Taylor M G, Nelson G S, Smith M, Andrews B J
Bull World Health Organ. 1973;49(1):57-65.
Observations were made on the development of immunity to Schistosoma mansoni in baboons using both homologous and heterologous systems. The baboons were immunized by either (a) a single exposure to cercariae of the homologous species S. mansoni, or (b) 1-2 exposures to cercariae of either a S. rodhaini/S. mansoni hybrid or a S. mattheei/S. haematobium hybrid, or (c) repeated exposure to the cercariae of S. rodhaini or S. bovis. Baboons immunized with 500 cercariae of the homologous parasite developed partial immunity to reinfection, as did the baboons immunized with multiple exposures to the heterologous cercariae of S. rodhaini and S. bovis, although these parasites produced neither adult worms nor eggs in the baboons. The hybrids gave rise to well-established adult worm infections, but produced less immunity, even though the S. rodhaini/S. mansoni hybrid was genetically very similar to S. mansoni. These results indicate that adult worms are not essential to produce a considerable degree of immunity to reinfection, which can be engendered by the earlier stages of the parasites. However, none of the immune responses prevented egg deposition in the tissues, and considerable pathological changes resulted from the challenge infection. These observations suggest that although heterologous infections show some promise as immunizing agents, further studies are needed of the pathological changes resulting from their use.
利用同源和异源系统对狒狒感染曼氏血吸虫后的免疫发展情况进行了观察。狒狒通过以下方式进行免疫:(a) 单次暴露于同源物种曼氏血吸虫的尾蚴;(b) 1 - 2次暴露于罗氏血吸虫/曼氏血吸虫杂交种或马修氏血吸虫/埃及血吸虫杂交种的尾蚴;(c) 反复暴露于罗氏血吸虫或牛血吸虫的尾蚴。用500条同源寄生虫尾蚴免疫的狒狒对再次感染产生了部分免疫力,用罗氏血吸虫和牛血吸虫的异源尾蚴多次免疫的狒狒也是如此,尽管这些寄生虫在狒狒体内既未产生成虫也未产卵。杂交种引发了成熟的成虫感染,但产生的免疫力较低,尽管罗氏血吸虫/曼氏血吸虫杂交种在基因上与曼氏血吸虫非常相似。这些结果表明,成虫并非产生相当程度的再次感染免疫力所必需的,寄生虫的早期阶段即可引发这种免疫力。然而,没有一种免疫反应能阻止虫卵在组织中的沉积,攻击感染导致了相当程度的病理变化。这些观察结果表明,尽管异源感染作为免疫剂显示出一些前景,但仍需进一步研究其使用所导致的病理变化。