H9N2 gene enrichment and immune cell infiltration based on GEO chip

Objective: To study the pathogenesis of H9N2 virus infection using GEO database analysis. Methods: GSE31471 dataset was analyzed for differential expression. Key genes were identified via STRING and Cytoscape. GSEA and CIBERSORT were used for pathway enrichment and immune cell infiltration analysis. Key genes were validated by RT-qPCR and ELISA in H9N2-infected mouse lung microvascular endothelial cells.Results: GSEA showed enrichment in upregulated pathways. Compared to controls, H9N2 infection increased Tregs and activated NK cells, while plasma cells decreased. RT-qPCR confirmed the upregulation of Mx1, IRF1, ISG15, and CXCL10. ELISA results showed that protein levels of IL-1β, IL-6, IL-18, and TNF-α were significantly increased, confirming the inflammatory response at the protein level. Conclusion: The JAK/STAT1, Toll-like, and RIG-I-like receptor pathways, along with CXCL10 and M1 macrophages, are key to H9N2 pathogenesis. This study provides new insights into the host's antiviral defense and therapeutic targets.