February 2017 | On occasion of the «GCB Symposium 2017», held on February 2, 2017, at the Department of Chemistry and Biochemistry and the Department of Physiology, University of Bern, the GCB Award for Best PhD Thesis for the year 2016 was conferred on Mariana De Niz, PhD of Science in Cell Biology, for her PhD thesis entitled «Imaging of malaria: conserved mechanisms of Plasmodium sequestration and virulence factor export in rodents and humans».
GCB Award for Best PhD Thesis 2016
Mariana De Niz, PhD, performed her work in the research group of Prof. Dr. Volker Heussler, at the Institute of Cell Biology, University of Bern. She received her PhD of Science in Cell Biology in January 2016.
Mariana is currently pursuing her career as SNF postdoctoral fellow in Prof. Matthias Marti’s lab, at the Harvard School of Public Health in Boston, USA, and the Wellcome Centre for Molecular Parasitology in Glasgow, Scotland. She is working on investigating mechanisms of Plasmodium gametocyte egress from the host bone marrow, migration to the host skin, and the dynamics of transmission from the skin to the mosquito vector.
Our warmest congratulations and best wishes for her future career go to Mariana De Niz, PhD.
Summary of the PhD Thesis:
«Imaging of malaria: conserved mechanisms of Plasmodium sequestration and virulence factor export in rodents and humans»
by Mariana De Niz
Plasmodium falciparum, the pathogen responsible for the most lethal form of malaria, readily invades red blood cells, and has evolved a range of mechanisms to avoid elimination by the human host including ‘sequestration’. This phenomenon is the arrest of infected red blood cells (iRBCs) in the vascular endothelium of multiple organs. Sequestration is associated to lethal complications such as cerebral malaria. To sequester, Plasmodium parasites export proteins to the surface of the iRBCs.
MAHRP1 and SBP1, are two key proteins of the export machinery associated with iRBC sequestration. So far, it was believed that this export machinery was exclusive to the human P. falciparum parasite. During my PhD in Prof. Heussler’s lab, we challenged this dogma and confirmed that the protein export machinery is conserved in all Plasmodium species investigated, including the rodent model P. berghei. This opened for the first time, the possibility to study sequestration in animal models. We could show that the knock-out of P. berghei MAHRP1 and SBP1 caused a completely altered sequestration phenotype of iRBCs resulting in a significant drop of virulence compared to wildtype control parasites, thereby confirming the relevance of sequestration for malaria pathology and lethality.
De Niz M, Burda PC, Kaiser G, del Portillo HA, Spielmann T*, Frischknecht F*, Heussler VT*, Progress in imaging tools: insights gained into Plasmodium biology, Nature Reviews Microbiology, (2017), doi: 10.1038/nrmicro.2016.158
De Niz M, Ullrich AK*, Heiber A*, Blancke Soares A, Pick C, Lyck R, Keller D, Kaiser G, Prado M, Flemming S, del Portillo HA, Janse CJ, Heussler VT*, Spielmann T*, The machinery underlying malaria parasite virulence is conserved between rodent and human malaria parasites, Nature Communications, (2016), 7:11659. doi: 10.1038/ncomms11659
De Niz M, Stanway RR, Wacker R, Keller D, Heussler VT, An ultrasensitive NanoLuc-based luminescence system for monitoring Plasmodium berghei throughout its life cycle, Malaria Journal, (2016), 15:232 DOI:10.1186/s12936-016-1291-9