Detection of cytomegalovirus antibodies by an enzyme-linked immunosorbent assay using recombinant polypeptides of the large phosphorylated tegument protein pp150.

Parts of the large phosphorylated tegument protein, pp150, of human cytomegalovirus (HCMV) were expressed in bacteria. The resulting fusion proteins were tested in a Western blot (immunoblot) assay for reactivity with a monoclonal antibody against pp150, with a polyspecific rabbit antiserum, and with human reconvalescent-phase sera. Those fusion proteins that performed well in the Western blot assay were used as antigens in enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against HCMV. Five different recombinant beta-galactosidase fusion proteins were evaluated by ELISA using 62 seropositive and 38 seronegative human serum samples. Of all the proteins tested, one peptide representing 162 amino acids of pp150 was superior to the others with regard to sensitivity and specificity. All sera known to be positive for antibodies against HCMV were identified by combining the results of the ELISAs with the different pp150 fusion proteins. Therefore, it appears that peptides from a single protein of HCMV might be sufficient to identify HCMV-seropositive individuals by recombinant ELISA.