Fig 1: HIV-1/HCV and HIV-1/HBV Co-Infection/Co- Culture Systems Philippe A. Gallay 1, Udayan Chatterji 1, Michael Bobardt 1, Daren Ure 2, Dan Trepanier 2, Robert Foster 2 and Cosme Ordonez 2 1 Department of Immunology & Microbial Science, The Scripps Research Institute, La Jolla, California 92037, USA. 2 Ciclofilin Pharmaceuticals BACKGROUND & AIMS HCV/HBV-related liver disease is the main cause of morbidity and mortality of HIV-1 patients co-infected with HCV and/or HBV. Despite the recent advent of anti-HCV DAAs, the treatment of HCV/HBV/HIV-1 co- infected patients remains a challenge, as these patients are less responsive to treatment, have higher rates of re-infection, and develop liver fibrosis, cirrhosis and liver cancer more often than mono-infected patients. In this study, we used a novel in vitro co-infection model to demonstrate that CPI , a novel cyclophilin A (CypA) inhibitor, simultaneously blocks replication of HCV, HBV and HIV-1 in human cells. RESULTS Fig 3: In HIV-1/HBV Co-Infection Model, CPI Simultaneously Inhibits HIV-1 and HBV Fig 4: Dual Block of HBV Infection CONCLUSIONS ACKNOWLEDGEMENTS METHODS Using a unique and novel in vitro co-infection model, we examined whether CPI interferes i) with HCV RNA synthesis of isolated replication complexes using a quantitative replicase assay, ii) with early steps of viral replication of HIV-1 primary isolates, and iii) HBV virus entry (NTCP binding) and viral replication. We also tested by ELISA the CPI inhibition of the interaction between CyPA and the viral proteins NS5A and p24 gag of HCV and HIV-1 viruses, respectively, to explore the mechanism of action of this drug. The unique broad-spectrum of antiviral activity shown by CPI might be related to the role of CypA in viral infection. CPI prevents binding of CypA, a protein-folding enzyme to viral proteins such as HCV NS5A and HIV p24 gag, which are critical for HCV and HIV-1 replication. We hypothesize that the inhibition of CypA by CPI is responsible for its broad-spectrum antiviral activity by preventing activation of specific viral proteins required for viral replication. Overall, this study suggests that CPI , a novel CypA inhibitor, could potentially become a candidate medicine for the treatment of HIV-1 patients co-infected with HCV and/or HBV. We thank F. Chisari for the Huh cells, T. Pietschmann, T. Wakita and R. Bartenschlager for the Luc-JFH-1 plasmid, and C. Seeger for HepAD38 cells. This work was supported by the U.S. Public Health Service grant no. AI from the National Institute of Allergy and Infectious Diseases (NIAID) and a research grant from the Canadian Institutes of Health Research (CIHR). Novel Cyclophilin Inhibitor CPI Shows Broad Spectrum Antiviral Activity by Blocking Replication of HCV, HBV and HIV-1 Viruses RESULTS We found that CPI blocked viral replication of HCV, HBV and HIV-1. CPI was more effective than alisporivir (ALV) (another CyPA inhibitor) inhibiting replication of each of these three viruses. We also demonstrated that CPI blocks nuclear import of HIV-1 virus. CPI blocked binding of CyPA to HCV NS5A and HIV-1 p24 gag more efficiently than ALV, and was more effective than ALV against established resistant- variants of HIV-1. No other antiviral agent tested in our assays was able to show such a broad- spectrum of antiviral activity. Fig 2: The Cyclophilin Inhibitor CPI , but not the HCV NS5A Inhibitor Daclatasvir nor the HIV-1 Protease Inhibitor Nelfinavir, Simultaneously Inhibits HCV/HIV-1 Viral Replication in a Co-Infection Model HCV JFH-1-infected hepatoma Huh7.5.1 cells and HIV-1 JR-CSF-infected PBMCs (duplicates) were incubated together for 3 days and then exposed to a single dose (2 µM) of the cyclophilin inhibitor CPI , the HCV NS5A inhibitor daclatasvir, the HIV-1 protease inhibitor Nelfinavir or drug combinations. HCV and HIV-1 replications were quantified by HCV core and HIV-1 capsid/p24 ELISA. Data are representative of 2 independent experiments. HIV HBV Fig 5. CPI Blocks Formation of HBV cccDNA HIV-1 JR-CSF-infected PBMCs and HBV AD38-infected NTCP- Huh 7 cells (duplicates) were exposed to a single dose (2 µM) of CPI and then incubated together for 3 days. Viral replication was quantified by HIV-1 capsid/p24 ELISA and HBV HBeAg ELISA. Data are representative of 2 independent experiments. HepaRG cells (duplicates) were exposed to HBV AD38 together with ALV or CPI and viral replication was quantified by HBV HBeAg ELISA at day 3. NTCP-Huh7 cells (duplicates) were incubated with HBV preS1- FITC peptide together with ALV or CPI HBV preS1 binding to cell surface NTCP was quantified by FACS. Fig 6. Mechanism of Anti-HBV Effect for CPI Huh7, HepG2 or NTCP-Huh7 cells were transfected with HBV in the presence of DMSO, ALV (2 µM) or CIP (2 µM). Three days post-transfection, amounts of HBV cccDNA were quantified by PCR as described previously (Gao and Hu, J. Virol. 2007).