Study of toll-like receptor 7 expression and interferon α in Egyptian patients with chronic hepatitis C Infection and Hepatocellular Carcinoma

Abstract

Background: Hepatitis C virus is considered to be one of the most important devastating causes of chronic hepatitis, cirrhosis, and hepatic cellular carcinoma. Toll-like receptor 7 (TLR7) is a pathogen-recognition receptor that is expressed on innate immune cells. It recognizes viral RNA which induces its activation with a subsequent increase in IFN-α transcription. It has been postulated that HCV may cause down regulation of these receptors as one of immune evading mechanisms that participate in viral persistence.
The aim of the work: Was to investigate the expression of TLR7 in peripheral blood of patients with chronic HCV infections and patients with HCC, comparing it with normal individuals, and correlating it with both serum levels of IFN-α and viral load.
Results: The results of this study showed a significant decrease in TLR7 expression in patients with chronic HCV and no detection at all in patients with HCC, in addition a significant negative correlation was observed between levels of TLR7expression and interferon a when compared to viral load.
Conclusion: Down regulation of TLR7 expression in HCV and HCC patients may contribute to the decrease of IFN-α and increase in viral load. These results raise the possibility that by targeting TLR7 with high affinity pharmacological stimulants may be able to control HCV infection by induction of IFN-α and direct activation of antiviral mechanisms in hepatocytes. Additionally, they provide insight about the potential use of TLR7 as a new set of molecular markers for prognosis and outcomes of chronic HCV infection and HCC.

Keywords: TLRs; TLR7; HCV; HCC; IFN-α; Innate immunity; Viral hepatitis; Viral load