Immunohistochemical detection of HCV proteins in liver tissue

Epidermal Growth Factor Receptor-Dependent Mutual Amplification between Netrin-1 and the Hepatitis C Virus

Hepatitis C virus (HCV) is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC). The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+) and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1)-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A) as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR), a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species.

Novel approach for quantification of hepatitis C virus in liver cirrhosis using real-time reverse transcriptase PCR

BACKGROUND

Hepatitis C virus (HCV) infects nearly 3% of the population worldwide and is a major cause of acute and chronic infections leading to fibrosis, cirrhosis, and hepatocellular carcinoma. Current laboratory diagnosis of HCV is based on specific antibody detection (anti-hepatitis C virus (anti-HCV)) in serum. As HCV replicates in the liver cells, detection and localization of HCV RNA in liver tissue are vital for diagnosis.

METHODS

Ten biopsy samples diagnosed for cryptogenic liver cirrhosis, negative for the presence of anti-HCV and serum HCV RNA, were studied for analyzing presence of viral nucleic acid in liver tissues. Qualitative screening for HCV was done through ELISA while the nucleic acid analysis was performed through COBAS Amplicor. Detection of HCV RNA in liver tissue biopsies was performed following standard protocol of HCV detection kit (Shenzhen PG Biotech) with modifications using Light Cycler 2.0 (minimum detection limit 10 copies/ml).

RESULT

Quantitative detection in liver biopsies following the modified method showed the presence of HCV RNA in three samples out of the ten studied.

CONCLUSION

The results indicate that using Light Cycler 2.0, following the modified technique described, constitutes a reliable method of quantitative detection and localization of HCV in tissue in "serosilent" HCV infection.