scholarly journals Evidence for Differential Roles for NKG2D Receptor Signaling in Innate Host Defense against Coronavirus-Induced Neurological and Liver Disease

2007 ◽  
Vol 82 (6) ◽  
pp. 3021-3030 ◽  
Author(s):  
Kevin B. Walsh ◽  
Melissa B. Lodoen ◽  
Robert A. Edwards ◽  
Lewis L. Lanier ◽  
Thomas E. Lane
Keyword(s):  
Liver Disease ◽  
Immune Responses ◽  
Host Defense ◽  
Nk Cell ◽  
Hepatitis Virus ◽  
Innate Immune ◽  
Liver Pathology ◽  
Innate Immune Responses ◽  
Ifn Γ ◽  
The Brain

ABSTRACT Infection of SCID mice with a recombinant murine coronavirus (mouse hepatitis virus [MHV]) expressing the T-cell chemoattractant CXC chemokine ligand 10 (CXCL10) resulted in increased survival and reduced viral burden within the brain and liver compared to those of mice infected with an isogenic control virus (MHV), supporting an important role for CXCL10 in innate immune responses following viral infection. Enhanced protection in MHV-CXCL10-infected mice correlated with increased gamma interferon (IFN-γ) production by infiltrating natural killer (NK) cells within the brain and reduced liver pathology. To explore the underlying mechanisms associated with protection from disease in MHV-CXCL10-infected mice, the functional contributions of the NK cell-activating receptor NKG2D in host defense were examined. The administration of an NKG2D-blocking antibody to MHV-CXCL10-infected mice did not reduce survival, dampen IFN-γ production in the brain, or affect liver pathology. However, NKG2D neutralization increased viral titers within the liver, suggesting a protective role for NKG2D signaling in this organ. These data indicate that (i) CXCL10 enhances innate immune responses, resulting in protection from MHV-induced neurological and liver disease; (ii) elevated NK cell IFN-γ expression in the brain of MHV-CXCL10-infected mice occurs independently of NKG2D; and (iii) NKG2D signaling promotes antiviral activity within the livers of MHV-infected mice that is not dependent on IFN-γ and tumor necrosis factor alpha secretion.

scholarly journals Innate Immune Responses of Bat and Human Cells to Filoviruses: Commonalities and Distinctions

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Ivan V. Kuzmin ◽  
Toni M. Schwarz ◽  
Philipp A. Ilinykh ◽  
Ingo Jordan ◽  
Thomas G. Ksiazek ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Antiviral Effect ◽  
Human Cells ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Symptomatic Disease ◽  
Ifn Γ

ABSTRACT Marburg (MARV) and Ebola (EBOV) viruses are zoonotic pathogens that cause severe hemorrhagic fever in humans. The natural reservoir of MARV is the Egyptian rousette bat (Rousettus aegyptiacus); that of EBOV is unknown but believed to be another bat species. The Egyptian rousette develops subclinical productive infection with MARV but is refractory to EBOV. Interaction of filoviruses with hosts is greatly affected by the viral interferon (IFN)-inhibiting domains (IID). Our study was aimed at characterization of innate immune responses to filoviruses and the role of filovirus IID in bat and human cells. The study demonstrated that EBOV and MARV replicate to similar levels in all tested cell lines, indicating that permissiveness for EBOV at cell and organism levels do not necessarily correlate. Filoviruses, particularly MARV, induced a potent innate immune response in rousette cells, which was generally stronger than that in human cells. Both EBOV VP35 and VP24 IID were found to suppress the innate immune response in rousette cells, but only VP35 IID appeared to promote virus replication. Along with IFN-α and IFN-β, IFN-γ was demonstrated to control filovirus infection in bat cells but not in human cells, suggesting host species specificity of the antiviral effect. The antiviral effects of bat IFNs appeared not to correlate with induction of IFN-stimulated genes 54 and 56, which were detected in human cells ectopically expressing bat IFN-α and IFN-β. As bat IFN-γ induced the type I IFN pathway, its antiviral effect is likely to be partially induced via cross talk. IMPORTANCE Bats serve as reservoirs for multiple emerging viruses, including filoviruses, henipaviruses, lyssaviruses, and zoonotic coronaviruses. Although there is no evidence for symptomatic disease caused by either Marburg or Ebola viruses in bats, spillover of these viruses into human populations causes deadly outbreaks. The reason for the lack of symptomatic disease in bats infected with filoviruses remains unknown. The outcome of a virus-host interaction depends on the ability of the host immune system to suppress viral replication and the ability of a virus to counteract the host defenses. Our study is a comparative analysis of the host innate immune response to either MARV or EBOV infection in bat and human cells and the role of viral interferon-inhibiting domains in the host innate immune responses. The data are useful for understanding the interactions of filoviruses with natural and accidental hosts and for identification of factors that influence filovirus evolution.

