TOXOPLASMA-GONDII - FUSION COMPETENCE OF PARASITOPHOROUS VACUOLES IN FC-RECEPTOR TRANSFECTED FIBROBLASTS
TOXOPLASMA-GONDII - FUSION COMPETENCE OF PARASITOPHOROUS VACUOLES IN FC-RECEPTOR TRANSFECTED FIBROBLASTS
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DOI：
10.1126/science.2200126
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发表时间：
1990-08-10
期刊：
影响因子：
56.9
通讯作者：
MELLMAN, I
中科院分区：
文献类型：
--
作者：
JOINER, KA;FUHRMAN, SA;MELLMAN, I
在主动进入其宿主细胞后，原生动物寄生虫弓形虫驻留在细胞内的空泡中，完全不能与其他内吞或生物合成细胞器融合。融合阻断需要活生物体的进入，但是不可逆的：如果寄生虫在进入后被杀死，则液泡的融合能力不会恢复。然而，通过改变寄生虫的进入途径，可以克服融合阻滞。因此，吞噬活性抗体包被T。转染巨噬细胞淋巴细胞Fc受体的中国仓鼠卵巢细胞感染弓形虫，导致能够融合和酸化的空泡形成。吞噬作用和融合似乎涉及Fc受体胞质尾区的一个域，该域不同于网格蛋白包被的凹坑定位所需的域。这些结果表明，融合抑制的机制可能反映了空泡膜在其形成时的修改，而不是由寄生虫分泌的可溶性抑制剂。
After actively entering its host cells, the protozoan parasite Toxoplasma gondii resides in an intracellular vacuole that is completely unable to fuse with other endocytic or biosynthetic organelles. The fusion blocking requires entry of viable organisms but is irreversible: fusion competence of the vacuole is not restored if the parasite is killed after entry. The fusion block can be overcome, however, by altering the parasite''s route of entry. Thus, phagocytosis of viable antibody-coated T. gondii by Chinese hamster ovary cells transfected with macrophage-lymphocyte Fc receptors results in the formation of vacuoles that are capable of both fusion and acidification. Phagocytosis and fusion appear to involve a domain of the Fc receptor cytoplasmic tail distinct from that required for localization at clathrin-coated pits. These results suggest that the mechanism of fusion inhibition is likely to reflect a modification of the vacuole membrane at the time of its formation, as opposed to the secretion of a soluble inhibitor by the parasite.