1
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Li S, Fan S, Peng X, Zheng D, Li D. Using ferrous-oxidizing bacteria to enhance the performance of a pH neutral all-iron flow battery. iScience 2024; 27:108595. [PMID: 38174320 PMCID: PMC10762366 DOI: 10.1016/j.isci.2023.108595] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 11/14/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
Among various redox flow batteries (RFBs), the all-iron RFBs have greater application potential due to high accessibility of electrolytes. However, the potential of microaerobic ferrous-oxidizing bacteria (FeOB) to improve the performance of RFB has been neglected. Here, several experiments were conducted using Fe2+-diethylenetriaminepentaacetic acid (DTPA)/Na3[Fe(CN)6] as a redox couple for investigating the enhanced performance by FeOB in this RFB. Results showed that the maximum current density of experimental reactors could achieve 22.56 A/m2 at 0.1 M, whereas power density could still maintain 3.42 W/m2(16.96 A/m2 and 1.58 W/m2 for control group); meantime, the polarization impedance of anode increased slower and Fe2+-DTPA oxidation peak emerged maximum 494 mV negative shift. With increased electrolyte concentration in chronopotentiometry experiments, the experimental reactor achieved higher discharging specific capacity at 0.3 M, 10 mA/cm2. Microbial composition analysis showed maximum 75% is Brucella, indicating Brucella has ferrous-oxidizing electroactivity.
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Affiliation(s)
- Sitao Li
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sen Fan
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
- Collage of Life Sciences, Sichuan University, Chengdu 610041, China
| | - Xinyuan Peng
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
- Collage of Life Sciences, Sichuan University, Chengdu 610041, China
| | - Decong Zheng
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daping Li
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Yang X, Goodwin ZI, Bhagyaraj E, Hoffman C, Pascual DW. Parenteral Vaccination with a Live Brucella melitensis Mutant Protects against Wild-Type B. melitensis 16M Challenge. Microorganisms 2024; 12:169. [PMID: 38257995 PMCID: PMC10820470 DOI: 10.3390/microorganisms12010169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Susceptibility to brucellosis remains prevalent, even in herds vaccinated with conventional vaccines. Efforts are underway to develop an improved brucellosis vaccine, and possibly a universal vaccine, given that Brucella species are highly homologous. To this end, two B. melitensis mutants were developed, znBM-lacZ (znBMZ) and znBM-mCherry (znBM-mC), and were tested for their ability to confer systemic immunity against virulent B. melitensis challenge. To assess the extent of their attenuation, bone-marrow-derived macrophages and human TF-1 myeloid cells were infected with both mutants, and the inability to replicate within these cells was noted. Mice infected with varying doses of znBM-mC cleared the brucellae within 6-10 weeks. To test for efficacy against systemic disease, groups of mice were vaccinated once by the intraperitoneal route with either znBMZ or B. abortus S19 vaccine. Relative to the PBS-dosed mice, znBMZ vaccination greatly reduced splenic brucellae colonization by ~25,000-fold compared to 700-fold for S19-vaccinated mice. Not surprisingly, both znBMZ and S19 strains induced IFN-γ+ CD4+ T cells, yet only znBMZ induced IFN-γ+ CD8+ T cells. While both strains induced CD4+ effector memory T cells (Tems), only znBMZ induced CD8+ Tems. Thus, these results show that the described znBM mutants are safe, able to elicit CD4+ and CD8+ T cell immunity without a boost, and highly effective, rendering them promising vaccine candidates for livestock.
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Affiliation(s)
| | | | | | | | - David W. Pascual
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; (X.Y.); (Z.I.G.); (E.B.); (C.H.)
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3
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Hop HT, Huy TXN, Lee HJ, Kim S. Intracellular growth of Brucella is mediated by Dps-dependent activation of ferritinophagy. EMBO Rep 2023; 24:e55376. [PMID: 37503678 PMCID: PMC10481649 DOI: 10.15252/embr.202255376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023] Open
Abstract
Bacteria of the genus Brucella cause brucellosis, one of the world's most common zoonotic diseases. A major contributor to Brucella's virulence is the ability to circumvent host immune defense mechanisms. Here, we find that the DNA-binding protein Dps from Brucella is secreted within the macrophage cytosol, modulating host iron homeostasis and mediating intracellular growth of Brucella. In addition to dampening iron-dependent production of reactive oxygen species (ROS), a key immune effector required for immediate bacterial clearance, cytosolic Dps mediates ferritinophagy activation to elevate intracellular free-iron levels, thereby promoting Brucella growth and inducing host cell necrosis. Inactivation of the ferritinophagy pathway by Ncoa4 gene knockout significantly inhibits intracellular growth of Brucella and host cell death. Our study uncovers an unconventional role of bacterial Dps, identifying a crucial virulence mechanism used by Brucella to adapt to the harsh environment inside macrophages.
