gms | German Medical Science

Malaria caused by Plasmodium falciparum remains one of the most devastating diseases in the world. According to the WHO, the disease claimed close to 650,000 lives in 2011 with 90% of the victims coming from the African region. Due to the persistent lack of an effective vaccine, the fight against malaria relies mostly on chemotherapy and chemoprophylaxis. However the treatment of the disease is complicated by the parasite ability to develop resistances against almost all the current antimalarial drugs and the vectors of the disease are resistant to most insecticides, a situation which further slows down the elimination strategies. Moreover, most drugs used to treat malaria kill the asexual stages of the parasite, but do not prevent gametocytes formation and maturation. Developing therapies which contain gametocytocidal antimalarial drugs are predicted to be the best way to further limit malaria transmission since asexual stages or non-viable gametocytes can’t develop inside the mosquito mitgut. The goal of our study was to develop an enzyme-linked immunosorbent assay (ELISA) to quantify the gametocyte load in drug-treated P. falciparum cultures, in order to investigate the gametocytocidal activity of antimalarial compounds. For this purpose, the surface protein of P. falciparum namely Pfs230 was chosen as the target for ELISA development. Pfs230 localizes to the surface of the parasite plasma membrane of the gametocyte stages III, IV and V. Polyclonal antibodies capable of recognizing this protein were successfully generated for this study. However, for the purpose of drug screening in 96 well plates, achieving an acceptable detection signal depends on a successful gametocytes growth in 96 well plates. To further improve the sensitivity of the assay, a monoclonal antibody directed against the above mentioned protein is currently being developed.