We propose two different sets of small molecule, high-throughput screens to identify (a) compounds that have enhanced activity against intracellular Mtb and (b) compounds that synergize with existing frontline drugs through enhancing drug action in the context of the host macrophage. Both screens exploit fluorescent reporter strain of Mtb that constitutively express mCherry with or without GFP, the expression of which is driven by conditionally-active promoters. Bacterial survival is evaluated by fluorescent plate reader, which has proven to be both reproducible and rapid. In a previous screen performed on a library of 340,000 compounds provided by Vertex Pharmaceuticals our throughput was 30,000 compounds per week.

The screens will be performed in collaboration with Calibr, who will provide the compound collections, manage the generation of sub-libraries and work with us on compound optimization, target identification and validation of efficacy in in vitro model systems.