Immune Response to Seasonal Influenza A Virus Infection: A Proteomic Approach

Background and AimsInfluenza viruses cause respiratory infection in humans and result in substantial illness, death, and economic burden. To date, however, the mechanisms by which these viruses cause disease are not fully understood.MethodsTo investigate the proteomic profile of children infected with seasonal influenza A virus, nasal aspirates derived from children (n = 12) experiencing flu symptoms caused by seasonal influenza A virus were analyzed using two-dimensional electrophoresis (2-DE). Control nasal samples were taken from the same group of children 8–10 weeks later when they were symptom free.ResultsAnalysis of the 2-DE gels revealed eight spots differentially expressed, which were further analyzed using mass spectrometry. Ten proteins were found to be differentially upregulated in the infected children including PLUNC, cystatin S, cystatin SA, S100A9, lipocalin 1 fragments (n = 2), truncated lactotransferrin, two immunoglobulin (Ig) kappa fragments and one immunoglobulin (Ig) lambda fragment.ConclusionsOur findings reveal that the composition of nasal secretions in influenza virus respiratory infections is different from that when children are healthy and may provide further insights into the pathogenesis of respiratory infections caused by seasonal influenza A viruses.