vii, 33 p.Monocytes are believed to participate in the host
response to cytomegalovirus (CMV), a DNA virus which may
exist in a latent form or may cause severe organ
pathology depending on the immune competence of the host.
To investigate monocyte-CMV interaction, the effect of
CMV on monocyte phenotype and function was explored.
Purified monocytes were inoculated at a multiplicity of
infection of 1.0-2.0 with an isolate of CMV, laboratory
propogated strain AD-169. The monocytes did not exhibit
cytopathic changes or release virions into the culture
supernatant. However, they did express immediate-early
(IE) and early antigen (EA) viral proteins as detected by
immunoperoxidase staining using monoclonal antibodies
against IE and EA. Activation studies revealed that the
CMV-infected monocytes spontaneously secreted increased
amounts of H2 02 and expressed high levels of surface
interleukin 2 and HLA-DR receptors. However, the CMV-infected
monocytes secreted significantly less H2 02
following stimulation with lipopolysaccharide, muramyl
dipeptide, or phorbol myristate acetate. Similarly,
studies of the accessory cell functions of CMV-infected
monocytes showed a marked decrease in ability to present
antigen and mitogen for lymphocyte proliferation. These
findings suggest that CMV infection alters monocyte
function and may contribute to immunosuppression in vivo.National Institutes of Health, Bethesda, M
