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Yang Y, Wang L, Peugnet-González I, Parada-Venegas D, Dijkstra G, Faber KN. cGAS-STING signaling pathway in intestinal homeostasis and diseases. Front Immunol 2023; 14:1239142. [PMID: 37781354 PMCID: PMC10538549 DOI: 10.3389/fimmu.2023.1239142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/18/2023] [Indexed: 10/03/2023] Open
Abstract
The intestinal mucosa is constantly exposed to commensal microbes, opportunistic pathogens, toxins, luminal components and other environmental stimuli. The intestinal mucosa consists of multiple differentiated cellular and extracellular components that form a critical barrier, but is also equipped for efficient absorption of nutrients. Combination of genetic susceptibility and environmental factors are known as critical components involved in the pathogenesis of intestinal diseases. The innate immune system plays a critical role in the recognition and elimination of potential threats by detecting pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). This host defense is facilitated by pattern recognition receptors (PRRs), in which the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway has gained attention due to its role in sensing host and foreign double-stranded DNA (dsDNA) as well as cyclic dinucleotides (CDNs) produced by bacteria. Upon binding with dsDNA, cGAS converts ATP and GTP to cyclic GMP-AMP (cGAMP), which binds to STING and activates TANK binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), inducing type I interferon (IFN) and nuclear factor kappa B (NF-κB)-mediated pro-inflammatory cytokines, which have diverse effects on innate and adaptive immune cells and intestinal epithelial cells (IECs). However, opposite perspectives exist regarding the role of the cGAS-STING pathway in different intestinal diseases. Activation of cGAS-STING signaling is associated with worse clinical outcomes in inflammation-associated diseases, while it also plays a critical role in protection against tumorigenesis and certain infections. Therefore, understanding the context-dependent mechanisms of the cGAS-STING pathway in the physiopathology of the intestinal mucosa is crucial for developing therapeutic strategies targeting the cGAS-STING pathway. This review aims to provide insight into recent findings of the protective and detrimental roles of the cGAS-STING pathway in intestinal diseases.
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Affiliation(s)
- Yuchen Yang
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Li Wang
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Ivonne Peugnet-González
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Daniela Parada-Venegas
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Gerard Dijkstra
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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Riggs JB, Medina EM, Perrenoud LJ, Bonilla DL, Clambey ET, van Dyk LF, Berg LJ. Optimized Detection of Acute MHV68 Infection With a Reporter System Identifies Large Peritoneal Macrophages as a Dominant Target of Primary Infection. Front Microbiol 2021; 12:656979. [PMID: 33767688 PMCID: PMC7985543 DOI: 10.3389/fmicb.2021.656979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Investigating the dynamics of virus-host interactions in vivo remains an important challenge, often limited by the ability to directly identify virally infected cells. Here, we utilize a beta-lactamase activated fluorescent substrate to identify primary targets of murine gammaherpesvirus 68 (MHV68) infection in the peritoneal cavity. By optimizing substrate and detection conditions, we were able to achieve multiparameter characterization of infected cells and the ensuing host response. MHV68 infection leads to a pronounced increase in immune cells, with CD8+ T cells increasing by 3 days, and total infiltrate peaking around 8 days post-infection. MHV68 infection results in near elimination of large peritoneal macrophages (LPMs) by 8 days post-infection, and a concordant increase in small peritoneal macrophages (SPMs) and monocytes. Infection is associated with prolonged changes to myeloid cells, with a distinct population of MHC IIhigh LPMs emerging by 14 days. Targets of MHV68 infection could be readily detected. Between 1 and 3 days post-infection, MHV68 infects ∼5–10% of peritoneal cells, with >75% being LPMs. By 8 days post-infection, the frequency of MHV68 infection is reduced at least 10-fold, with infection primarily in SPMs, with few infected dendritic cells and B cells. Importantly, limiting dilution analysis indicates that at 3 days post-infection, the majority of MHV68-infected cells harbor latent rather than lytic virus at frequencies consistent with those identified based on reporter gene expression. Our findings demonstrate the utility of the beta-lactamase MHV68 reporter system for high throughput single-cell analysis and identify dynamic changes during primary gammaherpesvirus infection.
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Affiliation(s)
- Julianne B Riggs
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Eva M Medina
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Loni J Perrenoud
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | | | - Eric T Clambey
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Linda F van Dyk
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Leslie J Berg
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Hennessy C, O'Connell S, Egan LJ, McKernan DP. Inhibition of anti-viral responses in intestinal epithelial cells by epigenetic modifying drugs is mediated by a reduction in viral pattern recognition receptor expression and activity. Immunopharmacol Immunotoxicol 2019; 41:527-537. [PMID: 31505962 DOI: 10.1080/08923973.2019.1661430] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 08/18/2019] [Indexed: 12/21/2022]
Abstract
Background: Pattern recognition receptors form an essential part of the host defenses against pathogens, in particular in the intestinal epithelium. However, despite their importance relatively little is understood about the regulation of their expression. Increasing evidence suggesting that epigenetic mechanisms such as DNA methylation and histone acetylation have substantial effects on gene expression and regulation. Epigenetic modifying drugs are now used to treat certain cancers but not a lot is known about their effects on the innate immune system. Thus, we set out to examine the role of such drugs in the expression and function of Toll-like receptors. Methods: Using the HCT116 epithelial cell line, we determined the effects of genetic knockout of the DNA methyltransferases enzymes (DNMTs), as well as pharmacological inhibition of the DNMTs and histone deacetylase complexes (HDACs) on TLR responses to their ligands. Results: Our initial results showed that anti-viral responses were affected by changes in the epigenome, with TLR3 responses showing the most dramatic differences. We determined that inhibition of methylation and acetylation inhibited poly I:C induced increases in signaling protein phosphorylation, as well as increases in cytokine mRNA expression and release. We also observed that treatment with epigenetic modifying drugs were leading to large increases in IRF8 expression, a protein that is a known negative regulator of TLR3. When we overexpressed IRF8 in our WT cells we noticed inhibition of poly I:C responses. Conclusion: This research highlighted the potential immunoregulatory role of epigenetic modifying drugs specifically in response to viral stimulation.
