scholarly journals Oligodendrocytes that survive acute coronavirus infection induce prolonged inflammatory responses in the CNS

2020 ◽  
Vol 117 (27) ◽  
pp. 15902-15910 ◽  
Author(s):  
Ruangang Pan ◽  
Qinran Zhang ◽  
Scott M. Anthony ◽  
Yu Zhou ◽  
Xiufen Zou ◽  
...  

Neurotropic strains of mouse hepatitis virus (MHV), a coronavirus, cause acute and chronic demyelinating encephalomyelitis with similarities to the human disease multiple sclerosis. Here, using a lineage-tracking system, we show that some cells, primarily oligodendrocytes (OLs) and oligodendrocyte precursor cells (OPCs), survive the acute MHV infection, are associated with regions of demyelination, and persist in the central nervous system (CNS) for at least 150 d. These surviving OLs express major histocompatibility complex (MHC) class I and other genes associated with an inflammatory response. Notably, the extent of inflammatory cell infiltration was variable, dependent on anatomic location within the CNS, and without obvious correlation with numbers of surviving cells. We detected more demyelination in regions with larger numbers of T cells and microglia/macrophages compared to those with fewer infiltrating cells. Conversely, in regions with less inflammation, these previously infected OLs more rapidly extended processes, consistent with normal myelinating function. Together, these results show that OLs are inducers as well as targets of the host immune response and demonstrate how a CNS infection, even after resolution, can induce prolonged inflammatory changes with CNS region-dependent impairment in remyelination.

2010 ◽  
Vol 84 (21) ◽  
pp. 11030-11044 ◽  
Author(s):  
Susan J. Bender ◽  
Judith M. Phillips ◽  
Erin P. Scott ◽  
Susan R. Weiss

ABSTRACT Coronavirus infection of the murine central nervous system (CNS) provides a model for studies of viral encephalitis and demyelinating disease. Mouse hepatitis virus (MHV) neurotropism varies by strain: MHV-A59 causes mild encephalomyelitis and demyelination, while the highly neurovirulent strain JHM.SD (MHV-4) causes fatal encephalitis with extensive neuronal spread of virus. In addition, while neurons are the predominant CNS cell type infected in vivo, the canonical receptor for MHV, the carcinoembryonic antigen family member CEACAM1a, has been demonstrated only on endothelial cells and microglia. In order to investigate whether CEACAM1a is also expressed in other cell types, ceacam1a mRNA expression was quantified in murine tissues and primary cells. As expected, among CNS cell types, microglia expressed the highest levels of ceacam1a, but lower levels were also detected in oligodendrocytes, astrocytes, and neurons. Given the low levels of neuronal expression of ceacam1a, primary neurons from wild-type and ceacam1a knockout mice were inoculated with MHV to determine the extent to which CEACAM1a-independent infection might contribute to CNS infection. While both A59 and JHM.SD infected small numbers of ceacam1a knockout neurons, only JHM.SD spread efficiently to adjacent cells in the absence of CEACAM1a. Quantification of mRNA for the ceacam1a-related genes ceacam2 and psg16 (bCEA), which encode proposed alternative MHV receptors, revealed low ceacam2 expression in microglia and oligodendrocytes and psg16 expression exclusively in neurons; however, only CEACAM2 mediated infection in human 293T cells. Therefore, neither CEACAM2 nor PSG16 is likely to be an MHV receptor on neurons, and the mechanism for CEACAM1a-independent neuronal spread of JHM.SD remains unknown.


2021 ◽  
Author(s):  
Gema M Olivarria ◽  
Yuting Cheng ◽  
Collin Pachow ◽  
Lindsay A Hohsfield ◽  
Charlene Smith-Geater ◽  
...  

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited anti-viral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, ~50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine (Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19) and cytokine (Ifn-λ and Tnf-α) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease.


2000 ◽  
Vol 74 (17) ◽  
pp. 7903-7910 ◽  
Author(s):  
Norman W. Marten ◽  
Stephen A. Stohlman ◽  
Cornelia C. Bergmann

ABSTRACT The continued presence of virus-specific CD8+ T cells within the central nervous system (CNS) following resolution of acute viral encephalomyelitis implicates organ-specific retention. The role of viral persistence in locally maintaining T cells was investigated by infecting mice with either a demyelinating, paralytic (V-1) or nonpathogenic (V-2) variant of a neurotropic mouse hepatitis virus, which differ in the ability to persist within the CNS. Class I tetramer technology revealed more infiltrating virus-specific CD8+ T cells during acute V-1 compared to V-2 infection. However, both total and virus-specific CD8+ T cells accumulated at similar peak levels in spinal cords by day 10 postinfection (p.i.). Decreasing viral RNA levels in both brains and spinal cords following initial virus clearance coincided with an overall progressive loss of both total and virus-specific CD8+ T cells. By 9 weeks p.i., T cells had largely disappeared from brains of both infected groups, consistent with the decline of viral RNA. T cells also completely disappeared from V-2-infected spinal cords coincident with the absence of viral RNA. By contrast, a significant number of CD8+ T cells which contained detectable viral RNA were recovered from spinal cords of V-1-infected mice. The data indicate that residual virus from a primary CNS infection is a vital component in mediating local retention of both CD8+ and CD4+ T cells and that once minimal thresholds of stimuli are lost, T cells within the CNS cannot survive in an autonomous fashion.


