The impact of CMV on the respiratory burst of macrophages in response to Pneumocystis carinii.
Infection of human monocyte-derived macrophages with CMV decreased the respiratory burst when cells were stimulated with opsonized zymosan or Pneumocystis carinii (P. carinii). Such an effect, though smaller, was also seen with heat-inactivated CMV, but only when triggered by zymosan. The effect was most pronounced in cells obtained from CMV antibody-negative donors. Dexamethasone further reduced the respiratory burst, both in uninfected and CMV-infected cells. Interferon-gamma increased the response in uninfected cells and, to a lesser extend, in cells treated with heat-inactivated CMV, whereas no effect was seen with infective CMV. No overt productive infection or cytopathology could be detected, however, the monocytes incubated with infective but also heat-inactivated CMV formed clusters, a phenomenon that was equally pronounced in cultures from CMV antibody positive and negative-donors. These results might help explain the worse prognosis of P. carinii pneumonia in patients coinfected with CMV and receiving dexamethasone.
Laursen
A L
AL
Department of Infectious Diseases, Marselisborg Hospital, University of Aarhus, Denmark. A.Laursen@Dadlnet.dk
Mogensen
S C
SC
Andersen
H M
HM
Andersen
P L
PL
Ellermann-Eriksen
S
S
D000818:Animals; D002478:Cells, Cultured; D003587:Cytomegalovirus; D003586:Cytomegalovirus Infections / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology / Q000821:virology; D008297:Male; D011010:Pneumocystis; D016720:Pneumocystis Infections / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016897:Respiratory Burst