Aims: Dengue virus (DENV) infection is commonly observed in countries with tropical climates and remains a significant health hazard. No real cure has been established for the infection to date. Methodology and results: To better understand the very early molecular events during the initial infection process, we exposed primary dendritic cells with Dengue virus and analysed proteins with increased phosphorylation signatures in the first 10 min using phospho-protein enrichment and tandem mass spectrometry analysis. Upon initial viral interaction, strong phosphorylation was observed for Endoplasmin, BiP, BID, Dok-2, GEF-H1 and Calpain-2. Reduced phosphorylation was noted for Importin-5, ERp72 and Rho-GDI. Knockdown of Calpain-2, a protease activated by calcium flux, reduced DENV infection rates of primary dendritic cells as measured by focus-forming units (FFUs). Conclusion, significance and impact of study We conclude that Calpain-2, BID, Importin 5 and ATP/GTPases are all active along the apoptosis pathway axis, indicating that dendritic cells commit to early signalling steps of cell death upon initial viral contact.

Abstracts Using Saccharomyces cerevisiae lysate, two in-solution trypsin digestions (chloroform-methanol-water precipitation and RapiGest) were compared to the recently reported gel-aided sample preparation (GASP) workflow. Our proteomic results showed that GASP afforded the highest number of overall protein identifications and peptide spectrum matches without systematic bias towards peptide or protein size.