The development by cytomegalovirus-infected cells of binding affinity for normal human immunoglobulin.

After infection with human cytomegalovirus (CMV), cells develop an affinity for normal human immunoglobulin G (IgG). This was demonstrated using 125iodine-labeled purified IgG. It was further demonstrated that the immunoglobulin molecule binds to CMV-infected cells via its Fc portion, and competition for binding to infected cells occurred between purified preparations of human IgG and the Fc fragment of human IgG. Whole sera from individuals with or without a high titer of anti-CMV antibody were labeled with 125iodine and it was demonstrated that serum from individuals with no anti-CMV antibody had an affinity for CMV-infected cells which probably reflected binding of IgG via its Fc fragment. The possible significance of these results in immunologic studies of human CMV is considered.