Syngeneic monoclonal anti-idiotype antibodies that bear the internal image of a human cytomegalovirus neutralization epitope.

Two glycoproteins have been identified on human CMV that induce neutralizing antibody; an 86,000-Da glycoprotein and a 130,000-, 92,000-, and 50,000-Da glycoprotein coimmunoprecipitating complex that appears to be the gB homologue of HSV. We have produced syngeneic monoclonal anti-Id antibodies (mAb2) of the IgM isotype to a CMV-neutralizing monoclonal antibody (mAb1) that is known to bind to the 86,000-Da glycoprotein on the virion envelope. These mAb2 bear the internal image of the original viral antigen as shown by their ability to 1) recognize an interspecies idiotype in CMV-positive human antisera, 2) block mAb1 binding to CMV antigen, and 3) block CMV neutralization by mAb1 in vitro. Immunization of mice with both of these affinity chromatography-purified mAb2 stimulated the production of anti-anti-Id monoclonal antibodies (which we termed mAb3), which bound to the mAb2 by ELISA and neutralized CMV infectivity.