, leading to the activation of innate antiviral effector mechanisms including the type I interferon (IFN) response and natural killer (NK) cells. This innate immune response helps to shape an effective adaptive T cell immune response mediated by cytotoxic T cells and CD4+ T helper cells and is also critical for the maintenance of protective T cells during chronic infection. The human gammaherpesvirus Epstein-Barr virus (EBV) is a highly prevalent lymphotropic oncovirus that establishes chronic lifelong infections in the vast majority of the adult population. Although acute EBV infection is controlled in an immunocompetent host, chronic EBV infection can lead to severe complications in immunosuppressed patients. Given that EBV is strictly host-specific, its murine homolog murid herpesvirus 4 or MHV68 is a widely used model to obtain in vivo insights into the interaction between gammaherpesviruses and their host. Despite the fact that EBV and MHV68 have developed strategies to evade the innate and adaptive immune response, innate antiviral effector mechanisms still play a vital role in not only controlling the acute infection but also shaping an efficient long-lasting adaptive immune response. Here, we summarize the current knowledge about the innate immune response mediated by the type I IFN system and NK cells, and the adaptive T cell-mediated response during EBV and MHV68 infection. Investigating the fine-tuned interplay between the innate immune and T cell response will provide valuable insights which may be exploited to design better therapeutic strategies to vanquish chronic herpesviral infection.
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Affiliation(s)
- Viktoria Rex
- Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Razieh Zargari
- Institute of Immunology, Hannover Medical School, Hannover, Germany
| | - Markus Stempel
- Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany
- Virology and Innate Immunity Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Stephan Halle
- Institute of Immunology, Hannover Medical School, Hannover, Germany
- Institute of Clinical Chemistry, Hannover Medical School, Hannover, Germany
- *Correspondence: Stephan Halle, ; Melanie M. Brinkmann,
| | - Melanie M. Brinkmann
- Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany
- Virology and Innate Immunity Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
- *Correspondence: Stephan Halle, ; Melanie M. Brinkmann,
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Sylvester PA, Jondle CN, Schmalzriedt DL, Dittel BN, Tarakanova VL. T Cell-Specific STAT1 Expression Promotes Lytic Replication and Supports the Establishment of Gammaherpesvirus Latent Reservoir in Splenic B Cells. mBio 2022; 13:e0210722. [PMID: 35968944 PMCID: PMC9430880 DOI: 10.1128/mbio.02107-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 11/30/2022] Open
Abstract
Gammaherpesviruses establish lifelong infections in most vertebrate species, including humans and rodents, and are associated with cancers, including B cell lymphomas. While type I and II interferon (IFN) systems of the host are critical for the control of acute and chronic gammaherpesvirus infection, the cell type-specific role(s) of IFN signaling during infection is poorly understood and is often masked by the profoundly altered viral pathogenesis in the hosts with global IFN deficiencies. STAT1 is a critical effector of all classical IFN responses along with its involvement in other cytokine signaling pathways. In this study, we defined the effect of T cell-specific STAT1 deficiency on the viral and host parameters of infection with murine gammaherpesvirus 68 (MHV68). MHV68 is a natural rodent pathogen that, similar to human gammaherpesviruses, manipulates and usurps B cell differentiation to establish a lifelong latent reservoir in B cells. Specifically, germinal center B cells host the majority of latent MHV68 reservoir in the lymphoid organs, particularly at the peak of viral latency. Unexpectedly, T cell-specific STAT1 expression, while limiting the overall expansion of the germinal center B cell population during chronic infection, rendered these B cells more effective at hosting the latent virus reservoir. Further, T cell-specific STAT1 expression in a wild type host limited circulating levels of IFNγ, with corresponding increases in lytic MHV68 replication and viral reactivation. Thus, our study unveils an unexpected proviral role of T cell-specific STAT1 expression during gammaherpesvirus infection of a natural intact host. IMPORTANCE Interferons (IFNs) represent a major antiviral host network vital to the control of multiple infections, including acute and chronic gammaherpesvirus infections. Ubiquitously expressed STAT1 plays a critical effector role in all classical IFN responses. This study utilized a mouse model of T cell-specific STAT1 deficiency to define cell type-intrinsic role of STAT1 during natural gammaherpesvirus infection. Unexpectedly, T cell-specific loss of STAT1 led to better control of acute and persistent gammaherpesvirus replication and decreased establishment of latent viral reservoir in B cells, revealing a surprisingly diverse proviral role of T cell-intrinsic STAT1.
