New Monoclonal Antibodies for the Detection of Immediate Early Antigens of Cytomegalovirus

Two new monoclonal antibodies, CIE-1 and CIE-2, were developed for the rapid detection of human cytomegalovirus (HCMV) infection. They were found to be reactive with immediate early protein of HCMV in the nuclei of infected fibroblasts, as early as 3 hours post-infection. By radioimmunoprecipitation, CIE-1 was found to react with a protein with an apparent molecular weight of 70,000, whereas CIE-2 precipitated 2 proteins of 70,000 and 72,000 daltons, respectively. Both monoclonal antibodies recognized three prototype strains of HCMV: AD-169, Towne, and Davis, and did not cross-react with other human herpesviruses. CIE-1 and CIE-2 were compared with four commercial anti-HCMV monoclonal antibodies (Clonab, Dupont, Sera-Lab and Syva) by testing 88 clinical isolates. Culture confirmation tests and shell vial assays showed that CIE-1 and CIE-2 were more sensitive than several of these reagents and equally sensitive to the Dupont reagent. Moreover, CIE-1 and CIE-2 produced a bright, sharp staining of the nuclei of infected cells. These monoclonal antibodies should thus be valuable in rapid diagnosis of HCMV.