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Stone ET, Pinto AK. T Cells in Tick-Borne Flavivirus Encephalitis: A Review of Current Paradigms in Protection and Disease Pathology. Viruses 2023; 15:958. [PMID: 37112938 PMCID: PMC10146733 DOI: 10.3390/v15040958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
The family Flaviviridae is comprised of a diverse group of arthropod-borne viruses that are the etiological agents of globally relevant diseases in humans. Among these, infection with several of these flaviviruses-including West Nile virus (WNV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), tick-borne encephalitis virus (TBEV), and Powassan virus (POWV)-can result in neuroinvasive disease presenting as meningitis or encephalitis. Factors contributing to the development and resolution of tick-borne flavivirus (TBEV, POWV) infection and neuropathology remain unclear, though many recently undertaken studies have described the virus-host interactions underlying encephalitic disease. With access to neural tissues despite the selectively permeable blood-brain barrier, T cells have emerged as one notable contributor to neuroinflammation. The goal of this review is to summarize the recent advances in tick-borne flavivirus immunology-particularly with respect to T cells-as it pertains to the development of encephalitis. We found that although T cell responses are rarely evaluated in a clinical setting, they are integral in conjunction with antibody responses to restricting the entry of TBFV into the CNS. The extent and means by which they can drive immune pathology, however, merits further study. Understanding the role of the T cell compartment in tick-borne flavivirus encephalitis is instrumental for improving vaccine safety and efficacy, and has implications for treatments and interventions for human disease.
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Affiliation(s)
| | - Amelia K. Pinto
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA
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2
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Viral Infection of the Central Nervous System and Neuroinflammation Precede Blood-Brain Barrier Disruption during Japanese Encephalitis Virus Infection. J Virol 2015; 89:5602-14. [PMID: 25762733 DOI: 10.1128/jvi.00143-15] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/02/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Japanese encephalitis is an acute zoonotic, mosquito-borne disease caused by Japanese encephalitis virus (JEV). Japanese encephalitis is characterized by extensive inflammation in the central nervous system (CNS) and disruption of the blood-brain barrier (BBB). However, the pathogenic mechanisms contributing to the BBB disruption are not known. Here, using a mouse model of intravenous JEV infection, we show that virus titers increased exponentially in the brain from 2 to 5 days postinfection. This was accompanied by an early, dramatic increase in the level of inflammatory cytokines and chemokines in the brain. Enhancement of BBB permeability, however, was not observed until day 4, suggesting that viral entry and the onset of inflammation in the CNS occurred prior to BBB damage. In vitro studies revealed that direct infection with JEV could not induce changes in the permeability of brain microvascular endothelial cell monolayers. However, brain extracts derived from symptomatic JEV-infected mice, but not from mock-infected mice, induced significant permeability of the endothelial monolayer. Consistent with a role for inflammatory mediators in BBB disruption, the administration of gamma interferon-neutralizing antibody ameliorated the enhancement of BBB permeability in JEV-infected mice. Taken together, our data suggest that JEV enters the CNS, propagates in neurons, and induces the production of inflammatory cytokines and chemokines, which result in the disruption of the BBB. IMPORTANCE Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia, resulting in 70,000 cases each year, in which approximately 20 to 30% of cases are fatal, and a high proportion of patients survive with serious neurological and psychiatric sequelae. Pathologically, JEV infection causes an acute encephalopathy accompanied by BBB dysfunction; however, the mechanism is not clear. Thus, understanding the mechanisms of BBB disruption in JEV infection is important. Our data demonstrate that JEV gains entry into the CNS prior to BBB disruption. Furthermore, it is not JEV infection per se, but the inflammatory cytokines/chemokines induced by JEV infection that inhibit the expression of TJ proteins and ultimately result in the enhancement of BBB permeability. Neutralization of gamma interferon (IFN-γ) ameliorated the enhancement of BBB permeability in JEV-infected mice, suggesting that IFN-γ could be a potential therapeutic target. This study would lead to identification of potential therapeutic avenues for the treatment of JEV infection.
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Suppressors of cytokine signaling 1 and 3 are upregulated in brain resident cells in response to virus-induced inflammation of the central nervous system via at least two distinctive pathways. J Virol 2014; 88:14090-104. [PMID: 25253351 DOI: 10.1128/jvi.01346-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Suppressors of cytokine signaling (SOCS) proteins are intracellular proteins that inhibit cytokine signaling in a variety of cell types. A number of viral infections have been associated with SOCS upregulation; however, not much is known about the mechanisms regulating SOCS expression during viral infection. In this study, we used two pathologically distinct intracerebral (i.c.) infection models to characterize temporal and spatial aspects of SOCS expression in the virus-infected central nervous system (CNS), and by employing various knockout mouse models, we sought to identify regulatory mechanisms that may underlie a virus induced upregulation of SOCS in the CNS. We found that i.c. infection with either lymphocytic choriomeningitis virus (LCMV) or yellow fever virus (YF) results in gradual upregulation of SOCS1/3 mRNA expression peaking at day 7 postinfection (p.i.). In the LCMV model, SOCS mRNA was expressed in brain resident cells, including astrocytes and some neurons, and for SOCS1 in particular this upregulation was almost entirely mediated by gamma interferon (IFN-γ) produced by infiltrating T cells. After infection with YF, we also found SOCS expression to be upregulated in brain resident cells with a peak on day 7 p.i., but in this model, the upregulation was only partially dependent on IFN-γ and T cells, indicating that at least one other mediator was involved in the upregulation of SOCS following YF infection. We conclude that virus-induced inflammation of the CNS is associated with upregulation of SOCS1/3 mRNA expression in brain resident cells and that at least two distinctive pathways can lead to this upregulation. IMPORTANCE In the present report, we have studied the induction of SOCS1 and SOCS3 expression in the context of virus-induced CNS infection. We found that both a noncytolytic and a cytolytic virus induce marked upregulation of SOCS1 and -3 expression. Notably, the kinetics of the observed upregulation follows that of activity within proinflammatory signaling pathways and, interestingly, type II interferon (IFN), which is also a key inducer of inflammatory mediators, seems to be essential in initiating this counterinflammatory response. Another key observation is that not only cells of the immune system but also CNS resident cells are actively involved in both the pro- and the counterinflammatory immune circuits; thus, for example, astrocytes upregulate both C-X-C-motif chemokine 10 (CXCL10) and SOCS when exposed to type II IFN in vivo.
