In addition to huDNA, LL37 complexes with free microbial/viral DNA for type I IFN induction in monocytes. (A) IFN-α produced by pDCs (5 × 104 cells/condition) and monocytes (2 × 105 cells/condition) after overnight stimulation with lysates of VV and HSV viruses alone or in complex with LL37 (10μM) with or without pretreatment with 50nM bafilomycin. Data are representative of at least 5 experiments; error bars represent the SD of triplicate wells. *P < .0001 (paired Student t test). **P < .01 (paired Student t test). (B) IFN-α produced by pDCs and monocytes after overnight stimulation with increasing titers of VV and HSV viruses. HSV failed to trigger IFN-α release in monocytes; error bars represent the SD of triplicate wells. (C) IFN-α produced by pDCs (5 × 104 cells/condition) and monocytes (2 × 105 cells/condition) after overnight stimulation with increasing concentration of either HSV, or VV, or human genomic DNA from U937 cells (huDNA) in complex with LL37 (10μM). Data are representative of at least 3 experiments.
