Clinical Significance of B7-H3 Expression During the Progression of Hepatitis B Virus Infection

B7-H3, one of the costimulatory members participating in checkpoint pathway, has been shown to be upregulated after hepatitis B virus (HBV) infection. To further explore the clinical significance of dynamic B7-H3 expression during the progression of HBV infection, we systematically investigated the expression pattern of B7-H3 and the correlation of B7-H3 expression with the ratio of T lymphocyte subsets and clinical parameters at different stages in the course of the disease. Flow cytometry and enzyme-linked immunosorbent assay data showed that soluble form of B7-H3 (sB7-H3) was positively correlated with the frequency of T-reg cells in acute hepatitis B (AHB), chronic hepatitis B (CHB), and hepatocellular carcinoma patients with HBV infection (HBV-HCC). Membrane form of B7-H3 (mB7-H3) expressed on T-reg cells and monocytes was positively correlated with the frequency of T-reg cells in CHB. SB7-H3 had relationship with mB7-H3 expressed on T-reg cells and monocytes at different stages during HBV infection, except for HBV-HCC. MB7-H3 expressed on T-reg cells was positively correlated with that on monocytes in AHB, CHB, HBV-liver cirrhosis, and HBV-HCC. The B7-H3 expression was positively correlated with aspartate aminotransferase and alanine aminotransferase levels in CHB and sB7-H3 level was higher in late tumor/node/metastasis (TNM) stage in HCC. Higher mB7-H3 expression was associated with greater tumor size, later TNM stage, and worse prognosis in HBV-HCC indicated by immunohistochemistry. Taken together, these results suggested that B7-H3 might contribute to the progression of HBV infection by triggering inhibitory signals in effector T cells and it was closely associated with the progression and poor prognosis during HBV infection. B7-H3 could be utilized as a potential clinical indicator and a potential target for therapeutic strategies against HBV infection.