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Interleukin-1R signaling is essential for induction of proapoptotic CD8 T cells, viral clearance, and pathology during lymphocytic choriomeningitis virus infection in mice. J Virol 2012; 86:8713-9. [PMID: 22674984 DOI: 10.1128/jvi.00682-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The T cell granule exocytosis pathway is essential to control hepatotropic lymphocytic choriomeningitis virus strain WE (LCMV-WE) but also contributes to the observed pathology in mice. Although effective antiviral T cell immunity and development of viral hepatitis are strictly dependent on perforin and granzymes, the molecular basis underlying induction of functionally competent virus-immune T cells, including participation of the innate immune system, is far from being resolved. We demonstrate here that LCMV-immune T cells of interleukin-1 receptor (IL-1R)-deficient mice readily express transcripts for perforin and granzymes but only translate perforin, resulting in the lack of proapoptotic potential in vitro. LCMV is not cleared in IL-1R-deficient mice, and yet the infected mice develop neither splenomegaly nor hepatitis. These results demonstrate that IL-1R signaling is central to the induction of proapoptotic CD8 T cell immunity, including viral clearance and associated tissue injuries in LCMV infection.
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Růžek D, Salát J, Singh SK, Kopecký J. Breakdown of the blood-brain barrier during tick-borne encephalitis in mice is not dependent on CD8+ T-cells. PLoS One 2011; 6:e20472. [PMID: 21629771 PMCID: PMC3100324 DOI: 10.1371/journal.pone.0020472] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 04/26/2011] [Indexed: 12/30/2022] Open
Abstract
Tick-borne encephalitis (TBE) virus causes severe encephalitis with serious sequelae in humans. The disease is characterized by fever and debilitating encephalitis that can progress to chronic illness or fatal infection. In this study, changes in permeability of the blood-brain barrier (BBB) in two susceptible animal models (BALB/c, and C57Bl/6 mice) infected with TBE virus were investigated at various days after infection by measuring fluorescence in brain homogenates after intraperitoneal injection of sodium fluorescein, a compound that is normally excluded from the central nervous system. We demonstrate here that TBE virus infection, in addition to causing fatal encephalitis in mice, induces considerable breakdown of the BBB. The permeability of the BBB increased at later stages of TBE infection when high virus load was present in the brain (i.e., BBB breakdown was not necessary for TBE virus entry into the brain), and at the onset of the first severe clinical symptoms of the disease, which included neurological signs associated with sharp declines in body weight and temperature. The increased BBB permeability was in association with dramatic upregulation of proinflammatory cytokine/chemokine mRNA expression in the brain. Breakdown of the BBB was also observed in mice deficient in CD8+ T-cells, indicating that these cells are not necessary for the increase in BBB permeability that occurs during TBE. These novel findings are highly relevant to the development of future therapies designed to control this important human infectious disease.
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Affiliation(s)
- Daniel Růžek
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic.
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6
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Pinschewer DD, Schedensack M, Bergthaler A, Horvath E, Brück W, Löhning M, Merkler D. T cells can mediate viral clearance from ependyma but not from brain parenchyma in a major histocompatibility class I- and perforin-independent manner. ACTA ACUST UNITED AC 2010; 133:1054-66. [PMID: 20354003 PMCID: PMC7110187 DOI: 10.1093/brain/awq028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Viral infection of the central nervous system can lead to disability and death. Yet the majority of viral infections with central nervous system involvement resolve with only mild clinical manifestations, if any. This is generally attributed to efficient elimination of the infection from the brain coverings, i.e. the meninges, ependyma and chorioplexus, which are the primary targets of haematogeneous viral spread. How the immune system is able to purge these structures from viral infection with only minimal detrimental effects is still poorly understood. In the present work we studied how an attenuated lymphocytic choriomeningitis virus can be cleared from the central nervous system in the absence of overt disease. We show that elimination of the virus from brain ependyma, but not from brain parenchyma, could be achieved by a T cell-dependent mechanism operating independently of major histocompatibility class I antigens and perforin. Considering that cytotoxic T lymphocyte-mediated cytotoxicity is a leading cause of viral immunopathology and tissue damage, our findings may explain why the most common viral intruders of the central nervous system rarely represent a serious threat to our health.
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Affiliation(s)
- Daniel D Pinschewer
- Department of Pathology and Immunology, W.H.O. Collaborating Centre for Neonatal Vaccinology, University of Geneva, Geneva, Switzerland
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7
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Lymphocytic choriomeningitis virus-induced mortality in mice is triggered by edema and brain herniation. J Virol 2010; 84:312-20. [PMID: 19828618 DOI: 10.1128/jvi.00727-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although much is known about lymphocytic choriomeningitis virus (LCMV) infection and the subsequent immune response in its natural murine host, some crucial aspects of LCMV-mediated pathogenesis remain undefined, including the underlying basis of the characteristic central nervous system disease that occurs following intracerebral (i.c.) challenge. We show that the classic seizures and paresis that occur following i.c. infection of adult, immunocompetent mice with LCMV are accompanied by anatomical and histological changes that are consistent with brain herniation, likely of the uncal subtype, as a causative basis for disease and precipitous death. Both by water weight determinations and by magnetic resonance imaging of infected brain tissues, edema was detected only at the terminal stages of disease, likely caused by the leakage of cerebrospinal fluid from the ventricles into the parenchyma. Furthermore, death was accompanied by unilateral pupillary dilation, which is indicative of uncal herniation. While immunohistochemical analysis revealed periventricular inflammation and a loss of integrity of the blood-brain barrier (BBB), these events preceded seizures by 2 to 3 days. Moreover, surviving perforin knockout mice showed barrier permeability equivalent to that of moribund, immunocompetent mice; thus, BBB damage does not appear to be the basis of LCMV-induced neuropathogenesis. Importantly, brain herniation can occur in humans as a consequence of injuries that would be predicted to increase intracranial pressure, including inflammation, head trauma, and brain tumors. Thus, a mechanistic dissection of the basis of LCMV neuropathogenesis may be informative for the development of interventive therapies to prevent this typically fatal human condition.
