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Granados-Durán P, López-Ávalos MD, Cifuentes M, Pérez-Martín M, Fernández-Arjona MDM, Hughes TR, Johnson K, Morgan BP, Fernández-Llebrez P, Grondona JM. Microbial Neuraminidase Induces a Moderate and Transient Myelin Vacuolation Independent of Complement System Activation. Front Neurol 2017; 8:78. [PMID: 28326060 PMCID: PMC5339270 DOI: 10.3389/fneur.2017.00078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/20/2017] [Indexed: 02/05/2023] Open
Abstract
AIMS Some central nervous system pathogens express neuraminidase (NA) on their surfaces. In the rat brain, a single intracerebroventricular (ICV) injection of NA induces myelin vacuolation in axonal tracts. Here, we explore the nature, the time course, and the role of the complement system in this damage. METHODS The spatiotemporal analysis of myelin vacuolation was performed by optical and electron microscopy. Myelin basic protein-positive area and oligodendrocyte transcription factor (Olig2)-positive cells were quantified in the damaged bundles. Neuronal death in the affected axonal tracts was assessed by Fluoro-Jade B and anti-caspase-3 staining. To evaluate the role of the complement, membrane attack complex (MAC) deposition on damaged bundles was analyzed using anti-C5b9. Rats ICV injected with the anaphylatoxin C5a were studied for myelin damage. In addition, NA-induced vacuolation was studied in rats with different degrees of complement inhibition: normal rats treated with anti-C5-blocking antibody and C6-deficient rats. RESULTS The stria medullaris, the optic chiasm, and the fimbria were the most consistently damaged axonal tracts. Vacuolation peaked 7 days after NA injection and reverted by day 15. Olig2+ cell number in the damaged tracts was unaltered, and neurodegeneration associated with myelin alterations was not detected. MAC was absent on damaged axonal tracts, as revealed by C5b9 immunostaining. Rats ICV injected with the anaphylatoxin C5a displayed no myelin injury. When the complement system was experimentally or constitutively inhibited, NA-induced myelin vacuolation was similar to that observed in normal rats. CONCLUSION Microbial NA induces a moderate and transient myelin vacuolation that is not caused either by neuroinflammation or complement system activation.
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Affiliation(s)
- Pablo Granados-Durán
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
| | - María Dolores López-Ávalos
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
| | - Manuel Cifuentes
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, Málaga, Spain; Centro de Investigaciones Biomédicas en Red de Bioingeniería, Biomateriales y Nanomedicina, CIBER BBN, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Margarita Pérez-Martín
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
| | - María Del Mar Fernández-Arjona
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
| | - Timothy R Hughes
- Division of Infection and Immunity, School of Medicine, Cardiff University , Cardiff , UK
| | | | - B Paul Morgan
- Division of Infection and Immunity, School of Medicine, Cardiff University , Cardiff , UK
| | - Pedro Fernández-Llebrez
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
| | - Jesús M Grondona
- Laboratorio de Fisiología Animal, Facultad de Ciencias, Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga , Málaga , Spain
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152
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Dickey LL, Hanley TM, Huffaker TB, Ramstead AG, O'Connell RM, Lane TE. MicroRNA 155 and viral-induced neuroinflammation. J Neuroimmunol 2017; 308:17-24. [PMID: 28139244 DOI: 10.1016/j.jneuroim.2017.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/11/2017] [Accepted: 01/23/2017] [Indexed: 02/07/2023]
Abstract
MicroRNA (miRNA) regulation of gene expression is becoming an increasingly recognized mechanism by which host immune responses are governed following microbial infection. miRNAs are short, non-coding RNAs that repress translation of target genes, and have been implicated in a number of activities that modulate host immune responses, including the regulation of immune cell proliferation, survival, expansion, differentiation, migration, polarization, and effector function. This review highlights several examples in which mammalian-encoded miR-155 influences immune responses following viral infection of the CNS.
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Affiliation(s)
- Laura L Dickey
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
| | - Timothy M Hanley
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
| | - Thomas B Huffaker
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
| | - Andrew G Ramstead
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
| | - Ryan M O'Connell
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
| | - Thomas E Lane
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, United States.
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153
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Savarin C, Bergmann CC. Viral-induced suppression of self-reactive T cells: Lessons from neurotropic coronavirus-induced demyelination. J Neuroimmunol 2017; 308:12-16. [PMID: 28108025 PMCID: PMC5474352 DOI: 10.1016/j.jneuroim.2017.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/06/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022]
Abstract
Genetic and environmental factors, i.e. infections, have been proposed to contribute to disease induction and relapsing events in multiple sclerosis (MS), an autoimmune demyelinating disease of the central nervous system (CNS). While research has mainly focused on virus associated autoimmune activation, less is known about prevention of autoimmunity, especially following resolving infections associated with CNS tissue damage. This review discusses novel insights on control of self-reactive (SR) T cells activated during neurotropic coronavirus-induced demyelination. A new concept is introduced that SR T cells can be dampened by distinct regulatory mechanisms in the periphery and the CNS, thereby preventing autoimmune disease. Virus-induced demyelination activates myelin specific T cells. Virus-induced regulatory mechanisms limit pathogenic self-reactive R CD4 T cells. Self-reactive CD4 T cells are controlled by distinct mechanisms in the CLN and CNS.
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Affiliation(s)
- Carine Savarin
- Lerner Research Institute, Cleveland Clinic, Neuroscience Department NC-30, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Cornelia C Bergmann
- Lerner Research Institute, Cleveland Clinic, Neuroscience Department NC-30, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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154
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Roles of regulatory T cells and IL-10 in virus-induced demyelination. J Neuroimmunol 2017; 308:6-11. [PMID: 28065579 PMCID: PMC5474348 DOI: 10.1016/j.jneuroim.2017.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/03/2017] [Indexed: 12/22/2022]
Abstract
Neurotropic viruses are important causes of morbidity and mortality in human populations. Some of these viruses preferentially infect oligodendrocytes in the white matter, causing either direct lysis of infected cells, or more commonly myelin damage as a consequence of the host immune response to the virus. Virus-induced demyelination has similarities to the human disease multiple sclerosis. To study this disease process in experimental animals, mice are infected, most commonly, with neurotropic strains of mouse hepatitis virus, a coronavirus or Theiler's murine encephalomyelitis, a picornavirus. While the diseases caused by these two viruses differ in some aspects, in both cases demyelination is a major consequence of the infection. As in autoimmune disease, therapeutic interventions that diminish an overactive immune response would be useful. However, unlike autoimmune disease, complete suppression would result in unchecked virus replication, generally leading to more severe disease. Here we discuss two approaches that dampen but do not fully suppress the host immune response. Regulatory T cells, especially those that are specific for antigens recognized by pathogenic T cells, and IL-10 are two anti-inflammatory/pro-resolution factors that demonstrate efficacy in experimental models of virus-induced demyelination and may be useful in patients infected with viruses that cause demyelination. MHV and TMEV are common causes of virus-induced demyelination in mice Virus-induced demyelination is often host cell-mediated. Virus-specific Treg dampen pathogenic T cells responding to cognate epitope IL-10 expressed by Tregs and Tr1 cells dampens pathogenic T cell responses Tregs and IL-10 suppress pathogenic T cells without broad immunosuppression
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155
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Savarin C, Bergmann CC, Hinton DR, Stohlman SA. Differential Regulation of Self-reactive CD4 + T Cells in Cervical Lymph Nodes and Central Nervous System during Viral Encephalomyelitis. Front Immunol 2016; 7:370. [PMID: 27708643 PMCID: PMC5030268 DOI: 10.3389/fimmu.2016.00370] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/07/2016] [Indexed: 12/12/2022] Open
Abstract
Viral infections have long been implicated as triggers of autoimmune diseases, including multiple sclerosis (MS), a central nervous system (CNS) inflammatory demyelinating disorder. Epitope spreading, molecular mimicry, cryptic antigen, and bystander activation have been implicated as mechanisms responsible for activating self-reactive (SR) immune cells, ultimately leading to organ-specific autoimmune disease. Taking advantage of coronavirus JHM strain of mouse hepatitis virus (JHMV)-induced demyelination, this study demonstrates that the host also mounts counteractive measures to specifically limit expansion of endogenous SR T cells. In this model, immune-mediated demyelination is associated with induction of SR T cells after viral control. However, their decline during persisting infection, despite ongoing demyelination, suggests an active control mechanism. Antigen-specific IL-10-secreting CD4+ T cells (Tr1) and Foxp3+ regulatory T cells (Tregs), both known to control autoimmunity and induced following JHMV infection, were assessed for their relative in vivo suppressive function of SR T cells. Ablation of Foxp3+ Tregs in chronically infected DEREG mice significantly increased SR CD4+ T cells within cervical lymph nodes (CLN), albeit without affecting their numbers or activation within the CNS compared to controls. In contrast, infected IL-27 receptor deficient (IL-27R-/-) mice, characterized by a drastic reduction of Tr1 cells, revealed that SR CD4+ T cells in CLN remained unchanged but were specifically increased within the CNS. These results suggest that distinct Treg subsets limit SR T cells in the draining lymph nodes and CNS to maximize suppression of SR T-cell-mediated autoimmune pathology. The JHMV model is thus valuable to decipher tissue-specific mechanisms preventing autoimmunity.
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Affiliation(s)
- Carine Savarin
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, OH , USA
| | - Cornelia C Bergmann
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, OH , USA
| | - David R Hinton
- Department of Pathology, Keck School of Medicine, University of Southern California , Los Angeles, CA , USA
| | - Stephen A Stohlman
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, OH , USA
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156
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Evonuk KS, Moseley CE, Doyle RE, Weaver CT, DeSilva TM. Determining Immune System Suppression versus CNS Protection for Pharmacological Interventions in Autoimmune Demyelination. J Vis Exp 2016. [PMID: 27685467 PMCID: PMC5092010 DOI: 10.3791/54348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A major hallmark of the autoimmune demyelinating disease multiple sclerosis (MS) is immune cell infiltration into the brain and spinal cord resulting in myelin destruction, which not only slows conduction of nerve impulses, but causes axonal injury resulting in motor and cognitive decline. Current treatments for MS focus on attenuating immune cell infiltration into the central nervous system (CNS). These treatments decrease the number of relapses, improving quality of life, but do not completely eliminate relapses so long-term disability is not improved. Therefore, therapeutic agents that protect the CNS are warranted. In both animal models as well as human patients with MS, T cell entry into the CNS is generally considered the initiating inflammatory event. In order to assess if a drug protects the CNS, any potential effects on immune cell infiltration or proliferation in the periphery must be ruled out. This protocol describes how to determine whether CNS protection observed after drug intervention is a consequence of attenuating CNS-infiltrating immune cells or blocking death of CNS cells during inflammatory insults. The ability to examine MS treatments that are protective to the CNS during inflammatory insults is highly critical for the advancement of therapeutic strategies since current treatments reduce, but do not completely eliminate, relapses (i.e., immune cell infiltration), leaving the CNS vulnerable to degeneration.