scholarly journals “Corneal Nerves, CD11c+ Dendritic Cells and Their Impact on Ocular Immune Privilege”

2021 ◽  
Vol 12 ◽  
Author(s):  
Jerry Y. Niederkorn
Keyword(s):  
Immune Responses ◽  
Inflammatory Diseases ◽  
Innate Immune ◽  
Immune Privilege ◽  
Innate Immune Responses ◽  
Regulatory Processes ◽  
Immune Mediated ◽  
Corneal Nerves ◽  
The Central Nervous System ◽  
The Brain

The eye and the brain have limited capacities for regeneration and as such, immune-mediated inflammation can produce devastating consequences in the form of neurodegenerative diseases of the central nervous system or blindness as a result of ocular inflammatory diseases such as uveitis. Accordingly, both the eye and the brain are designed to limit immune responses and inflammation – a condition known as “immune privilege”. Immune privilege is sustained by physiological, anatomical, and regulatory processes that conspire to restrict both adaptive and innate immune responses.

scholarly journals NOD1-Mediated Mucosal Host Defense againstHelicobacter pylori

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Tomohiro Watanabe ◽  
Naoki Asano ◽  
Atsushi Kitani ◽  
Ivan J. Fuss ◽  
Tsutomu Chiba ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Immune Responses ◽  
Host Defense ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Gastric Epithelial Cells ◽  
Innate Immune Responses ◽  
Cytokines And Chemokines ◽  
H Pylori ◽  
Oligomerization Domain

Infection of the stomach withHelicobacter pyloriis an important risk factor for gastritis, peptic ulcer, and gastric carcinoma. Although it has been well established that persistent colonization byH. pyloriis associated with adaptive Th1 responses, the innate immune responses leading to these Th1 responses are poorly defined. Recent studies have shown that the activation of nucleotide-binding oligomerization domain 1 (NOD1) in gastric epithelial cells plays an important role in innate immune responses againstH. pylori. The detection ofH. pylori-derived ligands by cytosolic NOD1 induces several host defense factors, including antimicrobial peptides, cytokines, and chemokines. In this paper, we review the molecular mechanisms by which NOD1 contributes to mucosal host defense againstH. pyloriinfection of the stomach.

scholarly journals Immunization with Attenuated Equine Herpesvirus 1 Strain KyA Induces Innate Immune Responses That Protect Mice from Lethal Challenge

2016 ◽  
Vol 90 (18) ◽  
pp. 8090-8104 ◽  
Author(s):  
Seong K. Kim ◽  
Akhalesh K. Shakya ◽  
Dennis J. O'Callaghan
Keyword(s):  
Immune Responses ◽  
Alveolar Macrophages ◽  
Innate Immune ◽  
Equine Herpesvirus ◽  
Innate Immune Responses ◽  
Lethal Challenge ◽  
Equine Herpesvirus 1 ◽  
Interferon Stimulated Genes ◽  
Ifn Γ ◽  
Herpesvirus 1