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Affiliation(s)
- P. A. Sylvester
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - C. N. Jondle
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - D. L. Schmalzriedt
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - B. N. Dittel
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Versiti Blood Research Institute, Milwaukee, Wisconsin, USA
| | - V. L. Tarakanova
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Cancer Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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5
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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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Brar G, Farhat NA, Sukhina A, Lam AK, Kim YH, Hsu T, Tong L, Lin WW, Ware CF, Blackman MA, Sun R, Wu TT. Deletion of immune evasion genes provides an effective vaccine design for tumor-associated herpesviruses. NPJ Vaccines 2020; 5:102. [PMID: 33298958 PMCID: PMC7644650 DOI: 10.1038/s41541-020-00251-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 10/02/2020] [Indexed: 12/13/2022] Open
Abstract
Vaccines based on live attenuated viruses often induce broad, multifaceted immune responses. However, they also usually sacrifice immunogenicity for attenuation. It is particularly difficult to elicit an effective vaccine for herpesviruses due to an armament of immune evasion genes and a latent phase. Here, to overcome the limitation of attenuation, we developed a rational herpesvirus vaccine in which viral immune evasion genes were deleted to enhance immunogenicity while also attaining safety. To test this vaccine strategy, we utilized murine gammaherpesvirus-68 (MHV-68) as a proof-of-concept model for the cancer-associated human γ-herpesviruses, Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus. We engineered a recombinant MHV-68 virus by targeted inactivation of viral antagonists of type I interferon (IFN-I) pathway and deletion of the latency locus responsible for persistent infection. This recombinant virus is highly attenuated with no measurable capacity for replication, latency, or persistence in immunocompetent hosts. It stimulates robust innate immunity, differentiates virus-specific memory T cells, and elicits neutralizing antibodies. A single vaccination affords durable protection that blocks the establishment of latency following challenge with the wild type MHV-68 for at least six months post-vaccination. These results provide a framework for effective vaccination against cancer-associated herpesviruses through the elimination of latency and key immune evasion mechanisms from the pathogen.
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Affiliation(s)
- Gurpreet Brar
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Nisar A Farhat
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Alisa Sukhina
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Alex K Lam
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Yong Hoon Kim
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Tiffany Hsu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Leming Tong
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Wai Wai Lin
- Laboratory of Molecular Immunology, Infectious and Inflammatory Diseases Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Carl F Ware
- Laboratory of Molecular Immunology, Infectious and Inflammatory Diseases Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | | | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA
| | - Ting-Ting Wu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, 90095, USA.
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7
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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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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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Lawler C, Simas JP, Stevenson PG. Vaccine protection against murid herpesvirus-4 is maintained when the priming virus lacks known latency genes. Immunol Cell Biol 2019; 98:67-78. [PMID: 31630452 DOI: 10.1111/imcb.12299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/13/2019] [Accepted: 10/16/2019] [Indexed: 11/30/2022]
Abstract
γ-Herpesviruses establish latent infections of lymphocytes and drive their proliferation, causing cancers and motivating a search for vaccines. Effective vaccination against murid herpesvirus-4 (MuHV-4)-driven lymphoproliferation by latency-impaired mutant viruses suggests that lytic access to the latency reservoir is a viable target for control. However, the vaccines retained the immunogenic MuHV-4 M2 latency gene. Here, a strong reduction in challenge virus load was maintained when the challenge virus lacked the main latency-associated CD8+ T-cell epitope of M2, or when the vaccine virus lacked M2 entirely. This protection was maintained also when the vaccine virus lacked both episome maintenance and the genomic region encompassing M1, M2, M3, M4 and ORF4. Therefore, protection did not require immunity to known MuHV-4 latency genes. As the remaining vaccine virus genes have clear homologs in human γ-herpesviruses, this approach of deleting viral latency genes could also be applied to them, to generate safe and effective vaccines against human disease.
