Influenza A viruses (IAV) are a group of respiratory viruses with the potential to cause severe disease, especially in children, pregnant women and the elderly. IAVs are responsible for both seasonal and pandemic outbreaks. Enhancing our understanding of interactions between viral and host proteins is crucial as existing therapeutic approaches are not sufficient to combat influenza.
Previous studies of viral-host protein interactions have previously focused on the global proteomic changes occurring during IAV infection. However, little attention has been given towards understanding how the host glycoproteome is perturbed throughout IAV infection. Host protein glycosylation plays a substantial role in mediating protein folding, stability and function, and is known to be perturbed in many diseased states. The central role IAV surface glycoproteins haemagglutinin (HA) and neuraminidase (NA) have during infection by facilitating virus attachment and release to sialylated host glycoconjugates makes understanding the host glycoproteome during infection particularly essential.
Here we employed an LC-MS/MS approach using tandem mass tag (TMT) labelling and hydrophilic liquid interaction chromatography (HILIC) enrichment of glycopeptides. Using this approach, we quantified and compared the site-specific glycoform abundances of both secreted and intracellular membrane glycoproteins throughout an in vitro time course infection of human A549 cells. Using the TMT labelling approach, we directly compare the relative glycoform abundances at each timepoint for infection with two IAV strains (A/Puerto Rico/8/1934, H1N1 ; A/X-31, H3N2) compared with a mock infection control.
Here, we demonstrate a significant global reduction in host glycoprotein sialylation that develops over the time course infection with both IAV strains and explore the implications of this change for host response to IAV infection.