Bacterial spores displaying heterologous antigens or enzymes have long been proposed as mucosal vaccines, functionalized probiotics or biocatalysts. Two main strategies have been developed to display heterologous molecules on the surface of Bacillus subtilis spores: (i) a recombinant approach, based on the construction of a gene fusion between a gene coding for a coat protein (carrier) and DNA coding for the protein to be displayed, and (ii) a non-recombinant approach, based on the spontaneous and stable adsorption of heterologous molecules on the spore surface. Both systems have advantages and drawbacks and the selection of one or the other depends on the protein to be displayed and on the final use of the activated spore. It has been recently shown that B. subtilis builds structurally and functionally different spores when grown at different temperatures; based on this finding B. subtilis spores prepared at 25, 37 or 42 °C were compared for their efficiency in displaying various model proteins by either the recombinant or the non-recombinant approach. Immune- and fluorescence-based assays were used to analyze the display of several model proteins on spores prepared at 25, 37 or 42 °C. Recombinant spores displayed different amounts of the same fusion protein in response to the temperature of spore production. In spores simultaneously displaying two fusion proteins, each of them was differentially displayed at the various temperatures. The display by the non-recombinant approach was only modestly affected by the temperature of spore production, with spores prepared at 37 or 42 °C slightly more efficient than 25 °C spores in adsorbing at least some of the model proteins tested. Our results indicate that the temperature of spore production allows control of the display of heterologous proteins on spores and, therefore, that the spore-display strategy can be optimized for the specific final use of the activated spores by selecting the display approach, the carrier protein and the temperature of spore production.

中文翻译：

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生长和孢子形成的温度调节孢子显示的在效率芽孢杆菌枯草杆菌小号

长期以来，展示异源抗原或酶的细菌孢子一直被用作粘膜疫苗，功能化益生菌或生物催化剂。已经开发出两种主要策略来在枯草芽孢杆菌孢子的表面上展示异源分子：（i）一种重组方法，基于在编码外壳蛋白（载体）的基因与编码该蛋白的DNA之间的基因融合体的构建（ii）一种非重组方法，基于异源分子在孢子表面上的自发和稳定吸附。两种系统都有优缺点，一种或另一种的选择取决于要展示的蛋白质和活化孢子的最终用途。最近显示B。当在不同温度下生长时，枯草杆菌会在结构和功能上形成不同的孢子；基于这一发现，比较了在25、37或42°C下制备的枯草芽孢杆菌孢子通过重组或非重组方法展示各种模型蛋白的效率。基于免疫和荧光的分析用于分析在25、37或42°C制备的孢子上几种模型蛋白的展示。响应孢子产生的温度，重组孢子显示出不同量的相同融合蛋白。在同时展示两种融合蛋白的孢子中，每种孢子在不同温度下都有差异展示。非重组方法的展示仅受孢子产生温度的影响，用37或42°C制备的孢子比至少25°C的孢子吸收至少一些测试的模型蛋白效率更高。我们的结果表明，孢子产生的温度允许控制孢子上异源蛋白质的展示，因此，可以通过选择展示方法，载体蛋白来针对活化的孢子的特定最终用途优化孢子展示策略。和孢子产生的温度。