Highly Pathogenic H5N1 and Novel H7N9 Influenza A Viruses Induce More Profound Proteomic Host Responses than Seasonal and Pandemic H1N1 Strains

Abstract

Influenza A viruses (IAV) are important human and animal pathogens with potential for causing pandemics. IAVs exhibit a wide spectrum of clinical illness in humans, from relatively mild infections by seasonal strains to acute respiratory distress syndrome during infections with some highly pathogenic avian influenza (HPAI) viruses. In the present study, we infected A549 human cells with seasonal H1N1 (sH1N1), 2009 pandemic H1N1 (pdmH1N1), or novel H7N9 and HPAI H5N1 strains. We used multiplexed isobaric tags for relative and absolute quantification to measure proteomic host responses to these different strains at 1, 3, and 6 h post-infection. Our analyses revealed that both H7N9 and H5N1 strains induced more profound changes to the A549 global proteome compared to those with low-pathogenicity H1N1 virus infection, which correlates with the higher pathogenicity these strains exhibit at the organismal level. Bioinformatics analysis revealed important modulation of the nuclear factor erythroid 2-related factor 2 (NRF2) oxidative stress response in infection. Cellular fractionation and Western blotting suggested that the phosphorylated form of NRF2 is not imported to the nucleus in H5N1 and H7N9 virus infections. Fibronectin was also strongly inhibited in infection with H5N1 and H7N9 strains. This is the first known comparative proteomic study of the host response to H7N9, H5N1, and H1N1 viruses and the first time NRF2 is shown to be implicated in infection with highly pathogenic strains of influenza.

Quantitative Proteomic Approach Identifies Vpr Binding Protein as Novel Host Factor Supporting Influenza A Virus Infections in Human Cells

“…7), which is in confirmation of the finding from a previous study that detected impaired propagation of influenza WSN/33 virus (H1N1) upon VprBP knockdown (21,24). In line with our own results, VprBP protein expression was also not changed in permissive infections with H7N9, H5N1 and seasonal H1N1 subtype influenza viruses (14). In contrast, VprBP levels were reduced in Mal virus infected cells and thereby compromised in their ability to promote virus replication (Table I, Fig.…”

“…Previous holistic analyses of IAV focused on the cellular responses to seasonal, pandemic or mouse-adapted influenza strains at early or late time-points of infection (14 -20), or identified host factors required for efficient IAV replication by genome-wide RNAi screens (21)(22)(23)(24). Simon and colleagues, for example, detected more profound changes in the global proteome of the human lung epithelial cell line A549 due to novel H7N9 and highly pathogenic H5N1 infection compared with infection with low-pathogenic H1N1 virus at early time points post infection (14). Permissive influenza virus infection depends on the virus' ability to suppress the anti-viral host cell response, as well as on adaptations within the viral genome that determine efficient viral entry or polymerase activity.…”

Autophagy is highly targeted among host comparative proteomes during infection with different virulent RABV strains

“…The IPA generated two algorithms for evaluating the identified biological functions: the p-value, which is used to determine the pertinence of a group of proteins belonging to specific functional categories, and the z-score, which is used to predict whether the functions were activated or inhibited based on the expression value and current knowledge [17]. …”

“…Proteomics technology has been widely used for probing virus-host interactions, and several comparative proteomes have identified factors that affect the pathogenesis of strains of differential virulence or at different stages of virus infection [8, 17, 20, 21]. Here, iTRAQ combined with LC-MS/MS was applied to analyze the protein profiles of mouse brains infected with pathogenic CVS-11 and attenuated SRV9 strains of RABV to identify the host factors that affect the pathogenesis of RABV.…”

“…Observations were then obtained with dogs to show that IT immunization of laboratory-attenuated RABV induces high levels of VNA at the periphery and in CSF while transiently enhancing the blood-brain barrier (BBB) permeability, whereas wt RABV does not show the capacity to induce VNA and specific antibodies against rabies viral glycoprotein, resulting in the death of the treated animals [14]. Due to the superior performance of the iTRAQ LC-MS/MS proteomics approach for the simultaneous comparison of multiple samples with wide dynamic ranges of protein abundance, an increasing number of studies have applied this method to explore the factors influencing the pathogenesis of virus strains with different degrees of virulence [15, 17, 21]. In the present study, we performed a comparative proteomics analysis of mouse brains infected with pathogenic CVS-11 and attenuated SRV9 strains of RABV and showed that the DEPs between the two groups were highly enriched in autophagy and related pathways.…”