Genetically attenuated malaria parasites for immunization studies

While our understanding of the immune response to malaria improves, an efficient malaria vaccine remains elusive. We intend to use blood stage attenuated parasites which can be transmitted through mosquitoes as tools to dissect human responses to malaria parasites and as a novel vaccination strategy. To rapidly screen genetically modified parasites for their utility, we use a rodent-infecting parasite (P. berghei) as model system. We already have identified two parasite lines which show the desired characteristics of slow blood stage growth and mosquito transmissibility. Interestingly, infected mice are able to control the infection leading to clearance of the parasite from the blood within roughly three weeks. Challenge experiments showed that these mice were protected from lethal wildtype infections. Our goal is to now identify more parasite lines displaying these characteristics followed by generation of P. falciparum lines with similar characteristics to ultimately conduct controlled human infections with our colleagues in Tübingen and Lambaréné.