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Zhao L, Toriumi H, Kuang Y, Chen H, Fu ZF. The roles of chemokines in rabies virus infection: overexpression may not always be beneficial. J Virol 2009; 83:11808-18. [PMID: 19740983 PMCID: PMC2772667 DOI: 10.1128/jvi.01346-09] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 08/31/2009] [Indexed: 12/24/2022] Open
Abstract
It was found previously that induction of innate immunity, particularly chemokines, is an important mechanism of rabies virus (RABV) attenuation. To evaluate the effect of overexpression of chemokines on RABV infection, chemokines macrophage inflammatory protein 1alpha (MIP-1alpha), RANTES, and IP-10 were individually cloned into the genome of attenuated RABV strain HEP-Flury. These recombinant RABVs were characterized in vitro for growth properties and expression of chemokines. It was found that all the recombinant viruses grew as well as the parent virus, and each of the viruses expressed the intended chemokine in a dose-dependent manner. When these viruses were evaluated for pathogenicity in the mouse model, it was found that overexpression of MIP-1alpha further decreased RABV pathogenicity by inducing a transient innate immune response. In contrast, overexpression of RANTES or IP-10 increased RABV pathogenicity by causing neurological diseases, which is due to persistent and high-level expression of chemokines, excessive infiltration and accumulation of inflammatory cells in the central nervous system, and severe enhancement of blood-brain barrier permeability. These studies indicate that overexpression of chemokines, although important in controlling virus infection, may not always be beneficial to the host.
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Affiliation(s)
- Ling Zhao
- Departments of Pathology, Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, State-Key Laboratory of Agricultural Microbiology, Department of Preventive Veterinary, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Harufusa Toriumi
- Departments of Pathology, Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, State-Key Laboratory of Agricultural Microbiology, Department of Preventive Veterinary, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Yi Kuang
- Departments of Pathology, Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, State-Key Laboratory of Agricultural Microbiology, Department of Preventive Veterinary, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Huanchun Chen
- Departments of Pathology, Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, State-Key Laboratory of Agricultural Microbiology, Department of Preventive Veterinary, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhen F. Fu
- Departments of Pathology, Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, State-Key Laboratory of Agricultural Microbiology, Department of Preventive Veterinary, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
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9
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Mouse adenovirus type 1-induced breakdown of the blood-brain barrier. J Virol 2009; 83:9398-410. [PMID: 19570856 DOI: 10.1128/jvi.00954-09] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Infection with mouse adenovirus type 1 (MAV-1) results in fatal acute encephalomyelitis in susceptible mouse strains via infection of brain endothelial cells. Wild-type (wt) MAV-1 causes less brain inflammation than an early region 3 (E3) null virus in C57BL/6 mice. A mouse brain microvascular endothelial cell line infected with wt MAV-1 had higher expression of mRNAs for the proinflammatory chemokines CCL2 and CCL5 than mock- and E3 null virus-infected cells. Primary mouse brain endothelial cells infected with wt virus had elevated levels of CCL2 compared to mock- or E3 null virus-infected cells. Infection of C57BL/6 mice with wt MAV-1 or the E3 null virus caused a dose-dependent breakdown of the blood-brain barrier, primarily due to direct effects of virus infection rather than inflammation. The tight junction proteins claudin-5 and occludin showed reduced surface expression on primary mouse brain endothelial cells following infection with either wt MAV-1 or the E3 null virus. mRNAs and protein for claudin-5, occludin, and zona occludens 2 were also reduced in infected cells. MAV-1 infection caused a loss of transendothelial electrical resistance in primary mouse brain endothelial cells that was not dependent on E3 or on MAV-1-induced CCL2 expression. Taken together, these results demonstrate that MAV-1 infection caused breakdown of the blood-brain barrier accompanied by decreased surface expression of tight junction proteins. Furthermore, while the MAV-1-induced pathogenesis and inflammation were dependent on E3, MAV-1-induced breakdown of the blood-brain barrier and alteration of endothelial cell function were not dependent on E3 or CCL2.
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10
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Myelomonocytic cell recruitment causes fatal CNS vascular injury during acute viral meningitis. Nature 2008; 457:191-5. [PMID: 19011611 PMCID: PMC2702264 DOI: 10.1038/nature07591] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Accepted: 10/30/2008] [Indexed: 12/27/2022]
Abstract
Lymphocytic choriomeningitis virus infection of the mouse central nervous system (CNS) elicits fatal immunopathology through blood-brain barrier breakdown and convulsive seizures. Although lymphocytic-choriomeningitis-virus-specific cytotoxic T lymphocytes (CTLs) are essential for disease, their mechanism of action is not known. To gain insights into disease pathogenesis, we observed the dynamics of immune cells in the meninges by two-photon microscopy. Here we report visualization of motile CTLs and massive secondary recruitment of pathogenic monocytes and neutrophils that were required for vascular leakage and acute lethality. CTLs expressed multiple chemoattractants capable of recruiting myelomonocytic cells. We conclude that a CD8(+) T-cell-dependent disorder can proceed in the absence of direct T-cell effector mechanisms and rely instead on CTL-recruited myelomonocytic cells.
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Lymphocytic choriomeningitis virus-induced central nervous system disease: a model for studying the role of chemokines in regulating the acute antiviral CD8+ T-cell response in an immune-privileged organ. J Virol 2008; 83:20-8. [PMID: 18787010 DOI: 10.1128/jvi.00682-08] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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12
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Zhou S, Halle A, Kurt-Jones EA, Cerny AM, Porpiglia E, Rogers M, Golenbock DT, Finberg RW. Lymphocytic choriomeningitis virus (LCMV) infection of CNS glial cells results in TLR2-MyD88/Mal-dependent inflammatory responses. J Neuroimmunol 2008; 194:70-82. [PMID: 18295350 DOI: 10.1016/j.jneuroim.2007.11.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 10/12/2007] [Accepted: 11/21/2007] [Indexed: 01/12/2023]
Abstract
In response to invading pathogens, Toll-like receptors (TLR) play a critical role in the initiation of the innate immune response, which can be either beneficial or detrimental to the host. In the present study, we demonstrated that central nervous system (CNS) glial cells are activated by Lymphocytic Choriomeningitis Virus (LCMV) in a TLR2-MyD88/Mal-dependent manner. Specifically, in response to LCMV, both astrocytes and microglial cells isolated from wild-type (WT) mice produced chemokines, such as MCP-1, RANTES and TNF-alpha. Similar responses occurred in TLR3 KO and TLR4 KO glial cells. In striking contrast, both astrocytes and microglial cells isolated from mice deficient in TLR2, MyD88, and Mal did not produce any of these chemokines. In addition, LCMV infection of glial cells induced up-regulation of TLR2, MHC class-I and II, CD40, CD86 in a MyD88-dependent manner. These results define a functional role for TLR signaling in viral infection-induced activation of CNS glial cells as well as for the immunopathology in the CNS.
