Fahey J R, Spitalny G L
Infect Immun. 1984 Apr;44(1):151-6. doi: 10.1128/iai.44.1.151-156.1984.
The present studies were designed to investigate whether the erythrocyte preferences displayed by both virulent and nonvirulent forms of Plasmodium yoelii were fastidious growth requirements of these parasites. When inoculated into mice depleted of reticulocytes by lethal irradiation (900 rad), virulent parasites, which have been reported to grow predominantly in mature erythrocytes, gave rise to high parasitemias which were equivalent to those seen in unirradiated, normal mice. In addition, virulent parasites serially passaged in lethally irradiated mice showed properties of enhanced virulence upon inoculation back into normal mice. When inoculated into lethally irradiated mice, nonvirulent P. yoelii, which were reported to preferentially invade reticulocytes, invaded mature erythrocytes, and the infection progressed at a higher level of parasitemia than in unirradiated, normal mice. The inoculation of virulent parasites into mice made reticulocytemic by pretreatment with phenylhydrazine produced infections marked by the invasion of reticulocytes rather than mature erythrocytes, yet these infections remained lethal for the murine host. When nonvirulent parasites were inoculated into reticulocytemic mice, lethal infections resulted in which the parasites predominantly invaded reticulocytes. These results indicate that both the virulent and nonvirulent forms of P. yoelii possess the ability to invade and proliferate within more than one erythrocyte type and that their apparent erythrocyte preferences are not strict growth requirements.
本研究旨在调查约氏疟原虫的强毒株和无毒株所表现出的红细胞偏好是否是这些寄生虫苛刻的生长需求。当接种到经致死剂量照射（900拉德）而耗尽网织红细胞的小鼠体内时，据报道主要在成熟红细胞中生长的强毒株寄生虫引发了高寄生虫血症，其程度与未照射的正常小鼠中所见相当。此外，在经致死照射的小鼠中连续传代的强毒株寄生虫在接种回正常小鼠时表现出毒力增强的特性。当接种到经苯肼预处理而产生网织红细胞血症的小鼠体内时，强毒株寄生虫引发的感染以网织红细胞而非成熟红细胞的侵入为特征，但这些感染对鼠宿主仍然是致命的。当将无毒株寄生虫接种到网织红细胞血症小鼠体内时，导致了致命感染，其中寄生虫主要侵入网织红细胞。这些结果表明，约氏疟原虫的强毒株和无毒株都具有在不止一种红细胞类型中侵入和增殖的能力，并且它们明显的红细胞偏好并非严格的生长需求。
