Ultrastructural localization of an intracellular Toxoplasma protein that induces protection in mice.
Ultrastructural localization of an intracellular Toxoplasma protein that induces protection in mice.
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诱导小鼠保护的细胞内弓形虫蛋白的超微结构定位。
DOI：
10.1128/iai.55.9.2137-2141.1987
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发表时间：
1987
影响因子：
3.1
通讯作者：
Sharma,SD
中科院分区：
文献类型：
--
作者：
Sibley,LD;Sharma,SD
我们报告了单克隆抗体 F3G3 识别的弓形虫抗原的超微结构定位，该抗体可以保护小鼠免受致命攻击。通过使用胶体免疫金标记，F3G3 未能与完整的弓形虫细胞表面发生反应，证实了之前的观察结果，即它识别细胞内抗原。仅当弓形虫细胞预先暴露于 Triton X-100 时，才能获得 F3G3 免疫过氧化物酶标记。特定的免疫过氧化物酶反应位于表膜区域的表面膜下方以及在进入宿主细胞期间从弓形虫细胞表面挤出的复杂的囊泡网络内。使用小鼠多克隆血清和第二种单克隆抗体 6-86-1E11 获得了类似的结果，这两种抗体都是针对 F3G3 亲和纯化蛋白产生的。通过纯化弓形虫来源的表面膜囊泡、通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离这些蛋白质以及免疫印迹来确认F3G3识别的表位的位置。单克隆抗体 6-86-1E11 和类似的多克隆血清与在完整生物体和纯化的表面膜囊泡中发现的 58 和 28 千道尔顿的抗原相关蛋白发生反应。这些结果表明F3G3识别的表位位于弓形虫细胞表面膜下方并且包含在质膜衍生的囊泡内。
We report the ultrastructural localization of Toxoplasma antigens recognized by monoclonal antibody F3G3, which protects mice against lethal challenge. By using colloidal immunogold labeling, F3G3 failed to react with the surface of intact Toxoplasma cells, confirming previous observations that it recognizes an intracellular antigen. Immunoperoxidase labeling with F3G3 was obtained only when Toxoplasma cells were previously exposed to Triton X-100. A specific immunoperoxidase reaction was located beneath the surface membrane in the region of the pellicle and within the elaborate network of vesicles which are extruded from the surface of Toxoplasma cells during entry into host cells. Similar results were obtained with mouse polyclonal sera and a second monoclonal antibody, 6-86-1E11, both of which were produced against the F3G3 affinity-purified protein. The location of the epitope recognized by F3G3 was confirmed by purifying T. gondii-derived surface membrane vesicles, separating these proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblotting. Monoclonal antibody 6-86-1E11 and the analogous polyclonal sera reacted with the antigenically related proteins of 58 and 28 kilodaltons that were found both in the intact organisms and in the purified surface membrane vesicles. These results indicate that the epitope recognized by F3G3 is located beneath the Toxoplasma cell surface membrane and is contained within plasma membrane-derived vesicles.