Cellular Binding of Hepatitis C Virus Envelope Glycoprotein E2 Requires Cell Surface Heparan Sulfate

• Published in: The Journal of biological chemistry Vol. 278; no. 42; pp. 41003 - 41012
• Main Authors: Barth, Heidi, Schäfer, Christiane, Adah, Mohammed I., Zhang, Fuming, Linhardt, Robert J., Toyoda, Hidenao, Kinoshita-Toyoda, Akiko, Toida, Toshihiko, van Kuppevelt, Toin H., Depla, Erik, von Weizsäcker, Fritz, Blum, Hubert E., Baumert, Thomas F.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 17.10.2003; American Society for Biochemistry and Molecular Biology
• Subjects: Cell Line; Cell Membrane - metabolism; Chlorates - pharmacology; Dimerization; Disaccharides - chemistry; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Gene Deletion; Heparitin Sulfate - metabolism; Humans; Kinetics; Ligands; Protein Binding; Protein Structure, Tertiary; Surface Plasmon Resonance; Temperature; Time Factors; Viral Envelope Proteins - chemistry; Viral Envelope Proteins - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M302267200

The conservation of positively charged residues in the N terminus of the hepatitis C virus (HCV) envelope glycoprotein E2 suggests an interaction of the viral envelope with cell surface glycosaminoglycans. Using recombinant envelope glycoprotein E2 and virus-like particles as ligands for cellular binding, we demonstrate that cell surface heparan sulfate proteoglycans (HSPG) play an important role in mediating HCV envelope-target cell interaction. Heparin and liver-derived highly sulfated heparan sulfate but not other soluble glycosaminoglycans inhibited cellular binding and entry of virus-like particles in a dose-dependent manner. Degradation of cell surface heparan sulfate by pretreatment with heparinases resulted in a marked reduction of viral envelope protein binding. Surface plasmon resonance analysis demonstrated a high affinity interaction (KD 5.2 × 10–9m) of E2 with heparin, a structural homologue of highly sulfated heparan sulfate. Deletion of E2 hypervariable region-1 reduced E2-heparin interaction suggesting that positively charged residues in the N-terminal E2 region play an important role in mediating E2-HSPG binding. In conclusion, our results demonstrate for the first time that cellular binding of HCV envelope requires E2-HSPG interaction. Docking of E2 to cellular HSPG may be the initial step in the interaction between HCV and the cell surface resulting in receptor-mediated entry and initiation of infection.