Direct uptake of Antagomirs and efficient knockdown of miRNA in primary B and T lymphocytes

Depending on their physiological expression level, microRNAs (miRNA) address different target genes, thus have different biological functions. To identify these, the physiological expression has to be blocked. Here, we describe the use of inhibitory cholesterol-modified oligonucleotides (Antagomirs) to inhibit miRNAs selectively in primary human and murine T and B lymphocytes. Due to their lipophilic cholesterol tag Antagomirs enter primary lymphocytes efficiently and quantitatively. We show here that at concentrations of 0.125 to 1 μM, Antagomirs selectively inhibit expression of their target miRNA up to 99.5% without affecting cell viability.