Chemical modifications and human PBMC assay. (A) Example of chemical modification motifs. Lowercase letters represent 2′-OMe-modified nucleotides. Underline denotes DNA residues, underline with italics indicates DNA residues with phosphorothioate linkage, and “P” designates a 5′ phosphate. (B,C) 133 nM canonical or Dicer-substrate siRNA listed in Table 1 was transfected into human PBMC using 8 μg/mL DOTAP. Supernatant was collected 24 h after transfection and analyzed for IFN-α (B) and TNF-α (C) by ELISA. Canonical siRNAs are depicted in dark gray and dsiRNAs in light gray, with chemical variants of each sequence sharing the same symbol. (*) Effect of structure as determined by ANOVA, p < 0.05. Modifications are (UU) unmodified/unmodified, (HL) heavy/light, (HA) heavy/alternating, and (UA) unmodified/alternating.
