ABSTRACT
Backgroud:The COVID-19 pandemic has swept the globe since 2019, threatening people's health. Many studies indicate that infection is closely related to immune response disorder. We searched for potential immune-related biomarkers through systems biological analysis, and performed immune infiltration analysis on relevant data. Methods and findings: We used CIBERSORT to analyze the blood transcriptomics data of the controls, the mild COVID-19 patients, and the severe COVID-19 patients. And we further obtained the essential infiltration immune cells of COVID-19 by the Wilcoxon test and LASSO algorithm. Then we used a limma package to find significant DE-IRGs. The GO and pathways analysis of these important immune genes were also applied. Subsequently, we used STRING and Cytoscape to screen hub genes and evaluated their value as a potential biomarker according to their expression at different stages and the ROC curve. Moreover, the results were verified by high-throughput data. Finally, we formed a TFs-mRNA-miRNA regulatory network diagram. Through the analysis above, we obtained four important immune cells. And the immune-related gene chip of the blood samples was analyzed to figure out the 36 significant DE-IRGs. Based on the operations above, we confirmed six immune-related hub genes involved in the pathogenesis of COVID-19 and analyzed their relationship with critical immune cells. Conclusions:It was concluded that TLR2, CAMP, S100A9, BCL6, CD4, and IL7R could be used as potential biomarkers to provide corresponding value for the diagnosis and the prognosis of COVID-19.