Neutrophil proteomics in respiratory viral infection

INNOVATE was a prospective observational cohort study of hospitalized patients admitted to Ninewells Hospital, Dundee, United Kingdom. INNOVATE recruited hospitalized patients between December 2022 and March 2023. Patients were recruited upon admission with PCR virus positive test for influenza, SARS-CoV-2 or other viruses. Overall 91 hospitalized patients with viral infections were recruited to the INNOVATE study. Cohort A: 20 patients with confirmed influenza. Cohort B: 36 patients with other viruses were recruited, that included 27 patients with SARS-CoV-2 and 9 patients with RSV. The control cohort: 35 patients with no signs of respiratory infection. Point of care inflammatory markers were measured in INNOVATE cohort patients upon admission to the hospital. And WBC did differ significantly between the cohorts. Neutrophil counts were higher in the other viruses cohort compared to controls (p=0.042). In influenza cohort the level of neutrophils appeared higher to controls, although not significantly so (p=0.136). CRP levels were significantly higher in both influenza (p=0.002) and other viruses (p=0.0003) vs controls, confirming the presence of systemic inflammation. Scoring of clinical severity showed that patients with influenza had worse clinical presentation according to WHO score, compared to other viruses cohort (p=0.005). Detected changes needed deeper analysis, therefore levels of inflammatory biomarkers IL-6 and resistin were measured as well as neutrophil proteomic analysis was done. Neutrophil proteomic analysis of neutrophils in response to influenza infection highlighted abundance of proteins responsible for cellular stress, DNA replication and cell proliferation. In influenza cohort in INNOVATE study, downregulation of proteins such as MANBA, MPPE1, and PDE4D was found, alongside with upregulation of IL1R2, OAS3, TOP2A reflecting neutrophil activation, degranulation and cell cycle disruptions. Proteomic changes that were unique to influenza cohort included markers of ER-stress (NUCB2, ERP29, CLCN7, ATP6V0A2) as well as decomposition of cellular membrane, not observed in other viruses’ cohort. In SARS-CoV-2, proteomic profile feature shared with influenza was IFN-induced immune response represented by proteins OASL, IFIT1, IFI44 in other viruses to control cohort comparison indicating distinguished from influenza pattern of proteomic profile. Resistin level ELISA analysis showed statistically significant difference in influenza to control cohort levels as well as Kruskal-Wallis test showed there was a significant difference in resistin levels in other viruses cohort patients and influenza. Patients with acute influenza infection compared to SARS-CoV-2 and RSV had higher levels of serum resistin (median 90.65 ng/ml vs 53.15ng/ml, p=0.0315) suggesting differences in the systemic inflammatory responses to diverse viruses.