Identification of transferrin receptor 1 as a hepatitis C virus entry factor Journal Article

Authors: Martin, D. N.; Uprichard, S. L.
Article Title: Identification of transferrin receptor 1 as a hepatitis C virus entry factor
Abstract: Hepatitis C virus (HCV) is a liver tropic pathogen that affects approximately 170 million people worldwide and causes liver pathologies including fibrosis, cirrhosis, steatosis, iron overload, and hepatocellular carcinoma. As part of a project initially directed at understanding how HCV may disrupt cellular iron homeostasis, we found that HCV alters expression of the iron uptake receptor transferrin receptor 1 (TfR1). After further investigation, we found that TfR1 mediates HCV entry. Specifically, functional studies showed that TfR1 knockdown and antibody blocking inhibit HCV cell culture (HCVcc) infection. Blocking cell surface TfR1 also inhibited HCV pseudoparticle (HCVpp) infection, demonstrating that TfR1 acts at the level of HCV glycoprotein-dependent entry. Likewise, a TfR1 small-molecule inhibitor that causes internalization of surface TfR1 resulted in a decrease in HCVcc and HCVpp infection. In kinetic studies, TfR1 antibody blocking lost its inhibitory activity after anti-CD81 blocking, suggesting that TfR1 acts during HCV entry at a postbinding step after CD81. In contrast, viral spread assays indicated that HCV cell-to-cell spread is less dependent on TfR1. Interestingly, silencing of the TfR1 trafficking protein, a TfR-1 specific adaptor protein required for TfR1 internalization, also inhibited HCVcc infection. On the basis of these results, we conclude that TfR1 plays a role in HCV infection at the level of glycoprotein-mediated entry, acts after CD81, and possibly is involved in HCV particle internalization.
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 110
Issue: 26
ISSN: 1091-6490; 0027-8424
Publisher: Unknown  
Journal Place: United States
Date Published: 2013
Start Page: 10777
End Page: 10782
Language: eng
Notes: GR: R21 AI092073/AI/NIAID NIH HHS/United States; JID: 7505876; OID: NLM: PMC3696786 [Available on 12/25/13]; OTO: NOTNLM; PMCR: 2013/12/25 00:00; 2013/06/10 [aheadofprint]; ppublish