The proteomic analysis were conducted by Majgrbi, Biotech (Shanghai, China). Totalprotein was extracted from lung tissues of mock and IBV infected chickens, usingprotein lysate containing protease inhibitors according to manufacturer's instructions.Protein samples were alkylated and digested by trypsin to prepared peptides. Afterdesalination and quantification, peptides were analyzed by an EASY nLC-1200 system(Thermo, USA) coupled with a timsTOE Pro2 (Bruker, Germany) mass spectrometer.MS/MS spectra were searched using MaxQuant software(version 2.0.3.1)Bioinformatic analysis of proteomic data was performed with the Majgrbig Cloudplatform (https://cloud.majorbio.com). Differential expression analysis betweensamples was performed using DESeq2. The differentially expressed proteins (DEPs)were defined as fold change (>1.5 or < 0.67) and p adjust < 0.05. Enrichment analysisfor the functions of DEPs was conducted based on Kyoto Encyclopedia of Genes andGenomes (KEGG) datasets. Gene set enrichment analysis (GSEA) was performed withGSEA PreRanked tool.