Title : Cell-based screening for anti-inflammatory drugs with the premise of innate immune tolerance induction
Inflammation is a poorly regulated reaction to pathogens or tissue injury that often requires medical therapy to prevent further tissue damage and to reduce the associated symptoms. Excessive inflammatory response may be triggered by evolutionarily conserved molecular determinants, termed pathogen- or damage-associated molecular patterns (PAMPs, DAMPs) that stimulate macrophages to produce inflammatory cytokines, including tumor necrosis factor-alpha (TNF-a), which in turn activates the inflammatory cascade. Current anti-inflammatory medications poorly block the early steps of inflammatory pathways and mainly act on downstream targets.
To find compounds that mimic innate immune tolerance and inhibit the initial steps of innate immune cell activation, we performed a cell-based screening campaign on a monocyte-macrophage cell-line. RAW264.7 cells were pre-exposed to biologically active drugs (Tocriscreen Plus Screening Library, 1280 compounds) and treated subsequently with the prototypical PAMP lipopolysaccharide (LPS). Inflammatory response was evaluated by measuring the TNF-a secretion with simultaneous assessment of cellular viability.
Test compounds induced a marked effect on cytokine production while hardly affected the cellular viability: 12.8% of drugs blocked the production of TNF-a by 50% or more. Our target-agnostic approach identified 20 clinical drugs that suppressed the inflammatory response (hit ratio of 1.5%) including steroids and the lipid-lowering atorvastatin, the b2-agonist salmeterol and the antidepressant escitalopram.
In conclusion, the initial steps of PAMP-induced inflammation may be modified by pharmacological interventions using currently available clinical drugs. Further testing of these compounds may be considered in experimental models of sepsis with a drug repurposing approach to test the translational potential of these findings.
1Dr. Domokos Gero is supported by the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences.
- A novel, target-agnostic approach to target inflammation
- A cell-based drug screening effort with a drug repurposing concept to target inflammation
- A summary of the results with approachable graphic representation of data giving an example of cell-based screen results.