Schwartzman J D, Pearson R D
Am J Trop Med Hyg. 1985 Sep;34(5):850-5. doi: 10.4269/ajtmh.1985.34.850.
Leishmania donovani promastigotes derived from infected hamster spleens, in either log phase or stationary phase growth, associated with human foreskin fibroblasts in vitro and assumed the morphological characteristics of amastigotes. This apparent conversion was noted within hours at 26 degrees C, 32 degrees C or 37 degrees C; in the continued presence of promastigotes, increasing numbers of amastigote-like forms were seen for 2 weeks at 26 degrees C or 32 degrees C. At 37 degrees C amastigote-like forms declined sharply after 6 days. Multiplication of amastigote-like forms was not observed at any temperature, this was also true of freshly isolated amastigotes from hamster spleens which associated with fibroblasts but did not multiply. Approximately 0.1% of promastigotes appeared to convert per day. Amastigote-like forms were seen within fibroblasts by transmission electron microscopy, surrounded by a closely applied host membrane. Scanning electron microscopy showed promastigotes with their flagellae under or within fibroblasts, but phagocytosis was not observed. These experiments suggest that the conditions required for promastigote-to-amastigote conversion may be different than those required for amastigote multiplication, and the mammalian core body temperature may not be required for promastigote conversion.
从受感染仓鼠脾脏中获取的杜氏利什曼原虫前鞭毛体，处于对数期或稳定期生长阶段，在体外与人包皮成纤维细胞相关联，并呈现出无鞭毛体的形态特征。在26℃、32℃或37℃下，数小时内即可观察到这种明显的转化；在前鞭毛体持续存在的情况下，在26℃或32℃下，2周内可见数量不断增加的类无鞭毛体形态。在37℃下，类无鞭毛体形态在6天后急剧减少。在任何温度下均未观察到类无鞭毛体形态的增殖，从仓鼠脾脏新分离的无鞭毛体与成纤维细胞相关联但不增殖的情况也是如此。每天约有0.1%的前鞭毛体似乎发生了转化。通过透射电子显微镜观察到成纤维细胞内存在类无鞭毛体形态，其周围紧密包裹着宿主细胞膜。扫描电子显微镜显示前鞭毛体的鞭毛位于成纤维细胞之下或之内，但未观察到吞噬现象。这些实验表明，前鞭毛体向无鞭毛体转化所需的条件可能不同于无鞭毛体增殖所需的条件，并且前鞭毛体转化可能不需要哺乳动物的核心体温。
