The ambiguous role of immunity in echinococcosis: protection of the host or of the parasite?
The ambiguous role of immunity in echinococcosis: protection of the host or of the parasite?
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DOI：
10.1016/s0001-706x(02)00230-9
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发表时间：
2003-02-01
期刊：
影响因子：
2.7
通讯作者：
Vuitton, DA
中科院分区：
文献类型：
--
作者：
Vuitton, DA
在棘球绦虫感染中，在后绦虫阶段，在实验鼠模型以及在人中的免疫应答的研究已经表明：（1）由Th 1型细胞因子分泌诱导的细胞免疫能够成功地杀死发育初始阶段的后绦虫;（2）抗原蛋白和碳水化合物（并且可能是非抗原性的，六钩蚴的促有丝分裂成分）/后绦虫能够干扰抗原呈递和细胞活化，使宿主淋巴细胞和其他免疫细胞能够产生细胞因子（特别是IL-10）和其他能够抑制细胞免疫反应的效应期的介质;和（3）宿主的免疫遗传学特征对于这种寄生虫诱导的免疫应答偏离是必不可少的。在多房棘球绦虫感染中，Th 1和Th 2细胞因子组合对后绦虫的生长和存活至关重要。可以假设，Th 1细胞因子促进了后绦虫周围的初始细胞募集，并参与了细胞浸润的慢性化，导致完全组织化的寄生虫周围肉芽肿及其后果，纤维化和坏死。另一方面，Th 2细胞因子可能负责抑制成功的寄生虫杀死，特别是因为IL-10的“抗炎”效力。免疫应答的各个分支的这种组合导致棘球绦虫和宿主的部分保护。然而，它也可能被认为是疾病的几种并发症的原因。众所周知，Th 2相关的IgE合成和肥大细胞活化是囊型包虫病过敏反应的原因，但在泡型包虫病（AE）的过敏性并发症中很少涉及。然而，有效的Th 1相关的细胞免疫应答的部分但慢性的影响是负责细胞毒性事件，这既有助于后绦虫的生长和传播，并导致中央坏死的病变和AE的临床并发症。此外，Th-1应答是导致胆管和血管阻塞的主要且不可逆的纤维化的原因。此外，寄生虫周围纤维化可能是抗寄生虫药物疗效相对不足的原因之一。例如，通过使用干扰素α调节宿主免疫应答可能是产生针对寄生虫的有效免疫应答并预防AE及其并发症的新工具。(C)2002 Elsevier Science B. V.保留所有权利。
In Echinococcus infection, at the metacestode stage, studies of the immune responses in the experimental murine model as well as in humans have shown that (1) cellular immunity induced by a Th1-type cytokine secretion was able to successfully kill the metacestode at the initial stages of development; (2) antigenic proteins and carbohydrates (and perhaps non-antigenic, mitogenic components) of the oncosphere/metacestode were able to interfere with antigen presentation and cell activation so that host lymphocytes and other immune cells could produce cytokines (especially IL-10) and other mediators able to inhibit the effector phase of cellular immune reaction; and (3) immunogenetic characteristics of the host were essential to this parasite-induced deviation of the immune response. In E multilocularis infection, a combined Th1 and Th2 cytokine profile appears crucial for prolonged metacestode growth and survival. It may be hypothesized that Th1 cytokines promote the initial cell recruitment around the metacestode and are involved in the chronicity of the cell infiltrate leading to a fully organized periparasitic granuloma and its consequences, fibrosis and necrosis. The Th2 cytokines, on the other hand, could be responsible for the inhibition of a successful parasite killing especially because of the 'anti-inflammatory' potency of IL-10. This combination of various arms of the immune response results in a partial protection of both Echinococcus metacestode and host. However, it may also be considered responsible for several complications of the disease. The Th2-related IgE synthesis and mast cell activation, well known to be responsible for anaphylactic reactions in cystic echinococcosis, are more rarely involved in 'allergic' complications in alveolar echinococcosis (AE). However, the partial but chronic effects of the efficient Th1-related cellular immune response are responsible for cytotoxic events which both help metacestode growth and dissemination and lead to the central necrosis of the lesions and clinical complications of AE. Moreover, the Th-1 response is responsible for the major and irreversible fibrosis which leads to bile duct and vessel obstruction. In addition, the peri-parasitic fibrosis may be one of the reasons for the relative lack of efficacy of antiparasitic drugs. Modulation of the host immune response, by using Interferon alpha for instance, may be a new tool to generate an effective immune response against the parasite and to prevent AE and its complications. (C) 2002 Elsevier Science B.V. All rights reserved.