Shigella flexneri Diguanylate Cyclases Regulate Virulence.
Shigella flexneri Diguanylate Cyclases Regulate Virulence.
复制标题
福氏志贺氏菌二鸟苷酸环化酶调节毒力。
DOI：
10.1128/jb.00242-21
复制
发表时间：
2021
影响因子：
3.2
通讯作者：
Koestler,BenjaminJ
中科院分区：
文献类型：
--
作者：
Ojha,Ruchi;Dittmar,AshleyA;Severin,GeoffreyB;Koestler,BenjaminJ
福氏志贺菌是一种细胞内的人类病原体，侵入结肠细胞并引起血性腹泻。S.弗氏志贺菌是从大肠杆菌进化而来的，基因组比较表明，S.福氏杆菌在病理适应过程中丢失了大约20%的基因，包括与基于核苷酸的第二信使环状二GMP（c-di-GMP）周转相关的不成比例的基因;然而，剩余的c-di-GMP周转酶是高度保守的。c-di-GMP调节其他细菌对变化的环境条件的许多行为变化，包括生物膜的形成，但这种信号系统尚未在S.弗莱克斯内里。在本研究中，我们表达VCA 0956，一个组成型活性的c-di-GMP合成双鸟苷酸环化酶（DGC）从霍乱弧菌，在S。以确定毒力表型是否受c-di-GMP调节。我们发现VCA 0956在S.福氏杆菌增加c-di-GMP水平，这与增加的生物膜形成和降低的耐酸性、宿主细胞侵袭和噬斑大小相对应。我们研究了VCA 0956表达对S. flexneri转录组，并发现与酸抗性相关的基因被抑制，这与酸休克存活率降低相对应。我们还发现，个人S。福氏DGC突变体表现出减少的生物膜形成和减少的宿主细胞侵袭和噬斑大小，以及增加的对酸休克的抗性。这项研究强调了c-di-GMP信号传导在调节S.细胞内的人类病原体志贺氏菌引起痢疾，每年导致多达一百万人死亡。目前，还没有批准的疫苗用于预防志贺氏菌病，并且志贺氏菌属的抗生素耐药性的发生率正在上升。在这里，我们探讨了广泛保守的c-di-GMP细菌信号系统如何改变与发病机制相关的志贺氏菌。我们发现表达或去除与c-di-GMP合成相关的酶导致志贺氏菌形成生物膜、侵入宿主细胞、在宿主细胞单层中形成损伤和抵抗酸应激的能力发生变化。
Shigella flexneri is an intracellular human pathogen that invades colonic cells and causes bloody diarrhea. S. flexneri evolved from commensal Escherichia coli, and genome comparisons reveal that S. flexneri has lost approximately 20% of its genes through the process of pathoadaptation, including a disproportionate number of genes associated with the turnover of the nucleotide-based second messenger cyclic di-GMP (c-di-GMP); however, the remaining c-di-GMP turnover enzymes are highly conserved. c-di-GMP regulates many behavioral changes in other bacteria in response to changing environmental conditions, including biofilm formation, but this signaling system has not been examined in S. flexneri. In this study, we expressed VCA0956, a constitutively active c-di-GMP synthesizing diguanylate cyclase (DGC) from Vibrio cholerae, in S. flexneri to determine if virulence phenotypes were regulated by c-di-GMP. We found that expressing VCA0956 in S. flexneri increased c-di-GMP levels, and this corresponds with increased biofilm formation and reduced acid resistance, host cell invasion, and plaque size. We examined the impact of VCA0956 expression on the S. flexneri transcriptome and found that genes related to acid resistance were repressed, and this corresponded with decreased survival to acid shock. We also found that individual S. flexneri DGC mutants exhibit reduced biofilm formation and reduced host cell invasion and plaque size, as well as increased resistance to acid shock. This study highlights the importance of c-di-GMP signaling in regulating S. flexneri virulence phenotypes.IMPORTANCEThe intracellular human pathogenShigellacauses dysentery, resulting in as many as one million deaths per year. Currently, there is no approved vaccine for the prevention of shigellosis, and the incidence of antimicrobial resistance amongShigellaspecies is on the rise. Here, we explored how the widely conserved c-di-GMP bacterial signaling system altersShigellabehaviors associated with pathogenesis. We found that expressing or removing enzymes associated with c-di-GMP synthesis results in changes inShigella’s ability to form biofilms, invade host cells, form lesions in host cell monolayers, and resist acid stress.