Evaluation of Immune Response in Mouse Blood Post Injection with Gamma Ray-Attenuated Sporozoites of Plasmodium berghei

Abstract

Abstract:Ionizing radiation has been successfully used to attenuate parasites for malaria vaccine development. To get a deeper insight in the immune response post injection of irradiated pre-erythrocytic stage of malaria parasites (sporozoites), we used Plasmodium berghei as a model. Anopheles sp. with infective parasites in their salivary glands was irradiated with 0-225 Gy of gamma rays. The isolated sporozoites were intravenously injected into groups of mouse followed by a booster and challenge in interval time of 2-4 weeks. The detection of parasite in the infected mosquito was done with nested-PCR (polymerase chain reaction). Immune response in mouse blood was examined with ELISA (enzime-linked immunosorbent assay) and protein profile of irradiated sporozoites was studied with SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis). By using Anopheles farauti as the more susceptible mosquito to parasite infection, based on molecular detection and parasites observation in mouse blood, there was low or no effect of irradiated sporozoites on the immune responses in mouse serum. Some factors affecting these results are discussed. There was a slight alteration of protein profile of sporozoite infected salivary glands post gamma ray irradiation except for its band intensity, indicating the low effectiveness of gamma irradiation at optimal dose. It can be concluded that irradiated sporozoite as vaccine materials was failed in eliciting immune response.