Lee D L, Shivers R R
Department of Pure & Applied Zoology, University of Leeds, England.
Tissue Cell. 1987;19(5):665-71. doi: 10.1016/0040-8166(87)90073-5.
The muscle fibres of mice containing the infective-stage larvae of the nematode Trichinella spiralis have been studied by means of the freeze-fracturing technique. The larva lies in what appears to be a fluid-filled cavity within the cytoplasm of an altered muscle fibre. There is no membrane separating the cytoplasm of the nurse cell from the cavity surrounding the larva which is therefore truly intracellular, unlike many parasites that reside within a membrane-lined parasitophorous vacuole within the host cell. This altered muscle fibre, known as a nurse cell, lacks myofilaments but does contain extensive cisternae of endoplasmic reticulum; membrane-bound vesicles are budded off from the endoplasmic reticulum and traverse the cytoplasm towards the cavity containing the nematode where they apparently pass into the cavity. It is suggested that the contents of these vesicles are used to sustain the nematode. Attention is drawn to the similarity to giant cells that have been induced by the plant-parasitic nematode Meloidogyne in the roots of host plants and which sustain the nematode. The conversion of the muscle fibre into a nurse cell is probably brought about by the presence of a metabolic sink, the larval nematode, within the cell. This take-over of the control of a metazoan cell by another metazoan organism is most unusual and warrants further study.
利用冷冻断裂技术对含有旋毛虫感染期幼虫的小鼠肌肉纤维进行了研究。幼虫位于一个似乎充满液体的腔室内，该腔室存在于发生改变的肌肉纤维的细胞质中。没有膜将滋养细胞的细胞质与围绕幼虫的腔室分隔开，因此该腔室是真正的细胞内结构，这与许多寄生于宿主细胞内由膜包被的寄生泡中的寄生虫不同。这种发生改变的肌肉纤维，即滋养细胞，缺乏肌丝，但含有大量内质网池；膜结合小泡从内质网芽生出来，穿过细胞质，朝着含有线虫的腔室移动，显然它们进入了该腔室。有人认为这些小泡的内容物用于维持线虫的生存。文中提请注意与植物寄生线虫根结线虫在宿主植物根中诱导形成的巨型细胞的相似性，这些巨型细胞维持着线虫的生存。肌肉纤维向滋养细胞的转变可能是由于细胞内存在代谢库，即幼虫线虫。一种后生动物对另一种后生动物细胞控制的这种接管非常不寻常，值得进一步研究。
