Functional genomics of malaria sporozoite - host hepatocyte interactions (360G-Wellcome-201477_Z_16_Z)

Intensive study of the ligand-receptor interactions by which malaria merozoites invade erythrocytes has yielded promising vaccine and drug targets. In contrast, there is little understanding of the process by which malaria sporozoites invade hepatocytes, despite the fact that antibody-inducing sporozoite-targeting vaccines are the leading approach to malaria vaccine development. I propose to use the following recently developed and complementary techniques to systematically elucidate ligand-receptor interactions involved in this process: 1. Biochemical identification of ligand-receptor interactions using an existing library of pentameric P. falciparum sporozoite proteins to probe plate-anchored recombinant hepatocyte surface proteins. 2. Genetic identification of receptors essential for in vitro hepatocyte invasion using a CRISPR-Cas9 gene-disruption strategy. A lead panel of 100 abundant candidate receptors will be selected using existing proteomic data, with potential for extension to the complete hepatocyte surface proteome. Identified interactions will be validated via host and parasite manipulations (gene disruption and antibody blockade), both in vitro using primary hepatocyte cultures and in vivo, including use of a humanized mouse model of P. falciparum liver-stage infection. As has been the case for study of merozoite-erythrocyte interactions, I anticipate the project will provide the basis for rational approaches to malaria prophylaxis via disruption of the identified interactions.