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1.
J Allergy Clin Immunol ; 149(3): 923-933.e6, 2022 03.
Article in English | MEDLINE | ID: covidwho-1560006

ABSTRACT

BACKGROUND: Treatments for coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are urgently needed but remain limited. SARS-CoV-2 infects cells through interactions of its spike (S) protein with angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) on host cells. Multiple cells and organs are targeted, particularly airway epithelial cells. OM-85, a standardized lysate of human airway bacteria with strong immunomodulating properties and an impeccable safety profile, is widely used to prevent recurrent respiratory infections. We found that airway OM-85 administration inhibits Ace2 and Tmprss2 transcription in the mouse lung, suggesting that OM-85 might hinder SARS-CoV-2/host cell interactions. OBJECTIVES: We sought to investigate whether and how OM-85 treatment protects nonhuman primate and human epithelial cells against SARS-CoV-2. METHODS: ACE2 and TMPRSS2 mRNA and protein expression, cell binding of SARS-CoV-2 S1 protein, cell entry of SARS-CoV-2 S protein-pseudotyped lentiviral particles, and SARS-CoV-2 cell infection were measured in kidney, lung, and intestinal epithelial cell lines, primary human bronchial epithelial cells, and ACE2-transfected HEK293T cells treated with OM-85 in vitro. RESULTS: OM-85 significantly downregulated ACE2 and TMPRSS2 transcription and surface ACE2 protein expression in epithelial cell lines and primary bronchial epithelial cells. OM-85 also strongly inhibited SARS-CoV-2 S1 protein binding to, SARS-CoV-2 S protein-pseudotyped lentivirus entry into, and SARS-CoV-2 infection of epithelial cells. These effects of OM-85 appeared to depend on SARS-CoV-2 receptor downregulation. CONCLUSIONS: OM-85 inhibits SARS-CoV-2 epithelial cell infection in vitro by downregulating SARS-CoV-2 receptor expression. Further studies are warranted to assess whether OM-85 may prevent and/or reduce the severity of coronavirus disease 2019.


Subject(s)
Adjuvants, Immunologic/administration & dosage , COVID-19/prevention & control , Cell Extracts/administration & dosage , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/immunology , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , COVID-19/immunology , COVID-19/virology , Caco-2 Cells , Cell Extracts/immunology , Cells, Cultured , Chlorocebus aethiops , Down-Regulation/drug effects , Epithelial Cells/drug effects , Epithelial Cells/immunology , Epithelial Cells/virology , HEK293 Cells , Host Microbial Interactions/drug effects , Host Microbial Interactions/immunology , Humans , In Vitro Techniques , Lung/drug effects , Lung/immunology , Lung/virology , Mice , Mice, Inbred BALB C , Serine Endopeptidases/drug effects , Serine Endopeptidases/genetics , Serine Endopeptidases/immunology , Transcription, Genetic/drug effects , Transcription, Genetic/immunology , Vero Cells
2.
Nat Commun ; 12(1): 5536, 2021 09 20.
Article in English | MEDLINE | ID: covidwho-1428813

ABSTRACT

Coronaviruses (CoVs) are important human pathogens for which no specific treatment is available. Here, we provide evidence that pharmacological reprogramming of ER stress pathways can be exploited to suppress CoV replication. The ER stress inducer thapsigargin efficiently inhibits coronavirus (HCoV-229E, MERS-CoV, SARS-CoV-2) replication in different cell types including primary differentiated human bronchial epithelial cells, (partially) reverses the virus-induced translational shut-down, improves viability of infected cells and counteracts the CoV-mediated downregulation of IRE1α and the ER chaperone BiP. Proteome-wide analyses revealed specific pathways, protein networks and components that likely mediate the thapsigargin-induced antiviral state, including essential (HERPUD1) or novel (UBA6 and ZNF622) factors of ER quality control, and ER-associated protein degradation complexes. Additionally, thapsigargin blocks the CoV-induced selective autophagic flux involving p62/SQSTM1. The data show that thapsigargin hits several central mechanisms required for CoV replication, suggesting that this compound (or derivatives thereof) may be developed into broad-spectrum anti-CoV drugs.


