Adjobimey T, Hoerauf A
Institute for Medical Microbiology, Immunology and Parasitology, University Clinic Bonn, Germany.
Ann Trop Med Parasitol. 2010 Sep;104(6):455-64. doi: 10.1179/136485910X12786389891407.
Filarial parasites are known to induce a large range of immunoregulatory mechanisms, including the induction of alternatively activated macrophages and regulatory T cells. These mechanisms are used to evade and down-modulate the host's immune system, to support parasite survival. Several reports have focused on some of these mechanisms, in humans and murine models, but the complex immunoregulatory networks associated with filarial infections remain unclear. Recent publications have conferred a role for regulatory T cells in the ability of helminth parasites to modulate human immune responses, such cells promoting the induction of the non-complement-fixing immunoglobulin G4 (IgG4). High plasma concentrations of IgG4 have been reported in hypo-responsive and asymptomatic cases of helminth infection. In both human lymphatic filariasis and onchocerciasis, the asymptomatic infections are characterised by high plasma concentrations of IgG4 (compared with those of IgE) and of the complement-fixing antibodies IgG1, IgG2 and IgG3. In asymptomatic filarial infection, elevations in IgG4 are also often associated with high worm loads and with high plasma levels of the immunomodulatory interleukin-10. Here, various aspects of the induction of IgG4 in humans and it roles in the immunomodulation of the human responses to filarial parasites are reviewed.
已知丝虫寄生虫可诱导多种免疫调节机制，包括诱导替代性活化巨噬细胞和调节性T细胞。这些机制被用于逃避和下调宿主免疫系统，以支持寄生虫存活。一些报告聚焦于人类和小鼠模型中的部分此类机制，但与丝虫感染相关的复杂免疫调节网络仍不清楚。最近的出版物揭示了调节性T细胞在蠕虫寄生虫调节人类免疫反应能力中的作用，这类细胞促进非补体结合免疫球蛋白G4（IgG4）的诱导。在蠕虫感染反应低下和无症状的病例中，已报告血浆中IgG4浓度很高。在人类淋巴丝虫病和盘尾丝虫病中，无症状感染的特征是血浆中IgG4（与IgE相比）以及补体结合抗体IgG1、IgG2和IgG3的浓度很高。在无症状丝虫感染中，IgG4升高通常还与高虫负荷以及免疫调节性白细胞介素-10的高血浆水平有关。在此，本文综述了人类中IgG4诱导的各个方面及其在人类对丝虫寄生虫反应的免疫调节中的作用。