ABSTRACTEquine herpesvirus 1 (EHV-1) is a major pathogen affecting equines worldwide. The virus causes respiratory disease, abortion, and, in some cases, neurological disease. EHV-1 strain KyA is attenuated in the mouse and equine, whereas wild-type strain RacL11 induces severe inflammation of the lung, causing infected mice to succumb at 4 to 6 days postinfection. Our previous results showed that KyA immunization protected CBA mice from pathogenic RacL11 challenge at 2 and 4 weeks postimmunization and that KyA infection elicited protective humoral and cell-mediated immune responses. To investigate the protective mechanisms of innate immune responses to KyA, KyA-immunized mice were challenged with RacL11 at various times postvaccination. KyA immunization protected mice from RacL11 challenge at 1 to 7 days postimmunization. Immunized mice lost less than 10% of their body weight and rapidly regained weight. Virus titers in the lungs of KyA-immunized mice were 1,000-fold lower at 2 days post-RacL11 challenge than virus titers in the lungs of nonimmunized mice, indicating accelerated virus clearance. Affymetrix microarray analysis revealed that gamma interferon (IFN-γ) and 16 antiviral interferon-stimulated genes (ISGs) were upregulated 3.1- to 48.2-fold at 8 h postchallenge in the lungs of RacL11-challenged mice that had been immunized with KyA. Murine IFN-γ inhibited EHV-1 infection of murine alveolar macrophages and protected mice against lethal EHV-1 challenge, suggesting that IFN-γ expression is important in mediating the protection elicited by KyA immunization. These results suggest that EHV-1 KyA may be used as a live attenuated EHV-1 vaccine as well as a prophylactic agent in horses.IMPORTANCEViral infection of cells initiates a signal cascade of events that ultimately attempts to limit viral replication and prevent infection through the expression of host antiviral proteins. In this study, we show that EHV-1 KyA immunization effectively protected CBA mice from pathogenic RacL11 challenge at 1 to 7 days postvaccination and increased the expression of IFN-γ and 16 antiviral interferon-stimulated genes (ISGs). The administration of IFN-γ blocked EHV-1 replication in murine alveolar macrophages and mouse lungs and protected mice from lethal challenge. To our knowledge, this is the first report of an attenuated EHV-1 vaccine that protects the animal at 1 to 7 days postimmunization by innate immune responses. Our findings suggested that IFN-γ serves as a novel prophylactic agent and may offer new strategies for the development of anti-EHV-1 agents in the equine.

Multidirectional interactions are bridging human NK cells with plasmacytoid and monocyte-derived dendritic cells during innate immune responses

Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3851-3858 ◽  
Author(s):  
Mariella Della Chiesa ◽  
Chiara Romagnani ◽  
Andreas Thiel ◽  
Lorenzo Moretta ◽  
Alessandro Moretta
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Nk Cells ◽  
De Novo ◽  
Nk Cell ◽  
Innate Immune ◽  
Dependent Manner ◽  
B Cell Differentiation ◽  
Innate Immune Responses ◽  
Intrinsic Resistance

AbstractDuring innate immune responses, natural killer (NK) cells may interact with both plasmacytoid dendritic cells (pDCs) and monocyte-derived dendritic cells (MDDCs). We show that freshly isolated NK cells promote the release by pDCs of IFN-α, in a CpG-dependent manner, whereas they induce IL-6 production in a CpG-independent manner. In turn pDC-derived IFN-α up-regulates NK-mediated killing, whereas IL-6 could promote B-cell differentiation. We also show that exposure to exogenous IL-12 or coculture with maturing MDDCs up-regulates the NK-cell–dependent IFN-α production by pDCs. On the other hand, NK cells cocultured with pDCs acquire the ability to kill immature MDDCs, thus favoring their editing process. Finally, we show that activated NK cells are unable to lyse pDCs because these cells display an intrinsic resistance to lysis. The exposure of pDCs to IL-3 increased their susceptibility to NK-cell cytotoxicity resulting from a de novo expression of ligands for activating NK-cell receptors, such as the DNAM-1 ligand nectin-2. Thus, different cell-to-cell interactions and various cytokines appear to control a multidirectional network between NK cells, MDDCs, and pDCs that is likely to play an important role during the early phase of innate immune responses to viral infections and to tumors.

scholarly journals Circadian regulation of the Drosophila astrocyte transcriptome

PLoS Genetics ◽  
2021 ◽  
Vol 17 (9) ◽  
pp. e1009790
Author(s):  
Samantha You ◽  
Alder M. Yu ◽  
Mary A. Roberts ◽  
Ivanna J. Joseph ◽  
F. Rob Jackson
Keyword(s):  
Immune Responses ◽  
Transcriptional Profiling ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Sleep Behavior ◽  
Circadian Control ◽  
Number Of Genes ◽  
Cell Type Specific ◽  
Normal Sleep ◽  
The Brain

Recent studies have demonstrated that astrocytes cooperate with neurons of the brain to mediate circadian control of many rhythmic processes including locomotor activity and sleep. Transcriptional profiling studies have described the overall rhythmic landscape of the brain, but few have employed approaches that reveal heterogeneous, cell-type specific rhythms of the brain. Using cell-specific isolation of ribosome-bound RNAs in Drosophila, we constructed the first circadian “translatome” for astrocytes. This analysis identified 293 “cycling genes” in astrocytes, most with mammalian orthologs. A subsequent behavioral genetic screen identified a number of genes whose expression is required in astrocytes for normal sleep behavior. In particular, we show that certain genes known to regulate fly innate immune responses are also required for normal sleep patterns.

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