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Affiliation(s)
- Clara Lawler
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - João Pedro Simas
- Instituto de Medicina Molecular, Universidade de Lisboa, Lisboa, Portugal
| | - Philip G Stevenson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia.,Royal Children's Hospital, Brisbane, QLD, Australia
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A Human STAT1 Gain-of-Function Mutation Impairs CD8 + T Cell Responses against Gammaherpesvirus 68. J Virol 2019; 93:JVI.00307-19. [PMID: 31315996 DOI: 10.1128/jvi.00307-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/05/2019] [Indexed: 01/14/2023] Open
Abstract
Autosomal dominant STAT1 mutations in humans have been associated with chronic mucocutaneous candidiasis (CMC), as well as with increased susceptibility to herpesvirus infections. Prior studies have focused on mucosal and Th17-mediated immunity against Candida, but mechanisms of impaired antiviral immunity have not previously been examined. To begin to explore the mechanisms of STAT1-associated immunodeficiency against herpesviruses, we generated heterozygous STAT1 R274W knock-in mice that have a frequently reported STAT1 mutation associated in humans with susceptibility to herpesvirus infections. In primary macrophages and fibroblasts, we found that STAT1 R274W had no appreciable effect on cell-intrinsic immunity against herpes simplex virus 1 (HSV-1) or gammaherpesvirus 68 (γHV68) infection. However, intraperitoneal inoculation of mice with γHV68 was associated with impaired control of infection at day 14 in STAT1 R274W mice compared with that in wild-type (WT) littermate control animals. Infection of STAT1 R274W mice was associated with paradoxically decreased expression of IFN-stimulated genes (ISGs) and gamma interferon (IFN-γ), likely secondary to defective CD4+ and CD8+ T cell responses, including diminished numbers of antigen-specific CD8+ T cells. Viral pathogenesis studies in WT and STAT1 R274W mixed bone marrow chimeric mice revealed that the presence of WT leukocytes was sufficient to limit infection and that antigen-specific STAT1 R274W CD8+ T cell responses were impaired even in the presence of WT leukocytes. Thus, in addition to regulating Th17 responses against Candida, a STAT1 gain-of-function mutant impedes antigen-specific T cell responses against a common gammaherpesvirus in mice.IMPORTANCE Mechanisms of immunodeficiency related to STAT1 gain of function have not been previously studied in an animal model of viral pathogenesis. Using virological and immunological techniques, we examined the immune response to γHV68 in heterozygous mice that have an autosomal dominant mutation in the STAT1 coiled-coil domain (STAT1 R274W). We observed impaired control of infection, which was associated with diminished production of gamma interferon (IFN-γ), fewer effector CD4+ and CD8+ T cells, and a reduction in the number of antigen-specific CD8+ T cells. These findings indicate that a STAT1 gain-of-function mutation limits production of antiviral T cells, likely contributing to immunodeficiency against herpesviruses.
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11
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Abstract
Vaccination against γ-herpesviruses has been hampered by our limited understanding of their normal control. Epstein–Barr virus (EBV)-transformed B cells are killed by viral latency antigen-specific CD8+ T cells in vitro, but attempts to block B cell infection with antibody or to prime anti-viral CD8+ T cells have protected poorly in vivo. The Doherty laboratory used Murid Herpesvirus-4 (MuHV-4) to analyze γ-herpesvirus control in mice and found CD4+ T cell dependence, with viral evasion limiting CD8+ T cell function. MuHV-4 colonizes germinal center (GC) B cells via lytic transfer from myeloid cells, and CD4+ T cells control myeloid infection. GC colonization and protective, lytic antigen-specific CD4+ T cells are now evident also for EBV. Subunit vaccines have protected only transiently against MuHV-4, but whole virus vaccines give long-term protection, via CD4+ T cells and antibody. They block infection transfer to B cells, and need include no known viral latency gene, nor any MuHV-4-specific gene. Thus, the Doherty approach of in vivo murine analysis has led to a plausible vaccine strategy for EBV and, perhaps, some insight into what CD8+ T cells really do.