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Affiliation(s)
- Kirsten S Evonuk
- Physical Medicine and Rehabilitation, University of Alabama at Birmingham
| | | | - Ryan E Doyle
- Physical Medicine and Rehabilitation, University of Alabama at Birmingham
| | - Casey T Weaver
- Department of Pathology, University of Alabama at Birmingham
| | - Tara M DeSilva
- Physical Medicine and Rehabilitation, University of Alabama at Birmingham; Department of Neurobiology, University of Alabama at Birmingham; Center for Glial Biology and Medicine, University of Alabama at Birmingham;
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157
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Dickey LL, Worne CL, Glover JL, Lane TE, O’Connell RM. MicroRNA-155 enhances T cell trafficking and antiviral effector function in a model of coronavirus-induced neurologic disease. J Neuroinflammation 2016; 13:240. [PMID: 27604627 PMCID: PMC5015201 DOI: 10.1186/s12974-016-0699-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 08/20/2016] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are noncoding RNAs that modulate cellular gene expression, primarily at the post-transcriptional level. We sought to examine the functional role of miR-155 in a model of viral-induced neuroinflammation. METHODS Acute encephalomyelitis and immune-mediated demyelination were induced by intracranial injection with the neurotropic JHM strain of mouse hepatitis virus (JHMV) into C57BL/6 miR-155 (+/+) wildtype (WT) mice or miR-155 (-/-) mice. Morbidity and mortality, viral load and immune cell accumulation in the CNS, and spinal cord demyelination were assessed at defined points post-infection. T cells harvested from infected mice were used to examine cytolytic activity, cytokine activity, and expression of certain chemokine receptors. To determine the impact of miR-155 on trafficking, T cells from infected WT or miR-155 (-/-) mice were adoptively transferred into RAG1 (-/-) mice, and T cell accumulation into the CNS was assessed using flow cytometry. Statistical significance was determined using the Mantel-Cox log-rank test or Student's T tests. RESULTS Compared to WT mice, JHMV-infected miR-155 (-/-) mice developed exacerbated disease concomitant with increased morbidity/mortality and an inability to control viral replication within the CNS. In corroboration with increased susceptibility to disease, miR-155 (-/-) mice had diminished CD8(+) T cell responses in terms of numbers, cytolytic activity, IFN-γ secretion, and homing to the CNS that corresponded with reduced expression of the chemokine receptor CXCR3. Both IFN-γ secretion and trafficking were impaired in miR-155 (-/-) , virus-specific CD4(+) T cells; however, expression of the chemokine homing receptors analyzed on CD4(+) cells was not affected. Except for very early during infection, there were not significant differences in macrophage infiltration into the CNS between WT and miR-155 (-/-) JHMV-infected mice, and the severity of demyelination was similar at 14 days p.i. between WT and miR-155 (-/-) JHMV-infected mice. CONCLUSIONS These findings support a novel role for miR-155 in host defense in a model of viral-induced encephalomyelitis. Specifically, miR-155 enhances antiviral T cell responses including cytokine secretion, cytolytic activity, and homing to the CNS in response to viral infection. Further, miR-155 can play either a host-protective or host-damaging role during neuroinflammation depending on the disease trigger.
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Affiliation(s)
- Laura L. Dickey
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
| | - Colleen L. Worne
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
| | - Jessica L. Glover
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
| | - Thomas E. Lane
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
| | - Ryan M. O’Connell
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
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158
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Biswas K, Chatterjee D, Addya S, Khan RS, Kenyon LC, Choe A, Cohrs RJ, Shindler KS, Das Sarma J. Demyelinating strain of mouse hepatitis virus infection bridging innate and adaptive immune response in the induction of demyelination. Clin Immunol 2016; 170:9-19. [PMID: 27394164 PMCID: PMC7106046 DOI: 10.1016/j.clim.2016.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 05/23/2016] [Accepted: 07/05/2016] [Indexed: 02/06/2023]
Abstract
The presence of immunoglobulin oligoclonal bands in the cerebrospinal fluid of Multiple Sclerosis (MS) patients supports the hypothesis of an infectious etiology, although the antigenic targets remain elusive. Neurotropic mouse hepatitis virus (MHV) infection in mice provides a useful tool for studying mechanisms of demyelination in a virus-induced experimental model of MS. This study uses Affymetrix microarray analysis to compare differential spinal cord mRNA levels between mice infected with demyelinating and non-demyelinating strains of MHV to identify host immune genes expressed in this demyelinating disease model. The study reveals that during the acute stage of infection, both strains induce inflammatory innate immune response genes, whereas upregulation of several immunoglobulin genes during chronic stage infection is unique to infection with the demyelinating strain. Results suggest that the demyelinating strain induced an innate-immune response during acute infection that may promote switching of Ig isotype genes during chronic infection, potentially playing a role in antibody-mediated progressive demyelination even after viral clearance.
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Affiliation(s)
- Kaushiki Biswas
- Department of Biological Sciences, Indian Institute of Science Education and ResearchKolkata (IISER-K), India
| | - Dhriti Chatterjee
- Department of Biological Sciences, Indian Institute of Science Education and ResearchKolkata (IISER-K), India
| | - Sankar Addya
- Kimmel Cancer Centre, Thomas Jefferson University, Philadelphia, PA, USA
| | - Reas S Khan
- Scheie Eye Institute and FM Kirby Centre for Molecular Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Lawrence C Kenyon
- Departments of Anatomy, Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Alexander Choe
- Department of Neurology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Randall J Cohrs
- Department of Neurology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kenneth S Shindler
- Scheie Eye Institute and FM Kirby Centre for Molecular Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jayasri Das Sarma
- Department of Biological Sciences, Indian Institute of Science Education and ResearchKolkata (IISER-K), India.
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159
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Nice TJ, Osborne LC, Tomov VT, Artis D, Wherry EJ, Virgin HW. Type I Interferon Receptor Deficiency in Dendritic Cells Facilitates Systemic Murine Norovirus Persistence Despite Enhanced Adaptive Immunity. PLoS Pathog 2016; 12:e1005684. [PMID: 27327515 PMCID: PMC4915689 DOI: 10.1371/journal.ppat.1005684] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 05/17/2016] [Indexed: 11/19/2022] Open
Abstract
In order for a virus to persist, there must be a balance between viral replication and immune clearance. It is commonly believed that adaptive immunity drives clearance of viral infections and, thus, dysfunction or viral evasion of adaptive immunity is required for a virus to persist. Type I interferons (IFNs) play pleiotropic roles in the antiviral response, including through innate control of viral replication. Murine norovirus (MNoV) replicates in dendritic cells (DCs) and type I IFN signaling in DCs is important for early control of MNoV replication. We show here that the non-persistent MNoV strain CW3 persists systemically when CD11c positive DCs are unable to respond to type I IFN. Persistence in this setting is associated with increased early viral titers, maintenance of DC numbers, increased expression of DC activation markers and an increase in CD8 T cell and antibody responses. Furthermore, CD8 T cell function is maintained during the persistent phase of infection and adaptive immune cells from persistently infected mice are functional when transferred to Rag1-/- recipients. Finally, increased early replication and persistence are also observed in mixed bone marrow chimeras where only half of the CD11c positive DCs are unable to respond to type I IFN. These findings demonstrate that increased early viral replication due to a cell-intrinsic innate immune deficiency is sufficient for persistence and a functional adaptive immune response is not sufficient for viral clearance.
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Affiliation(s)
- Timothy J. Nice
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Lisa C. Osborne
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vesselin T. Tomov
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - David Artis
- Department of Microbiology and Immunology, and Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - E. John Wherry
- Department of Microbiology, and Institute for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Herbert W. Virgin
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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160
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Blanc CA, Grist JJ, Rosen H, Sears-Kraxberger I, Steward O, Lane TE. Sphingosine-1-phosphate receptor antagonism enhances proliferation and migration of engrafted neural progenitor cells in a model of viral-induced demyelination. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 185:2819-32. [PMID: 26435414 DOI: 10.1016/j.ajpath.2015.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 06/22/2015] [Accepted: 06/25/2015] [Indexed: 01/12/2023]
Abstract
The oral drug FTY720 affects sphingosine-1-phosphate (S1P) signaling on targeted cells that bear the S1P receptors S1P1, S1P3, S1P4, and S1P5. We examined the effect of FTY720 treatment on the biology of mouse neural progenitor cells (NPCs) after transplantation in a viral model of demyelination. Intracerebral infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV) resulted in an acute encephalomyelitis, followed by demyelination similar in pathology to the human demyelinating disease, multiple sclerosis. We have previously reported that intraspinal transplantation of mouse NPCs into JHMV-infected animals resulted in selective colonization of demyelinated lesions, preferential differentiation into oligodendroglia accompanied by axonal preservation, and increased remyelination. Cultured NPCs expressed transcripts for S1P receptors S1P1, S1P2, S1P3, S1P4, and S1P5. FTY720 treatment of cultured NPCs resulted in increased mitogen-activated protein kinase phosphorylation and migration after exposure to the chemokine CXCL12. Administration of FTY720 to JHMV-infected mice resulted in enhanced migration and increased proliferation of transplanted NPCs after spinal cord engraftment. FTY720 treatment did not improve clinical disease, diminish neuroinflammation or the severity of demyelination, nor increase remyelination. These findings argue that FTY720 treatment selectively increases NPC proliferation and migration but does not either improve clinical outcome or enhance remyelination after transplantation into animals in which immune-mediated demyelination is initiated by the viral infection of the central nervous system.
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Affiliation(s)
- Caroline A Blanc
- Department of Molecular Biology and Biochemistry, Reeve-Irvine Research Center Irvine School of Medicine, University of California, Irvine, California
| | - Jonathan J Grist
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Hugh Rosen
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California
| | - Ilse Sears-Kraxberger
- Departments of Anatomy and Neurobiology and Neurobiology and Behavior, Reeve-Irvine Research Center Irvine School of Medicine, University of California, Irvine, California
| | - Oswald Steward
- Departments of Anatomy and Neurobiology and Neurobiology and Behavior, Reeve-Irvine Research Center Irvine School of Medicine, University of California, Irvine, California
| | - Thomas E Lane
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah.
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161
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Phares TW, DiSano KD, Stohlman SA, Segal BM, Bergmann CC. CXCL13 promotes isotype-switched B cell accumulation to the central nervous system during viral encephalomyelitis. Brain Behav Immun 2016; 54:128-139. [PMID: 26795429 PMCID: PMC4828287 DOI: 10.1016/j.bbi.2016.01.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/13/2016] [Accepted: 01/16/2016] [Indexed: 11/28/2022] Open
Abstract
Elevated CXCL13 within the central nervous system (CNS) correlates with humoral responses in several neuroinflammatory diseases, yet its role is controversial. During coronavirus encephalomyelitis CXCL13 deficiency impaired CNS accumulation of memory B cells and antibody-secreting cells (ASC) but not naïve/early-activated B cells. However, despite diminished germinal center B cells and follicular helper T cells in draining lymph nodes, ASC in bone marrow and antiviral serum antibody were intact in the absence of CXCL13. The data demonstrate that CXCL13 is not essential in mounting effective peripheral humoral responses, but specifically promotes CNS accumulation of differentiated B cells.
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Affiliation(s)
- Timothy W Phares
- Department of Neurosciences NC30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, USA.
| | - Krista D DiSano
- Department of Neurosciences NC30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, USA; School of Biomedical Sciences, Kent State University, Kent, OH, USA.
| | - Stephen A Stohlman
- Department of Neurosciences NC30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, USA.
| | - Benjamin M Segal
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Cornelia C Bergmann
- Department of Neurosciences NC30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, USA.
