A Role for Secreted Immune Effectors in Microbial Biofilm Formation Revealed by Simple In Vitro Assays
A Role for Secreted Immune Effectors in Microbial Biofilm Formation Revealed by Simple In Vitro Assays
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简单的体外测定揭示了分泌性免疫效应物在微生物生物膜形成中的作用
DOI：
10.1007/978-1-0716-1944-5_9
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发表时间：
2022
影响因子：
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通讯作者：
Assunta Liberti, Brittany A.
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文献类型：
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作者：
Assunta Liberti, Brittany A.
生物膜的形成对于微生物在粘膜表面的成功和稳定定殖至关重要，微生物通常通过渗出胞外多糖和其他大分子如蛋白质、脂质甚至DNA来构建三维环境。不仅是细菌，还有真菌，如酵母，形成了这些粘附的相互作用的群落。从历史上看，生物膜已经在发病机制的背景下进行了研究，但直到最近才认识到，在生物膜的背景下，宿主相关微生物组成员之间的重要关系得以维持。宿主免疫反应以各种方式影响生物膜的形成;例如，由非病原体形成的稳定生物膜可能不仅通过填充可用的生态位空间而且通过帮助直接抵御病原体来改善屏障防御。最近，发现哺乳动物中的可溶性免疫效应分子如免疫球蛋白A（伊加）在以有益于宿主的方式调节复杂生物膜群落中起重要作用。来自其他分泌型免疫效应物的额外证据，如原索动物中含有可变区的几丁质结合蛋白（VCBPs），现在表明这种现象比以前认识到的要普遍得多。这些免疫分子的活性也可能发挥超出简单防御策略的作用;相反，它们可能改善共生相互作用的结果，使宿主受益。因此，旨在研究分泌的免疫效应物的功能的传统免疫测定，如凝集测定，应考虑到如果所研究的微生物没有被直接杀死，则第一次观察可能不是最后一次观察的可能性。在这里，我们描述了一系列简单的方法来表征生物膜的形成时，细菌（或酵母）培养的存在下分泌的免疫效应。为了模拟这种方法，我们使用从Ciona robusta肠道中分离的微生物，每种微生物在存在或不存在VCBPs的情况下生长。这里定义的方法适用于不同的模型系统及其微生物。
The formation of biofilms is critical for the successful and stable colonization of mucosal surfaces by microbes, which often build three-dimensional environments by exuding exopolysaccharides and other macromolecules such as proteins, lipids, and even DNA. It is not just bacteria, but fungi such as yeast, that form these adherent interacting communities. Historically, biofilms have been studied in the context of pathogenesis, but only recently it has been recognized that important relationships among members of host-associated microbiomes are maintained within the context of biofilms. Host immune responses impact biofilm formation in various ways; for example, it is likely that formation of stable biofilms by non-pathogens improves barrier defenses by not just filling available niche spaces but also by helping to ward off pathogens directly. Recently, it was found that soluble immune effector molecules such as immunoglobulin A (IgA) in mammals serve essential roles in modulating complex biofilm communities in ways that benefit the host. Additional lines of evidence from other secreted immune effectors, such as the variable region-containing chitin-binding proteins (VCBPs) in protochordates, now suggest that this phenomenon is much more widespread than previously recognized. The activity of these immune molecules also likely serves roles beyond those of simple defense strategies; rather, they may be improving the outcome of symbiotic interactions benefiting the host. Thus, traditional immune assays that are aimed at studying the function of secreted immune effectors, such as agglutination assays, should take into account the possibility that the first observation may not be the last if the microbes under study are not directly killed. Here, we describe a series of simple approaches to characterize biofilm formation when bacteria (or yeast) are cultured in the presence of a secreted immune effector. To model this approach, we use microbes isolated from the gut ofCiona robusta, each grown in the presence or absence of VCBPs. The approaches defined here are amenable to diverse model systems and their microbes.