Published online Dec 7, 2016. doi: 10.3748/wjg.v22.i45.9954
Peer-review started: July 25, 2016
First decision: September 20, 2016
Revised: October 1, 2016
Accepted: October 27, 2016
Article in press: October 27, 2016
Published online: December 7, 2016
Processing time: 137 Days and 13.2 Hours
To characterize the role of apolipoprotein B100 (apoB100) in hepatitis C viral (HCV) infection.
In this study, we utilize a gene editing tool, transcription activator-like effector nucleases (TALENs), to generate human hepatoma cells with a stable genetic deletion of APOB to assess of apoB in HCV. Using infectious cell culture-competent HCV, viral pseudoparticles, replicon models, and lipidomic analysis we determined the contribution of apoB to each step of the viral lifecycle. We further studied the effect of mipomersen, an FDA-approved antisense inhibitor of apoB100, on HCV using in vitro cell-culture competent HCV and determined its impact on viral infectivity with the TCID50 method.
We found that apoB100 is indispensable for HCV infection. Using the JFH-1 fully infectious cell-culture competent virus in Huh 7 hepatoma cells with TALEN-mediated gene deletion of apoB (APOB KO), we found a significant reduction in HCV RNA and protein levels following infection. Pseudoparticle and replicon models demonstrated that apoB did not play a role in HCV entry or replication. However, the virus produced by APOB KO cells had significantly diminished infectivity as measured by the TCID-50 method compared to wild-type virus. Lipidomic analysis demonstrated that these virions have a fundamentally altered lipidome, with complete depletion of cholesterol esters. We further demonstrate that inhibition of apoB using mipomersen, an FDA-approved anti-sense oligonucleotide, results in a potent anti-HCV effect and significantly reduces the infectivity of the virus.
ApoB is required for the generation of fully infectious HCV virions, and inhibition of apoB with mipomersen blocks HCV. Targeting lipid metabolic pathways to impair viral infectivity represents a novel host targeted strategy to inhibit HCV.
Core tip: Hepatitis C virus (HCV) circulates as a very-low-density lipoprotein (VLDL)-like lipoviral particle. Apolipoprotein B100 (apoB100) is the core protein of VLDL, buts its role in HCV has remained incompletely characterized. Use of gene-editing with transcription activator-like effector nucleases permits the characterization of the role of apoB100 in HCV. We demonstrate that apoB100 is required for HCV infection. Loss of apoB100 results in the secretion of HCV virions with an altered lipid composition and limited ability to infect naive cells. Mipomersen, an FDA-approved antisense inhibitor of apoB100, has an anti-HCV effect and limits the viral infectivity.