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Affiliation(s)
- Shenghua Zhou
- Department of Medicine, University of Massachusetts Medical Center, 364 Plantation Street, Lazare Research Building, Worcester, MA 01605, USA.
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13
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Kang SS, McGavern DB. Lymphocytic choriomeningitis infection of the central nervous system. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2008; 13:4529-43. [PMID: 18508527 PMCID: PMC5279998 DOI: 10.2741/3021] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Viral infection of the central nervous system (CNS) can result in a multitude of responses including pathology, persistence or immune clearance. Lymphocytic choriomeningitis virus (LCMV) is a powerful model system to explore these potential outcomes of CNS infection due to the diversity of responses that can be achieved after viral inoculation. Several factors including tropism, timing, dose and variant of LCMV in combination with the development or suppression of the corresponding immune response dictates whether lethal meningitis, chronic infection or clearance of LCMV in the CNS will occur. Importantly, the functionality and positioning of the LCMV-specific CD8+ T cell response are critical in directing the subsequent outcome of CNS LCMV infection. Although a basic understanding of LCMV and immune interactions in the brain exists, the molecular machinery that shapes the balance between pathogenesis and clearance in the LCMV-infected CNS remains to be elucidated. This review covers the various outcomes of LCMV infection in the CNS and what is currently known about the impact of the virus itself versus the immune response in the development of disease or clearance.
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Affiliation(s)
- Silvia S. Kang
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA 92037
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037
| | - Dorian B. McGavern
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA 92037
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037
- Harold L. Dorris Neurological Research Institute, The Scripps Research Institute, La Jolla, CA 92037
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14
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Phares TW, Fabis MJ, Brimer CM, Kean RB, Hooper DC. A peroxynitrite-dependent pathway is responsible for blood-brain barrier permeability changes during a central nervous system inflammatory response: TNF-alpha is neither necessary nor sufficient. THE JOURNAL OF IMMUNOLOGY 2007; 178:7334-43. [PMID: 17513784 DOI: 10.4049/jimmunol.178.11.7334] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Elevated blood-brain barrier (BBB) permeability is associated with both the protective and pathological invasion of immune and inflammatory cells into CNS tissues. Although a variety of processes have been implicated in the changes at the BBB that result in the loss of integrity, there has been no consensus as to their induction. TNF-alpha has often been proposed to be responsible for increased BBB permeability but there is accumulating evidence that peroxynitrite (ONOO(-))-dependent radicals may be the direct trigger. We demonstrate here that enhanced BBB permeability in mice, whether associated with rabies virus (RV) clearance or CNS autoimmunity, is unaltered in the absence of TNF-alpha. Moreover, the induction of TNF-alpha expression in CNS tissues by RV infection has no impact on BBB integrity in the absence of T cells. CD4 T cells are required to enhance BBB permeability in response to the CNS infection whereas CD8 T cells and B cells are not. Like CNS autoimmunity, elevated BBB permeability in response to RV infection is evidently mediated by ONOO(-). However, as opposed to the invading cells producing ONOO(-) that have been implicated in the pathogenesis of CNS inflammation, during virus clearance ONOO(-) is produced without pathological sequelae by IFN-gamma-stimulated neurovascular endothelial cells.
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MESH Headings
- Animals
- Blood-Brain Barrier/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- CD4-Positive T-Lymphocytes/virology
- Cell Membrane Permeability/genetics
- Cell Membrane Permeability/immunology
- Cell Movement/genetics
- Cell Movement/immunology
- Cerebellum/immunology
- Cerebellum/pathology
- Cerebellum/virology
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/physiopathology
- Encephalomyelitis, Autoimmune, Experimental/virology
- Female
- Lymphopenia/immunology
- Lymphopenia/pathology
- Lymphopenia/virology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Peroxynitrous Acid/physiology
- Rabies virus/immunology
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/pathology
- T-Lymphocyte Subsets/virology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/deficiency
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/physiology
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
- Viral Load
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Affiliation(s)
- Timothy W Phares
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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15
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Roy A, Hooper DC. Lethal silver-haired bat rabies virus infection can be prevented by opening the blood-brain barrier. J Virol 2007; 81:7993-8. [PMID: 17507463 PMCID: PMC1951307 DOI: 10.1128/jvi.00710-07] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Silver-haired bat rabies virus (SHBRV) infection induces a strong virus-specific immune response in the periphery of the host, but death is common due to the failure to open the blood-brain barrier (BBB) and deliver immune effectors to central nervous system (CNS) tissues. Mice with an SJL background are less susceptible to lethal infection with rabies viruses. In addition, these animals are known to have reduced hypothalamus-pituitary-adrenal (HPA) axis activity and an elevated capacity to mediate CNS inflammatory responses. We show here that approximately one-half of PLSJL mice survive an SHBRV infection that is invariably lethal for 129/SvEv mice. This difference is associated with the elevated capacity of PLSJL mice to mediate BBB permeability changes in response to the infection. The induction of more extensive BBB permeability and CNS inflammation in these animals results in greater virus clearance and improved survival. On the other hand, treatment of SHBRV-infected PLSJL mice with the steroid hormone dehydroepiandrosterone reduced BBB permeability changes and caused greater mortality. We conclude that the infiltration of immune effectors across the BBB is critical to surviving a rabies virus infection and that HPA axis activity may influence this process.