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Affiliation(s)
- Conor Hennessy
- Pharmacology & Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
| | - Sarah O'Connell
- Pharmacology & Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
| | - Laurence J Egan
- Pharmacology & Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
| | - Declan P McKernan
- Pharmacology & Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
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Cho HS, Reboldi A, Hall JA, Berg LJ. The Tec kinase ITK is essential for ILC2 survival and epithelial integrity in the intestine. Nat Commun 2019; 10:784. [PMID: 30770814 PMCID: PMC6377622 DOI: 10.1038/s41467-019-08699-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/22/2019] [Indexed: 02/06/2023] Open
Abstract
Innate lymphoid cells (ILC) are lymphocytes that lack an antigen-specific receptor and are preferentially localized in non-lymphoid tissues, such as mucosal barriers. In these locations ILC respond to tissue perturbations by producing factors that promote tissue repair and improve barrier integrity. We show that mice lacking the Tec kinase ITK have impaired intestinal tissue integrity, and a reduced ability to restore homeostasis after tissue damage. This defect is associated with a substantial loss of Type 2 ILC (ILC2) in the intestinal lamina propria. Adoptive transfer of bone marrow ILC2 precursors confirms a cell-intrinsic role for ITK. Intestinal ILC2 numbers in Itk-/- mice are restored by the administration of IL-2 complexes, also leading to improved intestinal tissue damage repair. Reduced Bcl-2 expression in intestinal Itk-/- ILC2 is also restored to WT levels after IL-2 complex treatment, indicating a tissue-specific role for ITK in ILC2 survival in the intestine.
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Affiliation(s)
- Hyoung-Soo Cho
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Andrea Reboldi
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Jason A Hall
- The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY, 10016, USA
| | - Leslie J Berg
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
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Bielefeldt-Ohmann H, Bruce AG, Howard K, Ikoma M, Thouless ME, Rose TM. Macaque homologs of Kaposi's sarcoma-associated herpesvirus (KSHV) infect germinal center lymphoid cells, epithelial cells in skin and gastrointestinal tract and gonadal germ cells in naturally infected macaques. Virology 2018; 519:106-120. [PMID: 29689462 DOI: 10.1016/j.virol.2018.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/12/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
We developed a set of rabbit antisera to characterize infections by the macaque RV2 rhadinovirus homologs of KSHV. We analyzed tissues from rhesus and pig-tailed macaques naturally infected with rhesus rhadinovirus (RRV) or Macaca nemestrina rhadinovirus 2 (MneRV2). Our study demonstrates that RV2 rhadinoviruses have a tropism for epithelial cells, lymphocytes and gonadal germ cells in vivo. We observed latent infections in both undifferentiated and differentiated epithelial cells with expression of the latency marker, LANA. Expression of the early (ORF59) and late (glycoprotein B) lytic markers were detected in highly differentiated cells in epithelial ducts in oral, renal, dermal and gastric mucosal tissue as well as differentiated germ cells in male and female gonads. Our data provides evidence that epithelial and germ cell differentiation in vivo induces rhadinovirus reactivation and suggests that infected epithelial and germ cells play a role in transmission and dissemination of RV2 rhadinovirus infections in vivo.
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Affiliation(s)
| | - A Gregory Bruce
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA; Department of Pathobiology, University of Washington, Seattle, WA, USA.
| | - Kellie Howard
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA; Department of Pathobiology, University of Washington, Seattle, WA, USA.
| | - Minako Ikoma
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.
| | | | - Timothy M Rose
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA; Department of Pathobiology, University of Washington, Seattle, WA, USA; Department of Pediatrics, University of Washington, Seattle, WA, USA.
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Dong S, Forrest JC, Liang X. Murine Gammaherpesvirus 68: A Small Animal Model for Gammaherpesvirus-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1018:225-236. [DOI: 10.1007/978-981-10-5765-6_14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Nelson DA, Chauhan VS, Tolbert MD, Bost KL. An expanded myeloid derived suppressor cell population does not play a role in gammaherpesvirus-exacerbated breast cancer metastases. Infect Agent Cancer 2012; 7:22. [PMID: 22946998 PMCID: PMC3464903 DOI: 10.1186/1750-9378-7-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 08/30/2012] [Indexed: 11/12/2022] Open
Abstract
Background Mice latently infected with murine gammaherpesvirus 68 (HV-68) and transplanted with 4 T1 breast cancer cells developed exacerbated metastatic lesions when compared to controls. The mechanisms responsible for this viral-exacerbated disease were not clear. The ability of HV-68 infection to induce S100A8 and S100A9 production and to expand a population of CD11b+Gr-1+ cells suggested that increased numbers, or activity, of viral-expanded myeloid derived suppressor cells (MDSCs) might contribute to HV-68-associated metastatic breast cancer in this model. We questioned whether mock or HV-68 infected mice with significant breast cancer might have differences in the number and/or activity of MDSCs. Methods Myeloid-derived macrophages and dendritic cells were isolated from normal mice and cultured in vitro with HV-68 to assess S100A8 and S100A9 mRNA and protein expression. In vivo studies were performed using groups of mice that were mock treated or infected with HV-68. After viral latency was established, 4 T1 breast cancer cells were transplanted in mice. When primary breast tumors were present mice were euthanized and cells isolated for phenotyping of myeloid cell populations using FACS, and for ex vivo analysis of suppressor activity. Serum from these animals was also collected to quantify S100A8 and S100A9 levels. Results In vitro studies demonstrated that direct exposure of myeloid cells to HV-68 did not induce increased expression of S100A8 or S100A9 mRNAs or secreted protein. HV-68 infected mice with metastatic breast cancer disease had no increases in S100A8/A9 levels and no significant increases in the numbers or activation of CD11b+Gr-1+MDSCs when compared to mock treated mice with breast cancer. Conclusions Together these studies are consistent with the notion that expanded myeloid derived suppressor cells do not play a role in gammaherpesvirus-exacerbated breast cancer metastases. The mechanisms responsible for HV-68 induced exacerbation of metastatic breast cancer remain unclear.
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Affiliation(s)
- Daniel A Nelson
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA.
