Toll-like Receptors (TLRs) sense viral infections and induce production of type I interferons (IFNs), other cytokines, and chemokines. Viral recognition by TLRs and other pattern recognition receptors (PRRs) has been proven to be cell-type specific. Triggering of TLRs with selected ligands can be beneficial against some viral infections. Macrophages are antigen-presenting cells that express TLRs and have a key role in the innate and adaptive immunity against viruses. Coronaviruses (CoVs) are single-stranded, positive-sense RNA viruses that cause acute and chronic infections and can productively infect macrophages. Investigation of the interplay between CoVs and PRRs is in its infancy. We assessed the effect of triggering TLR2, TLR3, TLR4, and TLR7 with selected ligands on the susceptibility of the J774A.1 macrophage cell line to infection with murine coronavirus (mouse hepatitis virus, [MHV]). Stimulation of TLR2, TLR4, or TLR7 did not affect MHV production. In contrast, pre-stimulation of TLR3 with polyinosinic-polycytidylic acid (poly I:C) hindered MHV infection through induction of IFN-β in macrophages. We demonstrate that activation of TLR3 with the synthetic ligand poly I:C mediates antiviral immunity that diminishes (MHV-A59) or suppresses (MHV-JHM, MHV-3) virus production in macrophages.
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http://dx.doi.org/10.3390/v4050901 | DOI Listing |
Inflamm Res
January 2025
Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
Objective: We aimed to understand the potential therapeutic and anti-inflammatory effects of the phosphodiesterase-4 (PDE4) inhibitor roflumilast in models of pulmonary infection caused by betacoronaviruses.
Methods: Mice were infected intranasally with murine hepatitis virus (MHV-3) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Roflumilast was given to MHV-3-infected mice therapeutically at doses of 1 mg/kg or 10 mg/kg, or prophylactically at 10 mg/kg.
J Med Virol
January 2025
State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Coronaviruses (CoVs) pose a significant threat to human health, as demonstrated by the COVID-19 pandemic. The large size of the CoV genome (around 30 kb) represents a major obstacle to the development of reverse genetics systems, which are invaluable for basic research and antiviral drug screening. In this study, we established a rapid and convenient method for generating reverse genetic systems for various CoVs using a bacterial artificial chromosome (BAC) vector and Gibson DNA assembly.
View Article and Find Full Text PDFSci Total Environ
February 2025
Institute of Agrochemistry and Food Technology, IATA-CSIC, Av. Agustín Escardino 7, Paterna, Valencia 46980, Spain. Electronic address:
Human enteric viruses and emerging viruses such as severe acute respiratory syndrome coronavirus 2, influenza virus and monkeypox virus, are frequently detected in wastewater. Human enteric viruses are highly persistent in water, but there is limited information available for non-enteric viruses. The present study evaluated the stability of hepatitis A virus (HAV), murine norovirus (MNV), influenza A virus H3N2 (IAV H3N2), human coronavirus (HCoV) 229E, and vaccinia virus (VACV) in reference water (RW), effluent wastewater (EW) and drinking water (DW) under refrigeration and room temperature conditions.
View Article and Find Full Text PDFMedicine (Baltimore)
November 2024
Beijing Institute of Radiation Medicine, Beijing, P.R. China.
From the severe acute respiratory syndrome coronavirus in 2003 to the severe acute respiratory syndrome coronavirus 2 in 2019, coronavirus has seriously threatened human health. Electromagnetic waves not only own high penetration and low pollution but also can physically resonate with the virus. Several studies have demonstrated that electromagnetic waves can inactivate viruses efficiently.
View Article and Find Full Text PDFbioRxiv
January 2025
Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA.
Neurotropic viruses are a major public health concern as they can cause encephalitis and other severe brain diseases. Many of these viruses, including flaviviruses, herpesviruses, rhabdoviruses and alphaviruses enter the brain through the olfactory neuroepithelium (ONE) in the olfactory bulbs (OB). Due to the low percentage of encephalitis that occurs following these infections, it's thought that the OBs have specialized innate immune responses to eliminate viruses.
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