Trans-signalling: A novel mechanism of Leishmania host cell immune evasion through the release of parasite signalling proteins

• Applicant: Privatdozent Dr. Joachim Clos
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; Cell Biology
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 242589725

• Final Report Year: 2018

Final Report Abstract

Using a combination of pharmacological inhibition and genetic complementation, we analysed the impact of phosphorylation on the function of the major chaperone HSP90 in the context of viability, fitness and infectivity. We find that two phosphorylation sites impact on the in vitro infectivity, but also on the ability of casein kinase 1.2 to use HSP90 as substrate. MAP kinase 1 also uses HSP90 as substrate and shows stable interaction with the HSP90 complex. Using a ribosome profiling strategy, we analysed the impact of HSP90 inhibition on protein synthesis in Leishmania. In keeping with the morphological effects of HSP90 inhibition – promastigote-to-amastigote differentiation – we find a large number stress proteins with elevated synthesis, reflecting the challenges encountered by Leishmania upon transmission to a homeothermic mammalian host and the oxidative challenges inside macrophages. Moreover, we find a downregulation of fatty acid metabolism enzymes, reflecting changes in carbon source usage, and strong upregulation of histones, possibly reflecting a more compact chromatin structure of the amastigote.

Publications

• (2018) Ribosome Profiling Reveals HSP90 Inhibitor Effects on Stage-Specific Protein Synthesis in Leishmania donovani. mSystems 3 (6) e00214-18
  Bifeld, Eugenia; Lorenzen, Stephan; Bartsch, Katharina; Vasquez, Juan-José; Siegel, T. Nicolai; Clos, Joachim
  
• (2015). Leishmania donovani P23 protects parasites against HSP90 inhibitor-mediated growth arrest. Cell Stress Chaperones 20, 673-685
  Hombach, A., Ommen, G., Sattler, V., and Clos, J.
  
• (2016). Joining forces: first application of a rapamycin-induced dimerizable Cre system for conditional null mutant analysis in Leishmania. Mol Microbiol 100, 923-927
  Spath, G.F., and Clos, J.
  
• (2017). Hsp90 inhibitors radicicol and geldanamycin have opposing effects on Leishmania Aha1- dependent proliferation. Cell Stress Chaperones 22, 729-742
  Bartsch, K., Hombach-Barrigah, A., and Clos, J.
  
• (2017). Leishmania Heat Shock Proteins as Effectors of Immune Evasion and Virulence. Current Immunology Reviews 13
  Bartsch, K., Eick, J., Zirpel, H., and Clos, J.
  
• (2017). MAPK1 of Leishmania donovani interacts and phosphorylates HSP70 and HSP90 subunits of foldosome complex. Sci Rep 7, 10202
  Kaur, P., Garg, M., Hombach-Barrigah, A., Clos, J., and Goyal, N.