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Characterization of omental immune aggregates during establishment of a latent gammaherpesvirus infection. PLoS One 2012; 7:e43196. [PMID: 22952645 PMCID: PMC3430671 DOI: 10.1371/journal.pone.0043196] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/20/2012] [Indexed: 12/24/2022] Open
Abstract
Herpesviruses are characterized by their ability to establish lifelong latent infection. The gammaherpesvirus subfamily is distinguished by lymphotropism, establishing and maintaining latent infection predominantly in B lymphocytes. Consequently, gammaherpesvirus pathogenesis is closely linked to normal B cell physiology. Murine gammaherpesvirus 68 (MHV68) pathogenesis in laboratory mice has been extensively studied as a model system to gain insights into the nature of gammaherpesvirus infection in B cells and their associated lymphoid compartments. In addition to B cells, MHV68 infection of macrophages contributes significantly to the frequency of viral genome-positive cells in the peritoneal cavity throughout latency. The omentum, a sheet of richly-vascularized adipose tissue, resides in the peritoneal cavity and contains clusters of immune cell aggregates termed milky spots. Although the value of the omentum in surgical wound-healing has long been appreciated, the unique properties of this tissue and its contribution to both innate and adaptive immunity have only recently been recognized. To determine whether the omentum plays a role in gammaherpesvirus pathogenesis we examined this site during early MHV68 infection and long-term latency. Following intraperitoneal infection, immune aggregates within the omentum expanded in size and number and contained virus-infected cells. Notably, a germinal-center B cell population appeared in the omentum of infected animals with earlier kinetics and greater magnitude than that observed in the spleen. Furthermore, the omentum harbored a stable frequency of viral genome-positive cells through early and into long-term latency, while removal of the omentum prior to infection resulted in a slight decrease in the establishment of splenic latency following intraperitoneal infection. These data provide the first evidence that the omentum is a site of chronic MHV68 infection that may contribute to the maintenance of chronic infection.
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Chauhan VS, Nelson DA, Roy LD, Mukherjee P, Bost KL. Exacerbated metastatic disease in a mouse mammary tumor model following latent gammaherpesvirus infection. Infect Agent Cancer 2012; 7:11. [PMID: 22642913 PMCID: PMC3565933 DOI: 10.1186/1750-9378-7-11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 04/23/2012] [Indexed: 12/15/2022] Open
Abstract
Background Controversy exists as to the ability of human gammaherpesviruses to cause or exacerbate breast cancer disease in patients. The difficulty in conducting definitive human studies can be overcome by investigating developing breast cancer in a mouse model. In this study, we utilized mice latently infected with murine gammaherpesvirus 68 (HV-68) to question whether such a viral burden could exacerbate metastatic breast cancer disease using a mouse mammary tumor model. Results Mice latently infected with HV-68 had a similar primary tumor burden, but much greater metastatic disease, when compared to mock treated mice given the transplantable tumor, 4 T1. This was true for lung lesions, as well as secondary tumor masses. Increased expression of pan-cytokeratin and VEGF-A in tumors from HV-68 infected mice was consistent with increased metastatic disease in these animals. Surprisingly, no viral particles could be cultured from tumor tissues, and the presence of viral DNA or RNA transcripts could not be detected in primary or secondary tumor tissues. Conclusions Latent HV-68 infection had no significant effect on the size of primary 4 T1 mammary tumors, but exacerbated the number of metastatic lung lesions and secondary tumors when compared to mock treated mice. Increased expression of the tumor marker, pan-cytokeratin, and VEGF-A in tumors of mice harboring latent virus was consistent with an exacerbated metastatic disease. Mechanisms responsible for this exacerbation are indirect, since no virus could be detected in cancerous tissues.
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Affiliation(s)
- Vinita S Chauhan
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA
| | - Daniel A Nelson
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA
| | - Lopamudra Das Roy
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA
| | - Pinku Mukherjee
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA
| | - Kenneth L Bost
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, North Carolina, USA
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Nelson DA, Chauhan VS, Tolbert MD, Bost KL. Murine gammaherpesvirus-68 expands, but does not activate, CD11b+ gr-1+ splenocytes in vivo. JOURNAL OF INFLAMMATION-LONDON 2012; 9:14. [PMID: 22507226 PMCID: PMC3431986 DOI: 10.1186/1476-9255-9-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 02/22/2012] [Indexed: 12/15/2022]
Abstract
Background Murine gammaherpesvirus 68 (HV-68) is an efficient pathogen, capable of infecting and establishing lifelong latency in rodents. While many studies have demonstrated the ability of this viral infection to modulate immune responses, a unifying mechanism for HV-68-induced subversion of a protective host response remains elusive. We questioned whether infection with HV-68 could expand a population of myeloid derived suppressor cells (MDSC) as one mechanism for altering protective immunity. Methods Mice were infected with HV-68, with viral latency being established in these animals. At varying times post-infection, cells were isolated for detection of viral genomes, phenotyping of myeloid cell populations, and ex vivo analysis of suppressor activity of myeloid cells. Results CD11b + Gr-1+ myeloid cells accumulated in the spleens, but not the bone marrow, of HV-68 infected mice. These cells were predominantly Gr-1+ Ly-6 G+, and could be found to contain viral genomes. Increased levels of serum S100A8/A9 produced during viral infection were consistent with the expansion of these CD11b + Gr-1+ myeloid cells. Despite their expansion, these cells exhibited no increased arginase 1 or iNOS activity, and did not have the ability to suppress anti-CD3 antibody activated T lymphocyte responses. Conclusions We concluded that HV-68 infection was capable of expanding a population of myeloid cells which were phenotypically similar to MDSC. However these cells were not sufficiently activated during the establishment of viral latency to actively suppress T cell responses.
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Affiliation(s)
- Daniel A Nelson
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd,, Charlotte, NC, 28223, USA.
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Nelson DA, Singh SJ, Young AB, Tolbert MD, Bost KL. 3,4-Methylenedioxymethamphetamine (MDMA) alters acute gammaherpesvirus burden and limits interleukin 27 responses in a mouse model of viral infection. Drug Alcohol Depend 2011; 116:211-21. [PMID: 21269783 PMCID: PMC3105168 DOI: 10.1016/j.drugalcdep.2010.12.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 10/12/2010] [Accepted: 12/29/2010] [Indexed: 11/30/2022]
Abstract
AIMS To test whether 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") abuse might increase the susceptibility, or alter the immune response, to murine gammaherpesvirus 68 (HV-68) and/or bacterial lipopolysaccharide. METHODS Groups of experimental and control mice were subjected to three day binges of MDMA, and the effect of this drug abuse on acute and latent HV-68 viral burden were assessed. In vitro and in vivo studies were also performed to assess the MDMA effect on IL-27 expression in virally infected or LPS-exposed macrophages and dendritic cells, and latently infected animals, exposed to this drug of abuse. RESULTS Acute viral burden was significantly increased in MDMA-treated mice when compared to controls. However the latent viral burden, and physiological and behavioral responses were not altered in infected mice despite repeated bingeing with MDMA. MDMA could limit the IL-27 response of HV-68 infected or LPS-exposed macrophages and dendritic cells in vitro and in vivo, demonstrating the ability of this drug to alter normal cytokine responses in the context of a viral infection and/or a TLR4 agonist. CONCLUSION MDMA bingeing could alter the host's immune response resulting in greater acute viral replication and reductions in the production of the cytokine, IL-27 during immune responses.
