Faculty of Medicine and Health Technology, Tampere University, Tampere, 33014, Finland.
Natural Resources Institute Finland (Luke), Jokioinen, Finland.
BMC Immunol. 2023 Sep 9;24(1):29. doi: 10.1186/s12865-023-00565-0.
. Lack of exposure to the natural microbial diversity of the environment has been linked to dysregulation of the immune system and numerous noncommunicable diseases, such as allergies and autoimmune disorders. Our previous studies suggest that contact with soil material, rich in naturally occurring microbes, could have a beneficial immunoregulatory impact on the immune system in mice and humans. However, differences in the immunomodulatory properties of autoclaved, sterile soil material and non-autoclaved, live soil material have not been compared earlier.
. In this study, we exposed C57BL/6 mice to autoclaved and live soil powders that had the same rich microbiota before autoclaving. We studied the effect of the soil powders on the mouse immune system by analyzing different immune cell populations, gene expression in the gut, mesenteric lymph nodes and lung, and serum cytokines. Both autoclaved and live soil exposure were associated with changes in the immune system. The exposure to autoclaved soil resulted in higher levels of Rorγt, Inos and Foxp3 expression in the colon. The exposure to live soil was associated with elevated IFN-γ concentration in the serum. In the mesenteric lymph node, exposure to live soil reduced Gata3 and Foxp3 expression, increased the percentage of CD8 + T cells and the expression of activation marker CD80 in XCR1SIRPα migratory conventional dendritic cell 1 subset.
. Our results indicate that exposure to the live and autoclaved soil powders is not toxic for mice. Exposure to live soil powder slightly skews the immune system towards type 1 direction which might be beneficial for inhibiting type 2-related inflammation. Further studies are warranted to quantify the impact of this exposure in experimental type 2 inflammation.
缺乏对环境中天然微生物多样性的接触与免疫系统失调以及许多非传染性疾病（如过敏和自身免疫性疾病）有关。我们之前的研究表明，接触富含天然存在微生物的土壤物质可能对小鼠和人类的免疫系统产生有益的免疫调节作用。然而，以前尚未比较过经过高压灭菌的无菌土壤物质和未经高压灭菌的有生命的土壤物质的免疫调节特性差异。
在这项研究中，我们将 C57BL/6 小鼠暴露于经过高压灭菌和未经高压灭菌的土壤粉末中，这些粉末在高压灭菌前具有相同丰富的微生物群。我们通过分析不同的免疫细胞群、肠道、肠系膜淋巴结和肺部的基因表达以及血清细胞因子来研究土壤粉末对小鼠免疫系统的影响。暴露于高压灭菌和有生命的土壤都与免疫系统的变化有关。暴露于高压灭菌的土壤导致结肠中 Rorγt、Inos 和 Foxp3 的表达水平升高。暴露于有生命的土壤与血清中 IFN-γ 浓度升高有关。在肠系膜淋巴结中，暴露于有生命的土壤减少了 Gata3 和 Foxp3 的表达，增加了 CD8+T 细胞的百分比，并增加了 XCR1SIRPα 迁移的传统树突状细胞 1 亚群中激活标记物 CD80 的表达。
我们的结果表明，暴露于有生命和高压灭菌的土壤粉末对小鼠没有毒性。暴露于有生命的土壤粉末略微使免疫系统向 1 型方向倾斜，这可能有利于抑制 2 型相关炎症。需要进一步的研究来量化这种暴露对实验性 2 型炎症的影响。
