Bertsche Ute, Mayer Christoph, Götz Friedrich, Gust Andrea A
Microbial Genetics, Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076 Tübingen, Germany.
Microbiology/Biotechnology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076 Tübingen, Germany.
Int J Med Microbiol. 2015 Feb;305(2):217-23. doi: 10.1016/j.ijmm.2014.12.019. Epub 2014 Dec 24.
Most Eubacteria possess peptidoglycan (PGN) or murein that surrounds the cytoplasmic membrane. While on the one hand this PGN sacculus is a very protective shield that provides resistance to the internal turgor and adverse effects of the environment, it serves on the other hand as a major pattern of recognition due to its unique structure. Eukaryotes harness this particular bacterial macromolecule to perceive (pathogenic) microorganisms and initiate their immune defence. PGN fragments are generated by bacteria as turnover products during bacterial cell wall growth and these fragments can be sensed by plants and animals to assess a potential bacterial threat. To increase the sensitivity the concentration of PGN fragments can be amplified by host hydrolytic enzymes such as lysozyme or amidase. But also bacteria themselves are able to perceive information about the state of their cell wall by sensing small soluble fragments released from its PGN, which eventually leads to the induction of antibiotic responses or cell differentiation. How PGN is sensed by bacteria, plants and animals, and how the antibacterial defence is modulated by PGN perception is the issue of this review.
大多数真细菌都拥有围绕细胞质膜的肽聚糖（PGN）或胞壁质。一方面，这种PGN囊泡是一个非常有效的保护屏障，可抵抗内部膨压和环境的不利影响，另一方面，由于其独特的结构，它又作为一种主要的识别模式。真核生物利用这种特殊的细菌大分子来感知（致病）微生物并启动其免疫防御。PGN片段是细菌在细胞壁生长过程中作为周转产物产生的，这些片段可以被植物和动物感知，以评估潜在的细菌威胁。为了提高敏感性，PGN片段的浓度可以通过宿主水解酶如溶菌酶或酰胺酶来放大。而且细菌自身也能够通过感知从其PGN释放的小的可溶性片段来获取有关其细胞壁状态的信息，这最终会导致抗生素反应的诱导或细胞分化。细菌、植物和动物如何感知PGN，以及PGN感知如何调节抗菌防御是本综述的主题。
