Mechanism of eosinophilia in angiostrongyliasis cantonensis

本研究旨在探讨嗜酸性粒细胞在广州管圆线虫病中的作用及其机制。主要研究结果如下：1.广州管圆线虫幼成虫的排泄/分泌（E/S）产物含有一个主要因子，该因子负责诱导非允许性豚鼠宿主肺动脉转移蠕虫时的嗜酸性粒细胞增多。对于允许的大鼠宿主，这种因素可能与卵或第一阶段幼虫有关。在nonpermissive小鼠宿主中对年轻成虫提取物的嗜酸性粒细胞反应的T细胞独立性意味着提取物中存在直接的嗜酸性粒细胞生成活性。2.豚鼠嗜酸性粒细胞强烈响应嗜酸性粒细胞趋化（EC）物质从成虫在体外和体内，但大鼠嗜酸性粒细胞未能做到这一点。目前正在进行一项研究，以确定某些对EC物质具有特异性的受体是否存在于 ...更多信息 发送的豚鼠嗜酸性粒细胞，并确定是否鸡蛋和幼虫阶段有EC活动。3.在离体条件下，用幼成虫抗原刺激5-14天前转移幼蠕虫的豚鼠纵隔淋巴结细胞和脾细胞，它们产生并释放出一种造血因子。该因子不可透析，分子量大于10000。虽然液体骨髓培养迄今未能揭示的体细胞和E/S抗原的年轻的成年蠕虫的直接eosinopoietic活动，软琼脂培养，现在正在进行中，以确定存在或不存在这种活动。4.感染A.结果表明，广州鹅膏菌可引起脑脊液（CSF）中的嗜酸性粒细胞增多和白细胞增多，两者均具有T细胞依赖性。根据CSF嗜酸性粒细胞增多症，脑中活蠕虫的回收率突然下降，表明嗜酸性粒细胞增多症可能与杀虫相关。超微结构研究显示CSF嗜酸性粒细胞的降解和其他变化，例如，颗粒数量减少，出现小而圆的颗粒，提示细胞处于活化状态。CSF嗜酸性粒细胞在PMA和毛地黄皂苷刺激后产生超氧阴离子。本研究还提示了幼成虫抗原能够刺激细胞生成的可能性<O_2>。需要进一步的研究来确定为什么大鼠宿主尽管存在T细胞，但未能发生CSF嗜酸性粒细胞增多症。少

This study was performed to determine the mechanism of eosinophilia and the possible roles of the eosinophils in angiostrongyliasis cantonensis. The results obtained are summarized as follows: 1. The excretory/secretory (E/S) products of the young adult worms of Angiostrongylus cantonensis contain a major factor(s) responsible for inducing eosinophilia in the nonpermissive, guinea pig host with pulmonary arterial transfers of the worms. Such a factor(s) for the permissive rat host would possibly be associated with the eggs or lst-stage larvae. T cell-independency of the eosinophilic response to young adult worm extracts in the nonpermissive mouse host implies the presence of a direct eosinopoietic activity in the extracts. 2. Guinea pig-eosinophils strongly respond to the eosinophil chemotactic (EC) substance from adult worms both in vitro and in vivo, but rat-eosinophils failed to do so. A study is now underway to determine whether some receptors specific for the EC substances are pre … More sent on the guinea pig-eosinophils and also to determine whether eggs and larval stages have an EC activity. 3. When mediastinal lymph-node cells and splenic cells from the guinea pigs transferred with the young adult worms 5-14 days earlier were stimulated in vitro by young adult worm antigen, they generated and released an eosinopoietic factor(s) into the media. The factor is nondialysable and more than 10000 in molecular weight. Although the liquid marrow culture has so far failed to reveal the direct eosinopoietic activity of the somatic and E/S antigens of the young adult worms, soft-agar cultures are now in progress to determine the presence or absence of this activity. 4. Mice infected with A. cantonensis induced pleocytosis and eosinophilia in the cerebrospinal fluid (CSF), both of which were of T cell-dependence. The recovery of viable worms from the brains abruptly decreased in accordance with this CSF eosinophilia, suggesting the possible association of the eosinophilia with worm killing. An ultrastructural study revealed degraunlative and other changes in CSF eosinophils, e.g., the decrease in granule numbers and the appearance of small and round-shaped granules, suggesting the activated status of the cells. CSF eosinophils generated superoxide anion following the stimulation with PMA and digitonin. The present study is also suggestive of the possibility that young adult worm antigen is capable of stimulating <O_2> generation of the cells. A further study is required to determine why the rat host fails to develop CSF eosinophilia in spite of the presence of T cells in this animal. Less