Prokaryotic expression of immunogenic polypeptides of the large phosphoprotein (pp150) of human cytomegalovirus.

The large phosphorylated matrix protein pp150 of human cytomegalovirus (HCMV) is the polypeptide most frequently reactive in immunoblotting analyses with human antisera when compared with other viral proteins. Several defined regions of pp150 were expressed as beta-galactosidase fusion proteins and these were tested for their immunoreactivity with human sera and their immunogenicity. One antigenic region could be expressed in large amounts and was found to carry immunodominant epitopes, as shown by immunoblotting and ELISA. A rabbit antiserum raised against recombinant pp150 antigens produced in bacteria proved to be useful for immunofluorescence and immunohistochemistry studies of HCMV-infected cells and tissues. The results suggest that this anti-pp150 serum will help to elucidate the process of virus assembly and antigen detection in infected cells.