Cytomegalovirus Infection Impairs Immunosuppressive and Antimicrobial Effector Functions of Human Multipotent Mesenchymal Stromal Cells
Figure 4
CMV blocks IDO activity and IDO-mediated antimicrobial effects in human MSC. (a) PBL, stimulated with OKT3, were cocultured with MSC in the presence or absence of CMV. As controls UV-inactivated CMV (uvCMV), the IDO-specific inhibitor 1-L-methyl-tryptophan (1-MT; 1.5 mM), or a neutralising anti-IFN-γ antibody (αIFN-γ; 10 ng/mL) was used. After three days IDO activity was determined and is presented as mean kynurenine content ± SEM of three independent experiments, each done in triplicate. (b) PBL (1 × 105/well), stimulated with CD3-directed mAB OKT3, were cocultured with MSC (3 × 104/well) in the absence or presence of CMV (MOI 5). After three days cultures were infected with S. aureus (10–100 cfu/well) and bacterial growth was determined photometrically. As a control, cultures were supplemented with L-tryptophan (Trp; 0.6 mM) at the time point of bacterial infection. Data are given as mean ± SEM of three experiments, each done in triplicate. Significant differences () as compared to the positive control are marked by asterisks.
