Objective: This study is to explore the relationship between the chronic hepatitis B virus (HBV) infection and the expressions of toll-like receptor 2/4 (TLR2/4) in peripheral blood dendritic cells (DCs), to find out the immunological significance of TLR2/4 in HBV progression.
Methods: Patients had been divided into the HBV, HBV-related liver cirrhosis (HBV-LC), and HBV-related hepatocellular carcinoma (HBV-HCC) groups. Healthy individuals served as normal controls (NC). Flow cytometry was used to determine the percentage of DCs in peripheral blood, and the expression of TLR2/4 in DCs as well as the expression of HBeAg. Real-time quantitative PCR was performed to measure the content of HBV-DNA.
Results: The percentages of DCs in peripheral blood exhibited a slightly decreasing trend, without statistical significances, along with the disease severity in HBV patients (9.40 ± 2.05%, 7.11 ± 3.82%, 6.51 ± 4.38% and 6.00 ± 4.73% for the groups of NC, HBV, HBV-LC, and HBV-HCC, respectively). The expression of TLR2 was significantly increased in the disease progression, with the TLR2 expression rates of 2.60 ± 1.70%, 2.67 ± 2.89%, 3.53 ± 3.41% and 5.11 ± 4.93 for NC, HBV, HBV-LC, HBV-HCC, respectively. Similar results were found for TLR4 (expression rates: 45.34 ± 4.46%, 53.94 ± 5.21%, 65.16 ± 5.92% and 75.54 ± 6.12%), which was positively correlated with TLR2. Furthermore, the HBeAg level was increased, while the amount of HBV-DNA exhibited a declining trend, along with the disease severity. Correlation analysis revealed that the expression of HBeAg was positively correlated with TLR2.
Conclusions: The elevated expressions of TLR2/4 on DC cell surfaces in peripheral blood may synergistically promote the disease progression of chronic HBV infection.
Keywords: Hepatitis B virus; chronic infection; dendritic cells; toll-like receptors 2/4.