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162
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Middle East respiratory syndrome vaccines. Int J Infect Dis 2016; 47:23-8. [PMID: 27062985 PMCID: PMC4969153 DOI: 10.1016/j.ijid.2016.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 03/31/2016] [Accepted: 04/03/2016] [Indexed: 12/22/2022] Open
Abstract
Middle East respiratory syndrome (MERS), caused by a novel coronavirus, is a highly lethal respiratory disease. No vaccines or antiviral therapies are available. Camels are widely infected and may be good targets for vaccination. MERS monoclonal antibodies and human convalescent sera may be useful for prophylaxis and treatment. Active immunization strategies, based on the severe acute respiratory syndrome (SARS) experience, are under development.
The Middle East respiratory syndrome coronavirus (MERS-CoV) has infected over 1600 individuals with nearly 600 deaths since it was first identified in human populations in 2012. No antiviral therapies or vaccines are available for its treatment or prophylaxis. Approaches to the development of MERS vaccines are discussed herein, including a summary of previous efforts to develop vaccines useful against human and non-human coronaviruses. A striking feature of MERS is the important role that camels have in transmission. Camel vaccination may be a novel approach to preventing human infection.
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Central Nervous System Stromal Cells Control Local CD8(+) T Cell Responses during Virus-Induced Neuroinflammation. Immunity 2016; 44:622-633. [PMID: 26921107 PMCID: PMC7111064 DOI: 10.1016/j.immuni.2015.12.022] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 11/09/2015] [Accepted: 12/01/2015] [Indexed: 11/23/2022]
Abstract
Stromal cells generate a complex cellular scaffold that provides specialized microenvironments for lymphocyte activation in secondary lymphoid organs. Here, we assessed whether local activation of stromal cells in the central nervous system (CNS) is mandatory to transfer immune recognition from secondary lymphoid organs into the infected tissue. We report that neurotropic virus infection in mice triggered the establishment of such stromal cell niches in the CNS. CNS stromal cell activation was dominated by a rapid and vigorous production of CC-motif chemokine receptor (CCR) 7 ligands CCL19 and CCL21 by vascular endothelial cells and adjacent fibroblastic reticular cell (FRC)-like cells in the perivascular space. Moreover, CCR7 ligands produced by CNS stromal cells were crucial to support recruitment and local re-activation of antiviral CD8+ T cells and to protect the host from lethal neuroinflammatory disease, indicating that CNS stromal cells generate confined microenvironments that control protective T cell immunity. CNS stromal cells swiftly generate CCR7 ligands during neurotropic virus infection CCR7-expressing antiviral CD8+ T cells prevent lethal CNS disease Stromal cell-derived CCR7 ligands guide CD8+ T cells to infected target cells
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164
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Chaves DG, Sales CC, de Cássia Gonçalves P, da Silva-Malta MCF, Romanelli LC, Ribas JG, de Freitas Carneiro-Proietti AB, Martins ML. Plasmatic proinflammatory chemokines levels are tricky markers to monitoring HTLV-1 carriers. J Med Virol 2016; 88:1438-47. [DOI: 10.1002/jmv.24481] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Daniel Gonçalves Chaves
- Research Service; Minas Gerais State Blood Center (Fundação Hemominas); Belo Horizonte Brazil
| | - Camila Campos Sales
- Pharmacy College; Federal University of Minas Gerais (UFMG); Belo Horizonte Brazil
| | | | | | - Luiz Cláudio Romanelli
- Research Service; Minas Gerais State Blood Center (Fundação Hemominas); Belo Horizonte Brazil
- GIPH (Interdisciplinary HTLV Research Group); Belo Horizonte Minas Gerais Brazil
| | - João Gabriel Ribas
- GIPH (Interdisciplinary HTLV Research Group); Belo Horizonte Minas Gerais Brazil
| | - Anna Bárbara de Freitas Carneiro-Proietti
- Research Service; Minas Gerais State Blood Center (Fundação Hemominas); Belo Horizonte Brazil
- GIPH (Interdisciplinary HTLV Research Group); Belo Horizonte Minas Gerais Brazil
| | - Marina Lobato Martins
- Research Service; Minas Gerais State Blood Center (Fundação Hemominas); Belo Horizonte Brazil
- GIPH (Interdisciplinary HTLV Research Group); Belo Horizonte Minas Gerais Brazil
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165
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Marro BS, Grist JJ, Lane TE. Inducible Expression of CXCL1 within the Central Nervous System Amplifies Viral-Induced Demyelination. THE JOURNAL OF IMMUNOLOGY 2016; 196:1855-64. [PMID: 26773148 DOI: 10.4049/jimmunol.1501802] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/16/2015] [Indexed: 12/11/2022]
Abstract
The functional role of the ELR(+) chemokine CXCL1 in host defense and disease following infection of the CNS with the neurotropic JHM strain of mouse hepatitis virus (JHMV) was examined. Mice in which expression of CXCL1 is under the control of a tetracycline-inducible promoter active within glial fibrillary acidic protein-positive cells were generated and this allowed for selectively increasing CNS expression of CXCL1 in response to JHMV infection and evaluating the effects on neuroinflammation, control of viral replication, and demyelination. Inducible expression of CNS-derived CXCL1 resulted in increased levels of CXCL1 protein within the serum, brain, and spinal cord that correlated with increased frequency of Ly6G(+)CD11b(+) neutrophils present within the CNS. Elevated levels of CXCL1 did not influence the generation of virus-specific T cells, and there was no difference in control of JHMV replication compared with control mice, indicating that T cell infiltration into the CNS is CXCL1-independent. Sustained CXCL1 expression within the CNS resulted in increased mortality that correlated with elevated neutrophil infiltration, diminished numbers of mature oligodendrocytes, and an increase in the severity of demyelination. Neutrophil ablation in CXCL1-transgenic mice reduced the severity of demyelination in mice, arguing for a role for these cells in white matter damage. Collectively, these findings illustrate that sustained CXCL1 expression amplifies the severity of white matter damage and that neutrophils can contribute to this process in a model of viral-induced neurologic disease.
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Affiliation(s)
- Brett S Marro
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine CA 92697; and
| | - Jonathan J Grist
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Thomas E Lane
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112
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Abstract
Neurotropic strains of the mouse hepatitis virus (MHV) cause a range of diseases in infected mice ranging from mild encephalitis with clearance of the virus followed by demyelination to rapidly fatal encephalitis. This chapter discusses the structure, life cycle, transmission, and pathology of neurotropic coronaviruses, as well as the immune response to coronavirus infection. Mice infected with neurotropic strains of MHV have provided useful systems in which to study processes of virus- and immune-mediated demyelination and virus clearance and/or persistence in the CNS, and the mechanisms of virus evasion of the immune system.
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167
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Savarin C, Bergmann CC, Gaignage M, Stohlman SA. Self-reactive CD4(+) T cells activated during viral-induced demyelination do not prevent clinical recovery. J Neuroinflammation 2015; 12:207. [PMID: 26559484 PMCID: PMC4642610 DOI: 10.1186/s12974-015-0426-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/06/2015] [Indexed: 12/18/2022] Open
Abstract
Background Microbial infections have been implicated in initiating and enhancing severity of autoimmune diseases including the demyelinating disease multiple sclerosis (MS). Nevertheless, the incidence of both acute and persisting viral infections without evidence of autoimmune sequelae suggests that this process is well controlled. The conditions promoting or stemming self-reactive (SR) T cells following viral-induced tissue damage thus need to be better defined. Using a non-fatal viral mouse model of encephalomyelitis associated with demyelination and disability, yet ultimate clinical improvement, this study set out to monitor uptake and presentation of endogenous myelin antigens, as well as induction and fate of SR T cells. Methods Activation and central nervous system (CNS) recruitment of myelin-specific CD4 T cells was analyzed by flow cytometry during encephalomyelitis induced by a glia tropic murine coronavirus. Potential antigen-presenting cells (APC) ingesting myelin were characterized by flow cytometry and their ability to activate SR T cells tested by co-culture with carboxyfluorescein succinimidyl ester (CFSE)-labeled myelin-specific CD4 T cells. Endogenous SR T cell kinetics was analyzed within both cervical lymph nodes and CNS by Enzyme-Linked ImmunoSpot (ELISPOT) following viral infection. Results The data demonstrate the presence of APC capable of activating SR T cells in both draining lymph nodes and the CNS temporally correlating with overt demyelination. While both the CNS-infiltrating myeloid population and microglia ingested myelin, only CNS-infiltrating APC were capable of presenting endogenous myelin antigen to SR T cells ex vivo. Finally, SR T cell activation from the endogenous T cell repertoire was most notable when infectious virus was controlled and paralleled myelin damage. Although SR T cell accumulation peaked in the persistently infected CNS during maximal demyelination, they were not preferentially retained. Their gradual decline, despite ongoing demyelination, suggested minimal re-stimulation and pathogenic function in vivo consistent with the lack of autoimmune symptoms. Conclusions The results demonstrate the potential for CNS tissue destruction to induce and recruit SR T cells to the injury site and support a host suppressive mechanism limiting development of autoimmunity.
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Affiliation(s)
- Carine Savarin
- Department of Neurosciences NC-30, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
| | - Cornelia C Bergmann
- Department of Neurosciences NC-30, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
| | - Melanie Gaignage
- Department of Neurosciences NC-30, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, 44195, USA. .,Present address: Unit of Experimental Medicine, de Duve Institute, Universite Catholique de Louvain, Brussels, Belgium.
| | - Stephen A Stohlman
- Department of Neurosciences NC-30, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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168
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Louveau A, Harris TH, Kipnis J. Revisiting the Mechanisms of CNS Immune Privilege. Trends Immunol 2015; 36:569-577. [PMID: 26431936 PMCID: PMC4593064 DOI: 10.1016/j.it.2015.08.006] [Citation(s) in RCA: 451] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/13/2015] [Accepted: 08/13/2015] [Indexed: 12/25/2022]
Abstract
Whereas the study of the interactions between the immune system and the central nervous system (CNS) has often focused on pathological conditions, the importance of neuroimmune communication in CNS homeostasis and function has become clear over that last two decades. Here we discuss the progression of our understanding of the interaction between the peripheral immune system and the CNS. We examine the notion of immune privilege of the CNS in light of both earlier findings and recent studies revealing a functional meningeal lymphatic system that drains cerebrospinal fluid (CSF) to the deep cervical lymph nodes, and consider the implications of a revised perspective on the immune privilege of the CNS on the etiology and pathology of different neurological disorders.
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Affiliation(s)
- Antoine Louveau
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Tajie H Harris
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
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169
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MDA5 Is Critical to Host Defense during Infection with Murine Coronavirus. J Virol 2015; 89:12330-40. [PMID: 26423942 DOI: 10.1128/jvi.01470-15] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/22/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Infection with the murine coronavirus mouse hepatitis virus (MHV) activates the pattern recognition receptors melanoma differentiation-associated gene 5 (MDA5) and Toll-like receptor 7 (TLR7) to induce transcription of type I interferon. Type I interferon is crucial for control of viral replication and spread in the natural host, but the specific contributions of MDA5 signaling to this pathway as well as to pathogenesis and subsequent immune responses are largely unknown. In this study, we use MHV infection of the liver as a model to demonstrate that MDA5 signaling is critically important for controlling MHV-induced pathology and regulation of the immune response. Mice deficient in MDA5 expression (MDA5(-/-) mice) experienced more severe disease following MHV infection, with reduced survival, increased spread of virus to additional sites of infection, and more extensive liver damage than did wild-type mice. Although type I interferon transcription decreased in MDA5(-/-) mice, the interferon-stimulated gene response remained intact. Cytokine production by innate and adaptive immune cells was largely intact in MDA5(-/-) mice, but perforin induction by natural killer cells and levels of interferon gamma, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) in serum were elevated. These data suggest that MDA5 signaling reduces the severity of MHV-induced disease, at least in part by reducing the intensity of the proinflammatory cytokine response. IMPORTANCE Multicellular organisms employ a wide range of sensors to detect viruses and other pathogens. One such sensor, MDA5, detects viral RNA and triggers induction of type I interferons, chemical messengers that induce inflammation and help regulate the immune responses. In this study, we sought to determine the role of MDA5 during infection with mouse hepatitis virus, a murine coronavirus used to model viral hepatitis as well as other human diseases. We found that mice lacking the MDA5 sensor were more susceptible to infection than were mice with MDA5 and experienced decreased survival. Viral replication in the liver was similar in mice with and without MDA5, but liver damage was increased in MDA5(-/-) mice, suggesting that the immune response is causing the damage. Production of several proinflammatory cytokines was elevated in MDA5(-/-) mice, suggesting that MDA5 may be responsible for keeping pathological inflammatory responses in check.