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Affiliation(s)
- Daniel A. Nelson
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA
| | - Sam J. Singh
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA
| | - Amy B. Young
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA
| | - Melanie D. Tolbert
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA
| | - Kenneth L. Bost
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA,Corresponding author at: Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA. Tel: +1 704 687 8677; fax +1 704 687 3128
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Infection with murine gammaherpesvirus 68 exacerbates inflammatory bowel disease in IL-10-deficient mice. Inflamm Res 2009; 58:881-9. [DOI: 10.1007/s00011-009-0059-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 04/29/2009] [Accepted: 06/01/2009] [Indexed: 12/11/2022] Open
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Milho R, Smith CM, Marques S, Alenquer M, May JS, Gillet L, Gaspar M, Efstathiou S, Simas JP, Stevenson PG. In vivo imaging of murid herpesvirus-4 infection. J Gen Virol 2009; 90:21-32. [PMID: 19088269 PMCID: PMC2885022 DOI: 10.1099/vir.0.006569-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 10/06/2008] [Indexed: 12/27/2022] Open
Abstract
Luciferase-based imaging allows a global view of microbial pathogenesis. We applied this technique to gammaherpesvirus infection by inserting a luciferase expression cassette into the genome of murine herpesvirus-4 (MuHV-4). The recombinant virus strongly expressed luciferase in lytically infected cells without significant attenuation. We used it to compare different routes of virus inoculation. After intranasal infection of anaesthetized mice, luciferase was expressed in the nose and lungs for 7-10 days and in lymphoid tissue, most consistently the superficial cervical lymph nodes, for up to 30 days. Gastrointestinal infection was not observed. Intraperitoneal infection was very different to intranasal, with strong luciferase expression in the liver, kidneys, intestines, reproductive tract and spleen, but none in the nose or lungs. The nose has not previously been identified as a site of MuHV-4 infection. After intranasal infection of non-anaesthetized mice, it was the only site of non-lymphoid luciferase expression. Nevertheless, lymphoid colonization and persistence were still established, even at low inoculation doses. In contrast, virus delivered orally was very poorly infectious. Inoculation route therefore had a major impact on pathogenesis. Low dose intranasal infection without anaesthesia seems most likely to mimic natural transmission, and may therefore be particularly informative about normal viral gene functions.
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Affiliation(s)
- Ricardo Milho
- Division of Virology, Department of Pathology, University of Cambridge, UK
| | | | - Sofia Marques
- Instituto de Microbiologia e Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal
| | - Marta Alenquer
- Instituto de Microbiologia e Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal
| | - Janet S. May
- Division of Virology, Department of Pathology, University of Cambridge, UK
| | - Laurent Gillet
- Division of Virology, Department of Pathology, University of Cambridge, UK
| | - Miguel Gaspar
- Division of Virology, Department of Pathology, University of Cambridge, UK
| | - Stacey Efstathiou
- Division of Virology, Department of Pathology, University of Cambridge, UK
| | - J. Pedro Simas
- Instituto de Microbiologia e Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal
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Persistent gammaherpesvirus replication and dynamic interaction with the host in vivo. J Virol 2008; 82:12498-509. [PMID: 18842717 DOI: 10.1128/jvi.01152-08] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Gammaherpesviruses establish life-long persistency inside the host and cause various diseases during their persistent infection. However, the systemic interaction between the virus and host in vivo has not been studied in individual hosts continuously, although such information can be crucial to control the persistent infection of the gammaherpesviruses. For the noninvasive and continuous monitoring of the interaction between gammaherpesvirus and the host, a recombinant murine gammaherpesvirus 68 (MHV-68, a gammaherpesvirus 68) was constructed to express a firefly luciferase gene driven by the viral M3 promoter (M3FL). Real-time monitoring of M3FL infection revealed novel sites of viral replication, such as salivary glands, as well as acute replication in the nose and the lung and progression to the spleen. Continuous monitoring of M3FL infection in individual mice demonstrated the various kinetics of transition to different organs and local clearance, rather than systemically synchronized clearance. Moreover, in vivo spontaneous reactivation of M3FL from latency was detected after the initial clearance of acute infection and can be induced upon treatment with either a proteasome inhibitor Velcade or an immunosuppressant cyclosporine A. Taken together, our results demonstrate that the in vivo replication and reactivation of gammaherpesvirus are dynamically controlled by the locally defined interaction between the virus and the host immune system and that bioluminescence imaging can be successfully used for the real-time monitoring of this dynamic interaction of MHV-68 with its host in vivo.
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15
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Barcy S, De Rosa SC, Vieira J, Diem K, Ikoma M, Casper C, Corey L. Gamma delta+ T cells involvement in viral immune control of chronic human herpesvirus 8 infection. THE JOURNAL OF IMMUNOLOGY 2008; 180:3417-25. [PMID: 18292568 DOI: 10.4049/jimmunol.180.5.3417] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Little is known about what effector populations are associated with the control of human herpesvirus 8 (HHV-8) infection in vivo. We compared T lymphocyte subsets among HIV-HHV-8+ and HIV-HHV-8- infected human individuals. alphabeta+ T cells from HHV-8-infected individuals displayed a significantly higher percentage of differentiated effector cells among both CD4+ and CD8+ T cell subsets. HHV-8 infection was associated with significant expansion of gammadelta+ Vdelta1 T cells expressing a differentiated effector cell phenotype in peripheral blood. In vitro stimulation of PBMC from HHV-8-infected individuals with either infectious viral particles or different HHV-8 viral proteins resulted in gammadelta Vdelta1 T cell activation. In addition, gammadelta Vdelta1 T cells displayed a strong reactivity against HHV-8-infected cell lines and prevented the release of infectious viral particles following the induction of lyric replication. These data indicate that gammadelta T cells play a role in both innate and adaptive T cell responses against HHV-8 in immunocompetent individuals.
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Affiliation(s)
- Serge Barcy
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98109, USA.
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16
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(C)Re-combining textbook models of virus spread within the host. Cell Host Microbe 2008; 3:201-2. [PMID: 18407062 DOI: 10.1016/j.chom.2008.03.005] [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
Classic viral pathogenesis models postulate that tissues supporting efficient virus replication promote virus dissemination, which culminates in clinical illness. In this issue of Cell Host & Microbe, Sacher and colleagues use Cre/loxP recombination to label murine cytomegalovirus during replication in distinct cell types in vivo. Strikingly, they demonstrate that the most productive cell type in the host-the hepatocyte-contributes no progeny to dissemination to other tissues.
