Meliodosis, a serious infectious complication caused by the soil-borne gram-negative bacteria Burkholderia pseudomallei, presents a significant health problem throughout endemic areas in Asia and Northern Australia. Due to the lack of vaccines and the alarming increase in multi-resistant strains, new treatment options targeting the infected host immune cell - rather than the pathogen directly - may hold the key to clear infection and circumvent further antimicrobial resistance. In order for the pathogens to infect their host target cell and manifest disease, a multitude of host cellular defense strategies have to be evaded and host cell signaling pathways manipulated. A detailed understanding of host-pathogen interactions will enable us to uncover a potential Achilles’ heel and pave the way to develop novel therapeutic intervention strategies.
Alveolar macrophages are the first line defense against infection and critical host cell for Burkholderia pseudomallei. I have established a novel CRISPR/Cas9 in vitro screening platform by lentivirally transducing murine macrophages with a full genome CRISPR guide library. This macrophage knockout library was infected large-scale with Burkholderia pseudomallei and screened to decipher novel host-pathogen interactions that facilitate Burkholderia host cell entry as well as subvert host defense immune signaling and cell death pathways. The screens revealed hits that confer both known (which successfully confirms the applicability of this novel approach) but also novel unknown host-pathogen interactions. I am now interrogating the novel candidate genes and their relevant signaling pathways individually by both genetic knockout and drug intervention in vitro and in vivo.
Importantly, I am furthermore utilizing the established CRISPR/Cas9 screening platform with a wide variety of other macrophage resident high impact pathogens such as Mycobacterium tuberculosis, Candida albicans, Leishmania donovani and dengue virus.