Pimenta P F, Dos Santos M A, De Souza W
J Submicrosc Cytol. 1987 Jul;19(3):387-95.
The fine structure of the in vivo and in vitro interaction process between promastigote and amastigote forms of Leishmania mexicana amazonensis with rat peritoneal neutrophils and eosinophils was studied. For in vivo experiments the parasites were inoculated into the peritoneal cavity and samples were collected after different times. Both neutrophils and eosinophils readily ingested and digested the parasites within endocytic vacuoles. Attachment of the parasites to the eosinophils induced their degranulation with the release of granule contents onto parasite surface causing its destruction. Ingestion of parasites by eosinophils, but not by neutrophils, induced drastic morphological changes finally leading to leucocyte lysis with liberation of intact granules. This fact may increase the extracellular parasite killing. For in vitro interactions, peritoneal exudate cells were collected by washing. Normal rat autologous serum was shown to be required for both attachment and ingestion of the parasites by the granulocytes. Results were similar to those obtained from in vivo experiments. Parasites incubated with serum presented a thicker coat that appears to mediate their attachment and subsequent ingestion by leucocytes. The cytochemical localization of acid phosphatase and peroxidase showed that leucocyte granules fused with the parasite-containing endocytic vacuoles. Images were obtained suggesting that the binding of the parasites to eosinophil surface triggers an exocytic process with releasing of the granule content onto the parasite surface.
研究了亚马逊利什曼原虫前鞭毛体和无鞭毛体形式与大鼠腹腔嗜中性粒细胞和嗜酸性粒细胞在体内和体外相互作用过程的精细结构。在体内实验中，将寄生虫接种到腹腔中，并在不同时间后收集样本。嗜中性粒细胞和嗜酸性粒细胞都能在胞吞泡内轻易摄取并消化寄生虫。寄生虫附着在嗜酸性粒细胞上会诱导其脱颗粒，颗粒内容物释放到寄生虫表面导致其破坏。嗜酸性粒细胞摄取寄生虫而非嗜中性粒细胞摄取寄生虫会引发剧烈的形态变化，最终导致白细胞溶解并释放完整的颗粒。这一事实可能会增加细胞外寄生虫的杀伤作用。对于体外相互作用，通过冲洗收集腹腔渗出细胞。结果表明，正常大鼠自体血清是粒细胞附着和摄取寄生虫所必需的。结果与体内实验所得结果相似。与血清一起孵育的寄生虫呈现出更厚的包膜，这似乎介导了它们与白细胞的附着以及随后被白细胞摄取。酸性磷酸酶和过氧化物酶的细胞化学定位显示，白细胞颗粒与含有寄生虫的胞吞泡融合。获得的图像表明，寄生虫与嗜酸性粒细胞表面的结合触发了一个胞吐过程，颗粒内容物释放到寄生虫表面。
