Intra-macrophage expression of ArtAB toxin gene in Salmonella
Intra-macrophage expression of ArtAB toxin gene in Salmonella
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沙门氏菌 ArtAB 毒素基因的巨噬细胞内表达
DOI：
10.1099/mic.0.001152
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发表时间：
2022
期刊：
影响因子：
1.5
通讯作者：
Uchida Ikuo
中科院分区：
文献类型：
--
作者：
Miura Shou;Satoh Rin;Tamamura-Ando Yukino;Tokugawa Kanetaka;Beppu Miho;Nozaki Chiaru;Murata Ryo;Kusumoto Masahiro;Uchida Ikuo
沙门氏菌（Salmonella entericaserovar Typhimurium）鼠伤寒沙门氏菌（S. Worthington和S. bongori产生ArtAB毒素，其催化百日咳毒素敏感性G蛋白的ADP-核糖基化。ArtAB基因（artAB）编码于沙门氏菌的前噬菌体上，并且通过SOS诱导剂诱导的前噬菌体与体外ArtAB产量的增加相关。然而，对artAB在体内的表达知之甚少。在此，我们发现在巨噬细胞样RAW264.7细胞中DT 104的artAB转录显著增加。免疫荧光染色观察细胞内ArtAB的表达。在DT 104和S.用佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）处理RAW264.7细胞，可刺激活性氧（ROS）的产生，从而增强bongori;然而，在S. Worthington中未观察到这种诱导。在PMA处理的RAW 264.7细胞中观察到氧化应激的主要调节因子foxyR和前噬菌体诱导的抑制因子cI的上调，但在DT 104菌株中未观察到。虽然foxyR的表达增加，但是artAB在邦氏链霉菌中上调，其在不完全的artAB编码的原噬菌体中缺乏I基因。总之，氧化应激在巨噬细胞中artAB毒素的产生中起作用，并且高表达水平的oxyRandcI是artAB低表达的原因。因此，巨噬细胞内artAB表达水平的菌株变异可以通过细菌氧化应激反应的差异来解释，并可能反映在其毒力中。
Salmonella entericasubspeciesentericaserovar Typhimurium (S. Typhimurium) definitive phage type 104 (DT104),S. Worthington, andS. bongoriproduce ArtAB toxin, which catalyses ADP-ribosylation of pertussis toxin-sensitive G protein. ArtAB gene (artAB) is encoded on a prophage inSalmonella, and prophage induction by SOS-inducing agents is associated with increases in ArtAB productionin vitro. However, little is known about the expression ofartAB in vivo. Here, we showed a significant increase inartABtranscription of DT104 within macrophage-like RAW264.7 cells. Intracellular expression of ArtAB was also observed by immunofluorescence staining. The induced expression ofartABin DT104 andS. bongoriwas enhanced by treatment of RAW264.7 cells with phorbol 12-myristate 13-acetate (PMA), which stimulates the production of reactive oxygen species (ROS); however, such induction was not observed inS. Worthington. Upregulation ofoxyR, a major regulator of oxidative stress, andcI,a repressor of prophage induction, was observed inS. Worthington within RAW264.7 cells treated with PMA but not in the DT104 strain. Although the expression ofoxyRwas increased,artABwas upregulated inS. bongori,which lacks thecIgene in the incompleteartAB-encoded prophage. Taken together, oxidative stress plays a role in the production ofartABtoxins in macrophages, and high expression levels ofoxyRandcIare responsible for the low expression ofartAB. Therefore, strain variation in the level ofartABexpression within macrophages could be explained by differences in the oxidative stress response of bacteria and might be reflected in its virulence.