Affiliation: | aDepartment of Biological Sciences, Université du Québec à Montréal, Case postale 8888, Succursale Centre-Ville, Montréal, Que., Canada H3C 3P8 bFonds de recherche sur la nature et les technologies (FQRNT) Centre for Host–Parasite Interactions, Institute of Parasitology, McGill University, Ste-Anne-de-Bellevue, Que., Canada H9X3V9 cInstitute of Parasitology, McGill University, Ste-Anne-de-Bellevue, Que., Canada H9X3V9 dSchool of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia |
Abstract: | A current goal of malaria vaccine research is the development of vaccines that will cross-protect against multiple strains of malaria. In the present study, the breadth of cross-reactivity induced by a 30K multivalent DNA vaccine has been evaluated in susceptible A/J mice (H-2a) against infection with the Plasmodium chabaudi adami DK strain and a virulent parasite subspecies, Plasmodium chabaudi chabaudi AS. Immunized A/J mice were significantly protected against infection with both P. c. adami DK (31–40% reduction in cumulative parasitemia) and P. c. chabaudi AS parasites, where a 30–39% reduction in cumulative parasitemia as well as enhanced survival was observed. The 30K vaccine-induced specific IFN-γ production by splenocytes in response to native antigens from both P. c. chabaudi AS and P. c. adami DK. Specific antibodies reacting with surface antigens expressed on P. c. adami DS and P. c. chabaudi AS infected red blood cells, and with opsonizing properties, were detected. These results suggest that multivalent vaccines encoding conserved antigens can feasibly induce immune cross-reactivity that span Plasmodium strains and subspecies and can protect hosts of distinct major histocompatibility complex haplotypes. |