Identification and comparative analysis of hepatitis C virus-host cell protein interactions

Area of Science:

• Virology
• Molecular Biology
• Host-Pathogen Interactions

Background:

• Hepatitis C virus (HCV) manipulates host cell functions for replication, but the specific viral proteins and host factors involved are not fully understood.
• Investigating the virus-host interface is crucial for comprehending HCV infection dynamics and developing therapeutic strategies.

Purpose of the Study:

• To identify protein-protein interactions between Hepatitis C virus genotype 2a (HCV 2a) and host cellular factors using a large-scale yeast two-hybrid screen.
• To compare the HCV 2a interactome with those of other HCV genotypes and dengue virus to uncover conserved viral-host interactions.
• To validate the role of shared host factors in the replication of both HCV and dengue virus.

Main Methods:

• Large-scale yeast two-hybrid screening to map protein-protein interactions between HCV 2a and human proteins.
• Bioinformatic analysis to compare interactomes across different viral genotypes and related viruses.
• siRNA-mediated knockdown to functionally assess the role of identified host factors in viral replication.

Main Results:

• Identified 112 unique interactions involving 7 HCV proteins and 94 human proteins, with over 40% previously linked to HCV infection.
• Revealed HCV's manipulation of lipid metabolism, microtubule-organizing centers, complement system, and cell cycle regulation.
• Observed greater overlap in host targets between HCV and dengue virus than between different HCV genotypes.
• Demonstrated that five shared host factors (CUL7, PCM1, RILPL2, RNASET2, TCF7L2) are essential for the replication of both HCV and dengue virus.

Conclusions:

• The identified HCV-host protein interactions provide a comprehensive map of viral manipulation strategies and implicate novel therapeutic targets.
• Comparative interactome analysis highlights conserved host factors exploited by viruses within the Flaviviridae family.
• The essentiality of shared host factors for both HCV and dengue virus replication offers insights into common mechanisms of flaviviral pathogenesis and potential broad-spectrum antiviral strategies.