Fig. 4

IFN-α production induced by single- or double-stranded forms of synthetic oligonucleotides. Single-stranded DNA oligomers (ssDNA) with phosphodiester bonds were synthesized, based on sequences of ODN1585 and ODN2216 (Invivogen, San Diego, CA, USA). Double-stranded DNA oligomers (dsDNA) were prepared by annealing sense and antisense strands of ssDNA. Each synthesized oligomer (2 μg) was tested on Flt3L induced BM-DCs, and the production of IFN-α was measured. +: sense strand; −: antisense strand; ss-core: 6-base CpG motif of sense strand; ds-core: Hybrid of sense strand DNA oligomer with antisense strand of 6 base CpG motif. *not detected