Hydrodynamic flow-mediated protein sorting on the cell surface of trypanosomes
Hydrodynamic flow-mediated protein sorting on the cell surface of trypanosomes
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DOI：
10.1016/j.cell.2007.08.046
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发表时间：
2007-11-02
期刊：
影响因子：
64.5
通讯作者：
Overath, Peter
中科院分区：
文献类型：
--
作者：
Engstler, Markus;Pfohl, Thomas;Overath, Peter
单细胞寄生虫布鲁氏锥虫从其细胞表面迅速清除宿主来源的免疫球蛋白（Ig），这是由单一类型的糖基磷脂酰肌醇锚定的变异型表面糖蛋白（VSG）主导的。我们已经确定了抗体清除的机制，并发现igg - vsg免疫复合物被被动地分选到细胞后极，在那里它们被内吞。免疫复合物的反向运动需要细胞的正向运动，但不依赖于内吞作用和肌动蛋白的功能。我们认为，作用于游动锥虫的流体动力流导致Ig-VSG免疫复合物在质膜平面上定向运动，即附着在VSG上的免疫球蛋白起着分子帆的作用。在培养中以及可能在受感染的哺乳动物中，水动力的蛋白质分选有助于保护锥虫免受补体介导的免疫破坏，但同样可能在其他细胞类型（如血管内膜上皮细胞）的表面具有功能意义。
The unicellular parasite Trypanosoma brucei rapidly removes host-derived immunoglobulin (Ig) from its cell surface, which is dominated by a single type of glycosylphosphatidylinositol-anchored variant surface glycoprotein (VSG). We have determined the mechanism of antibody clearance and found that Ig-VSG immune complexes are passively sorted to the posterior cell pole, where they are endocytosed. The backward movement of immune complexes requires forward cellular motility but is independent of endocytosis and of actin function. We suggest that the hydrodynamic flow acting on swimming trypanosomes causes directional movement of Ig-VSG immune complexes in the plane of the plasmamembrane, that is, immunoglobulins attached to VSG function as molecular sails. Protein sorting by hydrodynamic forces helps to protect trypanosomes against complement-mediated immune destruction in culture and possibly in infected mammals but likewise may be of functional significance at the surface of other cell types such as epithelial cells lining blood vessels.