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170
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Abstract
Middle East respiratory syndrome (MERS) is a highly lethal respiratory disease caused by a novel single-stranded, positive-sense RNA betacoronavirus (MERS-CoV). Dromedary camels, hosts for MERS-CoV, are implicated in direct or indirect transmission to human beings, although the exact mode of transmission is unknown. The virus was first isolated from a patient who died from a severe respiratory illness in June, 2012, in Jeddah, Saudi Arabia. As of May 31, 2015, 1180 laboratory-confirmed cases (483 deaths; 40% mortality) have been reported to WHO. Both community-acquired and hospital-acquired cases have been reported with little human-to-human transmission reported in the community. Although most cases of MERS have occurred in Saudi Arabia and the United Arab Emirates, cases have been reported in Europe, the USA, and Asia in people who travelled from the Middle East or their contacts. Clinical features of MERS range from asymptomatic or mild disease to acute respiratory distress syndrome and multiorgan failure resulting in death, especially in individuals with underlying comorbidities. No specific drug treatment exists for MERS and infection prevention and control measures are crucial to prevent spread in health-care facilities. MERS-CoV continues to be an endemic, low-level public health threat. However, the virus could mutate to have increased interhuman transmissibility, increasing its pandemic potential.
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Affiliation(s)
- Alimuddin Zumla
- Division of Infection and Immunity, University College London, London, UK; NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, UK
| | - David S Hui
- Division of Respiratory Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, New Territories, Hong Kong Special Administrative Region, China; Stanley Ho Center for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, New Territories, Hong Kong Special Administrative Region, China
| | - Stanley Perlman
- Department of Microbiology, University of Iowa, Iowa City, IA, USA; Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
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171
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Abstract
Middle East respiratory syndrome (MERS) is a highly lethal respiratory disease caused by a novel single-stranded, positive-sense RNA betacoronavirus (MERS-CoV). Dromedary camels, hosts for MERS-CoV, are implicated in direct or indirect transmission to human beings, although the exact mode of transmission is unknown. The virus was first isolated from a patient who died from a severe respiratory illness in June, 2012, in Jeddah, Saudi Arabia. As of May 31, 2015, 1180 laboratory-confirmed cases (483 deaths; 40% mortality) have been reported to WHO. Both community-acquired and hospital-acquired cases have been reported with little human-to-human transmission reported in the community. Although most cases of MERS have occurred in Saudi Arabia and the United Arab Emirates, cases have been reported in Europe, the USA, and Asia in people who travelled from the Middle East or their contacts. Clinical features of MERS range from asymptomatic or mild disease to acute respiratory distress syndrome and multiorgan failure resulting in death, especially in individuals with underlying comorbidities. No specific drug treatment exists for MERS and infection prevention and control measures are crucial to prevent spread in health-care facilities. MERS-CoV continues to be an endemic, low-level public health threat. However, the virus could mutate to have increased interhuman transmissibility, increasing its pandemic potential.
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Affiliation(s)
- Alimuddin Zumla
- Division of Infection and Immunity, University College London, London, UK; NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, UK
| | - David S Hui
- Division of Respiratory Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, New Territories, Hong Kong Special Administrative Region, China; Stanley Ho Center for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, New Territories, Hong Kong Special Administrative Region, China
| | - Stanley Perlman
- Department of Microbiology, University of Iowa, Iowa City, IA, USA; Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
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172
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O'Donnell LA, Henkins KM, Kulkarni A, Matullo CM, Balachandran S, Pattisapu AK, Rall GF. Interferon gamma induces protective non-canonical signaling pathways in primary neurons. J Neurochem 2015; 135:309-22. [PMID: 26190522 DOI: 10.1111/jnc.13250] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 06/12/2015] [Accepted: 07/13/2015] [Indexed: 12/29/2022]
Abstract
The signal transduction molecule, Stat1, is critical for the expression of type I and II interferon (IFN)-responsive genes in most cells; however, we previously showed that primary hippocampal mouse neurons express low basal Stat1, with delayed and attenuated expression of IFN-responsive genes. Moreover, IFNγ-dependent resolution of a neurotropic viral challenge in permissive mice is Stat1-independent. Here, we show that exogenous IFNγ has no deleterious impact on neuronal viability, and staurosporine-induced apoptosis in neurons is significantly blunted by the addition of IFNγ, suggesting that IFNγ confers a pro-survival signal in neurons. To identify the pathways induced by IFNγ in neurons, the activation of alternative signal transducers associated with IFNγ signaling was assessed. Rapid and pronounced activation of extracellular signal regulated kinase (Erk1/2) was observed in neurons, compared to a modest response in fibroblasts. Moreover, the absence of Stat1 in primary fibroblasts led to enhanced Erk activation following IFNγ addition, implying that the cell-specific availability of signal transducers can diversify the cellular response following IFN engagement.
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Affiliation(s)
- Lauren A O'Donnell
- Fox Chase Cancer Center, Program in Immune Cell Development and Host Defense, Philadelphia, Pennsylvania, USA.,Duquesne University, Mylan School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Kristen M Henkins
- Fox Chase Cancer Center, Program in Immune Cell Development and Host Defense, Philadelphia, Pennsylvania, USA
| | - Apurva Kulkarni
- Duquesne University, Mylan School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Christine M Matullo
- Fox Chase Cancer Center, Program in Immune Cell Development and Host Defense, Philadelphia, Pennsylvania, USA
| | - Siddharth Balachandran
- Fox Chase Cancer Center, Program in Immune Cell Development and Host Defense, Philadelphia, Pennsylvania, USA
| | - Anil K Pattisapu
- Duquesne University, Mylan School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Glenn F Rall
- Fox Chase Cancer Center, Program in Immune Cell Development and Host Defense, Philadelphia, Pennsylvania, USA
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173
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Wu GF, Parker Harp CR, Shindler KS. Optic Neuritis: A Model for the Immuno-pathogenesis of Central Nervous System Inflammatory Demyelinating Diseases. ACTA ACUST UNITED AC 2015; 11:85-92. [PMID: 29399010 DOI: 10.2174/1573395511666150707181644] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Evidence for the tenuous regulation between the immune system and central nervous system (CNS) can be found with examples of interaction between these organ systems gone awry. Multiple sclerosis (MS) is the prototypical inflammatory disease of the CNS and is characterized by widely distributed inflammatory demyelinating plaques that can involve the brain, spinal cord and/or optic nerves. Optic neuritis (ON), inflammatory injury of the optic nerve that frequently occurs in patients with MS, has been the focus of intense study in part given the readily accessible nature of clinical outcome measures. Exploring the clinical and pathological features of ON in relation to other inflammatory demyelinating conditions of the CNS, namely MS and neuromyelitis optica, provides an opportunity to glean common and distinct mechanisms of disease. Emerging data from clinical studies along with various animal models involving ON implicate innate and adaptive immune responses directed at glial targets, including myelin oligodendrocyte glycoprotein and aquaporin 4. Resolution of inflammation in ON is commonly observed both clinically and experimentally, but persistent nerve injury is also one emerging hallmark of ON. One hypothesis seeking evaluation is that, in comparison to other sites targeted in MS, the optic nerve is a highly specialized target within the CNS predisposing to unique immunologic processes that generate ON. Overall, ON serves as a highly relevant entity for understanding the pathogenesis of other CNS demyelinating conditions, most notably MS.
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Affiliation(s)
- Gregory F Wu
- Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.,Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Chelsea R Parker Harp
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Kenneth S Shindler
- Department of Ophthalmology, University of Pennsylvania School of Medicine, Philadelphia, PA 19004, USA
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174
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Arabi YM, Harthi A, Hussein J, Bouchama A, Johani S, Hajeer AH, Saeed BT, Wahbi A, Saedy A, AlDabbagh T, Okaili R, Sadat M, Balkhy H. Severe neurologic syndrome associated with Middle East respiratory syndrome corona virus (MERS-CoV). Infection 2015; 43:495-501. [PMID: 25600929 PMCID: PMC4521086 DOI: 10.1007/s15010-015-0720-y] [Citation(s) in RCA: 299] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/04/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Since the identification of the first case of infection with the Middle East respiratory syndrome corona virus (MERS-CoV) in Saudi Arabia in June 2012, the number of laboratory-confirmed cases has exceeded 941 cases globally, of which 347 died. The disease presents as severe respiratory infection often with shock, acute kidney injury, and coagulopathy. Recently, we observed three cases who presented with neurologic symptoms. These are so far the first reported cases of neurologic injury associated with MERS-CoV infection. METHODS Data was retrospectively collected from three patients admitted with MERS-CoV infection to Intensive Care unit (ICU) at King Abdulaziz Medical City, Riyadh. They were managed separately in three different wards prior to their admission to ICU. FINDING The three patients presented with severe neurologic syndrome which included altered level of consciousness ranging from confusion to coma, ataxia, and focal motor deficit. Brain MRI revealed striking changes characterized by widespread, bilateral hyperintense lesions on T2-weighted imaging within the white matter and subcortical areas of the frontal, temporal, and parietal lobes, the basal ganglia, and corpus callosum. None of the lesions showed gadolinium enhancement. INTERPRETATION CNS involvement should be considered in patients with MERS-CoV and progressive neurological disease, and further elucidation of the pathophysiology of this virus is needed.
