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目的评估宿主与病原体相互作用中铁代谢的作用。方法用荧光定量PCR法检测感染及未感染鼠伤寒沙门菌的鼠RAW264.7巨噬细胞13种铁代谢相关基因的表达。结果活的野生型鼠伤寒沙门菌感染巨噬细胞1h或24h后可诱导转铁蛋白受体(Tfr1)的表达,引起细胞内动态铁池持续上涨。基因表达分析显示野生型鼠伤寒沙门菌通过诱导铁氧还原酶(Steap3)、铁膜转运蛋白(Dmt1)、铁调节蛋白(Irp1和Irp2)的表达主动吸收铁,而经铁转运蛋白(Fpn1)的铁外流并无明显改变。用鼠伤寒沙门菌spiC-突变株感染巨噬细胞1h或24h后并未引起Tfr1 mRNA水平增高,而Fpn1 mRNA水平在感染24h时要高于感染1h时,提示spiC-突变株感染24h后动态铁池下降。结论野生型沙门菌在感染1h或24h后积极地驱动了转铁蛋白介导的铁吸收程序。本研究使用的spiC-突变株感染细胞24h后铁外流高于感染1h时。
Objective To assess the role of iron metabolism in host-pathogen interactions. Methods The expression of 13 iron-related genes in murine RAW264.7 macrophages infected and non-infected with Salmonella typhimurium was detected by real-time fluorescence quantitative PCR. Results The live wild-type Salmonella typhimurium infection of macrophages induced the expression of transferrin receptor (Tfr1) 1 h or 24 h, which resulted in the continuous increase of intracellular dynamic iron pool. Gene expression analysis showed that wild-type Salmonella typhimurium actively absorbed iron through the induction of the expression of Steap3, Dmt1 and Irp1, whereas the expression of Fpn1 The iron outflow did not change significantly. Infection of macrophages with Salmonella typhimurium spiC-mutant for 1 or 24 hours did not result in an increase in Tfr1 mRNA levels, whereas Fpn1 mRNA levels were higher at 24h and 24 hours after infection, suggesting that the dynamic iron content of spiC- Pool drops. Conclusions Wild-type Salmonella actively drives transferrin-mediated iron uptake processes 1 h or 24 h after infection. The spiC mutant used in this study infected cells 24h after iron efflux higher than 1h infection.