Human monoclonal antibodies neutralizing human cytomegalovirus

Hybridomas producing human monoclonal antibodies (MAbs) against human cytomegalovirus (CMV) were generated by fusion of human spleen cells and mouse myeloma cells. Two of the six MAbs obtained neutralized viral infectivity even at concentrations lower than 1 microgram/ml. One MAb required complement for neutralization but the other did not. Both MAbs recognized viral proteins of Mr 130,000 and 55,000. Furthermore, these neutralizing MAbs bound to the surface membrane of CMV-infected cells. These results suggest that human MAbs may provide a new means of passive immunization against CMV infection in humans.