Forsyth L M, Minns F C, Kirvar E, Adamson R E, Hall F R, McOrist S, Brown C G, Preston P M
Division of Biological Sciences, University of Edinburgh, UK.
J Comp Pathol. 1999 Jan;120(1):39-57. doi: 10.1053/jcpa.1998.0256.
The distribution of schizont-infected cells in six calves undergoing acute, lethal sporozoite-induced infections with Theileria annulata was examined, the calves being killed in the early, middle or late stages of disease. A combination of histological and immunocytochemical techniques showed that schizont-infected cells became disseminated rapidly through the lymphoid tissues from the prescapular lymph node draining the site of inoculation to distant lymph nodes (e.g., precrural, mesenteric and mediastinal) and to the spleen and thymus. The parasitized cells also spread rapidly into non-lymphoid organs, being found in the liver, kidney, lung, abomasum, adrenal glands and pituitary gland by day 7, in the brain by day 12 and in the heart by day 14 after infection. As infection progressed, the schizonts differentiated into merozoites. By the late stages of disease, the cells containing merozoites greatly out-numbered schizont-infected cells. The parasitized mononuclear cells were labelled by antibodies to bovine interferon-alpha1 and tumour necrosis factor-alpha and, during the later stages of the disease, contained erythrocytes parasitized by piroplasms. The results suggested that the parasitized mononuclear cells themselves played a role in the development of clinical disease and in tissue damage. These findings provide new evidence that tropical theileriosis can no longer be viewed as a lymphoproliferative disease resulting from the uncontrolled multiplication and metastasis of lymphoid cells infected with T. annulata schizonts, but is caused by a parasite that lives in, and is disseminated by, cytokine-secreting, proliferating mononuclear phagocytes.
对6头犊牛进行急性、致死性环形泰勒虫子孢子诱导感染的过程中，检查了裂殖体感染细胞的分布情况，这些犊牛在疾病的早期、中期或晚期被宰杀。组织学和免疫细胞化学技术相结合显示，裂殖体感染细胞迅速通过淋巴组织传播，从接种部位引流的肩胛前淋巴结扩散到远处的淋巴结（如腹股沟前、肠系膜和纵隔淋巴结）以及脾脏和胸腺。被寄生的细胞也迅速扩散到非淋巴器官，感染后第7天在肝脏、肾脏、肺、皱胃、肾上腺和垂体中发现，第12天在大脑中发现，第14天在心脏中发现。随着感染的进展，裂殖体分化为裂殖子。在疾病后期，含有裂殖子的细胞数量大大超过裂殖体感染细胞。被寄生的单核细胞被抗牛α1干扰素和肿瘤坏死因子α的抗体标记，并且在疾病后期，含有被梨形虫寄生的红细胞。结果表明，被寄生的单核细胞本身在临床疾病的发展和组织损伤中起作用。这些发现提供了新的证据，表明热带泰勒虫病不能再被视为由感染环形泰勒虫裂殖体的淋巴细胞不受控制的增殖和转移导致的淋巴增生性疾病，而是由一种寄生于分泌细胞因子、增殖的单核吞噬细胞并通过其传播的寄生虫引起的。