Subject(s)
Endoplasmic Reticulum Stress , SARS-CoV-2/physiology , Virus Replication/physiology , Animals , Autophagy/drug effects , Bronchi/pathology , COVID-19/pathology , COVID-19/virology , Cell Differentiation/drug effects , Cell Extracts , Cell Line , Cell Survival/drug effects , Chlorocebus aethiops , Coronavirus 229E, Human/physiology , Down-Regulation/drug effects , Endoplasmic Reticulum Stress/drug effects , Endoplasmic Reticulum Stress/genetics , Endoplasmic Reticulum-Associated Degradation/drug effects , Epithelial Cells/drug effects , Epithelial Cells/virology , Heat-Shock Proteins/metabolism , Humans , Macrolides/pharmacology , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/physiology , Protein Biosynthesis/drug effects , Proteome/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reproducibility of Results , SARS-CoV-2/drug effects , Thapsigargin/pharmacology , Unfolded Protein Response/drug effects , Vero Cells , Virus Replication/drug effects
3.
Ter Arkh ; 93(1): 108-113, 2021 Jan 10.
Article in Russian | MEDLINE | ID: covidwho-1134694

ABSTRACT

During a pandemic, nonspecific immunoprophylaxis of SARS-CoV-2 infection and other acute respiratory infections (ARI), which can worsen the course of COVID-19, is increasingly in demand in addition to specific immunization. BCG vaccine appears to be one of the candidate immunostimulants in this regard. At the same time, other microbe-derived preparations capable of inducing a state of trained immunity deserve attention. BCG and other bacterial immunostimulatory agents containing a large number of biologically active subunits have long been considered as objects of search for promising pharmacological substances. The review analyzes the linkages between BCG, mycobacterial adjuvants, bacterial lysates, trained immunity, muramylpeptides (MPs) and NOD2 receptors in light of the choice of a low molecular weight alternative to multicomponent bacterial immunostimulants for ARI prevention during the COVID-19 pandemic. The search for key molecules by which bacteria stimulate innate and adaptive immune responses proceeds in a spiral. On different loops of this spiral, MPs have repeatedly reproduced the nonspecific effects of multicomponent bacterial adjuvants, vaccines and immunostimulants. MPs and peptidoglycans containing MPs determine the adjuvant properties of the cell walls of mycobacteria and their peptide-glycolipid fraction (wax D). MPs were able to replace Mycobacterium tuberculosis in complete Freunds adjuvant. MPs determine the NOD2-dependent ability of BCG to induce trained immunity. Probably, MPs provide NOD2-mediated long-term prophylactic action of bacterial lysates. All of the above has prompted revisiting the previously obtained evidence of the efficacy of glucosaminylmuramyl dipeptide (GMDP) as a NOD2 agonist in treatment/prevention of respiratory infections. We speculate here that MPs, in particular GMDP, at rational dosing regimens will be able to reproduce many aspects of the nonspecific effects of BCG and multicomponent bacterial immunostimulants in preventing ARI during the COVID-19 pandemic and in the post-pandemic period.


Subject(s)
COVID-19 , Pandemics , BCG Vaccine , Cell Extracts , Humans , Immunity, Innate , Molecular Weight , SARS-CoV-2
4.
Mar Biotechnol (NY) ; 23(1): 149-155, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1074429

ABSTRACT

An array of infections, including the novel coronavirus (SARS-CoV-2), trigger macrophage activation syndrome (MAS) and subsequently hypercytokinemia, commonly referred to as a cytokine storm (CS). It is postulated that CS is mainly responsible for critical COVID-19 cases, including acute respiratory distress syndrome (ARDS). Recognizing the therapeutic potential of Spirulina blue-green algae (Arthrospira platensis), in this in vitro stimulation study, LPS-activated macrophages and monocytes were treated with aqueous extracts of Spirulina, cultivated in either natural or controlled light conditions. We report that an extract of photosynthetically controlled Spirulina (LED Spirulina), at a concentration of 0.1 µg/mL, decreases macrophage and monocyte-induced TNF-α secretion levels by over 70% and 40%, respectively. We propose prompt in vivo studies in animal models and human subjects to determine the putative effectiveness of a natural, algae-based treatment for viral CS and ARDS, and explore the potential of a novel anti-TNF-α therapy.


Subject(s)
COVID-19/complications , COVID-19/therapy , Cell Extracts/pharmacology , Cell Extracts/therapeutic use , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/therapy , Macrophages/drug effects , Monocytes/drug effects , Cells, Cultured , Humans , In Vitro Techniques , Spirulina/chemistry
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