The Hepatitis C Virus-Induced Membranous Web and Associated Nuclear Transport Machinery Limit Access of Pattern Recognition Receptors to Viral Replication Sites

Neufeldt, Christopher J.; Joyce, Michael A.; Van Buuren, Nicholas; Levin, Aviad; Kirkegaard, Karla; Gale Jr., Michael; Tyrrell, D. Lorne J.; Wozniak, Richard W.

Using the exclusion of RIG-I from cytoplasmic regions containing HCV proteins as a marker for the MW, we observed that there are numerous smaller regions within the cytoplasm that harbour HCV replication and assembly complexes. These results are consistent with recent EM-tomography and correlative light-EM studies that reveal the MW is not confined to a single region in the cytoplasm, but rather it is made up of multiple regions that have higher abundance of NS5A and are enriched for single membrane vesicles and DMVs in conjunction with ER and lipid droplets [8] . This report describes~3-10 μm regions of the cytoplasm as MW, consistent with our observations that ectopically expressed RLRs are excluded from multiple cytoplasmic regions that generally ranged in size from~0.5-10 μm in size (Figs 1 and 3) . The nature of the barrier that defines the perimeter of multiple MW compartments and contributes to the exclusion of macromolecules such as PRRs is unclear. However, as discussed below, the nuclear transport machinery appears to facilitate access to these MW compartments.