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Affiliation(s)
- Y. M. Arabi
- Intensive Care Department, MC-1425, Respiratory Services, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center (KAIMRC), P.O. Box 22490, Riyadh, 11426 Kingdom of Saudi Arabia
| | - A. Harthi
- Neuro Physiology Services, Neurology Division, Department of Medicine, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - J. Hussein
- Neuro Radiology Section, Medical Imaging Department, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - A. Bouchama
- Intensive Care Unit, Experimental Medicine Department, King Abdullah International Medical Research Center (KAIMRC), King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - S. Johani
- Microbiology, Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - A. H. Hajeer
- Basic Medical Sciences, Microbiology, Pathology and Laboratory Department, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - B. T. Saeed
- Cardiac Sciences Department, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - A. Wahbi
- Vascular Surgery, Department of Surgery, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - A. Saedy
- Infectious Disease Section, Department of Medicine, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - T. AlDabbagh
- Intensive Care Unit, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - R. Okaili
- Neuro Radiology, Nuero Interventionalist, Medical Imaging Department, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - M. Sadat
- Intensive Care Unit, King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
| | - H. Balkhy
- Infection Prevention and Control Program, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center (KAIMRC), King Abdulaziz Medical City, Riyadh, 11426 Saudi Arabia
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175
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Myd88 Initiates Early Innate Immune Responses and Promotes CD4 T Cells during Coronavirus Encephalomyelitis. J Virol 2015; 89:9299-312. [PMID: 26136579 DOI: 10.1128/jvi.01199-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/22/2015] [Indexed: 02/08/2023] Open
Abstract
UNLABELLED Myd88 signaling is critical to the control of numerous central nervous system (CNS) infections by promoting both innate and adaptive immune responses. Nevertheless, the extent to which Myd88 regulates type I interferon (IFN) versus proinflammatory factors and T cell function, as well as the anatomical site of action, varies extensively with the pathogen. CNS infection by neurotropic coronavirus with replication confined to the brain and spinal cord induces protective IFN-α/β via Myd88-independent activation of melanoma differentiation-associated gene 5 (MDA5). However, a contribution of Myd88-dependent signals to CNS pathogenesis has not been assessed. Infected Myd88(-/-) mice failed to control virus, exhibited enhanced clinical disease coincident with increased demyelination, and succumbed to infection within 3 weeks. The induction of IFN-α/β, as well as of proinflammatory cytokines and chemokines, was impaired early during infection. However, defects in both IFN-α/β and select proinflammatory factors were rapidly overcome prior to T cell recruitment. Myd88 deficiency also specifically blunted myeloid and CD4 T cell recruitment into the CNS without affecting CD8 T cells. Moreover, CD4 T cells but not CD8 T cells were impaired in IFN-γ production. Ineffective virus control indeed correlated most prominently with reduced antiviral IFN-γ in the CNS of Myd88(-/-) mice. The results demonstrate a crucial role for Myd88 both in early induction of innate immune responses during coronavirus-induced encephalomyelitis and in specifically promoting protective CD4 T cell activation. In the absence of these responses, functional CD8 T cells are insufficient to control viral spread within the CNS, resulting in severe demyelination. IMPORTANCE During central nervous system (CNS) infections, signaling through the adaptor protein Myd88 promotes both innate and adaptive immune responses. The extent to which Myd88 regulates antiviral type I IFN, proinflammatory factors, adaptive immunity, and pathology is pathogen dependent. These results reveal that Myd88 protects from lethal neurotropic coronavirus-induced encephalomyelitis by accelerating but not enhancing the induction of IFN-α/β, as well as by promoting peripheral activation and CNS accumulation of virus-specific CD4 T cells secreting IFN-γ. By controlling both early innate immune responses and CD4 T cell-mediated antiviral IFN-γ, Myd88 signaling limits the initial viral dissemination and is vital for T cell-mediated control of viral loads. Uncontrolled viral replication in the absence of Myd88 leads to severe demyelination and pathology despite overall reduced inflammatory responses. These data support a vital role of Myd88 signaling in protective antimicrobial functions in the CNS by promoting proinflammatory mediators and T cell-mediated IFN-γ production.
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Puntambekar SS, Hinton DR, Yin X, Savarin C, Bergmann CC, Trapp BD, Stohlman SA. Interleukin-10 is a critical regulator of white matter lesion containment following viral induced demyelination. Glia 2015; 63:2106-2120. [PMID: 26132901 PMCID: PMC4755156 DOI: 10.1002/glia.22880] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 06/08/2015] [Accepted: 06/08/2015] [Indexed: 12/29/2022]
Abstract
Neurotropic coronavirus induces an acute encephalomyelitis accompanied by focal areas of demyelination distributed randomly along the spinal column. The initial areas of demyelination increase only slightly after the control of infection. These circumscribed focal lesions are characterized by axonal sparing, myelin ingestion by macrophage/microglia, and glial scars associated with hypertrophic astrocytes, which proliferate at the lesion border. Accelerated virus control in mice lacking the anti‐inflammatory cytokine IL‐10 was associated with limited initial demyelination, but low viral mRNA persistence similar to WT mice and declining antiviral cellular immunity. Nevertheless, lesions exhibited sustained expansion providing a model of dysregulated white matter injury temporally remote from the acute CNS insult. Expanding lesions in the absence of IL‐10 are characterized by sustained microglial activation and partial loss of macrophage/microglia exhibiting an acquired deactivation phenotype. Furthermore, IL‐10 deficiency impaired astrocyte organization into mesh like structures at the lesion borders, but did not prevent astrocyte hypertrophy. The formation of discrete foci of demyelination in IL‐10 sufficient mice correlated with IL‐10 receptor expression exclusively on astrocytes in areas of demyelination suggesting a critical role for IL‐10 signaling to astrocytes in limiting expansion of initial areas of white matter damage. GLIA 2015;63:2106–2120
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Affiliation(s)
- Shweta S Puntambekar
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - David R Hinton
- Department of Pathology, The University of Southern California Keck School of Medicine, Los Angeles, California
| | - Xinghua Yin
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Carine Savarin
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Cornelia C Bergmann
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Bruce D Trapp
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Stephen A Stohlman
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
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177
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Marro BS, Blanc CA, Loring JF, Cahalan MD, Lane TE. Promoting remyelination: utilizing a viral model of demyelination to assess cell-based therapies. Expert Rev Neurother 2015; 14:1169-79. [PMID: 25245576 DOI: 10.1586/14737175.2014.955854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS. While a broad range of therapeutics effectively reduce the incidence of focal white matter inflammation and plaque formation for patients with relapse-remitting forms of MS, a challenge within the field is to develop therapies that allow for axonal protection and remyelination. In the last decade, growing interest has focused on utilizing neural precursor cells (NPCs) to promote remyelination. To understand how NPCs function in chronic demyelinating environments, several excellent pre-clinical mouse models have been developed. One well accepted model is infection of susceptible mice with neurotropic variants of mouse hepatitis virus (MHV) that undergo chronic demyelination exhibiting clinical and histopathologic similarities to MS patients. Combined with the possibility that an environmental agent such as a virus could trigger MS, the MHV model of demyelination presents a relevant mouse model to assess the therapeutic potential of NPCs transplanted into an environment in which inflammatory-mediated demyelination is established.
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Affiliation(s)
- Brett S Marro
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
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178
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Weinger JG, Plaisted WC, Maciejewski SM, Lanier LL, Walsh CM, Lane TE. Activating receptor NKG2D targets RAE-1-expressing allogeneic neural precursor cells in a viral model of multiple sclerosis. Stem Cells 2015; 32:2690-701. [PMID: 24898518 DOI: 10.1002/stem.1760] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 04/25/2014] [Accepted: 04/25/2014] [Indexed: 12/11/2022]
Abstract
Transplantation of major histocompatibility complex-mismatched mouse neural precursor cells (NPCs) into mice persistently infected with the neurotropic JHM strain of mouse hepatitis virus (JHMV) results in rapid rejection that is mediated, in part, by T cells. However, the contribution of the innate immune response to allograft rejection in a model of viral-induced neurological disease has not been well defined. Herein, we demonstrate that the natural killer (NK) cell-expressing-activating receptor NKG2D participates in transplanted allogeneic NPC rejection in mice persistently infected with JHMV. Cultured NPCs derived from C57BL/6 (H-2(b) ) mice express the NKG2D ligand retinoic acid early precursor transcript (RAE)-1 but expression was dramatically reduced upon differentiation into either glia or neurons. RAE-1(+) NPCs were susceptible to NK cell-mediated killing whereas RAE-1(-) cells were resistant to lysis. Transplantation of C57BL/6-derived NPCs into JHMV-infected BALB/c (H-2(d) ) mice resulted in infiltration of NKG2D(+) CD49b(+) NK cells and treatment with blocking antibody specific for NKG2D increased survival of allogeneic NPCs. Furthermore, transplantation of differentiated RAE-1(-) allogeneic NPCs into JHMV-infected BALB/c mice resulted in enhanced survival, highlighting a role for the NKG2D/RAE-1 signaling axis in allograft rejection. We also demonstrate that transplantation of allogeneic NPCs into JHMV-infected mice resulted in infection of the transplanted cells suggesting that these cells may be targets for infection. Viral infection of cultured cells increased RAE-1 expression, resulting in enhanced NK cell-mediated killing through NKG2D recognition. Collectively, these results show that in a viral-induced demyelination model, NK cells contribute to rejection of allogeneic NPCs through an NKG2D signaling pathway.
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Affiliation(s)
- Jason G Weinger
- Department of Molecular Biology & Biochemistry; Sue and Bill Gross Stem Cell Center, University of California, Irvine, California, USA
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179
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Abstract
Emerging respiratory coronaviruses such as the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) pose potential biological threats to humans. SARS and MERS are manifested as severe atypical pneumonia associated with high morbidity and mortality in humans. The majority of studies carried out in SARS-CoV-infected humans and animals attribute a dysregulated/exuberant innate response as a leading contributor to SARS-CoV-mediated pathology. A decade after the 2002–2003 SARS epidemic, we do not have any approved preventive or therapeutic agents available in case of re-emergence of SARS-CoV or other related viruses. A strong neutralizing antibody response generated against the spike (S) glycoprotein of SARS-CoV is completely protective in the susceptible host. However, neutralizing antibody titers and the memory B cell response are short lived in SARS-recovered patients and the antibody will target primary homologous strain. Interestingly, the acute phase of SARS in humans is associated with a severe reduction in the number of T cells in the blood. Surprisingly, only a limited number of studies have explored the role of the T cell-mediated adaptive immune response in respiratory coronavirus pathogenesis. In this review, we discuss the role of anti-virus CD4 and CD8 T cells during respiratory coronavirus infections with a special emphasis on emerging coronaviruses.
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180
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Hwang M, Phares TW, Hinton DR, Stohlman SA, Bergmann CC, Min B. Distinct CD4 T-cell effects on primary versus recall CD8 T-cell responses during viral encephalomyelitis. Immunology 2015; 144:374-386. [PMID: 25187405 PMCID: PMC4557674 DOI: 10.1111/imm.12378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 12/23/2022] Open
Abstract
CD4 T-cell help is not a universal requirement for effective primary CD8 T cells but is essential to generate memory CD8 T cells capable of recall responses. This study examined how CD4 T cells affect primary and secondary anti-viral CD8 T-cell responses within the central nervous system (CNS) during encephalomyelitis induced by sublethal gliatropic coronavirus. CD4 T-cell depletion before infection did not impair peripheral expansion, interferon-γ production, CNS recruitment or initial CNS effector capacity of virus-specific CD8 T cells ex vivo. Nevertheless, impaired virus control in the absence of CD4 T cells was associated with gradually diminished CNS CD8 T-cell interferon-γ production. Furthermore, within the CD8 T-cell population short-lived effector cells were increased and memory precursor effector cells were significantly decreased, consistent with higher T-cell turnover. Transfer of memory CD8 T cells to reduce viral load in CD4-depleted mice reverted the recipient CNS CD8 T-cell phenotype to that in wild-type control mice. However, memory CD8 T cells primed without CD4 T cells and transferred into infected CD4-sufficient recipients expanded less efficiently and were not sustained in the CNS, contrasting with their helped counterparts. These data suggest that CD4 T cells are dispensable for initial expansion, CNS recruitment and differentiation of primary resident memory CD8 T cells as long as the duration of antigen exposure is limited. By contrast, CD4 T cells are essential to prolong primary CD8 T-cell function in the CNS and imprint memory CD8 T cells for recall responses.
