The impact of CMV on the respiratory burst of macrophages in response toPneumocystis carinii

Abstract

SUMMARYInfection 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-g 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.

Invasive aspergillosis in allogeneic stem cell transplant recipients: changes in epidemiology and risk factors

“…Other potential mechanisms include the immune-modulating effects of the virus itself: CMV can impair multiple antimicrobial effector mechanisms, including neutrophil activity and macrophage respiratory burst. 42,43 Results of recent studies that emphasized poor transplant outcomes associated with donor or recipient CMV seropositivity provide compelling evidence for direct effects of the virus. In one study, higher transplant-related mortality (TRM) was observed in CMV-seropositive recipients of T cell-depleted grafts than in CMV-seronegative recipients.…”

Assessment of cytomegalovirus and cell-mediated immunity for predicting outcomes in non-HIV-infected patients with Pneumocystis jirovecii pneumonia

“…Furthermore, studies using animal models have shown that CMV infection inhibits immune responses against P jirovecii , and contributes to delayed clearance of the organism. [ 25 , 26 ]…”

Risks and outcomes of invasive fungal infections in recipients of allogeneic hematopoietic stem cell transplants after nonmyeloablative conditioning

“…Other potential mechanisms included the immune-modulating effects of CMV itself, because this virus is known to impair neutrophil activity and macrophage respiratory burst. 41,42 Alternatively, clinical factors included in multivariable models might not adequately control for the immune variables that predicted both CMV and fungal infections.…”