Methods for Delivering DNA to Intracellular Receptors.

Cytosolic DNA can indicate infection and induces type I interferon (IFN) and AIM2 inflammasome responses. Characterization of these responses has required introduction of DNA into the cytosol of macrophages by either chemical transfection or electroporation, each of which has advantages in different applications. We describe here optimized procedures for both electroporation and chemical transfection, including the centrifugation of chemical transfection reagent onto cells, which greatly increases the speed and strength of responses. Appropriate choice of DNA and use of these methods allow study of either the cytosolic DNA responses in isolation or the simultaneous stimulation of cytosolic receptors and the CpG DNA receptor toll-like receptor 9 (TLR9) in the endosomes.