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Affiliation(s)
- Anirban Roy
- Center for Neurovirology, Thomas Jefferson University, 1020 Locust St., JAH 454, Philadelphia, PA 19107-6799, USA
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Olsen AL, Morrey JD, Smee DF, Sidwell RW. Correlation between breakdown of the blood-brain barrier and disease outcome of viral encephalitis in mice. Antiviral Res 2006; 75:104-12. [PMID: 17223204 PMCID: PMC2040264 DOI: 10.1016/j.antiviral.2006.11.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 11/28/2006] [Accepted: 11/29/2006] [Indexed: 11/28/2022]
Abstract
Changes in the permeability of the blood-brain barrier (BBB) were evaluated in two mouse models of viral encephalitis. The ability of sodium fluorescein (NaFl) to cross the BBB from the serum into the central nervous system was assayed in animals inoculated with virulent strains of either Banzi or Semliki Forest viruses. To test the hypothesis that increases in BBB permeability were associated with poor disease outcome subsequent experiments measured BBB permeability in conjunction with treatment with the interferon inducer Ampligen (poly I:poly C(12)U). A single intraperitoneal injection of Ampligen (1 mg/kg) administered either 24 h or 4-6 h before, but not 24 h after, virus inoculation with Banzi virus provided significant improvements in survival, viral brain titers, weight change and BBB permeability. In comparison, a similar treatment with Ampligen administered either 24 h or 4-6 h before inoculation with Semliki Forest virus was able to significantly improve weight change, and BBB permeability, but only animals receiving Ampligen 4-6 h pre-virus showed a significantly improved mortality. In general, it was found that evaluation of BBB permeability was a more sensitive indicator of disease outcome and the antiviral efficacy Ampligen than either weight change or brain viral titers.
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Affiliation(s)
- Aaron L Olsen
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University, 5600 Old Main Hill, Logan, UT 84322-5600, USA.
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Phares TW, Kean RB, Mikheeva T, Hooper DC. Regional differences in blood-brain barrier permeability changes and inflammation in the apathogenic clearance of virus from the central nervous system. THE JOURNAL OF IMMUNOLOGY 2006; 176:7666-75. [PMID: 16751414 DOI: 10.4049/jimmunol.176.12.7666] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The loss of blood-brain barrier (BBB) integrity in CNS inflammatory responses triggered by infection and autoimmunity has generally been associated with the development of neurological signs. In the present study, we demonstrate that the clearance of the attenuated rabies virus CVS-F3 from the CNS is an exception; increased BBB permeability and CNS inflammation occurs in the absence of neurological sequelae. We speculate that regionalization of the CNS inflammatory response contributes to its lack of pathogenicity. Despite virus replication and the expression of several chemokines and IL-6 in both regions being similar, the up-regulation of MIP-1beta, TNF-alpha, IFN-gamma, and ICAM-1 and the loss of BBB integrity was more extensive in the cerebellum than in the cerebral cortex. The accumulation of CD4- and CD19-positive cells was higher in the cerebellum than the cerebral cortex. Elevated CD19 levels were paralleled by kappa-L chain expression levels. The timing of BBB permeability changes, kappa-L chain expression in CNS tissues, and Ab production in the periphery suggest that the in situ production of virus-neutralizing Ab may be more important in virus clearance than the infiltration of circulating Ab. The data indicate that, with the possible exception of CD8 T cells, the effectors of rabies virus clearance are more commonly targeted to the cerebellum. This is likely the result of differences in the capacity of the tissues of the cerebellum and cerebral cortex to mediate the events required for BBB permeability changes and cell invasion during virus infection.
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Affiliation(s)
- Timothy W Phares
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Storm P, Bartholdy C, Sørensen MR, Christensen JP, Thomsen AR. Perforin-deficient CD8+ T cells mediate fatal lymphocytic choriomeningitis despite impaired cytokine production. J Virol 2006; 80:1222-30. [PMID: 16414999 PMCID: PMC1346958 DOI: 10.1128/jvi.80.3.1222-1230.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intracerebral (i.c.) infection with lymphocytic choriomeningitis virus (LCMV) is one of the most studied models for virus-induced immunopathology, and based on results from perforin-deficient mice, it is currently assumed that fatal disease directly reflects perforin-mediated cell lysis. However, recent studies have revealed additional functional defects within the effector T cells of LCMV-infected perforin-deficient mice, raising the possibility that perforin may not be directly involved in mediating lethal disease. For this reason, we decided to reevaluate the role of perforin in determining the outcome of i.c. infection with LCMV. We confirmed that the expansion of virus-specific CD8(+) T cells is unimpaired in perforin-deficient mice. However, despite the fact that the virus-specific CD8(+) effector T cells in perforin-deficient mice are broadly impaired in their effector function, these mice invariably succumb to i.c. infection with LCMV strain Armstrong, although a few days later than matched wild-type mice. Upon further investigation, we found that this delay correlates with the delayed recruitment of inflammatory cells to the central nervous system (CNS). However, CD8(+) effector T cells were not kept from the CNS by sequestering in infected extraneural organ sites such as liver or lungs. Thus, the observed dysfunctionality regarding the production of proinflammatory mediators probably results in the delayed recruitment of effector cells to the CNS, and this appears to be the main explanation for the delayed onset of fatal disease in perforin-deficient mice. However, once accumulated in the CNS, virus-specific CD8(+) T cells can induce fatal CNS pathology despite the absence of perforin-mediated lysis and reduced capacity to produce several key cytokines.
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Affiliation(s)
- Pernille Storm
- Institute of Medical Microbiology and Immunology, The Panum Institute, 3C Blegdamsvej, DK-2200 Copenhagen N, Denmark
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19
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Bartholdy C, Stryhn A, Christensen JP, Thomsen AR. Single-epitope DNA vaccination prevents exhaustion and facilitates a broad antiviral CD8+ T cell response during chronic viral infection. THE JOURNAL OF IMMUNOLOGY 2004; 173:6284-93. [PMID: 15528367 DOI: 10.4049/jimmunol.173.10.6284] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Induction of a monospecific antiviral CD8+ T cell response may pose a risk to the host due to the narrow T cell response induced. At the individual level, this may result in selection of CD8+ T cell escape variants, particularly during chronic viral infection. Second, prior immunization toward a single dominant epitope may suppress the response to other viral epitopes, and this may lead to increased susceptibility to reinfection with escape variants circulating in the host population. To address these issues, we induced a memory response consisting solely of monospecific, CD8+ T cells by use of DNA vaccines encoding immunodominant epitopes of lymphocytic choriomeningitis virus (LCMV). We analyzed the spectrum of the CD8+ T cell response and the susceptibility to infection in H-2(b) and H-2(d) mice. Priming for a monospecific, CD8+ T cell response did not render mice susceptible to viral variants. Thus, vaccinated mice were protected against chronic infection with LCMV, and no evidence indicating biologically relevant viral escape was obtained. In parallel, a broad and sustained CD8+ T cell response was generated upon infection, and in H-2(d) mice epitope spreading was observed. Even after acute LCMV infection, DNA vaccination did not significantly impair naturally induced immunity. Thus, the response to the other immunogenic epitopes was not dramatically suppressed in DNA-immunized mice undergoing normal immunizing infection, and the majority of mice were protected against rechallenge with escape variants. These findings underscore that a monospecific vaccine may induce efficient protective immunity given the right set of circumstances.