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17
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Gasper-Smith N, Marriott I, Bost KL. Murine γ-Herpesvirus 68 Limits Naturally Occurring CD4+CD25+T Regulatory Cell Activity following Infection. THE JOURNAL OF IMMUNOLOGY 2006; 177:4670-8. [PMID: 16982906 DOI: 10.4049/jimmunol.177.7.4670] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During microbial infections, naturally occurring CD4+CD25+ T regulatory cells can suppress protective host responses or they can limit pathogen-induced inflammatory responses. The particular role played by these cells seems to depend upon the infectious agent being investigated. Gamma-herpesviruses are efficacious pathogens which are well-known for their ability to induce lymphoproliferative disease and to establish latency in the host. However, no studies have investigated the importance of naturally occurring CD4+CD25+ T regulatory cells during infection with these viruses. Using the murine model of gamma-herpesvirus infection, murine gamma-herpesvirus 68 (gammaHV-68), we were surprised to find that levels of the CD4+CD25+ T regulatory cell transcript, FoxP3, continued to decrease as viral latency increased and as the leukocytosis phase of the disease progressed. Consistent with these results, the decrease in FoxP3 protein expression followed similar kinetics. Along with the reduced expression of this regulatory T cell marker, we also observed diminished CD4+CD25+ T regulatory cell activity in these cells isolated from gammaHV-68-infected animals. Dendritic cells infected in vitro with gammaHV-68 did not alter the ability of normal CD4+CD25+ regulatory T cells to limit the proliferation of CD4+ Th cells following stimulation. Taken together, these studies demonstrate a decreased presence and activity of CD4+CD25+ T regulatory cells during the mononucleosis-like phase of this viral infection. These alterations in naturally occurring T regulatory cell function may help to explain the dysregulation of the host's immune response which allows the uncontrolled expansion of leukocytes as viral latency is established.
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Affiliation(s)
- Nancy Gasper-Smith
- Department of Biology, University of North Carolina, 9201 University City Boulevard, Charlotte, NC 28223, USA
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18
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Pascual DW, Bost KL. Neuropeptides for Mucosal Immunity. Mucosal Immunol 2005. [DOI: 10.1016/b978-012491543-5/50042-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Gasper-Smith N, Bost KL. Initiation of the Host Response Against Murine Gammaherpesvirus Infection in Immunocompetent Mice. Viral Immunol 2004; 17:473-80. [PMID: 15671745 DOI: 10.1089/vim.2004.17.473] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Murine gammaherpesvirus 68 (gammaHV-68) provides a useful model for understanding the initiation of the host response against the gammaherpesviruses. Its value as a model for such studies lies in large part with the inherent difficulties in investigating human responses against EBV and HHV-8 during the first few days following infection. While studies aimed at defining the initiation of gammaHV-68 infection are far from complete, an unexpected trend in this early host response has already emerged. Despite viral replication and the beginnings of viral latency at the site of infection during the first few days following infection, the early host response seems surprisingly inadequate. For example, the pro-inflammatory response is quite limited, and with the exception of the type I interferons, it is not at all clear what innate responses are necessary to provide protection from acute infection. This confusion results from the lack of any significant effect on acute viral replication in several strains of mice which have been made genetically deficient in the expression of particular pro-inflammatory molecules. It is likely that these unexpected results reflect the ability of gammaherpesviruses to carefully control the initial response so that they are efficacious pathogens even in immunocompetent hosts.
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Affiliation(s)
- Nancy Gasper-Smith
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA
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20
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Deng H, Chu JT, Park NH, Sun R. Identification of cis sequences required for lytic DNA replication and packaging of murine gammaherpesvirus 68. J Virol 2004; 78:9123-31. [PMID: 15308708 PMCID: PMC506910 DOI: 10.1128/jvi.78.17.9123-9131.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Human gammaherpesviruses are associated with lymphomas and other malignancies. Murine gammaherpesvirus 68 (MHV-68) infection of mice has emerged as a model for understanding gammaherpesvirus pathogenesis in vivo. In contrast to human gammaherpesviruses, MHV-68 replicates in permissive cell lines in a robust manner, presenting an efficient model to study the basic mechanisms for DNA replication and recombination processes. In addition, MHV-68 also infects a broad range of cells of different tissue types and from different host species, and the viral genome persists as an episome in infected cells. These features make MHV-68 an attractive system on which to build gene delivery vectors. We have therefore undertaken a study to identify the cis elements required for MHV-68 genome replication and packaging. Here we report that an 8.4-kb MHV-68 genomic fragment between ORF66 and ORF73 conferred on the plasmid the ability to replicate; replication required the presence of either de novo viral infection or viral reactivation from latency. We further mapped the origin of lytic replication (oriLyt) to a 1.25-kb region. Moreover, we demonstrated that the terminal repeat of the viral genome is sufficient for packaging of the replicated oriLyt plasmid into mature viral particles. Functional identification of the MHV-68 oriLyt and packaging signal has laid a foundation for investigating the mechanisms controlling gammaherpesvirus DNA replication during the viral lytic phase and will also serve as a base on which to design gene delivery vectors.
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Affiliation(s)
- Hongyu Deng
- Department of Molecular & Medical Pharmacology, Dental Research Intsitute, UCLA AIDS Institute, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles 90095-1735, USA.
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21
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Duus KM, Lentchitsky V, Wagenaar T, Grose C, Webster-Cyriaque J. Wild-type Kaposi's sarcoma-associated herpesvirus isolated from the oropharynx of immune-competent individuals has tropism for cultured oral epithelial cells. J Virol 2004; 78:4074-84. [PMID: 15047824 PMCID: PMC374256 DOI: 10.1128/jvi.78.8.4074-4084.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Based on the observation that wild-type Kaposi's sarcoma-associated herpesvirus (KSHV) DNA can be detected in the oral cavity of healthy, immunocompetent individuals, we hypothesized that epithelial cells could be infected in vitro by wild-type (WT) KSHV isolated from immunocompetent individuals. Primary oral epithelial (P-EPI) cells and telomerase-immortalized oral epithelial cells were generated from human gingival tissue and were then infected in vitro with WT KSHV isolated from throat wash samples. Markers of lytic and latent KSHV infection were detected in cultures by 24 h postinfection by immunofluorescence confocal microscopic assays. The infectivity of the WT and BCBL virus was blocked by neutralizing antibodies against KSHV gB. The presence of KSHV DNA in these cells was confirmed by real-time PCR amplification of different regions of the viral genome. The significant in vitro viral replication that had occurred was inhibited by ganciclovir and by neutralizing antibodies against gB. When infected cultures were examined by scanning electron microscopy, thousands of KSHV particles were clearly visible across the surfaces of P-EPI cells. The detection of enveloped particles indicated that the infectious cycle had proceeded through assembly and egress. We thus demonstrated that oral WT KSHV isolated from immunocompetent individuals was able to infect and replicate in vitro in a relevant primary cell type. Furthermore, our results provide compelling evidence for KSHV transmission within infected oral epithelial cells derived from healthy, immunocompetent populations.