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Affiliation(s)
- Mihyun Hwang
- Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Timothy W Phares
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - David R Hinton
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Stephen A Stohlman
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Cornelia C Bergmann
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Booki Min
- Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
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The nsp3 macrodomain promotes virulence in mice with coronavirus-induced encephalitis. J Virol 2014; 89:1523-36. [PMID: 25428866 DOI: 10.1128/jvi.02596-14] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED All coronaviruses encode a macrodomain containing ADP-ribose-1"-phosphatase (ADRP) activity within the N terminus of nonstructural protein 3 (nsp3). Previous work showed that mouse hepatitis virus strain A59 (MHV-A59) with a mutated catalytic site (N1348A) replicated similarly to wild-type virus but was unable to cause acute hepatitis in mice. To determine whether this attenuated phenotype is applicable to multiple disease models, we mutated the catalytic residue in the JHM strain of MHV (JHMV), which causes acute and chronic encephalomyelitis, using a newly developed bacterial artificial chromosome (BAC)-based MHV reverse genetics system. Infection of mice with the macrodomain catalytic point mutant virus (N1347A) resulted in reductions in lethality, weight loss, viral titers, proinflammatory cytokine and chemokine expression, and immune cell infiltration in the brain compared to mice infected with wild-type virus. Specifically, macrophages were most affected, with approximately 2.5-fold fewer macrophages at day 5 postinfection in N1347A-infected brains. Tumor necrosis factor (TNF) and interferon (IFN) signaling were not required for effective host control of mutant virus as all N1347A virus-infected mice survived the infection. However, the adaptive immune system was required for protection since N1347A virus was able to cause lethal encephalitis in RAG1(-/-) (recombination activation gene 1 knockout) mice although disease onset was modestly delayed. Overall, these results indicate that the BAC-based MHV reverse genetics system will be useful for studies of JHMV and expand upon previous studies, showing that the macrodomain is critical for the ability of coronaviruses to evade the immune system and promote viral pathogenesis. IMPORTANCE Coronaviruses are an important cause of human and veterinary diseases worldwide. Viral processes that are conserved across a family are likely to be good targets for the development of antiviral therapeutics and vaccines. The macrodomain is a ubiquitous structural domain and is also conserved among all coronaviruses. The coronavirus macrodomain has ADP-ribose-1"-phosphatase activity; however, its function during infection remains unclear as does the reason that coronaviruses have maintained this enzymatic activity throughout evolution. For MHV, this domain has now been shown to promote multiple types of disease, including hepatitis and encephalitis. These data indicate that this domain is vital for the virus to replicate and cause disease. Understanding the mechanism used by this enzyme to promote viral pathogenesis will open up novel avenues for therapies and may give further insight into the role of macrodomain proteins in the host cell since these proteins are found in all living organisms.
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182
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Xie L, Choudhury GR, Winters A, Yang SH, Jin K. Cerebral regulatory T cells restrain microglia/macrophage-mediated inflammatory responses via IL-10. Eur J Immunol 2014; 45:180-91. [PMID: 25329858 DOI: 10.1002/eji.201444823] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 08/29/2014] [Accepted: 10/13/2014] [Indexed: 12/17/2022]
Abstract
Forkhead box P3 (Foxp3)(+) regulatory T (Treg) cells maintain the immune tolerance and prevent inflammatory responses in the periphery. However, the presence of Treg cells in the CNS under steady state has not been studied. Here, for the first time, we show a substantial TCRαβ (+) CD4(+) Foxp3(+) T-cell population (cerebral Treg cells) in the rat cerebrum, constituting more than 15% of the cerebral CD4(+) T-cell compartment. Cerebral Treg cells showed an activated/memory phenotype and expressed many Treg-cell signature genes at higher levels than peripheral Treg cells. Consistent with their activated/memory phenotype, cerebral Treg cells robustly restrained the LPS-induced inflammatory responses of brain microglia/macrophages, suggesting a role in maintaining the cerebral homeostasis by inhibiting the neuroinflammation. In addition, brain astrocytes were the helper cells that sustained Foxp3 expression in Treg cells through IL-2/STAT5 signaling, showing that the interaction between astrocytes and Treg cells contributes to the maintenance of Treg-cell identity in the brain. Taken together, our work represents the first study to characterize the phenotypic and functional features of Treg cells in the rat cerebrum. Our data have provided a novel insight for the contribution of Treg cells to the immunosurveillance and immunomodulation in the cerebrum under steady state.
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Affiliation(s)
- Luokun Xie
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
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183
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Huber AK, Duncker PC, Irani DN. Immune responses to non-tumor antigens in the central nervous system. Front Oncol 2014; 4:328. [PMID: 25431758 PMCID: PMC4230036 DOI: 10.3389/fonc.2014.00328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/30/2014] [Indexed: 12/16/2022] Open
Abstract
The central nervous system (CNS), once viewed as an immune-privileged site protected by the blood-brain barrier (BBB), is now known to be a dynamic immunological environment through which immune cells migrate to prevent and respond to events such as localized infection. During these responses, endogenous glial cells, including astrocytes and microglia, become highly reactive and may secrete inflammatory mediators that regulate BBB permeability and recruit additional circulating immune cells. Here, we discuss the various roles played by astrocytes, microglia, and infiltrating immune cells during host immunity to non-tumor antigens in the CNS, focusing first on bacterial and viral infections, and then turning to responses directed against self-antigens in the setting of CNS autoimmunity.
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Affiliation(s)
- Amanda K Huber
- Department of Neurology, University of Michigan Medical School , Ann Arbor, MI , USA
| | - Patrick C Duncker
- Department of Neurology, University of Michigan Medical School , Ann Arbor, MI , USA
| | - David N Irani
- Department of Neurology, University of Michigan Medical School , Ann Arbor, MI , USA
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184
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Blanc CA, Rosen H, Lane TE. FTY720 (fingolimod) modulates the severity of viral-induced encephalomyelitis and demyelination. J Neuroinflammation 2014; 11:138. [PMID: 25138356 PMCID: PMC4148542 DOI: 10.1186/s12974-014-0138-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/27/2014] [Indexed: 02/07/2023] Open
Abstract
Background FTY720 (fingolimod) is the first oral drug approved by the Food and Drug Administration for treatment of patients with the relapsing-remitting form of the human demyelinating disease multiple sclerosis. Evidence suggests that the therapeutic benefit of FTY720 occurs by preventing the egress of lymphocytes from lymph nodes thereby inhibiting the infiltration of disease-causing lymphocytes into the central nervous system (CNS). We hypothesized that FTY720 treatment would affect lymphocyte migration to the CNS and influence disease severity in a mouse model of viral-induced neurologic disease. Methods Mice were infected intracranially with the neurotropic JHM strain of mouse hepatitis virus. Infected animals were treated with increasing doses (1, 3 and 10 mg/kg) of FTY720 and morbidity and mortality recorded. Infiltration of inflammatory virus-specific T cells (tetramer staining) into the CNS of FTY720-treated mice was determined using flow cytometry. The effects of FTY720 treatment on virus-specific T cell proliferation, cytokine production and cytolytic activity were also determined. The severity of neuroinflammation and demyelination in FTY720-treated mice was examined by flow cytometry and histopathologically, respectively, in the spinal cords of the mice. Results Administration of FTY720 to JHMV-infected mice resulted in increased clinical disease severity and mortality. These results correlated with impaired ability to control viral replication (P < 0.05) within the CNS at days 7 and 14 post-infection, which was associated with diminished accumulation of virus-specific CD4+ and CD8+ T cells (P < 0.05) into the CNS. Reduced neuroinflammation in FTY720-treated mice correlated with increased retention of T lymphocytes within draining cervical lymph nodes (P < 0.05). Treatment with FTY720 did not affect virus-specific T cell proliferation, expression of IFN-γ, TNF-α or cytolytic activity. FTY720-treated mice exhibited a reduction in the severity of demyelination associated with dampened neuroinflammation. Conclusion These findings indicate that FTY720 mutes effective anti-viral immune responses through impacting migration and accumulation of virus-specific T cells within the CNS during acute viral-induced encephalomyelitis. FTY720 treatment reduces the severity of neuroinflammatory-mediated demyelination by restricting the access of disease-causing lymphocytes into the CNS but is not associated with viral recrudescence in this model.
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185
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Trujillo JA, Croft NP, Dudek NL, Channappanavar R, Theodossis A, Webb AI, Dunstone MA, Illing PT, Butler NS, Fett C, Tscharke DC, Rossjohn J, Perlman S, Purcell AW. The cellular redox environment alters antigen presentation. J Biol Chem 2014; 289:27979-91. [PMID: 25135637 DOI: 10.1074/jbc.m114.573402] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cysteine-containing peptides represent an important class of T cell epitopes, yet their prevalence remains underestimated. We have established and interrogated a database of around 70,000 naturally processed MHC-bound peptides and demonstrate that cysteine-containing peptides are presented on the surface of cells in an MHC allomorph-dependent manner and comprise on average 5-10% of the immunopeptidome. A significant proportion of these peptides are oxidatively modified, most commonly through covalent linkage with the antioxidant glutathione. Unlike some of the previously reported cysteine-based modifications, this represents a true physiological alteration of cysteine residues. Furthermore, our results suggest that alterations in the cellular redox state induced by viral infection are communicated to the immune system through the presentation of S-glutathionylated viral peptides, resulting in altered T cell recognition. Our data provide a structural basis for how the glutathione modification alters recognition by virus-specific T cells. Collectively, these results suggest that oxidative stress represents a mechanism for modulating the virus-specific T cell response.
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Affiliation(s)
- Jonathan A Trujillo
- From the Department of Microbiology and the Interdisciplinary Program in Immunology, University of Iowa, Iowa City, Iowa 52242
| | - Nathan P Croft
- the Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia, the Department of Biochemistry and Molecular Biology and
| | - Nadine L Dudek
- the Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia, the Department of Biochemistry and Molecular Biology and
| | | | | | - Andrew I Webb
- the Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Patricia T Illing
- the Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Noah S Butler
- From the Department of Microbiology and the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia, and
| | | | - David C Tscharke
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Jamie Rossjohn
- the Department of Biochemistry and Molecular Biology and Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia, the Institute of Infection and Immunity, Cardiff University, School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Stanley Perlman
- From the Department of Microbiology and the Interdisciplinary Program in Immunology, University of Iowa, Iowa City, Iowa 52242,
| | - Anthony W Purcell
- the Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia, the Department of Biochemistry and Molecular Biology and
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186
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Zhao J, Zhao J, Perlman S. Virus-specific regulatory T cells ameliorate encephalitis by repressing effector T cell functions from priming to effector stages. PLoS Pathog 2014; 10:e1004279. [PMID: 25102154 PMCID: PMC4125232 DOI: 10.1371/journal.ppat.1004279] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/12/2014] [Indexed: 11/18/2022] Open
Abstract
Several studies have demonstrated the presence of pathogen-specific Foxp3+ CD4 regulatory T cells (Treg) in infected animals, but little is known about where and how these cells affect the effector T cell responses and whether they are more suppressive than bulk Treg populations. We recently showed the presence of both epitope M133-specific Tregs (M133 Treg) and conventional CD4 T cells (M133 Tconv) in the brains of mice with coronavirus-induced encephalitis. Here, we provide new insights into the interactions between pathogenic Tconv and Tregs responding to the same epitope. M133 Tregs inhibited the proliferation but not initial activation of M133 Tconv in draining lymph nodes (DLN). Further, M133 Tregs inhibited migration of M133 Tconv from the DLN. In addition, M133 Tregs diminished microglia activation and decreased the number and function of Tconv in the infected brain. Thus, virus-specific Tregs inhibited pathogenic CD4 T cell responses during priming and effector stages, particularly those recognizing cognate antigen, and decreased mortality and morbidity without affecting virus clearance. These cells are more suppressive than bulk Tregs and provide a targeted approach to ameliorating immunopathological disease in infectious settings.