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MESH Headings
- Animals
- Antiviral Agents/administration & dosage
- Antiviral Agents/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/virology
- Cells, Cultured
- Chronic Disease
- Cytotoxicity, Immunologic
- Disease Susceptibility/immunology
- Dose-Response Relationship, Immunologic
- Epitopes, T-Lymphocyte/administration & dosage
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Female
- Genetic Variation/immunology
- H-2 Antigens/immunology
- Histocompatibility Antigen H-2D
- Immunologic Memory
- Lymphocytic Choriomeningitis/immunology
- Lymphocytic Choriomeningitis/prevention & control
- Lymphocytic choriomeningitis virus/genetics
- Lymphocytic choriomeningitis virus/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Secondary Prevention
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/genetics
- Viral Vaccines/immunology
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Affiliation(s)
- Christina Bartholdy
- Institute of Medical Microbiology and Immunology, Panum Institute, University of Copenhagen, 3C Blegdamsvej, DK-2200 Copenhagen, Denmark
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20
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Madsen AN, Nansen A, Christensen JP, Thomsen AR. Role of macrophage inflammatory protein-1alpha in T-cell-mediated immunity to viral infection. J Virol 2003; 77:12378-84. [PMID: 14581577 PMCID: PMC254281 DOI: 10.1128/jvi.77.22.12378-12384.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The immune response to lymphocytic choriomeningitis virus in mice lacking macrophage inflammatory protein-1alpha (MIP-1alpha) was evaluated. Generation of virus-specific effector T cells is unimpaired in MIP-1alpha-deficient mice. Furthermore, MIP-1alpha is not required for T-cell-mediated virus control or virus-induced T-cell-dependent inflammation. Thus, MIP-1alpha is not mandatory for T-cell-mediated antiviral immunity.
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Affiliation(s)
- Andreas N Madsen
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Copenhagen, Denmark
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21
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Taylor AW. Neuroimmunomodulation and immune privilege: the role of neuropeptides in ocular immunosuppression. Neuroimmunomodulation 2003; 10:189-98. [PMID: 12584406 DOI: 10.1159/000068325] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2002] [Accepted: 06/10/2002] [Indexed: 11/19/2022] Open
Abstract
Regional immunoregulatory mechanisms insure that the most effective immune defense mounted is in proportion with preserving unique tissue functionalities. Immune-privileged tissues, such as the eye, are tissue sites of extreme regional immunoregulation. They have evolutionarily adapted several mechanisms to prevent the induction of inflammation within their tissue microenvironment. With over half a century of experimental examinations of ocular immune privilege, only recently have we come to understand that neuropeptides constitutively present in ocular tissues are part of the mechanisms of immune privilege.
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Affiliation(s)
- Andrew W Taylor
- Department of Ophthalmology, Harvard Medical School, Boston, Massachussetts 02114, USA.
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22
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Evans CF, Redwine JM, Patterson CE, Askovic S, Rall GF. LCMV and the central nervous system: uncovering basic principles of CNS physiology and virus-induced disease. Curr Top Microbiol Immunol 2002; 263:177-95. [PMID: 11987814 DOI: 10.1007/978-3-642-56055-2_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- C F Evans
- Department of Neuropharmacology, Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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23
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Abstract
Using mice deficient of E-selectin and E/P-selectin, we have studied the requirement for endothelial selectins in extravasation of leukocytes at sites of viral infection, with major emphasis on the recruitment of virus-specific TC1 cells. Lymphocytic choriomeningitis virus (LCMV)–induced meningitis was used as our primary experimental model. Additionally, localized subdermal inflammation and virus clearance in internal organs were analyzed during LCMV infection. The generation of CD8+ effector T cells in infected mutants was unimpaired. Quantitative and qualitative analysis of the inflammatory exudate cells in intracerebrally infected mice gave identical results in all strains of mice. Expression of endothelial selectin was also found to be redundant regarding the ability of effector cells to eliminate virus in nonlymphoid organs. Concerning LCMV-induced footpad swelling, absent or marginal reduction was found in E/P-sel −/− mice, compared with wild-type mice after local challenge with virus or immunodominant viral MHC class I restricted peptide, respectively. Similar results were obtained after adoptive transfer of wild-type effector cells into E/P-sel −/− recipients, whereas footpad swelling was markedly decreased in P-sel/ICAM-1 −/− and ICAM-1 −/− recipients. LCMV-induced footpad swelling was completely inhibited in ICAM-deficient mice transfused with donor cell preincubated with soluble VCAM-1-Ig chimeric protein. Taken together, the current findings strongly indicate that the migration of TC1 effector cells to sites of viral infection can proceed in the absence of endothelial selectins, whereas ligands of the Ig superfamily are critically involved in this process.
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24
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Thomsen AR, Nansen A, Christensen JP. Virus-induced T cell activation and the inflammatory response. Curr Top Microbiol Immunol 1998; 231:99-123. [PMID: 9479863 DOI: 10.1007/978-3-642-71987-5_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A R Thomsen
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark
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25
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Christensen JP, Marker O, Thomsen AR. T-cell-mediated immunity to lymphocytic choriomeningitis virus in beta2-integrin (CD18)- and ICAM-1 (CD54)-deficient mice. J Virol 1996; 70:8997-9002. [PMID: 8971031 PMCID: PMC190999 DOI: 10.1128/jvi.70.12.8997-9002.1996] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The T-cell response to lymphocytic choriomeningitis virus was studied in mice with deficient expression of beta2-integrins or ICAM-1. In such mice, the generation of virus-specific cytotoxic T lymphocytes was only slightly impaired and bystander activation was as extensive as that observed in wild-type mice. T-cell-mediated inflammation, assessed as primary footpad swelling and susceptibility to intracerebral infection, was slightly compromised only in beta2-integrin-deficient mice. However, adoptive immunization of mutant mice soon after local infection did reveal a reduced capacity to support the inflammatory reaction, indicating that under conditions of more limited immune activation both molecules do play a role in formation of the inflammatory exudate. Finally, virus control was found to be somewhat impaired in both mutant strains. In conclusion, our results indicate that although LFA-1-ICAM-1 interaction is important for certain aspects of the T-cell-mediated response to viruses, T-cell activation is surprisingly intact in these mutant mice, indicating extensive functional redundancy within cell interaction molecules.
