Figure 1.

CpG(B)-STAT3dODN Design and Internalization into Specific Human and Mouse Target Cells

(A) Structure and sequence of CpG(B)-STAT3dODN synthesized chemically as a conjugate of CpG7909 ODN with a double-stranded STAT3 decoy ODN; asterisks indicate phosphorothioation sites in the oligonucleotide backbone; “o” indicates single unit of the C3 carbon chain (CH2)₃. (B) Dose-dependent internalization of CpG(B)-STAT3dODN^Cy3 or the unconjugated STAT3dODN^Cy3 by primary human peripheral blood mononuclear cells (PBMCs: CD1c⁺/pDCs; CD303⁺/mDCs; CD19⁺/B cells) or mouse splenocytes (CD11c⁺/DCs; F4/80⁺/macrophages; CD19⁺/B cells) after 4 hr incubation as measured using flow cytometry. (C) Uptake of 250 nM CpG(B)-STAT3dODN^Cy3 or STAT3dODN^Cy3 by human and mouse BCL cells after 1 or 6 hr. (D) Intracellular uptake of CpG(B)-STAT3dODN^Cy3 by target human OCI-Ly3, TMD8, and mouse A20 lymphoma cells. Cells were incubated with 100 nM fluorescently labeled CpG7909-STAT3dODN^Cy3 for 1 hr. The intracellular localization of the conjugate (red) and nuclei using DAPI (blue) was detected using phase contrast and confocal microscopy after 1 hr incubation. Shown are images from 1 of 3 independent experiments with similar results. Scale bars, 20 μm. % Max, percentage of maximum. *p < 0.05; **p < 0.01; ***p < 0.001.