Related Experiment Video
Updated: May 5, 2026
Modeling Dysplastic and Functional Lung Alveolar Repair after Influenza Infection
Published on: September 19, 2025
Quantitative phosphoproteomic analysis of host responses in human lung epithelial (A549) cells during influenza virus
Clyde Dapat1, Reiko Saito1, Hiroshi Suzuki2
1Division of International Health (Public Health), Graduate School of Medical, Dental Sciences, Niigata University, Japan.
Abstract:
The emergence of antiviral drug-resistant influenza viruses highlights the need for alternative therapeutic strategies. Elucidation of host factors required during virus infection provides information not only on the signaling pathways involved but also on the identification of novel drug targets. RNA interference screening method had been utilized by several studies to determine these host factors; however, proteomics data on influenza host factors are currently limited. In this study, quantitative phosphoproteomic analysis of human lung cell line (A549) infected with 2009 pandemic influenza virus A (H1N1) virus was performed. Phosphopeptides were enriched from tryptic digests of total protein of infected and mock-infected cells using a titania column on an automated purification system followed by iTRAQ labeling. Identification and quantitative analysis of iTRAQ-labeled phosphopeptides were performed using LC-MS/MS. We identified 366 phosphorylation sites on 283 proteins. Of these, we detected 43 upregulated and 35 downregulated proteins during influenza virus infection. Gene ontology enrichment analysis showed that majority of the identified proteins are phosphoproteins involved in RNA processing, immune system process and response to infection. Host-virus interaction network analysis had identified 23 densely connected subnetworks. Of which, 13 subnetworks contained proteins with altered phosphorylation levels during by influenza virus infection. Our results will help to identify potential drug targets that can be pursued for influenza antiviral drug development.
Insights
Antiviral resistance necessitates new influenza therapies. This study used phosphoproteomics to identify host proteins and phosphorylation changes during H1N1 infection, revealing potential drug targets for influenza treatment.
Area of Science:
- Virology
- Proteomics
- Host-Pathogen Interactions
Background:
- Antiviral drug resistance in influenza viruses necessitates novel therapeutic strategies.
- Understanding host factors during viral infection can identify new drug targets.
- Proteomics data on influenza host factors remain limited.
Purpose of the Study:
- To perform quantitative phosphoproteomic analysis of human lung cells infected with the 2009 pandemic influenza A (H1N1) virus.
- To identify host proteins and their phosphorylation changes during influenza infection.
- To discover potential drug targets for influenza antiviral development.
Main Methods:
- Quantitative phosphoproteomic analysis of A549 cells infected with H1N1 virus.
- Phosphopeptide enrichment using titania columns and iTRAQ labeling.
- LC-MS/MS for identification and quantification of phosphopeptides.
Main Results:
- Identified 366 phosphorylation sites on 283 proteins.
- Detected 43 upregulated and 35 downregulated proteins during H1N1 infection.
- Gene ontology analysis revealed proteins involved in RNA processing, immune response, and infection response.
- Host-virus interaction network analysis identified 13 subnetworks with altered phosphorylation.
Conclusions:
- The study identified key host proteins and phosphorylation events crucial for influenza virus infection.
- Altered phosphoproteins and subnetworks represent potential targets for novel antiviral drug development.
- This phosphoproteomic data provides valuable insights into host-virus interactions during influenza infection.