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MESH Headings
- Antiviral Agents/pharmacology
- Cell Line
- Cell Membrane/virology
- Cells, Cultured
- DNA, Viral/genetics
- DNA, Viral/isolation & purification
- Epithelial Cells/virology
- Gingiva/virology
- Herpesviridae Infections/etiology
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/isolation & purification
- Herpesvirus 8, Human/pathogenicity
- Herpesvirus 8, Human/physiology
- Humans
- Immunocompetence
- Microscopy, Electron, Scanning
- Models, Biological
- Organ Specificity
- Oropharynx/virology
- Virulence
- Virus Replication/drug effects
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Affiliation(s)
- Karen M Duus
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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22
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Bortz E, Whitelegge JP, Jia Q, Zhou ZH, Stewart JP, Wu TT, Sun R. Identification of proteins associated with murine gammaherpesvirus 68 virions. J Virol 2004; 77:13425-32. [PMID: 14645600 PMCID: PMC296060 DOI: 10.1128/jvi.77.24.13425-13432.2003] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Murine gammaherpesvirus 68 (MHV68 [also known as gammaHV-68]) is distinguished by its ability to replicate to high titers in cultured cells, making it an excellent candidate for studying gammaherpesvirus virion composition. Extracellular MHV68 virions were isolated, and abundant virion-associated proteins were identified by mass spectrometry. Five nucleocapsid protein homologues, the tegument protein homologue encoded by open reading frame (ORF) 75c, and envelope glycoproteins B and H were detected. In addition, gene products from MHV68 ORF20, ORF24, ORF28, ORF45, ORF48, and ORF52 were identified in association with virions, suggesting that these gammaherpesvirus genes are involved in the early phase of infection or virion assembly and egress.
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Affiliation(s)
- Eric Bortz
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
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23
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Elsawa SF, Bost KL. Murine γ-Herpesvirus-68-Induced IL-12 Contributes to the Control of Latent Viral Burden, but Also Contributes to Viral-Mediated Leukocytosis. THE JOURNAL OF IMMUNOLOGY 2003; 172:516-24. [PMID: 14688362 DOI: 10.4049/jimmunol.172.1.516] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Early IFN-alpha/beta production, followed by the development of a viral-specific CTL response, are critical factors in limiting the level of murine gamma-herpesvirus-68 (gammaHV-68) infection. Development of a long-lived CTL response requires T cell help, and these CTLs most likely function to limit the extent of infection following reactivation. The importance of IL-12 in the development and/or activity of Th1 cells and CTLs is well documented, and we investigated the kinetics and magnitude of gammaHV-68-induced IL-12 production. Following intranasal infection, IL-12 and IL-23 mRNA expression was up-regulated in lung and spleen and lung, respectively, followed by increased levels of IL-12p40 in lung homogenates and sera. Exposure of cultured macrophages or dendritic cells to gammaHV-68 induced secretion of IL-12, suggesting that these cells might be responsible for IL-12 production in vivo. gammaHV-68 infection of mice made genetically deficient in IL-12p40 expression (IL-12p40(-/-)) resulted in a leukocytosis and splenomegaly that was significantly less than that observed in syngeneic C57BL/6 mice. IL-12p40(-/-) mice showed increased levels of infectious virus in the lung, but only at day 9 postinfection. Increased levels of latent virus in the spleen at day 15 postinfection were also observed in IL-12p40(-/-) mice when compared with syngeneic C57BL/6 mice. An overall reduction in gammaHV-68-induced IFN-gamma production was observed in IL-12p40(-/-) mice, suggesting that most of the viral-induced IFN-gamma in C57BL/6 mice was IL-12 dependent. Taken together, these results suggest that gammaHV-68-induced IL-12 contributes to the pathophysiology of viral infection while also functioning to limit viral burden.
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Affiliation(s)
- Sherine F Elsawa
- Department of Biology, University of North Carolina, 9201 University City Boulevard, Charlotte, NC 28223, USA
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24
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Peacock J, Elsawa S, Petty C, Hickey W, Bost K. Exacerbation of experimental autoimmune encephalomyelitis in rodents infected with murine gammaherpesvirus-68. Eur J Immunol 2003; 33:1849-58. [PMID: 12811845 PMCID: PMC7163599 DOI: 10.1002/eji.200323148] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Viral infections have long been suspected to play a role in the pathogenesis of multiple sclerosis. In the present study, two different rodent models of experimental autoimmune encephalomyelitis (EAE) were used to demonstrate the ability of murine gammaherpesvirus-68 (gammaHV-68) to exacerbate development of neurological symptoms. SJL mice received UV-inactivated gammaHV-68 or intranasalgammaHV-68, followed by immunization against proteolipid-protein peptide 139-151. Infected mice became moribund within 10 days post-immunization, whereas mice exposed to UV-inactivated gammaHV-68 recovered. In the second model, Lewis rats were exposed to UV-inactivated gammaHV-68 or to gammaHV-68, followed by passive transfer of encephalitogenic T lymphocytes specific for myelin basic protein. Consistently, infected rats had higher clinical scores, and this result was observed during acute or latent gammaHV-68 infection. It is unlikely that this gammaHV-68-induced exacerbation was due to significant viral replication within the central nervous system since nested PCR, viral plaque assays, and infectious-centers assays demonstrated no detectable virus in spinal cords or brains of infected rodents undergoing EAE. Taken together, these studies demonstrate increased clinical symptoms of EAE in rodents infected by a gammaherpesvirus that has a limited ability to invade the central nervous system.
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Affiliation(s)
- James W. Peacock
- Department of Biology, The University of North Carolina at Charlotte, Charlotte, USA
| | - Sherine F. Elsawa
- Department of Biology, The University of North Carolina at Charlotte, Charlotte, USA
| | - Cynthia C. Petty
- Department of Biology, The University of North Carolina at Charlotte, Charlotte, USA
| | | | - Kenneth L. Bost
- Department of Biology, The University of North Carolina at Charlotte, Charlotte, USA
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25
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Taylor WR, Rasley A, Bost KL, Marriott I. Murine gammaherpesvirus-68 infects microglia and induces high levels of pro-inflammatory cytokine production. J Neuroimmunol 2003; 136:75-83. [PMID: 12620645 DOI: 10.1016/s0165-5728(03)00011-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Murine gammaherpesvirus-68 (MHV-68) has been established as a tractable model for the study of human herpesvirus infections. Recent associations between herpesvirus infections and inflammatory central nervous system (CNS) disorders, including multiple sclerosis (MS), have prompted us to investigate the susceptibility of cultured microglia and astrocytes to MHV-68 infection. In the present study, we demonstrate that MHV-68 can infect both cell types. Importantly, we show that MHV-68-infected microglia and astrocytes can produce pro-inflammatory cytokines. Such cytokine production may either contribute to protective host responses to viral challenges or could exacerbate damaging CNS inflammation.
