Jura W G, Brown C G, Kelly B
Vet Parasitol. 1983 Feb;12(1):31-44. doi: 10.1016/0304-4017(83)90085-7.
The interaction, in vitro, between bovine peripheral blood lymphocytes and sporozoites of Theileria annulata (Ankara) was studied by light and electron microscopy. Beginning five minutes following incubation, samples were taken for Giemsa-stained smears and glutaraldehyde-fixed pellets, for light and electron microscopy, respectively. Sporozoites of T. annulata measure an average of 0.9 microns long, 0.8 microns broad and possess a limiting unit membrane, the pellicle; a round-to-ovoid, eccentrically situated, non-chromocentric nucleus; double-membraned, tubular, acristate mitochondria; varying numbers of anisocytic, densely osmiophilic and pleomorphic organelles, the rhoptries which together with the polar ring form the apical complex; and numerous, loosely scattered, electron-dense ribosomal particles. As early as 5 min of incubation, sporozoites had made contact with, and penetrated, lymphocytes. Sporozoites consistently attached to the lymphocyte plasmalemma by their basal end, possibly at specific receptor sites. Apparently only a proportion of lymphocytes (up to 40% and more commonly 10-20%) were susceptible. Two subpopulations of the susceptible lymphocytes were observed; one which appeared to have receptor sites localized on one pole of the plasmalemma and the other subpopulation in which the receptor sites were distributed evenly around the plasmalemmal surface. Within individual susceptible lymphocytes, the number of interiorized sporozoites increased from 1 to 3 at 5-10 min to as many as 15 or more parasites at around 60 min of incubation. Theileria annulata sporozoites were interiorized by the invagination of the host cell plasmalemma which remained intact throughout the process but later fragmented. Within 30 min of interiorization, each sporozoite underwent dedifferentiation by the loss of its rhoptries and transformed into a trophozoite. Around 24 h, the trophozoite, a uninucleate, motile and feeding stage of the parasite, developed into a schizont by an acentric, closed mitosis.
运用光学显微镜和电子显微镜，对牛环形泰勒虫（安卡拉株）裂殖子与牛外周血淋巴细胞在体外的相互作用进行了研究。孵育开始5分钟后，分别采集样本用于制作吉姆萨染色涂片和戊二醛固定颗粒，以进行光学显微镜和电子显微镜观察。环形泰勒虫裂殖子平均长0.9微米，宽0.8微米，具有一层限制单位膜，即表膜；一个圆形至卵形、位于偏心位置、无染色中心的细胞核；双层膜、管状、无嵴的线粒体；数量不等的异形、嗜锇性强且形态多样的细胞器，即棒状体，其与极环共同构成顶端复合体；还有许多松散分布、电子密度高的核糖体颗粒。早在孵育5分钟时，裂殖子就已与淋巴细胞接触并侵入。裂殖子始终通过其基部末端附着于淋巴细胞质膜，可能是在特定的受体部位。显然，只有一部分淋巴细胞（高达40%，更常见的是10 - 20%）易感。观察到易感淋巴细胞有两个亚群；一个亚群的受体部位似乎位于质膜的一极，另一个亚群的受体部位则均匀分布在质膜表面。在单个易感淋巴细胞内，内化的裂殖子数量在5 - 10分钟时从1个增加到3个，在孵育约60分钟时多达15个或更多。环形泰勒虫裂殖子通过宿主细胞质膜内陷而被内化，整个过程中质膜保持完整，但随后会破裂。内化后30分钟内，每个裂殖子会因失去棒状体而发生去分化，转变为滋养体。约24小时后，滋养体，即寄生虫的单核、活动且摄食阶段，通过无中心、封闭的有丝分裂发育为裂殖体。
