Functional and pathogenic mechanism of Brucella type IV secretion system effector BPE043
LUO Wen-bo1, 2, FU Meng-jiao2, JIAO Jun2, FENG Jun-xia2, LU Zhi-yu2, HU Xue-yuan3, WEN Bo-hai2, ZHAO Xiao-dong2, XIONG Xiao-lu2, ZHOU Dong-sheng2, KE Yue-hua4
1. Anhui Medical University, Hefei 230032, China; 2. State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China; 3. Hebei Normal University, Shijiazhuang 050024, China; 4. Chinese People’s Liberation Army Center for Disease Control and Prevention, Beijing 100071, China;
Abstract:To study the role of Brucella type IV secretion system effector BPE043 in Brucella infection and intracellular replication, a ΔBPE043 mutant strain of Brucella was constructed by homologous recombination based on Brucella melitensis wild strain 104. Brucella wild strains 104 and mutant strains 104 ΔBPE043 were cultured under the same initial concentration, and their growth rate were observed. Then the mice were infected with wild strain and mutant strain respectively, and the spleen weight of mice was measured and the bacteria load in the spleen was calculated. Co-Immunoprecipitation was used to identify the host target of BPE043. Results showed that the BPE043 deletion mutant of Brucella 104 was successfully constructed. Compared with wildtype strain, the 104 ΔBPE043 exhibited similar growth rate, with slightly different in concentration. In infected mice model, splenomegaly was observed in both 104 and 104 ΔBPE043 infected groups on day 7 post-infection (pi), while the spleen weight of mice infected with the 104 ΔBPE043 was lighter than that of mice infected with 104. In addition, the splenomegaly of both infected groups reduced after day 14 pi. The bacteria load in the spleen of mice infected with 104 ΔBPE043 was lower than that of mice infected with 104 at day 7 pi, and the bacteria load in the spleen of mice infected with the 104 ΔBPE043 reduced sharply after day 14 pi. The results of Co-Immunoprecipitation showed that BPE043 interacts with Rab4 and Rab11(small GTPases from mouse). Our results showed that Brucella type IV secretion system (T4SS) effector BPE043 is a virulence-associated factor of Brucella. This study laid a foundation for further research on the role of BPE043 in brucella infection and intracellular replication.
罗文博, 付梦姣, 焦俊, 冯俊霞, 卢志宇, 胡雪媛, 温博海, 赵晓冬, 熊小路, 周冬生, 柯跃华. 布鲁氏菌IV型分泌系统效应蛋白BPE043的功能和致病机制研究[J]. 中国人兽共患病学报, 2020, 36(8): 618-623.
LUO Wen-bo, FU Meng-jiao, JIAO Jun, FENG Jun-xia, LU Zhi-yu, HU Xue-yuan, WEN Bo-hai, ZHAO Xiao-dong, XIONG Xiao-lu, ZHOU Dong-sheng, KE Yue-hua. Functional and pathogenic mechanism of Brucella type IV secretion system effector BPE043. Chinese Journal of Zoonoses, 2020, 36(8): 618-623.
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