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Affiliation(s)
- J P Christensen
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark
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26
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Selmaj K. Pathophysiology of the blood-brain barrier. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1996; 18:57-73. [PMID: 8984680 DOI: 10.1007/bf00792609] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- K Selmaj
- Department of Neurology, Medical Academy of Lodz, Poland
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27
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Rall GF, Mucke L, Oldstone MB. Consequences of cytotoxic T lymphocyte interaction with major histocompatibility complex class I-expressing neurons in vivo. J Exp Med 1995; 182:1201-12. [PMID: 7595191 PMCID: PMC2192211 DOI: 10.1084/jem.182.5.1201] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neurons have evolved strategies to evade immune surveillance that include an inability to synthesize the heavy chain of the class I major histocompatibility complex (MHC), proteins that are necessary for cytotoxic T lymphocyte (CTL) recognition of target cells. Multiple viruses have taken advantage of the lack of CTL-mediated recognition and killing of neurons by establishing persistent neuronal infections and thereby escaping attack by antiviral CTL. We have expressed a class I MHC molecule (Db) in neurons of transgenic mice using the neuron-specific enolase (NSE) promoter to determine the pathogenic consequences of CTL recognition of virally infected, MHC-expressing central nervous system (CNS) neurons. The NSE-Db transgene was expressed in H-2b founder mice, and transgene-derived messenger RNA was detected by reverse transcriptase-polymerase chain reaction in transgenic brains from several lines. Purified primary neurons from transgenic but not from nontransgenic mice adhered to coverslips coated with a conformation-dependent monoclonal antibody directed against the Dv molecule and presented viral peptide to CTL in an MHC-restricted manner, indicating that the Db molecule was expressed on transgenic neurons in a functional form. Transgenic mice infected with the neurotropic lymphocytic choriomeningitis virus (LCMV) and given anti-LCMV, MHC-restricted CTL displayed a high morbidity and mortality when compared with controls receiving MHC-mismatched CTL or expressing alternative transgenes. After CTL transfer, transgenic brains showed an increased number of CD8+ cells compared with nontransgenic controls as well as an increased rate of clearance of infectious virus from the CNS. Additionally, an increase in blood-brain barrier permeability was detected during viral clearance in NSE-Db transgenic mice and lasted several months after clearance of virus from neurons. In contrast, LCMV-infected, nontransgenic littermates and mice expressing other gene products from the NSE promoter showed no CNS disease, no increased intraparenchymal CTL, and no blood-brain barrier damage after the adoptive transfer of antiviral CTL. Our study indicates that viral infections and CTL-CNS interactions may induce blood-brain barrier disruptions and neurologic disease by a "hit-and-run" mechanism, triggering a cascade of pathogenic events that proceeds in the absence of continual viral stimulation.
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Affiliation(s)
- G F Rall
- Scripps Research Institute, Department of Neuropharmacology, La Jolla, California 92037, USA
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28
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Marker O, Scheynius A, Christensen JP, Thomsen AR. Virus-activated T cells regulate expression of adhesion molecules on endothelial cells in sites of infection. J Neuroimmunol 1995; 62:35-42. [PMID: 7499490 DOI: 10.1016/0165-5728(95)00099-n] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To study the role of cell adhesion molecules in the fatal CD8+ T-cell mediated meningitis which is induced by intracerebral infection with lymphocytic choriomeningitis virus, the expression of relevant molecules on inflammatory cells and local endothelium was analyzed immunohistochemically. Most inflammatory cells were strongly positive for LFA-1, VLA-4, Pgp-1 and ICAM-1. Expression of ICAM-1 and VCAM-1 was upregulated on the endothelial cells in immunocompetent mice, but not in T-cell deficient nude mice. Analysis of mice deficient in either CD4+ or CD8+ T cells, revealed that not only was the inflammatory reaction dependent on the presence of CD8+ cells, but these cells also appeared to be required for maximal upregulation of ICAM-1 and VCAM-1 on the endothelial cells. These results indicate that virus-specific CD8+ T cells are crucially involved in regulating the inflammatory reaction through effects on endothelial expression of adhesion molecules.
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Affiliation(s)
- O Marker
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Panum Institute, Denmark
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29
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Andersson EC, Christensen JP, Scheynius A, Marker O, Thomsen AR. Lymphocytic choriomeningitis virus infection is associated with long-standing perturbation of LFA-1 expression on CD8+ T cells. Scand J Immunol 1995; 42:110-8. [PMID: 7543210 DOI: 10.1111/j.1365-3083.1995.tb03633.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Flow cytometric analysis of splenocytes from mice infected with lymphocytic choriomeningitis virus revealed marked and long-standing up-regulation of LFA-1 expression on CD8+, but not on CD4+ T cells. Appearance of CD8+ T cells with a changed expression of adhesion molecules reflected polyclonal activation and expansion which was demonstrated not to depend on CD4+ T cells or their products. Cell sorting experiments defined virus-specific CTL to be included in this population (LFA-1hiMEL-14lo), but since about 80% of splenic CD8+ T cells have a changed phenotype, extensive bystander activation must take place; this is indicated also by the finding that CD8+LFA-1hi cells transiently express several markers of cellular activation, e.g. transferrin receptor, IL-2R alpha and beta. Analysis of cells from the cerebrospinal fluid of mice infected intracerebrally showed that virtually all T cells present belonged to the CD8+LFA-1hi subset and, correspondingly, the ligand ICAM-1 was found to be up-regulated on endothelial cells in the inflamed meninges. Preincubation of LCMV-primed donor splenocytes with anti-LFA-1 markedly inhibited the transfer of virus-specific delayed-type hypersensitivity to naive recipients. Together, these findings indicate that up-regulation of LFA-1 expression is a critical factor involved in directing activated CD8+ T cells to sites of viral infection.
