Cd302 and Cr1l restrict human hepatotropic virus cross-species transmission to mice [1Library screen]

Virus species- and tissue-tropism is governed by host dependency and restriction factors. Hepatitis C virus (HCV) exhibits a narrow species-tropism and murine hepatocytes are refractory to infection. Using murine liver cDNA library screening we identified Cd302, a lectin, and Cr1l, a complement receptor, as pan-genotypic restrictors of HCV infection. Cd302/Cr1l interact to impede virion uptake and co-operatively induce a non-canonical transcriptional program, inhibiting HCV and hepatitis B virus (HBV) infection in vitro. CAS9 disruption of murine hepatocyte Cd302 expression increased HCV permissiveness in-vivo and ex-vivo, and modulated the intrinsic hepatocyte transcriptome dysregulating metabolic process and host defense genes. In contrast, co-operative CD302/CR1L expression was absent and HCV restriction reduced in human hepatocytes. The Cd302/Cr1l axis therefore contributes to limiting hepatotropic virus cross-species transmission to mice, opening new avenues for step-wise development of mouse models for these important human pathogens, which cause substantial disease burden globally. Overall design: We performed a murine hepatic restriction factor screening using a cDNA library generated from the liver of an IFN-treated mouse. The library was packaged in chimeric lentiviral/VSV pseudoparticles and transduced into HCV-permissive n4mBid cells which are highly permissive for HCV but undergo apoptosis upon HCV replication due to HCV NS3 protease-mediated cleavage of the modified BH3 interacting domain death agonist (mBID) protein. Two rounds of selection with HCV were then performed, with surviving cells expanded after each round of selection. Total RNA-Seq of cell population S0, the initial n4mBid cell population after delivery of the cDNA library, and cell population S2, the population of cells after two consecutive challenges with HCV, were performed. Two technical replicates were performed for each sample. Transcriptomes were mapped against the human hg19 reference to ascertain the host cell background, and the mm9 mouse reference to quantify the integrated murine library. S0 and S2 mouse integrations were then compared to identify restriction factors.