Exploration of immune infiltration and feature genes in viral hepatitis-associated liver fibrosis using transcriptome data

BACKGROUND: Immune cells play an essential role in virus-induced liver fibrosis. However, the underlying mechanisms remain unclear. In this study, we systematically explored immune cell infiltration and feature genes to provide new insights into viral hepatitis-associated liver fibrosis. METHODS: The expression datasets GSE14323, GSE33650, GSE6764 (for testing), and GSE84044 (for validation) were downloaded from the Gene Expression Omnibus (GEO) database. Immune cell infiltration was assessed using the CIBERSORT algorithm, and characteristic subgroups were obtained using least absolute shrinkage and selection operator (LASSO) regression and Wilcoxon test. The association between feature genes and immune-infiltrating cells was explored using Spearman’s correlation analysis. R software and IBM SPSS Statistics were utilized for data analysis and visualization. RESULTS: We identified 10 differential immune cells between viral hepatitis-associated liver fibrosis and non-fibrosis, including naive B cells, plasma cells, resting CD4(+) memory T cells, T follicular helper (Tfh) cells, regulatory T (Treg) cells, M0-M2 macrophages, and resting and activated mast cells. Six feature genes were identified: STAT1, CXCL10, PTPRC, IFIT3, OAS2, and MX1. They also differed significantly in the subgroups of non-fibrosis, mild to moderate fibrosis and severe fibrosis. Both the feature genes and immune cells were verified in the validation group. All the genes were positively associated with macrophages M1 and negatively associated with macrophages M2. CONCLUSIONS: The six feature genes may be involved in viral hepatitis-associated liver fibrosis by promoting the polarization of macrophages from M0 to M1 and inhibiting their conversion to M2. Thus, these genes may serve as potential therapeutic targets.