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Affiliation(s)
- E C Andersson
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark
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30
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Sandberg K, Eloranta ML, Campbell IL. Expression of alpha/beta interferons (IFN-alpha/beta) and their relationship to IFN-alpha/beta-induced genes in lymphocytic choriomeningitis. J Virol 1994; 68:7358-66. [PMID: 7933119 PMCID: PMC237178 DOI: 10.1128/jvi.68.11.7358-7366.1994] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Expression of alpha interferon (IFN-alpha)-, IFN-beta-, and IFN-alpha/beta-induced genes was monitored during the development of lymphocytic choriomeningitis (LCM) to assess whether a restricted influence of these antiviral cytokines could be found in the central nervous system (CNS). High levels of IFN-alpha (83 +/- 42 U/ml) were present in the blood of LCM virus-infected mice 3 days postinfection, whereas IFN-beta was not detected (< 1.0 U/ml) at any time point. Spleens contained high levels of IFN-alpha and IFN-beta mRNAs at days 1 and 3 postinfection, whereas no IFN-alpha mRNA and only low levels of IFN-beta mRNA were detected in brains. In situ hybridization showed IFN-alpha mRNA-expressing cells in the marginal zones of the spleen and in the subcapsular sinus and outer cortex of cervical lymph nodes. The expression of 2',5'-oligoadenylate synthetase (2',5'-OAS) mRNA followed the expression of IFN-beta mRNA in the brain, whereas 2',5'-OAS mRNA in the periphery was associated with systemic IFN-alpha. The localization of IFN-alpha-expressing cells in the spleen and lymph nodes in proximity to T- and B-cell compartments is consistent with a role for these cytokines in immune regulation. Furthermore, the absence of IFN-alpha and the relatively low level and delayed expression of IFN-beta in the brain suggest that the CNS is an especially vulnerable organ for virus replication. With certain strains of LCM virus, the absence of early antiviral IFN-alpha/beta activity and preferential virus growth in the brain might lead to targeted T-cell inflammation of the CNS, resulting in death of the animal.
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Affiliation(s)
- K Sandberg
- Department of Neuropharmacology, Scripps Research Institute, La Jolla, California
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31
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Neuenschwander AU, Marker O, Thomsen AR. Analysis of the capacity to produce IL-3 in murine AIDS. Scand J Immunol 1994; 40:410-4. [PMID: 7939413 DOI: 10.1111/j.1365-3083.1994.tb03482.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Adult C57BL/6 mice infected with LP-BM5 murine leukaemia virus represent a model of murine AIDS (MAIDS). In this study we have analysed the capacity of CD4+ T cells from infected mice to produce IL-3 following stimulation with ConA for 24-72 h. In contrast to the position with IL-2, the production of which is markedly impaired during LP-BM5 infection, similar levels of IL-3 were measured in culture supernatants of splenocytes from infected and uninfected mice harvested at 24 h of stimulation. Forty eight and 72 h of ConA stimulation led to increasing levels of IL-3 being measured in cultures from uninfected mice, whilst in cultures from infected animals, IL-3 levels remained stagnant. Similar results were obtained 4, 8 and 13 weeks post-infection. In view of the fact that parallel experiments revealed markedly impaired proliferative responses to ConA during MAIDS, we conclude that IL-3 production is basically intact at the cellular level in T cells during MAIDS; but when in a situation requiring clonal expansion of the activated T cells, IL-3 production will be inhibited owing to the impaired capacity for proliferation.
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Affiliation(s)
- A U Neuenschwander
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark
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32
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Christensen JP, Marker O, Thomsen AR. The role of CD4+ T cells in cell-mediated immunity to LCMV: studies in MHC class I and class II deficient mice. Scand J Immunol 1994; 40:373-82. [PMID: 7939408 DOI: 10.1111/j.1365-3083.1994.tb03477.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Parameters of the virus-specific T-cell response were analysed in order to dissect the contribution of CD4+ and CD8+ T cells to cell-mediated immunity to lymphocytic choriomeningitis virus. In MHC class II deficient mice, initial T-cell responsiveness was not impaired, but virus clearance was delayed, and virus-specific Td activity declined more rapidly. Furthermore, class I restricted Tc memory appeared to be impaired in these mice. To directly evaluate the role of CD4+ cells in virus clearance and T-cell mediated inflammation, MHC class I deficient mice were also studied. No virus-specific delayed-type hypersensitivity reaction was detected following infection of the footpad, and only a few mice died from intracerebral challenge. However analysis of markers of T-cell activation as well as direct evaluation of CSF inflammation unveiled a low degree of T-cell activation and a chronic cellular exudate. This low-grade response was associated with some degree of virus control as organ titres were lower in these animals than in matched T-cell deficient nu/nu mice or class I deficient mice treated with anti-CD4 monoclonal antibody. This confirms that CD4+ cells are not needed to induce a virus-specific CD8+ T-cell response, but our findings strongly suggest that CD4+ T cells are critical for maintaining full antiviral immunity. Furthermore, CD4+ T cells per se have a low potential for mediating virus-specific inflammation that is associated with a low degree of virus control.
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Affiliation(s)
- J P Christensen
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Panum Institute, Denmark
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33
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Christensen JP, Marker O, Thomsen AR. T-cell responsiveness to LCMV segregates as a single locus in crosses between BALB/cA and C.B-17 mice. Evidence for regulation by a gene outside the Igh region. Scand J Immunol 1993; 38:215-24. [PMID: 8356397 DOI: 10.1111/j.1365-3083.1993.tb01717.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The course of systemic infection with lymphocytic choriomeningitis virus (LCMV) was studied in BALB/cA and C.B-17 mouse strains differing in the immunoglobulin heavy chain region (Igh). Susceptibility to intracerebral infection and the ability to clear the virus differed significantly between these presumably congenic strains, suggesting that a gene in the Igh region might influence the course of this infection. A difference in virus spread prior to appearance of the immune response could not explain the observed differences. On the other hand, the differences in course of infection correlated with a difference in virus-specific T-cell responsiveness measured in terms of virus-specific cytotoxicity in vitro and delayed-type hypersensitivity in vivo. Analysis of F1, BC1 and F2 progeny showed that differential T-cell responsiveness was influenced by a single gene or gene complex; however, no linkage was found between this locus and the Igh-C region. Taken together, these results indicate that an additional, and previously unknown, genetic difference exists between these two mouse strains, and that the involved locus carries a gene which significantly affects T-cell responsiveness to LCMV.
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Affiliation(s)
- J P Christensen
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark
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