tetano
Editor, Senior Moderator
Am J Physiol Lung Cell Mol Physiol. 2014 Oct 31:ajplung.00011.2014. doi: 10.1152/ajplung.00011.2014. [Epub ahead of print]
Suppression of Influenza A Virus Replication in Human Lung Epithelial Cells by Non-cytotoxic Concentrations Bafilomycin A1.
Yeganeh B1, Ghavami S1, Kroeker AL2, Mahood TH3, Stelmack GL, Klonisch T2, Coombs KM2, Halayko AJ4.
Author information
Abstract
Subcellular trafficking within host cells plays a critical role in viral life cycles, including influenza A virus (IAV). Thus, targeting relevant subcellular compartments holds promise for effective intervention to control the impact of influenza infection. Bafilomycin A1 (Baf-A1), when used at relative high concentrations (≥10 nM) inhibits vacuolar ATPase (V-ATPase), reduces endosome acidification and lysosome number, thus inhibiting IAV replication, but promoting host cell cytotoxicity. We tested the hypothesis that much lower doses of Baf-A1 also have anti-IAV activity, but without toxic effects. Thus, we assessed the anti-viral activity of Baf-A1 at different concentrations (0.1 nM-100 nM) in human alveolar epithelial cells (A549) infected with IAV strain A/PR/8/34 (H1N1). Infected and mock-infected cells pre and co-treated with Baf-A1 were harvested 0-24hrs post infection, and analyzed by immunoblotting, immunofluorescence, confocal and electron microscopy. We found that Baf-A1 had disparate concentration-dependent effects on subcellular organelles and suppressed affected IAV replication. At concentrations ≥ 10 nM Baf-A1, inhibited acid lysosome formation, which resulted in greatly reduced IAV replication and release. Notably, at a very low concentration of 0.1 nM that is insufficient to reduce lysosome number, Baf-A1 retained the capacity to significantly impair IAV nuclear accumulation as well as IAV replication and release. In contrast to the effects of high concentrations of Baf-A1, very low concentrations did not exhibit cytotoxic effects or induce apoptotic cell death, based on morphological and FACS analyses. In conclusion, our results reveal that low concentration Baf-A1 is an effective inhibitor of IAV replication, without impacting host cell viability.
Copyright ? 2014, American Journal of Physiology - Lung Cellular and Molecular Physiology.
KEYWORDS:
Apoptotic cell death; Autophagy; Influenza A Virus; Low dose Bafilomycin A1; Non-cytotoxic
PMID:
25361566
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25361566
Suppression of Influenza A Virus Replication in Human Lung Epithelial Cells by Non-cytotoxic Concentrations Bafilomycin A1.
Yeganeh B1, Ghavami S1, Kroeker AL2, Mahood TH3, Stelmack GL, Klonisch T2, Coombs KM2, Halayko AJ4.
Author information
Abstract
Subcellular trafficking within host cells plays a critical role in viral life cycles, including influenza A virus (IAV). Thus, targeting relevant subcellular compartments holds promise for effective intervention to control the impact of influenza infection. Bafilomycin A1 (Baf-A1), when used at relative high concentrations (≥10 nM) inhibits vacuolar ATPase (V-ATPase), reduces endosome acidification and lysosome number, thus inhibiting IAV replication, but promoting host cell cytotoxicity. We tested the hypothesis that much lower doses of Baf-A1 also have anti-IAV activity, but without toxic effects. Thus, we assessed the anti-viral activity of Baf-A1 at different concentrations (0.1 nM-100 nM) in human alveolar epithelial cells (A549) infected with IAV strain A/PR/8/34 (H1N1). Infected and mock-infected cells pre and co-treated with Baf-A1 were harvested 0-24hrs post infection, and analyzed by immunoblotting, immunofluorescence, confocal and electron microscopy. We found that Baf-A1 had disparate concentration-dependent effects on subcellular organelles and suppressed affected IAV replication. At concentrations ≥ 10 nM Baf-A1, inhibited acid lysosome formation, which resulted in greatly reduced IAV replication and release. Notably, at a very low concentration of 0.1 nM that is insufficient to reduce lysosome number, Baf-A1 retained the capacity to significantly impair IAV nuclear accumulation as well as IAV replication and release. In contrast to the effects of high concentrations of Baf-A1, very low concentrations did not exhibit cytotoxic effects or induce apoptotic cell death, based on morphological and FACS analyses. In conclusion, our results reveal that low concentration Baf-A1 is an effective inhibitor of IAV replication, without impacting host cell viability.
Copyright ? 2014, American Journal of Physiology - Lung Cellular and Molecular Physiology.
KEYWORDS:
Apoptotic cell death; Autophagy; Influenza A Virus; Low dose Bafilomycin A1; Non-cytotoxic
PMID:
25361566
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25361566