Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany.
Eur J Cell Biol. 2010 Jan;89(1):113-6. doi: 10.1016/j.ejcb.2009.10.006. Epub 2009 Nov 11.
The protozoan parasite Trypanosoma cruzi (T. cruzi) is transmitted by blood-sucking insect vectors. After transmission, parasites circulate in the blood as trypomastigotes and invade a variety of cells to multiply intracellularly as amastigotes. The acute phase triggers an immune response that restricts the dissemination and proliferation of parasites. However, parasites are able to persist in different tissues for decades causing the pathology of Chagas' disease. T. cruzi expresses a trans-sialidase (TS). This unique enzyme transfers sialic acid from host glycoconjugates to mucin-like molecules on the parasite and is supposed to be a major virulence factor. TS and sialylated structures were implicated in the persistence of parasites. We discuss here the recent findings on the function of sialylated structures on the surface of T. cruzi with a special emphasis on their property to interact with sialic acid-binding Ig-like lectins, which may allow the parasite to modulate the immune system of the host.
原生动物寄生虫克氏锥虫（T. cruzi）通过吸血昆虫媒介传播。传播后，寄生虫以锥鞭毛体的形式在血液中循环，并侵入各种细胞内以无鞭毛体形式进行细胞内繁殖。急性期会引发免疫反应，限制寄生虫的传播和增殖。然而，寄生虫能够在不同的组织中持续存在数十年，导致恰加斯病的病理学发生。T. cruzi 表达一种转涎酸酶（TS）。这种独特的酶将唾液酸从宿主糖缀合物转移到寄生虫上类似粘蛋白的分子上，被认为是主要的毒力因子。TS 和唾液酸化结构与寄生虫的持续存在有关。我们在这里讨论了表面带有唾液酸的 T. cruzi 结构的最新功能发现，特别强调了它们与唾液酸结合型 Ig 样凝集素相互作用的特性，这可能使寄生虫能够调节宿主的免疫系统。
