A possible role for natural killer cells in providing protection against Plasmodium berghei in early stages of infection.

Beige mutant mice, which are deficient in natural killer (NK) cells, exhibited a significantly higher parasitaemia than the parental C57BL/6 strain between days 4 and 10 after infection with Plasmodium berghei. Within 8-12 days after infection 70% of beige mice were dead but no deaths occurred in the parental strain until day 16. The median survival time of the beige mice (10 days) was significantly lower than that of the parental strain (22 days). It appears that NK cells may be protective in the early stages of malarial infection.