Knopf P M, Spitalny K C, Dang A
Parasite Immunol. 1984 Mar;6(2):171-83. doi: 10.1111/j.1365-3024.1984.tb00790.x.
Resistance to S. mansoni cercarial challenge, induced by prior infection of rats with cercariae, is analysed by substitution of alternatives to the primary cercarial exposure. Intravenous injections of either live or killed 4-week stage worms have been examined, utilizing two different routes of injection, one or two injected doses, and two different methods to kill worms. In addition to assessing peripheral blood eosinophil levels, anti-schistosome antibody titres, and challenge worm burdens in the injected and control recipients, sera from these rat groups collected 3 weeks after challenge were used for passive immunization studies in rats. Recipients of intravenous live worm injections were resistant to a cercarial challenge and yielded sera capable of passively immunizing rats. Recipients of intravenous killed worm injections were not significantly resistant to a challenge infection, yet paradoxically, yielded sera capable of passively immunizing rats. Serum from challenge control rats was not significantly protective in the passive immunization assay. There were no correlations between peripheral blood eosinophil levels or anti-schistosome antibody titres and resistance (either active or passive). We conclude that killed worms induce an immune response which, although insufficient to provide protection by itself, can be recalled or augmented by a challenge infection to result in significant levels of serum protective activity.
通过用替代初次尾蚴暴露的方法，分析了预先感染尾蚴的大鼠对曼氏血吸虫尾蚴攻击的抵抗力。研究了静脉注射活的或灭活的4周龄虫体，采用两种不同的注射途径、一或两个注射剂量以及两种不同的杀虫方法。除了评估外周血嗜酸性粒细胞水平、抗血吸虫抗体滴度以及注射组和对照组受体中攻击虫体的负荷外，还将攻击后3周收集的这些大鼠组的血清用于大鼠的被动免疫研究。静脉注射活虫的受体对尾蚴攻击具有抵抗力，并产生了能够被动免疫大鼠的血清。静脉注射灭活虫体的受体对攻击感染没有显著抵抗力，但矛盾的是，它们产生了能够被动免疫大鼠的血清。攻击对照组大鼠的血清在被动免疫试验中没有显著的保护作用。外周血嗜酸性粒细胞水平或抗血吸虫抗体滴度与抵抗力（主动或被动）之间没有相关性。我们得出结论，灭活虫体诱导了一种免疫反应，尽管这种反应本身不足以提供保护，但可以通过攻击感染来唤起或增强，从而导致显著水平的血清保护活性。
