Identification of gp350 as the viral glycoprotein mediating attachment of Epstein-Barr virus (EBV) to the EBV/C3d receptor of B cells: sequence homology of gp350 and C3 complement fragment C3d.
The major Epstein-Barr virus (EBV) envelope glycoprotein, gp350, was purified from the B95-8 cell line and analyzed for its ability to mediate virus attachment to the isolated EBV/C3d receptor (CR2) of human B lymphocytes. Purified gp350 and EBV, but not cytomegalovirus, exhibited dose-dependent binding to purified CR2 in dot blot immunoassays. Binding was inhibited by certain monoclonal antibodies to CR2 and to gp350. Liposomes bearing incorporated gp350 bound to CR2-positive B-cell lines but not to CR2-negative lines. Liposome binding was also inhibited by the OKB7 anti-CR2 monoclonal antibody. A computer-generated comparison of the deduced gp350 amino acid sequence with that of the human C3d complement fragment revealed two regions of significant primary sequence homology, a finding which suggests that a common region on these two unrelated proteins may be involved in CR2 binding.
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D003176:Complement C3 / Q000378:metabolism; D015933:Complement C3d; D006023:Glycoproteins / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D008081:Liposomes; D011951:Receptors, Complement / Q000378:metabolism*; D017464:Receptors, Complement 3d; D011991:Receptors, Virus / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003176:Complement C3; D006023:Glycoproteins; D008081:Liposomes; D011951:Receptors, Complement; D017464:Receptors, Complement 3d; D011991:Receptors, Virus; D014759:Viral Envelope Proteins; D015933:Complement C3d