Control of cytokine gene expression using small RNA interference: Blockade of interleukin-10 and interferon-gamma gene expression in pig cells

The ability of small RNA interference (RNAi) to reduce specific gene expression was tested using interleukin-10 (IL-10) and interferon-gamma (IFN-γ) production by cultured swine blood mononuclear cells stimulated by Escherichia coli lipopolysaccharide or concanavalin A. Antisense (AS) phosphorothioate oligodeoxynucleotides (ODNs) corresponding to a sequence in the region of the AUG initiation codon of swine IL-10 or IFN-γ mRNA inhibited production of IL-10 (≥93.5%) and IFN-γ (≥99%) mRNAs. Interleukin-10 and IFN-γ protein production was inhibited more than 95% by the AS ODNs. Scrambled and sense ODNs RNAi used as negative controls did not alter mRNA expression for either cytokine but slightly reduced IL-10 protein production. Cytokine-specific and control RNAi did not inhibit β 2-microglobulin mRNA expression in mitogen-stimulated blood mononuclear cells. Thus AS ODNs RNAi specifically inhibit expression of pig IL-10 and IFN-γ mRNAs by cultured, mitogen-stimulated blood mononuclear cells and may be an attractive alternative method for studying cytokine function.