感染环形泰勒焦虫(Theileria annulata)的牛外周血白细胞的形态观察

用光镜及扫描电镜观察了体外高代培养的含牛焦虫颗粒的牛外周血白细胞的形态及在细胞周期中细胞表面的特征性变化。这种经多年传代的含虫的牛外周血白细胞恢复了分裂和繁殖的能力,目前已成为较稳定的细胞系。细胞表面具多种伪足突起,如叶状、丝状及绒毛状。细胞周期中备期细胞表面的主要特征是:S期:细胞平扁,边缘具薄的时状伪足及丝状伪足;G_2期:细胞中部隆起,表面具少量绒毛状伪足;G_1期:绒毛状结构少或无,而出现丝状及小的叶状伪足,细胞仍保持球形;M期:细胞球形,表面密被以绒毛。作者根据扫描电镜的观察认为光镜下所观察的两类细胞,实际上是反映了一种细胞处于不同发育阶段时的特征。

SURFACE MORPHOLOGY OF THEILERIA-INFECTED BOVINE PERIPHERAL WHITE BLOOD CELLS

Bovine peripheral white blood cells infected with Theileria annulata have been successfully cultured in. vitro for sewn years in Xinjiang. The morphological characters of these cells in different phases of cell cycle were studied by mean of phase microscopy and SEM.Under in vitro culture conditions the infected white cells have resumed division, i.e., they have transformed into lymphoblastoid cells.Under light microscope, the cells apparently fell into two morphological categories: Most of the cells were large and flat, with well developed lead-like pseudopodia in addition to filiform pseudopodia. The number of the schizonts (Koch's body) in the cell varied from one to several. Chromatin granules were clearly seen in the schizonts. Cells of the other category were smaller and more condensed as compared with the large flat cells. The cell surface was usually covered with a layer of densely packed villus-like processes. Filiform pseudopodia of various length were also seen scattered amidst the villus layer. Chromatin granules of the parasite could be seen in the cytoplasm as well as in the filiform pseudopodia.By SEM, the .2 categories of cells discerned by phase microscopy were found to be different developmental stages of lymphoblastoid cells. Flat cells with broad leaf-like pseudopodia were cells of S phase. All the other cells, smaller and thicker with filiform pseudopodia on their surface, were cells of G1, G2 and M stage. Mitosis was usually seen. Chromatin granules of the schizont in the cell were distributed to 2 daughter cells during mitosis. In addition, it seemed that mature merozoites were discharged to the medium.