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Li C, Wang J, Sun W, Liu X, Wang J, Peng Q. The Brucella Effector BspI Suppresses Inflammation via Inhibition of IRE1 Kinase Activity during Brucella Infection. THE JOURNAL OF IMMUNOLOGY 2022; 209:488-497. [DOI: 10.4049/jimmunol.2200001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 05/26/2022] [Indexed: 01/04/2023]
Abstract
Abstract
Mammalian GTPase-activating proteins (GAPs) can inhibit innate immunity signaling in a spatiotemporal fashion; however, the role of bacterial GAPs in mediating innate immunity remains unknown. In this study, we show that BspI, a Brucella type IV secretion system (T4SS) effector protein, containing a GAP domain at the C terminus, negatively regulates proinflammatory responses and host protection to Brucella abotus infection in a mouse model. In macrophages, BspI inhibits the activation of inositol-requiring enzyme 1 (IRE1) kinase, but it does not inhibit activation of ATF6 and PERK. BspI suppresses induction of proinflammatory cytokines via inhibiting the activity of IRE1 kinase caused by VceC, a type IV secretion system effector protein that localizes to the endoplasmic reticulum. Ectopically expressed BspI interacts with IRE1 in HeLa cells. The inhibitory function of BspI depends on its GAP domain but not on interaction with small GTPase Ras-associated binding protein 1B (RAB1B). Collectively, these data support a model where BspI, in a GAP domain–dependent manner, inhibits activation of IRE1 to prevent proinflammatory cytokine responses.
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Affiliation(s)
- Chen Li
- *Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun, China
| | - Jingyu Wang
- *Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun, China
| | - Wanchun Sun
- *Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun, China
| | - Xiaofeng Liu
- †Tumor Hospital of Jilin Province, Changchun, China; and
| | - Jun Wang
- §Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Qisheng Peng
- *Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun, China
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Sauceda-Becerra R, Barrios-García H, Martínez-Burnes J, Arellano-Reynoso B, Benítez-Guzmán A, Hernández-Castro R, Alva-Pérez J. Brucella melitensis invA gene (BME_RS01060) transcription is promoted under acidic stress conditions. Arch Microbiol 2021; 204:52. [DOI: 10.1007/s00203-021-02664-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/08/2021] [Accepted: 10/14/2021] [Indexed: 10/19/2022]
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Liu X, Zhou M, Yang Y, Wu J, Peng Q. Overexpression of Cu-Zn SOD in Brucella abortus suppresses bacterial intracellular replication via down-regulation of Sar1 activity. Oncotarget 2018. [PMID: 29515756 PMCID: PMC5839387 DOI: 10.18632/oncotarget.24073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Brucella Cu-Zn superoxide dismutase (Cu-Zn SOD) is a periplasmic protein, and immunization of mice with recombinant Cu-Zn SOD protein confers protection against Brucella abortus infection. However, the role of Cu-Zn SOD during the process of Brucella infection remains unknown. Here, we report that Cu-Zn SOD is secreted into culture medium and is translocated into host cells independent of type IV secretion systems (T4SS). Furthermore, co-immunoprecipitation and immunofluorescence studies reveal that Brucella abortus Cu-Zn SOD interacts with the small GTPase Sar1. Overexpression of Cu-Zn SOD in Brucella abortus inhibits bacterial intracellular growth by abolishing Sar1 activity in a manner independent of reactive oxygen species (ROS) production.
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Affiliation(s)
- Xiaofeng Liu
- Tumor Hospital of Jilin Province, Changchun 130021, China
| | - Mi Zhou
- Changchun Medical College, Changchun 130031, China
| | - Yanling Yang
- Institute of Special Wild Animal and Plant Science, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Jing Wu
- School of Nursing, Gansu University of Chinese Medicine, Lanzhou 730000, China
| | - Qisheng Peng
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China
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