体外培养牛白细胞中环形泰勒焦虫(Theileria annulata)的增殖、释放与感染

在体外培养的牛外周血白细胞中,环形泰勒焦虫裂殖子与裂殖体寄生于宿主细胞的细胞质中,并且随着宿主细胞的分裂而分到两个子细胞中。焦虫染色质粒的分裂方式为二分裂,随着焦虫颗粒的不断增殖,逐渐发育为成熟的裂殖体。体外培养感染焦虫的牛白细胞可通过伪足与细胞裂解两种途径向培养液中释放焦虫颗粒。释放到培养液中的焦虫颗粒对体外培养的健康牛外周血白细胞具有感染能力,感染细胞能在体外连续传代培养。

IN VITRO INFECTION OF THEILERIA ANNULATA TO BOVINE WHITE BLOOD CELLS

In vitro culture of bovine peripheral white blood cells infected with Theileria annulata were used for this study. The infected white cells divided successively in vitro and the parasites divided asynchronously with the host cells. After division the two daughter cells received either 1 or 2 multinucleated schizonts or a few number of isolated merozoites. The chromatin granules divided in the infected cells by binary fisson and different developing stages of schizonts containing various number of chromatin granules were seen in the cells.Free merozoites were always present in the culture medium. They escaped from the white cells through the extended pseudopodia or when the cells ruptured. The cell-free supernatant containing discharged merozoites were transferred to in vitro cultured healthy white cells. After about 13 days the cells were infected and resumed cell division. Cultures of the in vitro infected white cells have been maintained in the laboratory for more than three months.