Effects of Salmonella enterica serovar typhimurium sseK1 on macrophage inflammation-related cytokines and glycolysis

• Published in: Cytokine (Philadelphia, Pa.) Vol. 140; p. 155424
• Main Authors: Lu, Xia, Yu, Chuan, Zhang, Chunjie, Zhang, Hewei, Li, Yinju, Cheng, Xiangchao, Jia, Yanyan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-04-2021
• Subjects: Animals; Bacterial Proteins - metabolism; Cell Line; Cytokines; Cytokines - metabolism; Down-Regulation - physiology; Glycolysis; Glycolysis - physiology; Inflammation - metabolism; Macrophages; Macrophages - metabolism; Mice; RAW 264.7 Cells; S. Typhimurium; Salmonella enterica - metabolism; Salmonella typhimurium - metabolism; Serogroup; SseK1; Glycolysis; Cytokines; SseK1; Macrophages; S. Typhimurium
• ISSN: 1043-4666; 1096-0023
• DOI: 10.1016/j.cyto.2021.155424

•SseK1 can down-regulate the production of IL-1β, IL-2, IL-4, IL-6 and IFN-γ.•SseK1 can inhibit the pro-inflammatory mediator production of NO.•SseK1 can enhance macrophages glycolysis, which may benefit S. Typhimurium survival.
Salmonella enterica serovar Typhimurium (S. Typhimurium), an important virulent intracellular pathogen, causes inflammatory gastroenteritis or typhoid. Macrophages play a key role in innate immunity against Salmonella. Salmonella secreted effector K1 (SseK1) encoded by SPI2 has been identified a novel translocated protein. To investigate the role of Salmonella enterica serovar Typhimurium sseK1 about the inflammation and glycolysis in macrophages, the levels of IL-1β, IL-2, IL-4, IL-6, IFN-γ and Nitric Oxide in macrophages infected by S. Typhimurium SL1344 wild-type (WT) group, ΔsseK1 mutant group and sseK1-complemented group were measured. And the glycolysis level was determined in RAW 264.7 cells infected with these different Salmonella strains. The results showed that groups infected by wild-type strain, sseK1 mutant and sseK1-complemented strain upregulated the production of IL-1β, IL-2, IL-4, IL-6, IFN-γ and NO at 3 h, 6 h and 12 h, respectively. The production of IL-1β, IL-2, IL-4, IL-6, IFN-γ and NO in wild-type strain group were significantly decreased compared with the ΔsseK1 mutant group, which suggested that sseK1 down-regulated the production of related inflammatory factors. Moreover, hexokinase, lactic acid and pyruvic acid levels significantly decreased by infection with sseK1 mutant compared to the wild-type strain. The ATP level of ΔsseK1 mutant group was remarkably increased than WT group and sseK1-complemented group. These indicated that the sseK1 enhanced the level of glycolysis of macrophages infected by S. Typhimurium. In summary, the results demonstrated that sseK1 can down-regulate the inflammation-related cytokines and enhance the glycolysis level in macrophages infected by S. Typhimurium, which may be beneficial for S. typhimurium survival in macrophages.