The virulence of Plasmodium falciparum is largely attributed to the ability of asexual blood-stage parasites to cytoadhere to the microvascular endothelium of the human host. This pathogenic behavior is mediated by the primary parasite virulence factor P. falciparum erythrocyte membrane protein 1 (PfEMP1), an understanding of which is crucial to develop interventions to ameliorate the morbidity and mortality of P. falciparum malaria. The work presented in this thesis describes the application of a phenotype-to-genotype experimental approach to identify novel parasite proteins involved in the trafficking and display of PfEMP1. Guided by the overall hypothesis that the in vitro culture-adapted parasite line 3D7 harbors 1 or more genetic determinants of impaired PfEMP1 trafficking, surface PfEMP1 levels were first measured in 3D7, the presumably trafficking-competent parasite line HB3, and 16 unique progeny from an HB3 x 3D7 genetic cross (chapter 2). These phenotypes were then combined with genome-wide SNP data in QTL analysis to identify genetic polymorphisms potentially responsible for the impaired trafficking in 3D7 (chapter 3). A near-significant QTL containing a single protein-coding gene, the putative kinesin Pf3D7_1245600, was identified, characterized, and investigated in CRISPR-Cas9-driven allele-exchange parasite transfection experiments to establish a causal link between the gene and PfEMP1 trafficking (chapter 4). The parasite transfections were unsuccessful, but the potential role of Pf3D7_1245600 in PfEMP1 trafficking was indirectly assessed through the disruption of microtubules with colchicine (chapter 4), which significantly impacted the surface PfEMP1 levels of HB3 but not 3D7. The findings of this thesis suggest that kinesins and microtubules may play previously unconsidered roles in the regulation, production, or trafficking of PfEMP1.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:644709 |
| Date | January 2014 |
| Creators | Neal, Aaron T. |
| Contributors | Newbold, Chris I.; Fairhurst, Rick M. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:0cc3f09c-9178-448b-92f8-8f9564398585 |
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