After incubation for further 24 h, an ELISA specific for incorporated BrdU in DNA of proliferating cells was performed according to the manufacturer’s instructions, and absorbance was read at

450 nm on a 96-well plate spectrophotometer (Versamax; Molecular Devices, Sunnyvale CA, USA). Values were corrected for turbidity by measuring absorbance at 595 nm. Data sets were compared by the Student’s t-test using the Microsoft Excel program. Differences were considered significant when P-values were <0·05. To quantify DCs, peritoneal cells from mice infected with E. multilocularis metacestodes and from naïve C57BL/6 mice were stained with anti-CD11c and analysed by flow cytometry. The percentage of CD11c-positive AE-pe-DCs at the early stage of infection (6 weeks p.i.) increased AZD4547 nmr to reach 4% of the total number of Nutlin-3 ic50 peritoneal cells (12% of gated cells), while naive pe-DCs (as control)

represented 2% (3% of gated cells), (Figure 1a). Thus, DCs were clearly recruited into the peritoneal cavity, the site of metacestode infection. CD11c+ pe-DCs were enriched and analysed for the mRNA levels of selected cytokines. Pe-DCs from metacestode-infected mice had significantly higher mRNA levels of TGF-β as compared to naïve DCs, while IL-10 and IL-12 mRNA levels remained low and practically similar to that of naive DCs (Figure 1b). CD4+ pe-T cells obtained from naive mice (as control) and AE-infected mice were enriched and analysed for mRNA levels of selected cytokines. As shown in Figure 2,

CD4+ pe-T cells from AE-infected mice had significantly higher levels of IL-4 than IFN-γ mRNA, representative, respectively, for a Th2- vs. a Th1-oriented Suplatast tosilate immune response. Furthermore, these cells expressed a high level of IL-2 and particularly TGF-β mRNA, while CD4+ pe-T cells from noninfected control mice had low and not significantly different expression levels for all cytokines assessed. These results suggested that at a transcriptional level, the intraperitoneal immune response of AE-infected mice was rather Th2 oriented and that immunomodulatory effects via TGF-β may be predominantly involved in determining the development of infection and disease. Pe-DCs were obtained from AE-infected mice at early and late stages of infection, as well as from naïve mice, and analysed by flow cytometry for the surface expression of selected major co-stimulatory molecules. Figure 3 demonstrates that in comparison with naive pe-DCs (control), the surface expression of CD80 and CD86 was down-regulated, while CD40 remained significantly expressed on pe-DCs from early and late stages of AE-infection. The expression of the adhesion molecule ICAM-1 (CD54) was slightly up-regulated on AE-pe-DCs at early stage of infection, but remained practically unchanged on late-stage AE-pe-DCs. Co-stimulatory molecules CD80 and CD86, prerequisites for an efficient T-cell stimulation, appeared to be suppressed in AE-infected mice.