TOXOPLASMA-GONDII - CHARACTERIZATION AND LOCALIZATION OF ANTIGENS SECRETED FROM TACHYZOITES
TOXOPLASMA-GONDII - CHARACTERIZATION AND LOCALIZATION OF ANTIGENS SECRETED FROM TACHYZOITES
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DOI：
10.1016/0014-4894(90)90014-4
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发表时间：
1990-07-01
影响因子：
2.1
通讯作者：
CAPRON, A
中科院分区：
文献类型：
--
作者：
CHARIF, H;DARCY, F;CAPRON, A
由于我们以前已经证明了弓形虫排泄分泌抗原所起的保护作用，目前工作的目的是生产针对这些抗原的单克隆抗体，以确定它们在寄生虫中的定位是否与排泄或分泌机制相容。Western免疫印迹分析显示三种单克隆抗体（TG 17 -179，TG 17 -43和TG 17 -113）分别针对28.5，27和21 kDa的排泄分泌抗原。与通过伴刀豆球蛋白A亲和层析分离的抗原反应的TG 17 -179针对糖基化的28.5-kDa组分。胶体金免疫标记显示21-27-，和28.5- kDa抗原的致密颗粒的速殖子的基质中的超微结构定位和相关的寄生虫空泡的微绒毛网络，宿主细胞入侵后。这些观察结果表明以下机制的弓形虫分泌分泌抗原首先储存在速殖子致密颗粒，然后释放内的寄生虫空泡。在这里的分泌分子的特点，天然的27 kDa抗原识别的TG 17 -43是一种钙结合蛋白，发现是与21和28.5 kDa抗原内的致密颗粒混合，因此可以发挥作用的分泌产品的包装。此外，21-和28.5-kDa抗原也位于寄生虫质膜下。该特定位置可以反映T的瞬态阶跃特性。弓形虫分泌物
Since we had previously demonstrated the protective role played by Toxoplasma excreted-secreted antigens, the aim of the present work was to produce monoclonal antibodies directed against these antigens in order to determine if their localization in the parasite is compatible with a mechanism of excretion or secretion. Western immunoblotting analysis revealed three monoclonal antibodies (TG17-179, TG17-43, and TG17-113) raised against excreted-secreted antigens of 28.5, 27, and 21 kDa, respectively. The TG17-179 which reacts with antigens isolated by Concanavalin A affinity chromatography is directed against a glycosylated 28.5-kDa component. Colloidal immunogold labeling showed the ultrastructural localization of the 21-27-, and 28.5- kDa antigens in the matrix of the dense granules of tachyzoites and associated with the microvilli network of the parasitophorous vacuole, after host cell invasion. These observations suggest the following mechanism of Toxoplasma secretion; secreted antigens are first stored in tachyzoite-dense granules and are then released inside the parasitophorous vacuole. Among the secretory molecules characterized here, the native 27-kDa antigen recognized by TG17-43 is a calcium-binding protein found to be intermixed with the 21- and 28.5-kDa antigens inside the dense granules and hence could play a role in the packaging of secretory products. In addition, the 21- and 28.5-kDa antigens were also located beneath the parasite plasmalemma. This particular location could reflect a transient step characteristic of T. gondii secretion.