Acta Pharmacologica Sinica 2008 February; 29 (2): 239-244; doi: 10.1111/j.1745-7254.2008.00711.x

Aim: The aim of the present study was to investigate the expression of Toll-like receptors (TLR) 7 and 9 in peripheral blood mononuclear cells (PBMC) of patients with chronic hepatitis B virus (HBV) infection and related hepatocellular carcinoma.

Methods: The study group was comprised of 52 patients: 41 with chronic hepatitis B and 11 healthy controls. The protein and mRNA levels of TLR7 and TLR9 were evaluated using real-time PCR, Western blot analysis, and flow cytometry. We also detected the serum viral load of HBV in the patients and analyzed the correlation between HBV_DNA copies and the TLR expression.

Results: Our results demonstrated a lower TLR7 expression in all HBV infection groups compared to the controls. We found that HBV infection led to a decreased expression of TLR9 mRNA, but an increased expression of the TLR9 protein compared to the healthy group. The TLR protein levels are related to serum HBV_DNA (P<0.01).

Conclusion: There are downregulations of TLR7 expression and TLR9 mRNA in PBMC of HBV-infected patients, but an increased TLR9 expression at the protein level.

Keywords: hepatocellular carcinoma; peripheral blood mononuclear cells; hepatitis B; innate immunity; receptors; viruses; Toll-like receptor 7; Toll-like receptor 9