Anthrax-toxin-mediated delivery of a 19 kDa antigen of Mycobacterium tuberculosis into the cytosol of mammalian cells
Anthrax-toxin-mediated delivery of a 19 kDa antigen of Mycobacterium tuberculosis into the cytosol of mammalian cells
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DOI：
10.1042/ba20000072
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发表时间：
2001-04-01
影响因子：
2.8
通讯作者：
Singh, Y
中科院分区：
文献类型：
--
作者：
Mehra, V;Khanna, H;Singh, Y
PA63是蛋白水解激活的保护性抗原（PA, 83kDa）的63 kDa片段，介导致死性因子（LF）和水肿因子转运到细胞质中。LF （LFn）的N端需要254个氨基酸才能与PA63结合并介导融合到N端或c端的活性配体的易位。在这里，我们报道了一个19kDa的结核分枝杆菌抗原在融合到LFn的c端（LFn- 19kda）时转移到哺乳动物细胞的细胞质中。该融合蛋白与PA结合后对J774A.1巨噬细胞无毒性，与中国仓鼠卵巢K1细胞孵育后仍能与PA63结合。数据显示，炭疽毒素可以介导结核杆菌抗原在哺乳动物细胞胞质中的易位，并且可能有助于将携带免疫优势分枝杆菌抗原的蛋白质和肽输送到胞质中。
PA63, the proteolytically activated 63 kDa fragment of protective antigen (PA, 83kDa), mediates translocation of lethal factor (LF) and oedema factor into the cytosol. The N-terminal 254 amino acids of LF (LFn) are required for binding to PA63 and mediating translocation of active ligands fused to either the N- or C-terminus. Here we report translocation of a 19 kDa antigen of Mycobocterium tuberculosis into the cytosol of mammalian cells when fused to the C-terminus of LFn (LFn-19kDa). The fusion protein was non-toxic to J774A.1 macrophage cells in combination with PA and retained the ability to bind to PA63 when incubated with Chinese hamster ovary K1 cells. The data show the efficacy of anthrax toxin to mediate translocation of M, tuberculosis antigens into the cytosol of mammalian cells and may prove useful in delivering proteins and peptides carrying immunodominant mycobacterial antigens into the cytosol.