VITAMIN-E-DEFICIENT DIETS ENRICHED WITH FISH-OIL SUPPRESS LETHAL PLASMODIUM-YOELII INFECTIONS IN ATHYMIC AND SCID BG MICE/

Mice fed vitamin E-deficient diets containing omega-3 fatty acids surv ive infection with lethal Plasmodium yoelii. The current study sought to determine if antimalarial T- and B-cell responses were required for such dietary-mediated protection, In the first set of experiments, nu /nu mice (which lack alpha beta T-cell-receptor-positive T cells and d o not produce antimalarial antibody) and nu/+ mice were fed casein-bas ed diets containing 3% menhaden oil, with or without vitamin E supplem entation, for 4 weeks prior to infection with lethal P. yoelii. All mi ce fed diets containing vitamin E developed fulminating parasitemias a nd quickly died, whereas both nu/nu and nu/+ mice fed diets deficient in vitamin E controlled their parasitemias for the first 18 days of in fection, Thereafter, the nu/nu mice became anemic and died, whereas th e nu/+ mice produced antimalarial antibodies and survived, In the seco nd set of experiments, scid/scid.bg/bg mice (which lack B cells and al pha beta and gamma delta T cells and have reduced NK-cell activity) we re fed the experimental diet for 6 weeks and then infected with the le ss virulent 17XNL strain of P. yoelii, Mice fed vitamin E-containing d iets quickly died, whereas those fed the vitamin E-deficient diet surv ived without developing detectable parasitemias, Results from these ex periments show that under prooxidant dietary conditions, mice were abl e to control and even survive malaria in the absence of malaria-primed T cells and antimalarial antibody, These results emphasize the import ance of cellular oxidative processes in parasite elimination.