益生菌的功能基因导入和基因编辑

Functional Gene Introduction and Gene Editing of Probiotics

益生菌已经在临床和食品领域应用多年,其安全性和有效性已经获得人们的认可。随着分子生物学技术的发展,采用益生菌作为载体进行基因导入或基因编辑,这些遗传改造的益生菌一部分已经作为新的药品或疫苗进入到临床应用阶段。携带功能基因的益生菌定殖于肠道进行表达和缓慢释放,这类益生菌作为活体药物获得益生菌和功能基因的双重功效,可用于治疗某些疑难病症。携带蛋白质抗原基因的益生菌定殖于肠道进行表达,可诱导肠道黏膜免疫、细胞免疫和体液免疫,这是一条更安全的口服疫苗途径。成簇的规则间隔短回文重复序列(clustered regularly interspaced short palindromic repeats, CRISPR)及其相关蛋白(CRISPR-associated protein, Cas)以其高效与便捷性推动了益生菌基因编辑的发展。这篇综述介绍了CRISPR-Cas9操作系统在益生菌方面的应用。对传统遗传操作较难的益生菌采用CRISPR-Cas9技术进行基因编辑,使其基因敲除和基因突变,基因敲入和基因调控等更为简单、高效和易操作。这些CRISPR/Cas9、CRISPRa和CRISPRi技术在益生菌的基因表达调控和代谢工程等领域具有巨大的应用潜力,例如医药、食品以及工业等相关重要产品的获得。本文总结了益生菌基因导入和基因编辑在生物制品生产中的相关应用,最后对其未来的研究方向进行展望。

Probiotics have been used in clinical and food fields for many years, and their safety and effectiveness have been widely recognized. The engineered probiotics with functional exogenous genes have entered the stage of clinical application as new drugs or vaccines with the development of molecular biology technology. The engineered probiotics with functional exogenous genes were also a kind of colonized microorganisms in the human intestine for gene expression and controlled release of functional proteins, which have achieved dual effects of probiotics and functional genes. Probiotics can act in combination with functional genes to treat some difficult diseases as living drugs in the clinical research. These genetically modified microorganisms have shown that the mucosal administration of therapeutic molecules was able to induce an immune response mediated by specific serum IgG and mucosal IgA antibodies along with mucosal cell-mediated immune responses. This is a safer oral vaccine route that has attracted widespread attention. Clustered regular interspaced short palindromic repeats(CRISPR) and its related proteins(CRISPR associated, Cas) have promoted the development of probiotics gene editing with their high efficiency and convenience. This review introduces the application of the CRISPR-Cas9 operating system in probiotics. The CRISPR/Cas9 technology is more simple, efficient and easy for the genome editing of probiotics, such as gene knockout, gene knock-in, gene mutation or gene regulation, especially those that are difficult to manipulate using the traditional genetic operation method. CRISPR/Cas9, CRISPRa and CRISPRi have great application potentials in genome editing of probiotics for the regulation of gene expression, metabolic engineering and other fields, such as the acquisition of important products related to medicine, food or industry. This review introduces the application of functional gene introduction and gene editing of probiotics in the production of biological products. Finally, the future research directions of the engineered probiotics are proposed.