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1.
J Neuroinflammation ; 19(1): 8, 2022 Jan 06.
Article in English | MEDLINE | ID: covidwho-1613238

ABSTRACT

BACKGROUND: The serine protease inhibitor nafamostat has been proposed as a treatment for COVID-19, by inhibiting TMPRSS2-mediated viral cell entry. Nafamostat has been shown to have other, immunomodulatory effects, which may be beneficial for treatment, however animal models of ssRNA virus infection are lacking. In this study, we examined the potential of the dual TLR7/8 agonist R848 to mimic the host response to an ssRNA virus infection and the associated behavioural response. In addition, we evaluated the anti-inflammatory effects of nafamostat in this model. METHODS: CD-1 mice received an intraperitoneal injection of R848 (200 µg, prepared in DMSO, diluted 1:10 in saline) or diluted DMSO alone, and an intravenous injection of either nafamostat (100 µL, 3 mg/kg in 5% dextrose) or 5% dextrose alone. Sickness behaviour was determined by temperature, food intake, sucrose preference test, open field and forced swim test. Blood and fresh liver, lung and brain were collected 6 h post-challenge to measure markers of peripheral and central inflammation by blood analysis, immunohistochemistry and qPCR. RESULTS: R848 induced a robust inflammatory response, as evidenced by increased expression of TNF, IFN-γ, CXCL1 and CXCL10 in the liver, lung and brain, as well as a sickness behaviour phenotype. Exogenous administration of nafamostat suppressed the hepatic inflammatory response, significantly reducing TNF and IFN-γ expression, but had no effect on lung or brain cytokine production. R848 administration depleted circulating leukocytes, which was restored by nafamostat treatment. CONCLUSIONS: Our data indicate that R848 administration provides a useful model of ssRNA virus infection, which induces inflammation in the periphery and CNS, and virus infection-like illness. In turn, we show that nafamostat has a systemic anti-inflammatory effect in the presence of the TLR7/8 agonist. Therefore, the results indicate that nafamostat has anti-inflammatory actions, beyond its ability to inhibit TMPRSS2, that might potentiate its anti-viral actions in pathologies such as COVID-19.


Subject(s)
Benzamidines , Guanidines , Inflammation/drug therapy , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors , Toll-Like Receptor 7/immunology , Virus Diseases/drug therapy , Animals , Benzamidines/pharmacology , Benzamidines/therapeutic use , COVID-19/complications , COVID-19/drug therapy , Guanidines/pharmacology , Guanidines/therapeutic use , Illness Behavior/drug effects , Imidazoles/administration & dosage , Imidazoles/immunology , Inflammation/metabolism , Inflammation/virology , Male , Mice , Serine Proteinase Inhibitors/pharmacology , Serine Proteinase Inhibitors/therapeutic use , Toll-Like Receptor 7/agonists , Virus Diseases/metabolism , Virus Diseases/virology
2.
Sci Rep ; 11(1): 23741, 2021 12 09.
Article in English | MEDLINE | ID: covidwho-1565734

ABSTRACT

The mechanisms explaining excess morbidity and mortality in respiratory infections among males are poorly understood. Innate immune responses are critical in protection against respiratory virus infections. We hypothesised that innate immune responses to respiratory viruses may be deficient in males. We stimulated peripheral blood mononuclear cells from 345 participants at age 16 years in a population-based birth cohort with three live respiratory viruses (rhinoviruses A16 and A1, and respiratory syncytial virus) and two viral mimics (R848 and CpG-A, to mimic responses to SARS-CoV-2) and investigated sex differences in interferon (IFN) responses. IFN-α responses to all viruses and stimuli were 1.34-2.06-fold lower in males than females (P = 0.018 - < 0.001). IFN-ß, IFN-γ and IFN-induced chemokines were also deficient in males across all stimuli/viruses. Healthcare records revealed 12.1% of males and 6.6% of females were hospitalized with respiratory infections in infancy (P = 0.017). In conclusion, impaired innate anti-viral immunity in males likely results in high male morbidity and mortality from respiratory virus infections.


