期刊
CELLULAR MICROBIOLOGY
卷 23, 期 8, 页码 -出版社
WILEY
DOI: 10.1111/cmi.13329
关键词
ABCA1; Akt; cholesterol; FAK; macrophage; Salmonella; SCV; SseJ; T3SS2
资金
- NIH [RO1DK58536]
This study demonstrates that Salmonella enterica serovar Typhimurium uses the T3SS-2 effector SseJ to downregulate the expression of host cholesterol transporter ABCA1 in macrophages, leading to a significant increase in cellular cholesterol and promoting bacterial survival within the cell.
Upon infection of host cells, Salmonella enterica serovar Typhimurium resides in a modified-endosomal compartment referred to as the Salmonella-containing vacuole (SCV). SCV biogenesis is driven by multiple effector proteins translocated through two type III secretion systems (T3SS-1 and T3SS-2). While many host proteins targeted by these effector proteins have been characterised, the role of host lipids in SCV dynamics remains poorly understood. Previous studies have shown that S. Typhimurium infection in macrophages leads to accumulation of intracellular cholesterol, some of which concentrates in and around SCVs; however, the underlying mechanisms remain unknown. Here, we show that S. Typhimurium utilises the T3SS-2 effector SseJ to downregulate expression of the host cholesterol transporter ABCA1 in macrophages, leading to a similar to 45% increase in cellular cholesterol. Mechanistically, SseJ activates a signalling cascade involving the host kinases FAK and Akt to suppress Abca1 expression. Mutational inactivation of SseJ acyltransferase activity, silencing FAK, or inhibiting Akt prevents Abca1 downregulation and the corresponding accumulation of cholesterol during infection. Importantly, RNAI-imediated silencing of ABCA1 rescued bacterial survival in FAK-deficient macrophages, suggesting that Abca1 downregulation and cholesterol accumulation are important for intracellular survival.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据