Plant-derived secretory component gives protease-resistance to Shiga toxin 1-specific dimeric IgA
Plant-derived secretory component gives protease-resistance to Shiga toxin 1-specific dimeric IgA
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DOI：
10.1007/s11103-021-01151-x
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发表时间：
2021-04-19
影响因子：
5.1
通讯作者：
Imai, Yasuyuki
中科院分区：
文献类型：
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作者：
Nakanishi, Katsuhiro;Mogi, Noriko;Imai, Yasuyuki
关键信息一种植物来源的分泌成分使其对志贺毒素特异的哺乳动物免疫球蛋白A具有蛋白酶抗性。通过毒素中和试验从功能上证明了该蛋白的抗性。分泌成分(SC)被认为在分泌型免疫球蛋白A(SIgA)的抗蛋白酶中发挥作用，使其能够在粘膜上发挥作用。虽然植物表达系统在SIGA生产中的应用越来越多，但对于异源表达的SC是否在功能上与SIGA的蛋白酶抗性有关还没有得到充分的评价。在这里，我们用植物来源的SC重组了SIgA，并测试了对蛋白酶挑战的易感性的变化。在谷胱甘肽氧化还原缓冲液的作用下，植物来源的SC和哺乳动物细胞来源的志贺毒素1(STX1)的二聚体IgA(DigA)有效地形成了SIgA。预先沉淀DIGA的硫酸铵也有助于促进SIGA的形成。重组的SIgA用胃蛋白酶和胰酶两种胃肠道蛋白酶处理。经2 h胃酶处理后，经植物来源的SC重组后，SIgA的信号保持在42%，而在没有SC重组的情况下，DIGA的信号保持在12%。同样，经4h胰酶处理后，有SC的SIgA信号保持在74%，而没有SC的DIGA信号保持在36%。此外，在Vero细胞的毒素中和试验中，观察到Diga的SC重组对胃蛋白酶抗性的影响。这些结果表明，植物来源的SC有助于口服型SIgA的产生。
Key message A plant-derived secretory component conferred protease-resistance to Shiga toxin-specific mammalian immunoglobulin A. The protease-resistance was functionally demonstrated by a toxin neutralization assay. Secretory component (SC) is believed to play roles in such as the protease-resistance of secretory immunoglobulin A (SIgA), allowing it to function on mucosae. Although the use of a plant expression system for SIgA production has been increasing, it has not been sufficiently assessed as to whether heterologously expressed SC could functionally contribute to the protease-resistance of SIgA. Here, we reconstituted SIgA using plant-derived SC and tested for changes in vulnerability to protease challenge. With glutathione redox buffers, plant-derived SC and mammalian cell-derived dimeric IgA (dIgA) specific for Shiga toxin 1 (Stx1) efficiently formed SIgA. Prior ammonium sulfate precipitation of dIgA was also shown to be useful to enhance the formation of SIgA. The reconstituted SIgA was treated with two gastrointestinal proteases, pepsin and trypsin. After 2-h pepsin treatment, the signal from SIgA remained at 42% with plant-derived SC-reconstitution while that from dIgA remained at 12% without SC-reconstitution on western blot analysis. Similarly, the signal from SIgA remained at 74% with SC but that from dIgA remained at 36% without SC after 4-h trypsin treatment. Furthermore, an effect of SC-reconstitution of dIgA on pepsin-resistance was observed in a toxin neutralization assay involving Vero cells. These results indicated that the plant-derived SC could contribute to the production of orally applicable SIgA.