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Affiliation(s)
- Jingxian Zhao
- Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America
| | - Jincun Zhao
- Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America
| | - Stanley Perlman
- Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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de Aquino MTP, Kapil P, Hinton DR, Phares TW, Puntambekar SS, Savarin C, Bergmann CC, Stohlman SA. IL-27 limits central nervous system viral clearance by promoting IL-10 and enhances demyelination. THE JOURNAL OF IMMUNOLOGY 2014; 193:285-94. [PMID: 24890725 DOI: 10.4049/jimmunol.1400058] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
IL-27 is a pleiotropic member of the IL-6 and IL-12 cytokine family composed of the IL-27p28 and the EBV-induced gene 3. IL-27 and its receptor mRNA are both upregulated in the CNS during acute encephalomyelitis induced by the JHM strain of mouse hepatitis virus (JHMV) and sustained during viral persistence. Contributions of IL-27 to viral pathogenesis were evaluated by infection of IL-27Rα-chain-deficient (IL-27Rα(-/-)) mice. The absence of IL-27 signaling accelerated virus control within the CNS associated with increased IFN-γ secreting virus-specific CD4+ and CD8+ T cells. Abrogation of IL-27 signaling did not affect virus-specific CD8+ T cell-mediated IL-10 production or cytolytic activity or Foxp3+ regulatory T cell populations. However, IL-10 production by virus-specific CD4+ T cells was reduced significantly. Despite increased T cell-mediated antiviral function in IL-27Rα(-/-) mice, the virus persisted in the CNS at similar levels as in wild-type mice. Nevertheless, IL-27Rα(-/-) mice exhibited decreased clinical disease during persistence, coincident with less severe demyelination, the hallmark tissue damage associated with JHMV infection. Overall, these data demonstrate that in contrast to viral infections at other sites, IL-27 does not play a proinflammatory role during JHMV-induced encephalomyelitis. Rather, it limits CNS inflammation and impairs control of CNS virus replication via induction of IL-10 in virus-specific CD4+ T cells. Furthermore, in contrast to its protective role in limiting CNS autoimmunity and preventing immunopathology, these data define a detrimental role of IL-27 in promoting demyelination by delaying viral control.
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Affiliation(s)
- Maria Teresa P de Aquino
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - Parul Kapil
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - David R Hinton
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, CA 90089
| | - Timothy W Phares
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - Shweta S Puntambekar
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - Carine Savarin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - Cornelia C Bergmann
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
| | - Stephen A Stohlman
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195; and
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Progression from IgD+ IgM+ to isotype-switched B cells is site specific during coronavirus-induced encephalomyelitis. J Virol 2014; 88:8853-67. [PMID: 24872583 DOI: 10.1128/jvi.00861-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Various infections in the central nervous system (CNS) trigger B cell accumulation; however, the relative dynamics between viral replication and alterations in distinct B cell subsets are largely unknown. Using a glia-tropic coronavirus infection, which is initiated in the brain but rapidly spreads to and predominantly persists in the spinal cord, this study characterizes longitudinal changes in B cell subsets at both infected anatomical sites. The phase of T cell-dependent, antibody-independent control of infectious virus was associated with a similar recruitment of naive/early-activated IgD(+) IgM(+) B cells into both the brain and spinal cord. This population was progressively replaced by CD138(-) IgD(-) IgM(+) B cells, isotype-switched CD138(-) IgD(-) IgM(-) memory B cells (B(mem)), and CD138(+) antibody-secreting cells (ASC). A more rapid transition to B(mem) and ASC in spinal cord than in brain was associated with higher levels of persisting viral RNA and transcripts encoding factors promoting B cell migration, differentiation, and survival. The results demonstrate that naive/early-activated B cells are recruited early during coronavirus CNS infection but are subsequently replaced by more differentiated B cells. Furthermore, viral persistence, even at low levels, is a driving force for accumulation of isotype-switched B(mem) and ASC. IMPORTANCE Acute and chronic human CNS infections are associated with an accumulation of heterogeneous B cell subsets; however, their influence on viral load and disease is unclear. Using a glia-tropic coronavirus model, we demonstrate that the accumulation of B cells ranging from early-activated to isotype-switched differentiation stages is both temporally and spatially orchestrated. Acutely infected brains and spinal cords indiscriminately recruit a homogeneous population of early-activated B cells, which is progressively replaced by diverse, more differentiated subsets. The latter process is accelerated by elevated proinflammatory responses associated with viral persistence. The results imply that early-recruited B cells do not have antiviral function but may contribute to the inflammatory environment or act as antigen-presenting cells. Moreover, CNS viral persistence is a driving force promoting differentiated B cells with protective potential.
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189
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Two-photon imaging of remyelination of spinal cord axons by engrafted neural precursor cells in a viral model of multiple sclerosis. Proc Natl Acad Sci U S A 2014; 111:E2349-55. [PMID: 24843159 DOI: 10.1073/pnas.1406658111] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Neural precursor cells (NPCs) offer a promising approach for treating demyelinating diseases. However, the cellular dynamics that underlie transplanted NPC-mediated remyelination have not been described. Using two-photon imaging of a newly developed ventral spinal cord preparation and a viral model of demyelination, we describe the motility and intercellular interactions of transplanted mouse NPCs expressing green fluorescent protein (GFP) with damaged axons expressing yellow fluorescent protein (YFP). Our findings reveal focal axonal degeneration that occurs in the ventral side of the spinal cord within 1 wk following intracranial instillation with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Axonal damage precedes extensive demyelination and is characterized by swelling along the length of the axon, loss of YFP signal, and transected appearance. NPCs engrafted into spinal cords of JHMV-infected mice exhibited diminished migration velocities and increased proliferation compared with transplanted cells in noninfected mice. NPCs preferentially accumulated within areas of axonal damage, initiated direct contact with axons, and subsequently expressed the myelin proteolipid protein gene, initiating remyelination. These findings indicate that NPCs transplanted into an inflammatory demyelinating microenvironment participate directly in therapeutic outcome through the wrapping of myelin around damaged neurons.
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190
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Trujillo JA, Gras S, Twist KA, Croft NP, Channappanavar R, Rossjohn J, Purcell AW, Perlman S. Structural and functional correlates of enhanced antiviral immunity generated by heteroclitic CD8 T cell epitopes. THE JOURNAL OF IMMUNOLOGY 2014; 192:5245-56. [PMID: 24795457 DOI: 10.4049/jimmunol.1400111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peptides that bind poorly to MHC class I molecules often elicit low-functional avidity T cell responses. Peptide modification by altering the anchor residue facilitates increased binding affinity and may elicit T cells with increased functional avidity toward the native epitope ("heteroclitic"). This augmented MHC binding is likely to increase the half-life and surface density of the heteroclitic complex, but precisely how this enhanced T cell response occurs in vivo is not known. Furthermore, the ideal heteroclitic epitope will elicit T cell responses that completely cross-react with the native epitope, maximizing protection and minimizing undesirable off-target effects. Such epitopes have been difficult to identify. In this study, using mice infected with a murine coronavirus that encodes epitopes that elicit high (S510, CSLWNGPHL)- and low (S598, RCQIFANI)-functional avidity responses, we show that increased expression of peptide S598 but not S510 generated T cells with enhanced functional avidity. Thus, immune responses can be augmented toward T cell epitopes with low functional avidity by increasing Ag density. We also identified a heteroclitic epitope (RCVIFANI) that elicited a T cell response with nearly complete cross-reactivity with native epitope and demonstrated increased MHC/peptide abundance compared with native S598. Structural and thermal melt analyses indicated that the Q600V substitution enhanced stability of the peptide/MHC complex without greatly altering the antigenic surface, resulting in highly cross-reactive T cell responses. Our data highlight that increased peptide/MHC complex display contributes to heteroclitic epitope efficacy and describe parameters for maximizing immune responses that cross-react with the native epitope.
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Affiliation(s)
- Jonathan A Trujillo
- Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242
| | - Stephanie Gras
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Kelly-Anne Twist
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Nathan P Croft
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | | | - Jamie Rossjohn
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia; and Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Anthony W Purcell
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Stanley Perlman
- Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242; Department of Microbiology, University of Iowa, Iowa City, IA 52242;
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191
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Up-regulation of pro-inflammatory factors by HP-PRRSV infection in microglia: Implications for HP-PRRSV neuropathogenesis. Vet Microbiol 2014; 170:48-57. [DOI: 10.1016/j.vetmic.2014.01.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 01/24/2014] [Accepted: 01/28/2014] [Indexed: 11/24/2022]
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192
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Protein interferon-stimulated gene 15 conjugation delays but does not overcome coronavirus proliferation in a model of fulminant hepatitis. J Virol 2014; 88:6195-204. [PMID: 24648452 DOI: 10.1128/jvi.03801-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Coronaviruses express a deubiquitinating protein, the papain-like protease-2 (PLP2), that removes both ubiquitin and the ubiquitin-like interferon (IFN)-stimulated gene 15 (ISG15) protein from target proteins. ISG15 has antiviral activity against a number of viruses; therefore, we examined the effect of ISG15 conjugation (ISGylation) in a model of acute viral hepatitis induced by the murine hepatitis virus strain 3 (MHV-3) coronavirus. Mice deficient in the ISG15 deconjugating enzyme, ubiquitin-specific peptidase-18 (USP18), accumulate high levels of ISG15-conjugated proteins and are hypersensitive to type I IFN. Infecting USP18(-/-) mice with MHV-3 resulted in extended survival (8 ± 1.2 versus 4 days) and in improved liver histology, a decreased inflammatory response, and viral titers 1 to 2 logs lower than in USP18(+/+) mice. The suppression of viral replication was not due to increased IFN since infected USP18(-/-) mice had neither increased hepatic IFN-α, -β, or -γ mRNA nor circulating protein. Instead, delayed MHV-3 replication coincided with high levels of cellular ISGylation. Decreasing ISGylation by knockdown of the ISG15 E1 enzyme, Ube1L, in primary USP18(+/+) and USP18(-/-) hepatocytes led to increased MHV-3 replication. Both in vitro and in vivo, increasing MHV-3 titers were coincident with increased PLP2 mRNA and decreased ISGylation over the course of infection. The pharmacologic inhibition of the PLP2 enzyme in vitro led to decreased MHV-3 replication. Overall, these results demonstrate the antiviral effect of ISGylation in an in vivo model of coronavirus-induced mouse hepatitis and illustrate that PLP2 manipulates the host innate immune response through the ISG15/USP18 pathway. IMPORTANCE There have been a number of serious worldwide pandemics due to widespread infections by coronavirus. This virus (in its many forms) is difficult to treat, in part because it is very good at finding "holes" in the way that the host (the infected individual) tries to control and eliminate the virus. In this study, we demonstrate that an important host viral defense-the ISG15 pathway-is only partially effective in controlling severe coronavirus infection. Activation of the pathway is very good at suppressing viral production, but over time the virus overwhelms the host response and the effects of the ISG15 pathway. These data provide insight into host-virus interactions during coronavirus infection and suggest that the ISG15 pathway is a reasonable target for controlling severe coronavirus infection although the best treatment will likely involve multiple pathways and targets.
