Immunology of cytomegalovirus: immunosuppressive effects during infections.

Acute CMV infection in the mouse results in depressed antibody production, IFN induction, lymphocyte proliferation responses to mitogens, allogeneic skin graft rejection, and clearance of certain bacteria and fungi from the blood stream. CMV mononucleosis in humans is associated with decreased lymphocyte proliferation responses to mitogens and herpesvirus antigens, decreased IFN production, and reversal of the T-helper to suppressor cell ratio. In recent studies, we have shown that NK activity is depressed after renal transplantation and the use of cyA, and is poorly enhanced by the addition of IFN to in vitro assays. In vitro induction of alpha-IFN as well as gamma-IFN by NDV and enterotoxin-A is also inhibited. These deficits may contribute to the severity of CMV infections in this patient population.