Escamilla A, Bautista M J, Zafra R, Pacheco I L, Ruiz M T, Martínez-Cruz S, Méndez A, Martínez-Moreno A, Molina-Hernández V, Pérez J
Department of Anatomy and Comparative Pathology, Faculty of Veterinary Medicine, University of Córdoba, Spain.
Department of Animal Health (Parasitology), Faculty of Veterinary Medicine, University of Córdoba, Spain.
Vet Parasitol. 2016 Jan 30;216:84-8. doi: 10.1016/j.vetpar.2015.12.013. Epub 2015 Dec 18.
The aim of the present work was to evaluate the number of apoptotic eosinophils in the livers of sheep experimentally infected with Fasciola hepatica during the migratory and biliary stages of infection. Four groups (n=5) of sheep were used; groups 1-3 were orally infected with 200 metacercariae (mc) and sacrificed at 8 and 28 days post-infection (dpi), and 17 weeks post-infection (wpi), respectively. Group 4 was used as an uninfected control. Apoptosis was detected using immunohistochemistry with a polyclonal antibody against anti-active caspase-3, and transmission electron microscopy (TEM). Eosinophils were identified using the Hansel stain in serial sections for caspase-3, and by ultrastructural features using TEM. At 8 and 28 dpi, numerous caspase-3(+) eosinophils were mainly found at the periphery of acute hepatic necrotic foci. The percentage of caspase -3(+) apoptotic eosinophils in the periphery of necrotic foci was high (46.1-53.9) at 8 and 28 dpi, respectively, and decreased in granulomas found at 28 dpi (6%). Transmission electron microscopy confirmed the presence of apoptotic eosinophils in hepatic lesions at 8 and 28 dpi. At 17 wpi, apoptotic eosinophils were detected in the infiltrate surrounding some enlarged bile ducts containing adult flukes. This is the first report of apoptosis induced by F. hepatica in sheep and the first study reporting apoptosis in eosinophils in hepatic inflammatory infiltrates in vivo. The high number of apoptotic eosinophils in acute necrotic tracts during the migratory and biliary stages of infection suggests that eosinophil apoptosis may play a role in F. hepatica survival during different stages of infection.
本研究的目的是评估在实验性感染肝片吸虫的绵羊肝脏中，处于感染移行期和胆管期时凋亡嗜酸性粒细胞的数量。使用了四组（每组n = 5）绵羊；第1 - 3组经口感染200个囊蚴，并分别在感染后8天、28天以及感染后17周处死。第4组用作未感染对照。使用抗活性半胱天冬酶 - 3的多克隆抗体通过免疫组织化学以及透射电子显微镜（TEM）检测凋亡情况。通过在连续切片中使用汉斯el染色检测半胱天冬酶 - 3来鉴定嗜酸性粒细胞，并通过TEM的超微结构特征进行鉴定。在感染后8天和28天，大量半胱天冬酶 - 3阳性嗜酸性粒细胞主要出现在急性肝坏死灶的周边。坏死灶周边半胱天冬酶 - 3阳性凋亡嗜酸性粒细胞的百分比在感染后8天和28天分别很高（46.1 - 53.9），而在感染后28天的肉芽肿中有所下降（6%）。透射电子显微镜证实了在感染后8天和28天肝脏病变中存在凋亡嗜酸性粒细胞。在感染后17周，在一些含有成虫的扩张胆管周围的浸润物中检测到凋亡嗜酸性粒细胞。这是肝片吸虫在绵羊中诱导凋亡的首次报道，也是首次在体内肝脏炎性浸润中的嗜酸性粒细胞中报道凋亡的研究。在感染移行期和胆管期的急性坏死区域中大量凋亡嗜酸性粒细胞表明，嗜酸性粒细胞凋亡可能在肝片吸虫感染的不同阶段的生存中发挥作用。
