Epstein-Barr virus binding to virus-carrying cell lines is enhanced in the presence of C3 and C3d.
The relationship between the receptors for the Epstein-Barr virus (EBV) and the C3d fragment of complement was investigated at the molecular level. In the presence of cell-bound C3, virus binding was enhanced in EBV genome-carrying lines. An identical effect could be elicited by C3d at one-quarter the weight amount; C3b and methylamine-treated C3 had no effect on virus binding. The minimum concentration of C3 which produced significant enhancement was 25 micrograms/ml. Virus binding increases were observed only after 20 min of complement-cell co-incubation. The response was not noted with EBV-negative lines and was independent of virus strain assayed (B95-8 and P3HR-1). These studies suggest that the binding sites for the two moieties are distinct, although they both involve the same cell surface complex. The two receptors are believed to display cooperativity.
D002460:Cell Line; D003176:Complement C3 / Q000378:metabolism*; D015933:Complement C3d; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D011951:Receptors, Complement / Q000032:analysis*; D011991:Receptors, Virus / Q000032:analysis*
D003176:Complement C3; D011951:Receptors, Complement; D011991:Receptors, Virus; D015933:Complement C3d