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Affiliation(s)
- Philip G Stevenson
- School of Chemistry and Molecular Biosciences, University of Queensland and Brisbane, Australia.,Child Health Research Center, Brisbane, Australia
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12
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A Human Gain-of-Function STING Mutation Causes Immunodeficiency and Gammaherpesvirus-Induced Pulmonary Fibrosis in Mice. J Virol 2019; 93:JVI.01806-18. [PMID: 30463976 DOI: 10.1128/jvi.01806-18] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/15/2018] [Indexed: 12/11/2022] Open
Abstract
We previously generated STING N153S knock-in mice that have a human disease-associated gain-of-function mutation in STING. Patients with this mutation (STING N154S in humans) develop STING-associated vasculopathy with onset in infancy (SAVI), a severe pediatric autoinflammatory disease characterized by pulmonary fibrosis. Since this mutation promotes the upregulation of antiviral type I interferon-stimulated genes (ISGs), we hypothesized that STING N153S knock-in mice may develop more severe autoinflammatory disease in response to a virus challenge. To test this hypothesis, we infected heterozygous STING N153S mice with murine gammaherpesvirus 68 (γHV68). STING N153S mice were highly vulnerable to infection and developed pulmonary fibrosis after infection. In addition to impairing CD8+ T cell responses and humoral immunity, STING N153S also promoted the replication of γHV68 in cultured macrophages. In further support of a combined innate and adaptive immunodeficiency, γHV68 infection was more severe in Rag1-/- STING N153S mice than in Rag1-/- littermate mice, which completely lack adaptive immunity. Thus, a gain-of-function STING mutation creates a combined innate and adaptive immunodeficiency that leads to virus-induced pulmonary fibrosis.IMPORTANCE A variety of human rheumatologic disease-causing mutations have recently been identified. Some of these mutations are found in viral nucleic acid-sensing proteins, but whether viruses can influence the onset or progression of these human diseases is less well understood. One such autoinflammatory disease, called STING-associated vasculopathy with onset in infancy (SAVI), affects children and leads to severe lung disease. We generated mice with a SAVI-associated STING mutation and infected them with γHV68, a common DNA virus that is related to human Epstein-Barr virus. Mice with the human disease-causing STING mutation were more vulnerable to infection than wild-type littermate control animals. Furthermore, the STING mutant mice developed lung fibrosis similar to that of patients with SAVI. These findings reveal that a human STING mutation creates severe immunodeficiency, leading to virus-induced lung disease in mice.
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Helminth-induced IL-4 expands bystander memory CD8 + T cells for early control of viral infection. Nat Commun 2018; 9:4516. [PMID: 30375396 PMCID: PMC6207712 DOI: 10.1038/s41467-018-06978-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/05/2018] [Indexed: 12/26/2022] Open
Abstract
Infection with parasitic helminths can imprint the immune system to modulate bystander inflammatory processes. Bystander or virtual memory CD8+ T cells (TVM) are non-conventional T cells displaying memory properties that can be generated through responsiveness to interleukin (IL)-4. However, it is not clear if helminth-induced type 2 immunity functionally affects the TVM compartment. Here, we show that helminths expand CD44hiCD62LhiCXCR3hiCD49dlo TVM cells through direct IL-4 signaling in CD8+ T cells. Importantly, helminth-mediated conditioning of TVM cells provided enhanced control of acute respiratory infection with the murid gammaherpesvirus 4 (MuHV-4). This enhanced control of MuHV-4 infection could further be explained by an increase in antigen-specific CD8+ T cell effector responses in the lung and was directly dependent on IL-4 signaling. These results demonstrate that IL-4 during helminth infection can non-specifically condition CD8+ T cells, leading to a subsequently raised antigen-specific CD8+ T cell activation that enhances control of viral infection. Parasitic helminth infection is known to impact upon the host response to other bystander inflammatory processes. Here the authors show that IL4 production induced by helminth infection results in expansion of bystander CD8+ memory T cells and enhanced control to viral infection.
