The uptake of poly I:C is prevented by ssDNA-ODN. (A-B) B-cell proliferation after TLR stimulation was measured by (A) 3H-thymidine incorporation and (B) flow cytometry-based cell counting. Data from 3 independent experiments run in triplicates are shown. (C) DC maturation was assessed after 48 hours of culture with ssCpG-ODN and increasing concentrations of poly I:C. The results are depicted as the MFI and are the mean ± SEM values from 6 donors. (D) Kinetic analyses of the inhibitory effect of ssCpG-ODN in poly I:C–stimulated DCs performed in 6 donors. (E) Endocytosis of pHrodo-labeled dextran beads by DCs was measured after 2 hours of culture with ssCpG-ODN, poly I:C, or combined treatment with ssCpG-ODN and poly I:C. (F) Single-stranded CpG-ODN and Cy5-labeled poly I:C (red) was cultured with DC for 15 minutes either alone or in combination and the subcellular location visualized with confocal microscopy. Scale bars are 5 μm. Representative data from 3 independent experiments are shown. (G) Quantitative measurement of Cy5-labeled poly I:C uptake into DC was performed with flow cytometry.
