1. Prevention of influenza virus induced bacterial superinfection by standardized Echinacea purpurea, via regulation of surface receptor expression in human bronchial epithelial cells.
- Author
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Vimalanathan S, Schoop R, Suter A, and Hudson J
- Subjects
- Cell Line, Coinfection, Epithelial Cells cytology, Epithelial Cells microbiology, Epithelial Cells virology, Fibronectins genetics, Fibronectins immunology, Gene Expression Regulation, Haemophilus influenzae drug effects, Haemophilus influenzae growth & development, Haemophilus influenzae pathogenicity, Host-Pathogen Interactions, Humans, Influenza A Virus, H3N2 Subtype drug effects, Influenza A Virus, H3N2 Subtype growth & development, Influenza A Virus, H3N2 Subtype pathogenicity, Intercellular Adhesion Molecule-1 genetics, Intercellular Adhesion Molecule-1 immunology, Interleukin-6 genetics, Interleukin-6 immunology, Interleukin-8 genetics, Interleukin-8 immunology, Lung cytology, Lung drug effects, Lung microbiology, Lung virology, Plant Extracts pharmacology, Platelet Membrane Glycoproteins genetics, Platelet Membrane Glycoproteins immunology, Receptors, G-Protein-Coupled genetics, Receptors, G-Protein-Coupled immunology, Signal Transduction, Staphylococcus aureus drug effects, Staphylococcus aureus growth & development, Staphylococcus aureus pathogenicity, Superinfection microbiology, Superinfection virology, Toll-Like Receptor 4 genetics, Toll-Like Receptor 4 immunology, Transcription Factor RelA genetics, Transcription Factor RelA immunology, Anti-Infective Agents pharmacology, Echinacea chemistry, Epithelial Cells drug effects, Superinfection prevention & control, Toll-Like Receptor 4 antagonists & inhibitors, Transcription Factor RelA antagonists & inhibitors
- Abstract
Viral infections may predispose the airways to secondary bacterial infections that can lead to unfavorable progression of principally self-limiting illnesses. Such complicated respiratory infections include pneumonia, bronchitis, sinusitis, acute otitis media, and sepsis, which cause high morbidity and lethality. Some of the pathogenic consequences of viral infections, like the expression of bacterial adhesion receptors and the disturbance of physical barrier integrity due to inflammation, may create permissive conditions for co-infections. Influenza virus A (H3N2) is a major pathogen that causes secondary bacterial infections and inflammation that lead to pneumonia. The herbal medicine Echinacea purpurea, on the other hand, has been widely used to prevent and treat viral respiratory infections, and recent clinical data suggest that it may prevent secondary infection complications as well. We investigated the role of standardized E. purpurea (Echinaforce
® extract or EF) on H3N2-induced adhesion of live nontypeable Haemophilus influenzae (NTHi) and Staphylococcus aureus, along with the expression of bacterial receptors, intracellular adhesion molecule-1 (ICAM-1), fibronectin, and platelet activating factor receptor (PAFr), by BEAS-2B cells. Inflammatory processes were investigated by determining the cellular expression of IL-6 and IL-8 and the involvement of Toll-like receptor (TLR-4) and NFκB p65. We found that influenza virus A infection increased the adhesion of H. influenzae and S. aureus to bronchial epithelial cells via upregulated expression of the ICAM-1 receptor and, to some extent, of fibronectin and PAFr. Echinaforce (EF) significantly reduced the expression of ICAM-1, fibronectin, and PAFr and consequently the adhesion of both bacterial strains. EF also effectively prevented the super-expression of inflammatory cytokines by suppressing the expression of NFκB and possibly TLR-4. These results indicate that E. purpurea has the potential to reduce the risk of respiratory complications by preventing virus-induced bacterial adhesion and through the inhibition of inflammation super-stimulation (cytokine storms)., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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