Cell-mediated immune response in calves to single-dose, trickle, and challenge infections with Fasciola hepatica
Cell-mediated immune response in calves to single-dose, trickle, and challenge infections with Fasciola hepatica
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DOI：
10.1016/s0304-4017(99)00200-9
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发表时间：
2000-02-29
影响因子：
2.6
通讯作者：
Losson, B
中科院分区：
文献类型：
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作者：
Bossaert, K;Jacquinet, E;Losson, B
使用外周血单核细胞 (PBMC) 增殖测定来研究八头实验感染肝片形吸虫的小牛的细胞介导的免疫反应。还评估了与超敏反应相关的嗜酸性粒细胞和肥大细胞反应。 500 个囊蚴的初次感染可作为单剂量或在 4 周内进行滴流感染。 4 个月后，用 100 个囊蚴对小牛进行攻击感染，并在初次感染后 24 周宰杀。感染前根据对植物血凝素（PHA）的皮内反应（IDR）确定皮肤嗜酸性粒细胞计数（SEC）。这些计数与平均吸虫长度呈负相关，但与尸检时发现的吸虫负担无关。实验结束时，与迟发型超敏反应 (DTH) 反应相比，引发了非特异性 (PHA) 和特异性（分泌性寄生虫产物 FhESAg 和全虫提取物 FhSomAg）即刻型超敏反应 IDR。 SEC 与血液嗜酸性粒细胞增多相关，但与寄生虫参数无关。这些发现表明，嗜酸性粒细胞反应与牛对肝镰刀菌感染的抵抗力的发展并没有明显的相关性。在两个感染组中，早在感染后 7 天就可以检测到对 FhSomAg 的特异性单核细胞反应，在单剂量感染的犊牛幼体的早期迁徙阶段，该反应明显高于滴流感染的犊牛。在整个实验过程中，感染组的这种反应明显高于对照组。攻击引发了显着的增殖反应，但不如初次感染后明显。攻击后3周没有记录到γ-干扰素(INF-γ)的产生。尸检时，两个感染组中恢复的吸虫平均数量相似，这表明感染的速度对保护性免疫没有影响。两个感染组的肝脏病变相似，其特征是明显的嗜酸性粒细胞和肥大细胞浸润。进行了肝活检并讨论了其诊断价值。所有结果表明，肝镰刀菌感染主要诱导牛的 2 型反应，并且这种反应几乎没有保护作用。 (C)2000 Elsevier Science B.V. 保留所有权利。
A peripheral blood mononuclear cell (PBMC) proliferation assay was used to study the cell-mediated immune response in eight calves experimentally infected with Fasciola hepatica. Hypersensitivity-related eosinophil and mast-cell responses were also assessed. The primary infection of 500 metacercariae was administered either as a single-dose or as a trickle infection over a 4-week period. Calves were challenge-infected 4 months later with 100 metacercariae and slaughtered 24 weeks postprimary infection. Skin eosinophil counts (SEC) were determined prior to infection on the basis of the intradermal reaction (IDR) to phytohaemagglutinin (PHA). These counts correlated negatively with the mean fluke length but not with the fluke burden found at necropsy. At the end of the experiment, non-specific (PHA) and specific (excretory-secretory parasite products, FhESAg, and whole-worm extract, FhSomAg) immediate type hypersensitivity IDR were elicited in contrast to delayed type hypersensitivity (DTH) responses. The SEC correlated with blood eosinophilia but not with parasite parameters. These findings suggest that the eosinophil response does not correlate clearly with the development of resistance to F. hepatica infection in cattle. A specific mononuclear cell response to FhSomAg was detectable as early as 7 days after infection in both infected groups, being significantly higher during the very early migratory phase of the juveniles in the single-dose infected calves than in the trickle infected calves. This response remained significantly higher in infected groups than in the control group throughout the experiment. Challenge elicited a significant proliferative response, less pronounced than after primary infection. No production of gamma-interferon (INF-gamma) was recorded 3 weeks after challenge. At necropsy, the mean number of flukes recovered was similar in both infected groups, suggesting that the rate at which the infection is administrated has no effect on protective immunity. Hepatic lesions, similar in both infected groups, were characterised by marked eosinophil and mast-cell infiltration. Liver biopsies were performed and their diagnostic value is discussed. All results suggest that F. hepatica infection predominantly induces a Type-2 response in cattle, and that this response has little protective effect. (C)2000 Elsevier Science B.V. All rights reserved.