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Gammaherpesvirus Colonization of the Spleen Requires Lytic Replication in B Cells. J Virol 2018; 92:JVI.02199-17. [PMID: 29343572 DOI: 10.1128/jvi.02199-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 01/09/2018] [Indexed: 11/20/2022] Open
Abstract
Gammaherpesviruses infect lymphocytes and cause lymphocytic cancers. Murid herpesvirus-4 (MuHV-4), Epstein-Barr virus, and Kaposi's sarcoma-associated herpesvirus all infect B cells. Latent infection can spread by B cell recirculation and proliferation, but whether this alone achieves systemic infection is unclear. To test the need of MuHV-4 for lytic infection in B cells, we flanked its essential ORF50 lytic transactivator with loxP sites and then infected mice expressing B cell-specific Cre (CD19-Cre). The floxed virus replicated normally in Cre- mice. In CD19-Cre mice, nasal and lymph node infections were maintained; but there was little splenomegaly, and splenic virus loads remained low. Cre-mediated removal of other essential lytic genes gave a similar phenotype. CD19-Cre spleen infection by intraperitoneal virus was also impaired. Therefore, MuHV-4 had to emerge lytically from B cells to colonize the spleen. An important role for B cell lytic infection in host colonization is consistent with the large CD8+ T cell responses made to gammaherpesvirus lytic antigens during infectious mononucleosis and suggests that vaccine-induced immunity capable of suppressing B cell lytic infection might reduce long-term virus loads.IMPORTANCE Gammaherpesviruses cause B cell cancers. Most models of host colonization derive from cell cultures with continuous, virus-driven B cell proliferation. However, vaccines based on these models have worked poorly. To test whether proliferating B cells suffice for host colonization, we inactivated the capacity of MuHV-4, a gammaherpesvirus of mice, to reemerge from B cells. The modified virus was able to colonize a first wave of B cells in lymph nodes but spread poorly to B cells in secondary sites such as the spleen. Consequently, viral loads remained low. These results were consistent with virus-driven B cell proliferation exploiting normal host pathways and thus having to transfer lytically to new B cells for new proliferation. We conclude that viral lytic infection is a potential target to reduce B cell proliferation.
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Murine cytomegalovirus degrades MHC class II to colonize the salivary glands. PLoS Pathog 2018; 14:e1006905. [PMID: 29447285 PMCID: PMC5831752 DOI: 10.1371/journal.ppat.1006905] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/28/2018] [Accepted: 01/24/2018] [Indexed: 12/24/2022] Open
Abstract
Cytomegaloviruses (CMVs) persistently and systemically infect the myeloid cells of immunocompetent hosts. Persistence implies immune evasion, and CMVs evade CD8+ T cells by inhibiting MHC class I-restricted antigen presentation. Myeloid cells can also interact with CD4+ T cells via MHC class II (MHC II). Human CMV (HCMV) attacks the MHC II presentation pathway in vitro, but what role this evasion might play in host colonization is unknown. We show that Murine CMV (MCMV) down-regulates MHC II via M78, a multi-membrane spanning viral protein that captured MHC II from the cell surface and was necessary although not sufficient for its degradation in low pH endosomes. M78-deficient MCMV down-regulated MHC I but not MHC II. After intranasal inoculation, it showed a severe defect in salivary gland colonization that was associated with increased MHC II expression on infected cells, and was significantly rescued by CD4+ T cell loss. Therefore MCMV requires CD4+ T cell evasion by M78 to colonize the salivary glands, its main site of long-term shedding. Human cytomegalovirus is the commonest infectious cause of harm to unborn children. Vaccines have not stopped it establishing chronic, systemic infections. Murine cytomegalovirus (MCMV) provides an accessible model to understand why. We show that MCMV evades CD4+ T cells via its M78 protein, and that this helps infection to spread despite the immune response. Thus while CD4+ T cells are important for host defence, viral evasion limits their capacity to act alone in controlling infection.
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