Chemical Attenuation of Plasmodium berghei Sporozoites Induces Sterile Immunity in Mice

LA Purcell, SK Yanow, M Lee, TW Spithill… - Infection and …, 2008 - Am Soc Microbiol
Infection and immunity, 2008Am Soc Microbiol
Radiation and genetic attenuation of Plasmodium sporozoites are two approaches for whole-
organism vaccines that protect against malaria. We evaluated chemical attenuation of
sporozoites as an alternative vaccine strategy. Sporozoites were treated with the DNA
sequence-specific alkylating agent centanamycin, a compound that significantly affects
blood stage parasitemia and transmission of murine malaria and also inhibits Plasmodium
falciparum growth in vitro. Here we show that treatment of Plasmodium berghei sporozoites …
Abstract
Radiation and genetic attenuation of Plasmodium sporozoites are two approaches for whole-organism vaccines that protect against malaria. We evaluated chemical attenuation of sporozoites as an alternative vaccine strategy. Sporozoites were treated with the DNA sequence-specific alkylating agent centanamycin, a compound that significantly affects blood stage parasitemia and transmission of murine malaria and also inhibits Plasmodium falciparum growth in vitro. Here we show that treatment of Plasmodium berghei sporozoites with centanamycin impaired parasite function both in vitro and in vivo. The infection of hepatocytes by sporozoites in vitro was significantly reduced, and treated parasites showed arrested liver stage development. Inoculation of mice with sporozoites that were treated in vitro with centanamycin failed to produce blood stage infections. Furthermore, BALB/c and C57BL/6 mice vaccinated with treated sporozoites were protected against subsequent challenge with wild-type sporozoites. Our findings demonstrate that chemically attenuated sporozoites could be a viable alternative for the production of an effective liver stage vaccine for malaria.
American Society for Microbiology