Subject(s)
Imidazoles/immunology , Immunity, Innate , Oligodeoxyribonucleotides/immunology , Picornaviridae Infections/immunology , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus, Human/immunology , Rhinovirus/immunology , Adolescent , Cohort Studies , Female , Humans , Interferons/immunology , Interferons/metabolism , Leukocytes, Mononuclear/immunology , Male , Picornaviridae Infections/mortality , Picornaviridae Infections/virology , Respiratory Syncytial Virus Infections/mortality , Respiratory Syncytial Virus Infections/virology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/mortality , Respiratory Tract Infections/virology , SARS-CoV-2 , Sex Factors
3.
PLoS Pathog ; 17(10): e1009928, 2021 10.
Article in English | MEDLINE | ID: covidwho-1484868

ABSTRACT

Non-specific protective effects of certain vaccines have been reported, and long-term boosting of innate immunity, termed trained immunity, has been proposed as one of the mechanisms mediating these effects. Several epidemiological studies suggested cross-protection between influenza vaccination and COVID-19. In a large academic Dutch hospital, we found that SARS-CoV-2 infection was less common among employees who had received a previous influenza vaccination: relative risk reductions of 37% and 49% were observed following influenza vaccination during the first and second COVID-19 waves, respectively. The quadrivalent inactivated influenza vaccine induced a trained immunity program that boosted innate immune responses against various viral stimuli and fine-tuned the anti-SARS-CoV-2 response, which may result in better protection against COVID-19. Influenza vaccination led to transcriptional reprogramming of monocytes and reduced systemic inflammation. These epidemiological and immunological data argue for potential benefits of influenza vaccination against COVID-19, and future randomized trials are warranted to test this possibility.


Subject(s)
COVID-19/immunology , Cross Protection/physiology , Immunity, Innate/physiology , Influenza Vaccines/administration & dosage , COVID-19/epidemiology , COVID-19/prevention & control , Cytokines/immunology , Cytokines/metabolism , Down-Regulation , Imidazoles/immunology , Incidence , Influenza Vaccines/immunology , Netherlands/epidemiology , Personnel, Hospital , Poly I-C/immunology , Proteomics , Risk Factors , Sequence Analysis, RNA
4.
Angew Chem Int Ed Engl ; 60(17): 9467-9473, 2021 04 19.
Article in English | MEDLINE | ID: covidwho-1037522

ABSTRACT

The search for vaccines that protect from severe morbidity and mortality because of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19) is a race against the clock and the virus. Here we describe an amphiphilic imidazoquinoline (IMDQ-PEG-CHOL) TLR7/8 adjuvant, consisting of an imidazoquinoline conjugated to the chain end of a cholesterol-poly(ethylene glycol) macromolecular amphiphile. It is water-soluble and exhibits massive translocation to lymph nodes upon local administration through binding to albumin, affording localized innate immune activation and reduction in systemic inflammation. The adjuvanticity of IMDQ-PEG-CHOL was validated in a licensed vaccine setting (quadrivalent influenza vaccine) and an experimental trimeric recombinant SARS-CoV-2 spike protein vaccine, showing robust IgG2a and IgG1 antibody titers in mice that could neutralize viral infection in vitro and in vivo in a mouse model.


Subject(s)
Adjuvants, Immunologic/therapeutic use , COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Imidazoles/therapeutic use , Immunity, Innate/drug effects , Quinolines/therapeutic use , Animals , COVID-19 Vaccines/immunology , Cholesterol/analogs & derivatives , Cholesterol/immunology , Cholesterol/therapeutic use , Female , Humans , Imidazoles/immunology , Influenza A Virus, H1N1 Subtype/drug effects , Influenza Vaccines/immunology , Influenza Vaccines/therapeutic use , Influenza, Human/prevention & control , Membrane Glycoproteins/agonists , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Transgenic , Polyethylene Glycols/therapeutic use , Quinolines/immunology , Recombinant Proteins/immunology , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/immunology , Surface-Active Agents/therapeutic use , Toll-Like Receptor 7/agonists , Toll-Like Receptor 8/agonists
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