Fibronectin and asialoglyprotein receptor mediate hepatitis B surface antigen binding to the cell surface.
Both fibronectin and the asialoglycoprotein receptor (ASGPR) have been identified by some investigators as partners for hepatitis B virus (HBV) envelope proteins. Because fibronectin is a natural ligand for ASGPR, we speculated that HBV might attach to ASGPR expressed on the hepatocyte surface via fibronectin. To test this hypothesis, we first confirmed by co-immunoprecipitation that ASGPR, fibronectin and HBsAg bind to each other in HepG2.2.15 cells, and possible binding domains were identified by GST pull-down. In addition, by measuring binding of HBsAg to cells, we found that ASGPR and fibronectin enhanced the binding capability of HBsAg to HepG2 cells, and even to 293T and CHO cells, which normally do not bind HBV. In conclusion, our findings suggest that both fibronectin and ASGPR mediate HBsAg binding to the cell surface, which provides further evidence for the potential roles of these two proteins in mediating HBV binding to liver cells.
Yang
Jing
J
Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, People's Republic of China.
Wang
Feng
F
Tian
Linlin
L
Su
Jing
J
Zhu
Xiangqian
X
Lin
Li
L
Ding
Xiaoran
X
Wang
Xuejun
X
Wang
Shengqi
S
D000818:Animals; D037263:Asialoglycoprotein Receptor / Q000378:metabolism*; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005353:Fibronectins / Q000378:metabolism*; D056945:Hep G2 Cells; D006514:Hepatitis B Surface Antigens / Q000378:metabolism*; D006515:Hepatitis B virus / Q000378:metabolism / Q000472:pathogenicity*; D022781:Hepatocytes / Q000378:metabolism / Q000821:virology*; D006801:Humans; D047468:Immunoprecipitation; D011991:Receptors, Virus / Q000378:metabolism
D037263:Asialoglycoprotein Receptor; D005353:Fibronectins; D006514:Hepatitis B Surface Antigens; D011991:Receptors, Virus