Project Summary/Abstract Malaria is a leading cause of human death and illness, causing over 200 million cases of clinical malaria and 400,000 deaths each year. Traditional measures to control and cure malaria are threatened by emergence of artemisinin resistance (ART-R). Research into ART-R has focused mostly on mechanisms allowing parasite to tolerate the oxidative stress and protein damage resulting from ART’s mechanism of action. However, recent discoveries indicate that resistance- associated mutations in the K13 slows cytostome function to diminish the available hemoglobin in the food vacuole. Our preliminary results revealed that the parasite’s sensitivity and tolerance to ART significantly overlaps with innate stress response pathways that enable P. falciparum survival of malaria fever. Our experimental approach is to elucidate drug-gene associations and decipher mechanisms of action and resistance to ART and other antimalarial drugs, using forward genetic screens of P. falciparum mutants created by random piggyBac mutagenesis. This approach has determined that genetic mutations in the major parasite processes critical for P. falciparum malarial fever survival response significantly correlate with altered sensitivity to ART (DHA, AS), indicating the parasite hijacked the heat-shock stress response pathways to cope with ART toxicity. We will use small libraries of piggyBac clones and GO-focused libraries for iterative screens of different phenotypes to functionally annotate interacting partners, pathways, and regulatory processes linked to ART mechanism of action and resistance. We will use genome-level screens to identify factors linked to ART mechanism of action. We will extend our analysis to P. knowlesi to characterize the conserved high-value antimalarial drug targets by adapting and applying chemogenomic profiling analysis to this vivax-like malaria parasite.

Narrative Malaria remains a devastating global health problem, although tremendous progress has been achieved in the past decade. Much of the progress can be attributed to effective use of drug treatments for Plasmodium falciparum, especially artemisinin (ART) combination therapies (ACTs); however, emerging resistance to ART (ART-R) and the ACT partner drugs threatens this progress. Our experimental approach is to elucidate drug-gene associations and decipher mechanisms of action and resistance to ART and other antimalarial drugs, using forward genetic screens of P. falciparum mutants created by random piggyBac mutagenesis.