Abstract
The innate immunity of host defends universally against various invading viruses, providing attractive targets for development of novel broad-spectrum antivirals. However, the antiviral innate immunity usually has "double-edged sword" effects, and clinical applications of either innate immune enhancers or suppressors depend highly on the timing of administration, which requires precision diagnosis and careful evaluation of the disease status. Irrational use of a single-directional immune modulator may greatly compromise the efficacy or even cause more severe diseases. The bi-directional modulators can balance the protective-vs.-detrimental effects of antiviral innate immunities, showing expanded "window of therapeutic opportunity" and advanced translational potency. Previously, we identified the potential bi-directional immune modulatory effect of Scutellaria barbata D. Don (SBD) in vitro. In the present study, we further validated that SBD maintained a relatively stable proportion of proinflammatory polarization among the lung macrophages of mice, regardless of with or without LPS stimulation, in a mode of bi-directional modulation. In addition, we explored the material basis underlying the bi-directional immune modulatory effect of SBD. Our study consolidated the bi-directional immune modulatory property of SBD and shed light on the development of next-generation innate immune modulatory agents.