Purification and characterization of Epstein-Barr virus gp340/220 produced by a bovine papillomavirus virus expression vector system

Abstract

Our initial results with a bovine papilloma virus (BPV) vector expression system indicated that we could produce significant amounts of Epstein-Barr virus (EBV) gp340/220 in the supernatant of a mouse fibroblast cell line1. We have now extended these findings to show that the truncated version of gp340/220, where the membrane anchor sequence is deleted, is produced even after extended passage of the cells, at a level of ≈ 1 mg/4 × 108 cells. A simple purification protocol using Sephacryl S300HR and gelatin agarose gives a product which is > 90% pure. This product is recognized by anti-gp340 monoclonal antibodies from five different epitope groups and induces antibody that recognizes the authentic gp340/220 and neutralizes EBV in vitro. The purified gp340/220 can be used in ELISA and stimulates the proliferation of T-cell clones specific for gp340/220. These characteristics, together with the fact that BPV-transformed lines have been utilized for the production of pharmaceuticals for use in humans2, suggest that this gp340/220 is suitable as a source of antigen for vaccination to prevent EBV infection and related diseases.