Cell experiment:

Alisporivir is prepared in DMSO at 4 mM and diluted in cell culture medium at the indicated concentrations (0.1, 0.2, 0.3, 0.4, 0.5 μM). UHCV-32 and UHCVcon-57.3 are U-2 OS human osteosar coma-derived cell lines inducibly expressing the entire open reading frame derived from the HCV H77 prototype and consensus clones, respectively. Cell viability is measured by trypan blue exclusion analysis. HCV protein expression in these cells is induced by withdrawal of tetracycline from the culture medium. The effect of tetracycline on the naive U2 OS cell line is tested measuring mitochondria-related respiration and reactive oxygen species (ROS) production, which remains unchanged[2].

Alisporivir (DEB-025; Debio-025) is a cyclophilin inhibitor molecule with potent anti-hepatitis C virus (HCV) activity.

DEB025 binds to CypA, a peptidyl-prolyl cis-trans isomerase which is a crucial cofactor for HCV replication[1]. Alisporivir (Debio-025) is an analogue of cyclosporine A and represents the prototype of a new class of non-immunosuppressive cyclophilin inhibitors. Alisporivir prevents HCV protein-mediated collapse of the respiration-driven mitochondrial membrane potential. Alisporivir prevents HCV protein-mediated mitochondrial dysfunction outside the context of apoptosis, calcium overload, production of ROS, dysfunction[2]. In cell culture models, low-micromolar doses of alisporivir block SARS-CoV and MERS-CoV replication. Combination treatment with alisporivir and ribavirin increases the anti-MERS-CoV activity in cell culture[3]. Alisporivir pretreatment stimulates antigen presentation by hepatoma target cells, leading to enhancement of antigen-specific CD8+ T cell activation by 40%. Alisporivir induces an increase of MHC-I and beta-2 microglobulin on the surface of several cell lines[4].

Combination treatment with alisporivir and ribavirin does not protect against SARS-CoV infection in a mouse model[3].

[1]. Coelmont L, et al. DEB025 (Alisporivir) inhibits hepatitis C virus replication by preventing a cyclophilin A induced cis-trans isomerisation in domain II of NS5A. PLoS One. 2010 Oct 27;5(10):e13687. [2]. Quarato G, et al. The cyclophilin inhibitor alisporivir prevents hepatitis C virus-mediated mitochondrial dysfunction. Hepatology. 2012 May;55(5):1333-43. [3]. de Wilde AH, et al. Alisporivir inhibits MERS- and SARS-coronavirus replication in cell culture, but not SARS-coronavirus infection in a mouse model. Virus Res. 2017 Jan 15;228:7-13. [4]. Esser-Nobis K, et al. The cyclophilin-inhibitor alisporivir stimulates antigen presentation thereby promoting antigen-specific CD8(+) T cell activation. J Hepatol. 2016 Jun;64(6):1305-14.