Figure 4

Profiling immunostimulatory small interfering (si)RNAs. (a) A panel of siRNAs including negative and positive controls were evaluated in an in vitro human peripheral blood mononuclear cell (PBMC) assay as described previously [10] with supernatants examined for tumor necrosis factor (TNF) (left panel) and interferon-α (right panel) levels. The right-hand side of each panel has a chemically unmodified siRNA, which is compared with the same sequence after incorporation of a combination of phosphorothioate and 2'-O-methyl chemical modifications. (b) The left-hand panels show a series of immunostimulatory (A-D) and non- immunostimulatory (X-Z) siRNAs evaluated in an in vitro PBMC assay. The right-hand panel shows plasma cytokine profiles in mice injected intravenously with the same siRNAs formulated in LNP01 [26]. Common immunostimulatory siRNAs are identified by the in vitro and in vivo assays.