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193
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Abstract
Virus infections usually begin in peripheral tissues and can invade the mammalian nervous system (NS), spreading into the peripheral (PNS) and more rarely the central (CNS) nervous systems. The CNS is protected from most virus infections by effective immune responses and multilayer barriers. However, some viruses enter the NS with high efficiency via the bloodstream or by directly infecting nerves that innervate peripheral tissues, resulting in debilitating direct and immune-mediated pathology. Most viruses in the NS are opportunistic or accidental pathogens, but a few, most notably the alpha herpesviruses and rabies virus, have evolved to enter the NS efficiently and exploit neuronal cell biology. Remarkably, the alpha herpesviruses can establish quiescent infections in the PNS, with rare but often fatal CNS pathology. Here we review how viruses gain access to and spread in the well-protected CNS, with particular emphasis on alpha herpesviruses, which establish and maintain persistent NS infections.
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Affiliation(s)
- Orkide O Koyuncu
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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194
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Kapil P, Stohlman SA, Hinton DR, Bergmann CC. PKR mediated regulation of inflammation and IL-10 during viral encephalomyelitis. J Neuroimmunol 2014; 270:1-12. [PMID: 24642385 PMCID: PMC4019976 DOI: 10.1016/j.jneuroim.2014.02.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 12/21/2022]
Abstract
Double-stranded RNA-dependent protein kinase (PKR) regulates antiviral activity, immune responses, apoptosis and neurotoxicity. Gliatropic coronavirus infection induced PKR activation in infected as well uninfected cells within the central nervous system (CNS). However, PKR deficiency only modestly increased viral replication and did not affect IFN-α/β or IL-1β expression. Despite reduced Il-6, Ccl5, and Cxcl10 mRNA, protein levels remained unaltered. Furthermore, PKR deficiency selectively reduced IL-10 production in CD4, but not CD8 T cells, without affecting CNS pathology. The results demonstrate the ability of PKR to balance neuroinflammation by selectively modulating key cytokines and chemokines in CNS resident and CD4 T cells.
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Affiliation(s)
- Parul Kapil
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Stephen A Stohlman
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - David R Hinton
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Cornelia C Bergmann
- Department of Neurosciences, NC-30, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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195
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Mathematical models for CFSE labelled lymphocyte dynamics: asymmetry and time-lag in division. J Math Biol 2013; 69:1547-83. [PMID: 24337680 DOI: 10.1007/s00285-013-0741-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 11/07/2013] [Indexed: 12/17/2022]
Abstract
Since their invention in 1994, fluorescent dyes such as carboxyfluorescein diacetate succinimidyl ester (CFSE) are used for cell proliferation analysis in flow cytometry. Importantly, the interpretation of such assays relies on the assumption that the label is divided equally between the daughter cells upon cell division. However, recent experimental studies indicate that division of cells is not perfectly symmetric and there is unequal distribution of protein between sister cell pairs. The uneven partition of protein or mass to daughter cells can lead to an overlap in the generations of CFSE-labelled cells with straightforward consequences for the resolution of individual generations. Numerous mathematical models developed so far for the analysis of CFSE proliferation assay incorporate the premise that the CFSE fluorescence intensity is halved in the two daughter cells. Here, we propose a novel modelling approach for the analysis of the CFSE cell proliferation assays which are characterized by poorly resolved peaks of cell generations in flow cytometric histograms. We formulate a mathematical model in the form of a system of delay hyperbolic partial differential equations which provides a good agreement with the CFSE histograms time-series data and allows an analytical treatment. The model is a further generalization of the recently proposed class of division- and label-structured models as it considers an asymmetric cell division. In addition, the basic structure of the cell cycle, i.e. the resting and cycling cell compartments, is taken into account. The model is used to estimate fundamental parameters such as activation rate, duration of the cell cycle, apoptosis rate, CFSE decay rate and asymmetry factor in cell division of monoclonal T cells during cognate interaction with dendritic cells.
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196
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Abstract
Infection of the CNS (central nervous system) with a sublethal neurotropic coronavirus (JHMV) induces a vigorous inflammatory response. CD4+ and CD8+ T cells are essential to control infectious virus but at the cost of tissue damage. An enigma in understanding the contribution of T cell subsets in pathogenesis resides in their distinct migration pattern across the BBB (blood brain barrier). CD4+ T cells transiently accumulate within the perivascular space, whereas CD8+ T cells migrate directly into the CNS parenchyma. As MMPs (matrix metalloproteinases) facilitate migration across the glia limitans, specific expression of the TIMP (tissue inhibitor of MMPs)-1 by CD4+ T cells present in the perivascular cuffs suggested that TIMP-1 is responsible for stalling CD4+ T cell migration into the CNS parenchyma. Using TIMP-1 deficient mice, the present data demonstrate an increase rather than a decrease in CD4+ T cell accumulation within the perivascular space during JHMV infection. Whereas virus control was not affected by perivascular retention of CD4+ T cells, disease severity was decreased and associated with reduced IFNγ (interferon γ) production. Moreover, decreased CD4+ T cell recruitment into the CNS parenchyma of TIMP-1 deficient mice was not associated with impaired T cell recruiting chemokines or MMP expression, and no compensation by other TIMP molecules was identified. These data suggest an MMP-independent role of TIMP-1 in regulating CD4+ T cell access into the CNS parenchyma during acute JHMV encephalitis.
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197
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de Aquino MTP, Puntambekar SS, Savarin C, Bergmann CC, Phares TW, Hinton DR, Stohlman SA. Role of CD25(+) CD4(+) T cells in acute and persistent coronavirus infection of the central nervous system. Virology 2013; 447:112-20. [PMID: 24210105 PMCID: PMC3906923 DOI: 10.1016/j.virol.2013.08.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/04/2013] [Accepted: 08/26/2013] [Indexed: 02/04/2023]
Abstract
The influence of CD25(+)CD4(+) regulatory T cells (Treg) on acute and chronic viral infection of the central nervous system (CNS) was examined using a glial tropic murine coronavirus. Treg in the CNS were highest during initial T cell mediated virus control, decreased and then remained relatively stable during persistence. Anti-CD25 treatment did not affect CNS recruitment of inflammatory cells. Viral control was initially delayed; however, neither the kinetics of viral control nor viral persistence were affected. By contrast, the absence of Treg during the acute phase resulted in increased demyelination during viral persistence. These data suggest that CNS inflammation, progression of viral control and viral persistence are relatively independent of CD25(+)CD4(+) Treg. However, their absence during acute infection alters the ability of the host to limit tissue damage.
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Affiliation(s)
- Maria Teresa P de Aquino
- Department of Neurosciences, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, NC30, Cleveland, OH 44195, United States
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198
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Elliott R, Li F, Dragomir I, Chua MMW, Gregory BD, Weiss SR. Analysis of the host transcriptome from demyelinating spinal cord of murine coronavirus-infected mice. PLoS One 2013; 8:e75346. [PMID: 24058676 PMCID: PMC3776850 DOI: 10.1371/journal.pone.0075346] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/12/2013] [Indexed: 01/29/2023] Open
Abstract
Persistent infection of the mouse central nervous system (CNS) with mouse hepatitis virus (MHV) induces a demyelinating disease pathologically similar to multiple sclerosis and is therefore used as a model system. There is little information regarding the host factors that correlate with and contribute to MHV-induced demyelination. Here, we detail the genes and pathways associated with MHV-induced demyelinating disease in the spinal cord. High-throughput sequencing of the host transcriptome revealed that demyelination is accompanied by numerous transcriptional changes indicative of immune infiltration as well as changes in the cytokine milieu and lipid metabolism. We found evidence that a Th1-biased cytokine/chemokine response and eicosanoid-derived inflammation accompany persistent MHV infection and that antigen presentation is ongoing. Interestingly, increased expression of genes involved in lipid transport, processing, and catabolism, including some with known roles in neurodegenerative diseases, coincided with demyelination. Lastly, expression of several genes involved in osteoclast or bone-resident macrophage function, most notably TREM2 and DAP12, was upregulated in persistently infected mouse spinal cord. This study highlights the complexity of the host antiviral response, which accompany MHV-induced demyelination, and further supports previous findings that MHV-induced demyelination is immune-mediated. Interestingly, these data suggest a parallel between bone reabsorption by osteoclasts and myelin debris clearance by microglia in the bone and the CNS, respectively. To our knowledge, this is the first report of using an RNA-seq approach to study the host CNS response to persistent viral infection.
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Affiliation(s)
- Ruth Elliott
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fan Li
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Isabelle Dragomir
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ming Ming W. Chua
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Brian D. Gregory
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Susan R. Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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199
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Abstract
Enteroviruses can frequently target the human central nervous system to induce a variety of neurological diseases. Although enteroviruses are highly cytolytic, emerging evidence has shown that these viruses can establish persistent infections both in vivo and in vitro. Here, we investigated the susceptibility of three human brain cell lines, CCF-STTG1, T98G, and SK-N-SH, to infection with three enterovirus serotypes: coxsackievirus B3 (CVB3), enterovirus 71, and coxsackievirus A9. Persistent infection was observed in CVB3-infected CCF-STTG1 cells, as evidenced by prolonged detection of infectious virions, viral RNA, and viral antigens. Of note, infected CCF-STTG1 cells expressed the nonfunctional canonical viral receptors coxsackievirus-adenovirus receptor and decay-accelerating factor, while removal of cell surface chondroitin sulfate from CCF-STTG1 cells inhibited the replication of CVB3, suggesting that receptor usage was one of the major limiting factors in CVB3 persistence. In addition, CVB3 curtailed the induction of beta interferon in infected CCF-STTG1 cells, which likely contributed to the initiation of persistence. Furthermore, proinflammatory chemokines and cytokines, such as vascular cell adhesion molecule 1, interleukin-8 (IL-8), and IL-6, were upregulated in CVB3-infected CCF-STTG1 cells and human progenitor-derived astrocytes. Our data together demonstrate the potential of CCF-STTG1 cells to be a novel cell model for studying CVB3-central nervous system interactions, providing the basis toward a better understanding of CVB3-induced chronic neuropathogenesis.
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200
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Bocharov G, Luzyanina T, Cupovic J, Ludewig B. Asymmetry of Cell Division in CFSE-Based Lymphocyte Proliferation Analysis. Front Immunol 2013; 4:264. [PMID: 24032033 PMCID: PMC3759284 DOI: 10.3389/fimmu.2013.00264] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/19/2013] [Indexed: 12/31/2022] Open
Abstract
Flow cytometry-based analysis of lymphocyte division using carboxyfluorescein succinimidyl ester (CFSE) dye dilution permits acquisition of data describing cellular proliferation and differentiation. For example, CFSE histogram data enable quantitative insight into cellular turnover rates by applying mathematical models and parameter estimation techniques. Several mathematical models have been developed using different types of deterministic or stochastic approaches. However, analysis of CFSE proliferation assays is based on the premise that the label is halved in the two daughter cells. Importantly, asymmetry of protein distribution in lymphocyte division is a basic biological feature of cell division with the degree of the asymmetry depending on various factors. Here, we review the recent literature on asymmetric lymphocyte division and CFSE-based lymphocyte proliferation analysis. We suggest that division- and label-structured mathematical models describing CFSE-based cell proliferation should take into account asymmetry and time-lag in cell proliferation. Utilization of improved modeling algorithms will permit straightforward quantification of essential parameters describing the performance of activated lymphocytes.
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Affiliation(s)
- Gennady Bocharov
- Institute of Numerical Mathematics, Russian Academy of Sciences , Moscow , Russia
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