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Affiliation(s)
- William R Taylor
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Boulevard, 28223, USA
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26
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Elsawa SF, Taylor W, Petty CC, Marriott I, Weinstock JV, Bost KL. Reduced CTL response and increased viral burden in substance P receptor-deficient mice infected with murine gamma-herpesvirus 68. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:2605-12. [PMID: 12594288 DOI: 10.4049/jimmunol.170.5.2605] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
One component of the protective host response against mucosal pathogens includes the local production and increased expression of certain neuropeptides and their receptors. The present study further demonstrates this fact by investigating the contribution that substance P receptor expression makes toward immunity against a gamma-herpesvirus infection. Following intragastric inoculation with murine gamma-herpesvirus 68 (gamma HV-68), expression of substance P and its receptor was increased in mucosal and peripheral lymphoid organs in wild-type strains of mice. These results suggested that this receptor/ligand pair might be an important component of the host response against this viral infection. Such a hypothesis was supported by the demonstration that mice, genetically deficient in substance P receptor expression, showed an increased viral burden when compared with syngeneic C57BL/6 mice. Furthermore, substance P receptor-deficient mice showed a reduced CTL response against gamma HV-68, suggesting a mechanism to explain this increased viral burden. Such limitations in the Ag-specific CTL response in substance P receptor-deficient mice could result from lowered expression of IL-12 during viral infection. Consistent with this hypothesis, increases in mRNA encoding IL-12 and secretion of this cytokine into sera of infected, wild-type animals were markedly reduced in substance P receptor-deficient mice. These studies demonstrate that genetic elimination of substance P receptors in mice results in an increased gamma-herpesvirus burden and an altered host response.
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MESH Headings
- Animals
- Down-Regulation/genetics
- Down-Regulation/immunology
- Epitopes, T-Lymphocyte/immunology
- Gene Expression Regulation/immunology
- Herpesviridae Infections/genetics
- Herpesviridae Infections/immunology
- Herpesviridae Infections/virology
- Interleukin-12/antagonists & inhibitors
- Interleukin-12/biosynthesis
- Lac Operon/immunology
- Leukocytosis/genetics
- Leukocytosis/immunology
- Leukocytosis/virology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Protein Precursors/biosynthesis
- Protein Precursors/genetics
- RNA, Messenger/genetics
- Receptors, Neurokinin-1/deficiency
- Receptors, Neurokinin-1/genetics
- Receptors, Neurokinin-1/physiology
- Rhadinovirus/immunology
- Rhadinovirus/physiology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- T-Lymphocytes, Cytotoxic/virology
- Tachykinins/biosynthesis
- Tachykinins/genetics
- Virus Latency/genetics
- Virus Latency/immunology
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Affiliation(s)
- Sherine F Elsawa
- Department of Biology, University of North Carolina, Charlotte, NC 28223, USA
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27
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Peacock JW, Bost KL. Murine gammaherpesvirus-68-induced interleukin-10 increases viral burden, but limits virus-induced splenomegaly and leukocytosis. Immunology 2001; 104:109-17. [PMID: 11576228 PMCID: PMC1783283 DOI: 10.1046/j.1365-2567.2001.01286.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Based on its genomic sequence and its pathogenesis, murine gammaherpesvirus-68 (gammaHV-68) has been established as a tractable model for the study of viral infections caused by the human gammaherpesviruses, Epstein-Barr virus or human herpesvirus-8. Despite significant advances, the mechanisms responsible for gammaHV-68-induced alterations in the protective host response, and the accompanying virus-induced leukocytosis, are not clear. In the present study, we questioned whether viral infection resulted in endogenous interleukin-10 (IL-10) production that might alter the host response. Infection of C57BL/6 mice resulted in increased IL-10 expression, demonstrating that gammaHV-68 could induce endogenous production of this cytokine. Infected C57BL/6 mice demonstrated the characteristic splenomegaly associated with this viral infection, however, we were surprised to discover that the splenomegaly was greater in syngeneic mice genetically deficient in IL-10 (IL-10-/-). These results strongly suggested that endogenously produced IL-10 might serve to limit leukocytosis in wild-type mice. Quantification of viral burden demonstrated a significant elevation in C57BL/6 versus IL-10-/- mice, with increases in virus being observed in both the macrophage and B-lymphocyte populations. The decreased viral load in syngeneic IL-10-/- mice correlated with an increased expression of endogenous IL-12, suggesting a mechanism of protection that was IL-12 dependent. Taken together, these studies demonstrate a surprising dichotomy for endogenous IL-10 production during gammaHV-68 infection. While the lack of IL-10 results in increased IL-12 expression and a lower viral burden, IL-10-/- mice also experience an increased leukocytosis.
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Affiliation(s)
- J W Peacock
- Department of Biology, University of North Carolina at Charlotte, NC 28223, USA
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28
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Raslova H, Berebbi M, Rajcani J, Sarasin A, Matis J, Kudelova M. Susceptibility of mouse mammary glands to murine gammaherpesvirus 72 (MHV-72) infection: evidence of MHV-72 transmission via breast milk. Microb Pathog 2001; 31:47-58. [PMID: 11453700 DOI: 10.1006/mpat.2001.0441] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Murine gammaherpesvirus 72 (MHV-72) is a virus of wild rodents and serves as a convenient small animal model to understand the pathogenesis of Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV8) infection. In laboratory mice MHV-72 causes an acute infection of lung epithelial cells and establishes the latency in B lymphocytes. In this study, we investigated athymic nude and immunocompetent mice for distribution of virus in organs after infection with MHV-72. Ten days following subcutaneous dorsal injection of nude mice, virus replicated in lungs, lymphoid organs, salivary glands and also in mammary glands. The virus titre decreased by day 21 post-infection in former tissues, but increased in mammary glands. Presence of virus DNA sequences was detected in the lymphoid and non-lymphoid tissues until the death of the animals (about 1 month post-infection). Infection of immunocompetent mice with MHV-72 induced replication of virus up to 42 days post-infection in mammary glands reaching the highest level of infectious virus at day 8 post-infection. These data show that there is latent infection in mice never detected before. Moreover, virus DNA was detected using nested PCR (by amplification of a portion of gp150 gene sequence) in the mammary glands and the milk of mouse mothers infected with MHV-72 2 days before delivery. We demonstrated the presence of virus DNA also in the milk removed from the stomach of non-infected newborn mice, which were nourished by infected mothers (wet-nurses) for 1 or 2 days. The failure to detect the virus DNA in newborn mice lungs confirmed that they did not become infected from wet-nurses by the intranasal route. This suggests that MHV may be naturally transmitted to newborn mice via breast milk.
