Search

Attenuated measles virus (MV) exerts its oncolytic activity in malignant pleural mesothelioma (MPM) cells that lack type-I interferon (IFN-I) production or responsiveness. However, other cells in the tumor microenvironment (TME), such as myeloid cells, possess functional antiviral pathways. In this study, we aimed to characterize the interplay between MV and the myeloid cells in human MPM. We cocultured MPM cell lines with monocytes or macrophages and infected them with MV. We analyzed the transcriptome of each cell type and studied their secretion and phenotypes by high-dimensional flow cytometry. We also measured transgene expression using an MV encoding GFP (MV-GFP). We show that MPM cells drive the differentiation of monocytes into M2-like macrophages. These macrophages inhibit GFP expression in tumor cells harboring a defect in IFN-I production and a functional signaling downstream of the IFN-I receptor, while having minimal effects on GFP expression in tumor cells with defect of responsiveness to IFN-I. Interestingly, inhibition of the IFN-I signaling by ruxolitinib restores GFP expression in tumor cells. Upon MV infection, cocultured macrophages express antiviral pro-inflammatory genes and induce the expression of IFN-stimulated genes in tumor cells. MV also increases the expression of HLA and costimulatory molecules on macrophages and their phagocytic activity. Finally, MV induces the secretion of inflammatory cytokines, especially IFN-I, and PD-L1 expression in tumor cells and macrophages. These results show that macrophages reduce viral proteins expression in some MPM cell lines through their IFN-I production and generate a pro-inflammatory interplay that may stimulate the patient's anti-tumor immune response. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) is a major cause of liver disease, but therapeutic options are limited and there are no prevention strategies. Viral entry is the first step of infection and requires the cooperative interaction of several host cell factors. Using a functional RNAi kinase screen, we identified epidermal growth factor receptor and ephrin receptor A2 as host cofactors for HCV entry. Blocking receptor kinase activity by approved inhibitors broadly impaired infection by all major HCV genotypes and viral escape variants in cell culture and in a human liver chimeric mouse model in vivo. The identified receptor tyrosine kinases (RTKs) mediate HCV entry by regulating CD81-claudin-1 co-receptor associations and viral glycoprotein-- dependent membrane fusion. These results identify RTKs as previously unknown HCV entry cofactors and show that tyrosine kinase inhibitors have substantial antiviral activity. Inhibition of RTK function may constitute a new approach for prevention and treatment of HCV infection., HCV is a major cause of liver cirrhosis and hepatocellular carcinoma. Current antiviral treatment is limited by drug resistance, toxicity and high costs (1). Although newly developed antiviral substances targeting [...]

Hepatitis B is leading cause of liver related morbidity in Asia with predominant genotypes B and C in East-Asia. Data on Serum, intrahepatic viral-markers, and long-term follow-up of prevalent genotypes (GT) B and C in patients with biopsy proven advanced fibrosis are sparse. To compare serum, intrahepatic viral-markers and development of hepatocellular carcinoma (HCC) in GT-B and C in patients with advanced fibrosis (Ishak ≥ 4). Sixty-three treatment-naïve patients identified with advanced fibrosis on liver-biopsy performed between 1998 and 2000 at Singapore General Hospital. FFPE tissue was available for 59 patients and serum for 42 patients. HBV-DNA was quantified in serum and liver while qHBsAg quantified in serum. Patients were followed-up till December 2015. The median age was 47 ± 16 years, with 77.7% males. About 19 were GT-B, 43 patients were GT-C, and 1 had both GT-B and C. Mean follow-up was 13.5 years. The median serum HBV-DNA was 6.25 ± 2.17 and 6.58 ± 1.85 log IU/ml, serum HBsAg was 3.29 ± 0.80 and 3.45 ± 1.85 log IU/ml, and intrahepatic HBV-DNA was 0.52 ± 3.73 copies/cell and 0.4 ± 1.37 copies/cell in the GT-B and C, respectively ( P > 0.1 in all). Complete cirrhosis (Ishak-6) was present in 47.6%, Ishak-5 fibrosis in 33.3%, and Ishak-4 fibrosis in 19% at recruitment. On follow-up HCC developed in 8/43 in GT-C and in 3/19 GT-B ( P = 0.86). Advanced age and cirrhosis were significant factors for development of HCC. No difference in serum HBV-DNA, qHBsAg or intrahepatic HBV-DNA was seen in the two genotypes. HCC development seen over long-term follow-up was independent of genotypes in patients with advanced fibrosis. J. Med. Virol. 89:845-848, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]