ISOLATION AND CHARACTERIZATION OF A CHIMPANZEE MONOCLONAL-ANTIBODY TOTHE G-GLYCOPROTEIN OF HUMAN RESPIRATORY SYNCYTIAL VIRUS

Respiratory syncytial virus (RSV) is the most common cause of serious lower respiratory tract disease in infants and young children. In this study a hybridoma line secreting a chimpanzee monoclonal antibody tha t neutralizes RSV was isolated. Two chimpanzees were immunized with re combinant vaccinia viruses that express the RSV F or G surface glycopr otein and 1 month later were infected intranasally with the wild-type RSV strain A2. Peripheral blood lymphocytes obtained from the animals were transformed with Epstein-Barr virus, and lymphoblastoid cell line s that secreted anti-RSV antibodies were identified by an RSV antigen- binding enzyme-linked immunosorbent assay. Supernatants from RSV antib ody-secreting lymphoblastoid cell lines were tested for in vitro virus neutralization before being fused to the heteromyeloma cell GLI-H7. A chimpanzee antibody [immunoglobulin G3(lambda) subclass] produced fro m a hybridoma line designated E1.4/2 was shown to bind to the RSV G gl ycoprotein and neutralize a panel of subgroup A viruses, but not subgr oup B viruses, at low (nanomolar) concentrations. Mice passively immun ized with this antibody were partially resistant to RSV strain A2 chal lenge. The usefulness of such antibodies in immunoprophylaxis and immu notherapy of RSV infection is discussed.