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Affiliation(s)
- H Raslova
- Institute of Virology, Slovak Academy of Sciences, Dubravska cesta 9, 842 45 Bratislava, Slovak Republic
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29
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Doherty PC, Christensen JP, Belz GT, Stevenson PG, Sangster MY. Dissecting the host response to a gamma-herpesvirus. Philos Trans R Soc Lond B Biol Sci 2001; 356:581-93. [PMID: 11313013 PMCID: PMC1088446 DOI: 10.1098/rstb.2000.0786] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The murine gamma-herpesvirus 68 (MHV-68) provides a unique experimental model for dissecting immunity to large DNA viruses that persist in B lymphocytes. The analysis is greatly facilitated by the availability of genetically disrupted (-/-) mice that lack key host-response elements, and by the fact that MHV-68 is a lytic virus that can readily be manipulated for mutational analysis. The mutant virus strategy is being used, for example, to characterize the part played in vivo by an MHV-68-encoded chemokine-binding protein that may ultimately find an application in human therapeutics. Experiments with various -/- mice and monoclonal antibody depletion protocols have shown very clearly that type I interferons (IFNs) are essential for the early control of MHV-68 replication, while CD4+ T cells producing IFN-gamma function to limit the consequences of viral persistence. Virus-specific CD8+ effectors acting in the absence of the CD4+ subset seem initially to control the lytic phase in the lung following respiratory challenge, but are then unable to prevent the reactivation of replicative infection in epithelia and the eventual death of CD4+ T-cell-deficient mice. This could reflect the fact that the interaction between the CD8+ T cells and the virus-infected targets is partially compromised by the MHV-68 K3 protein, which inhibits antigen presentation by MHC class I glycoproteins. Immunization strategies focusing on the CD8+ T-cell response to epitopes expressed during the lytic phase of MHV-68 infection can limit virus replication, but are unable to prevent the establishment of latency. Other experiments with mutant viruses also suggest that there is a disconnection between lytic MHV-68 infection and latency. The massive nonspecific immunoglobulin response and the dramatic expansion of Vbeta4+ CD8+ T cells, which is apparently MHC independent, could represent some sort of 'smoke screen' used by MHV-68 to subvert immunity. Although MHV-68 is neither Epstein-Barr virus nor human herpesvirus-8, the results generated from this system suggest possibilities that may usefully be addressed with these human pathogens. Perhaps the main lesson learned to date is that all the components of immunity are likely to be important for the control of these complex viruses.
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Affiliation(s)
- P C Doherty
- Department of Immunology, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
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Nash AA, Dutia BM, Stewart JP, Davison AJ. Natural history of murine gamma-herpesvirus infection. Philos Trans R Soc Lond B Biol Sci 2001; 356:569-79. [PMID: 11313012 PMCID: PMC1088445 DOI: 10.1098/rstb.2000.0779] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Murine gamma-herpesvirus 68 (MHV-68) is a natural pathogen of small rodents and insectivores (mice, voles and shrews). The primary infection is characterized by virus replication in lung epithelial cells and the establishment of a latent infection in B lymphocytes. The virus is also observed to persist in lung epithelial cells, dendritic cells and macrophages. Splenomegaly is observed two weeks after infection, in which there is a CD4+ T-cell-mediated expansion of B and T cells in the spleen. At three weeks post-infection an infectious mononucleosis-like syndrome is observed involving a major expansion of Vbeta4+CD8+ T cells. Later in the course of persistent infection, ca. 10% of mice develop lymphoproliferative disease characterized as lymphomas of B-cell origin. The genome from MHV-68 strain g2.4 has been sequenced and contains ca. 73 genes, the majority of which are collinear and homologous to other gamma-herpesviruses. The genome includes cellular homologues for a complement-regulatory protein, Bcl-2, cyclin D and interleukin-8 receptor and a set of novel genes M1 to M4. The function of these genes in the context of latent infections, evasion of immune responses and virus-mediated pathologies is discussed. Both innate and adaptive immune responses play an active role in limiting virus infection. The absence of type I interferon (IFN) results in a lethal MHV-68 infection, emphasizing the central role of these cytokines at the initial stages of infection. In contrast, type II IFN is not essential for the recovery from infection in the lung, but a failure of type II IFN receptor signalling results in the atrophy of lymphoid tissue associated with virus persistence. Splenic atrophy appears to be the result of immunopathology, since in the absence of CD8+ T cells no pathology occurs. CD8+ T cells play a major role in recovery from the primary infection, and also in regulating latently infected cells expressing the M2 gene product. CD4+ T cells have a key role in surveillance against virus recurrences in the lung, in part mediated through 'help' in the genesis of neutralizing antibodies. In the absence of CD4+ T cells, virus-specific CD8+ T cells are able to control the primary infection in the respiratory tract, yet surprisingly the memory CD8+ T cells generated are unable to inhibit virus recurrences in the lung. This could be explained in part by the observations that this virus can downregulate major histocompatibility complex class I expression and also restrict inflammatory cell responses by producing a chemokine-binding protein (M3 gene product). MHV-68 provides an excellent model to explore methods for controlling gamma-herpesvirus infection through vaccination and chemotherapy. Vaccination with gp150 (a homologue of gp350 of Epstein-Barr virus) results in a reduction in splenomegaly and virus latency but does not block replication in the lung, nor the establishment of a latent infection. Even when lung virus infection is greatly reduced following the action of CD8+ T cells, induced via a prime-boost vaccination strategy, a latent infection is established. Potent antiviral compounds such as the nucleoside analogue 2'deoxy-5-ethyl-beta-4'-thiouridine, which disrupts virus replication in vivo, cannot inhibit the establishment of a latent infection. Clearly, devising strategies to interrupt the establishment of latent virus infections may well prove impossible with existing methods.
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Affiliation(s)
- A A Nash
- Laboratory for Clinical and Molecular Virology, Department of Veterinary Pathology, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK.
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