2020 ◽  
Vol 19 (7) ◽  
pp. 483-494
Author(s):  
Tyler J. Wenzel ◽  
Evan Kwong ◽  
Ekta Bajwa ◽  
Andis Klegeris

: Glial cells, including microglia and astrocytes, facilitate the survival and health of all cells within the Central Nervous System (CNS) by secreting a range of growth factors and contributing to tissue and synaptic remodeling. Microglia and astrocytes can also secrete cytotoxins in response to specific stimuli, such as exogenous Pathogen-Associated Molecular Patterns (PAMPs), or endogenous Damage-Associated Molecular Patterns (DAMPs). Excessive cytotoxic secretions can induce the death of neurons and contribute to the progression of neurodegenerative disorders, such as Alzheimer’s disease (AD). The transition between various activation states of glia, which include beneficial and detrimental modes, is regulated by endogenous molecules that include DAMPs, cytokines, neurotransmitters, and bioactive lipids, as well as a diverse group of mediators sometimes collectively referred to as Resolution-Associated Molecular Patterns (RAMPs). RAMPs are released by damaged or dying CNS cells into the extracellular space where they can induce signals in autocrine and paracrine fashions by interacting with glial cell receptors. While the complete range of their effects on glia has not been described yet, it is believed that their overall function is to inhibit adverse CNS inflammatory responses, facilitate tissue remodeling and cellular debris removal. This article summarizes the available evidence implicating the following RAMPs in CNS physiological processes and neurodegenerative diseases: cardiolipin (CL), prothymosin α (ProTα), binding immunoglobulin protein (BiP), heat shock protein (HSP) 10, HSP 27, and αB-crystallin. Studies on the molecular mechanisms engaged by RAMPs could identify novel glial targets for development of therapeutic agents that effectively slow down neuroinflammatory disorders including AD.


1968 ◽  
Vol 66 (3) ◽  
pp. 355-364 ◽  
Author(s):  
H. E. Webb ◽  
D. G. D. Wight ◽  
G. Wiernik ◽  
G. S. Platt ◽  
C. E. G. Smith

Summary1. Irradiation in a whole body dose of 200 rads or more increased the sensitivity of mice to intraperitoneal infection with Langat virus so that the LD 50 was increased to about the intracerebral LD 50.2. In mice given 500 rads before infection: (a) viraemia was prolonged by about 5 days; (b) the IgM response was depressed; (c) the IgG response was delayed by about 3 days and depressed in titre; (d) virus concentration in the brain rose continuously until death on about the tenth day while in the controls it reached a peak on the fifth day then subsided; (e) histological changes in the CNS were delayed and minimal even at death; (f) irradiated mice died with little evidence of paralysis while the controls died with severe paralysis.3. In irradiated mice, protection was observed when antibody was administered on the third day following infection. Antibody given on the 3 days after infection to control mice aggravated the disease.4. The results in this and the preceding paper are discussed in relation to the pathogenesis of encephalitis. It is concluded that neuronal damage is caused both by virus multiplication in neurones and by damage superimposed by inflammatory changes with associated oedema and hypoxia. The inflammatory changes appear to be due to an allergic reaction to virus-antibody complexes formed in the circulation and in the central nervous system.We are grateful to Miss S. J. Illavia, B.Sc., and Miss G. E. Fairbairn for their skilled technical assistance; to the Department of Radiotherapy at St Thomas's Hospital for providing time and staff to help with the irradiation experiments; and to Mr S. Peto of the Microbiological Research Establishment for statistical advice.This work was made possible by a generous grant from the Wellcome Trust and the Endowment Funds of St Thomas's Hospital.


Author(s):  
Luis D’Marco ◽  
María Jesús Puchades ◽  
Miguel Ángel Serra ◽  
Lorena Gandía ◽  
Sergio Romero-Alcaide ◽  
...  

Since the dramatic rise of the coronavirus infection disease 2019 (COVID-19) pandemic, patients receiving dialysis have emerged as especially susceptible to this infection because of their impaired immunologic state, chronic inflammation and the high incidence of comorbidities. Although several strategies have thus been implemented to minimize the risk of transmission and acquisition in this population worldwide, the reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence varies across studies but is higher than in the general population. On the contrary, the screening for hepatitis viruses (HBV and HCV) has seen significant improvements in recent years, with vaccination in the case of HBV and effective viral infection treatment for HCV. In this sense, a universal SARS-CoV-2 screening and contact precaution appear to be effective in preventing further transmission. Finally, regarding the progress, an international consensus with updated protocols that prioritize between old and new indicators would seem a reasonable tool to address these unexpended changes for the nephrology community.


2021 ◽  
pp. 107385842110249
Author(s):  
Dallin Dressman ◽  
Wassim Elyaman

T cells play a central role in homeostasis and host defense against infectious diseases. T cell dysregulation can lead to recognizing self-antigens as foreign antigens, causing a detrimental autoimmune response. T cell involvement in multiple sclerosis (MS), long understood to be an autoimmune-mediated neurodegenerative disease, is well characterized. More recently, a role for T cells has also been identified for the neurodegenerative diseases Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). Interestingly, several alleles and variants of human leukocyte antigen (HLA) genes have been classified as AD and PD risk genes. HLA codes for components of major histocompatibility complex (MHC) class I or class II, both of which are expressed by microglia, the innate immune cells of the central nervous system (CNS). Thus, both microglia and T cells may potentially interact in an antigen-dependent or independent fashion to shape the inflammatory cascade occurring in neurodegenerative diseases. Dissecting the antigen specificity of T cells may lead to new options for disease-modifying treatments in neurodegenerative diseases. Here, we review the current understanding of T cells in neurodegenerative diseases. We summarize the subsets of T cells, their phenotype and potential functions in animal models and in human studies of neurodegenerative diseases.


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