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Affiliation(s)
- Huynh Tan Hop
- University Center for Bioscience and BiotechnologyNational Cheng Kung UniversityTainanTaiwan
| | | | - Hu Jang Lee
- College of Veterinary MedicineGyeongsang National UniversityJinjuKorea
| | - Suk Kim
- College of Veterinary MedicineGyeongsang National UniversityJinjuKorea
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4
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Sun D, Liu Y, Peng X, Dong H, Jiang H, Fan X, Feng Y, Sun J, Han K, Gao Q, Niu J, Ding J. ClpP protease modulates bacterial growth, stress response, and bacterial virulence in Brucella abortus. Vet Res 2023; 54:68. [PMID: 37612737 PMCID: PMC10464072 DOI: 10.1186/s13567-023-01200-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/20/2023] [Indexed: 08/25/2023] Open
Abstract
The process of intracellular proteolysis through ATP-dependent proteases is a biologically conserved phenomenon. The stress responses and bacterial virulence of various pathogenic bacteria are associated with the ATP-dependent Clp protease. In this study, a Brucella abortus 2308 strain, ΔclpP, was constructed to characterize the function of ClpP peptidase. The growth of the ΔclpP mutant strain was significantly impaired in the TSB medium. The results showed that the ΔclpP mutant was sensitive to acidic pH stress, oxidative stress, high temperature, detergents, high osmotic environment, and iron deficient environment. Additionally, the deletion of clpP significantly affected Brucella virulence in macrophage and mouse infection models. Integrated transcriptomic and proteomic analyses of the ΔclpP strain showed that 1965 genes were significantly affected at the mRNA and/or protein levels. The RNA-seq analysis indicated that the ΔclpP strain exhibited distinct gene expression patterns related to energy production and conversion, cell wall/membrane/envelope biogenesis, carbohydrate transport, and metabolism. The iTRAQ analysis revealed that the differentially expressed proteins primarily participated in amino acid transport and metabolism, energy production and conversion, and secondary metabolites biosynthesis, transport and catabolism. This study provided insights into the preliminary molecular mechanism between Clp protease to bacterial growth, stress response, and bacterial virulence in Brucella strains.
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Affiliation(s)
- Dongjie Sun
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yufu Liu
- Zhaoqing Institute Biotechnology Co., Ltd., Zhaoqing, China
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | - Xiaowei Peng
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | - Hao Dong
- Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing, China
| | - Hui Jiang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xuezheng Fan
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yu Feng
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | - Jiali Sun
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | - Kun Han
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qiang Gao
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | | | - Jiabo Ding
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
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5
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Verbeke J, Fayt Y, Martin L, Yilmaz O, Sedzicki J, Reboul A, Jadot M, Renard P, Dehio C, Renard H, Letesson J, De Bolle X, Arnould T. Host cell egress of Brucella abortus requires BNIP3L-mediated mitophagy. EMBO J 2023; 42:e112817. [PMID: 37232029 PMCID: PMC10350838 DOI: 10.15252/embj.2022112817] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
The facultative intracellular pathogen Brucella abortus interacts with several organelles of the host cell to reach its replicative niche inside the endoplasmic reticulum. However, little is known about the interplay between the intracellular bacteria and the host cell mitochondria. Here, we showed that B. abortus triggers substantive mitochondrial network fragmentation, accompanied by mitophagy and the formation of mitochondrial Brucella-containing vacuoles during the late steps of cellular infection. Brucella-induced expression of the mitophagy receptor BNIP3L is essential for these events and relies on the iron-dependent stabilisation of the hypoxia-inducible factor 1α. Functionally, BNIP3L-mediated mitophagy appears to be advantageous for bacterial exit from the host cell as BNIP3L depletion drastically reduces the number of reinfection events. Altogether, these findings highlight the intricate link between Brucella trafficking and the mitochondria during host cell infection.
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Affiliation(s)
- Jérémy Verbeke
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Youri Fayt
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Lisa Martin
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Oya Yilmaz
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | | | - Angéline Reboul
- Research Unit in Microorganisms Biology (URBM)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Michel Jadot
- Research Unit in Molecular Physiology (URPhyM)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Patricia Renard
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | | | - Henri‐François Renard
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Jean‐Jacques Letesson
- Research Unit in Microorganisms Biology (URBM)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Xavier De Bolle
- Research Unit in Microorganisms Biology (URBM)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
| | - Thierry Arnould
- Research Unit in Cell Biology (URBC)—Namur Research Institute for Life Sciences (NARILIS)University of NamurNamurBelgium
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6
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Zhang H, Sun T, Cao X, Wang Y, Ma Z, Wang Y, Yang N, Xu M, Deng X, Li H, Wang B, Yi J, Wang Z, Zhang Q, Chen C. Scanning iron response regulator binding sites using Dap-seq in the Brucella genome. PLoS Negl Trop Dis 2023; 17:e0011481. [PMID: 37459300 PMCID: PMC10374146 DOI: 10.1371/journal.pntd.0011481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 07/27/2023] [Accepted: 06/26/2023] [Indexed: 07/28/2023] Open
Abstract
Iron is an essential element required for all organisms. Iron response regulator (Irr) is a crucial transcriptional regulator and can affect the growth and iron uptake of Brucella. The growth rate of Brucella melitensis M5-90 irr mutant was significantly lower than that of B. melitensis M5-90 under normal or iron-sufficient conditions, however, the growth rate of the B. melitensis M5-90 irr mutant was significantly higher than that of B. melitensis M5-90 under iron-limited conditions. In addition, irr mutation significantly reduced iron uptake under iron-limited conditions. Previous studies suggested that the Irr protein has multiple target genes in the Brucella genome that are involved in iron metabolism. Therefore, in the present study, a Dap-seq approach was used to investigate the other iron metabolism genes that are also regulated by the Irr protein in Brucella. A total of seven genes were identified as target genes for Irr in this study and the expression levels of these seven genes was identified using qRT-PCR. The electrophoretic mobility shift assay confirmed that six out of the seven genes, namely rirA (BME_RS13665), membrane protein (BME_RS01725), hypothetical protein (BME_RS09560), ftrA (BME_RS14525), cation-transporting P-type ATPase (zntA) (BME_RS10660), and 2Fe-2S binding protein (BME_RS13655), interact with the Irr protein. Furthermore, the iron utilization and growth assay experiments confirmed that rirA was involve in iron metabolism and growth of Brucella. In summary, our results identified six genes regulated by the Irr protein that may participate in iron metabolism, and the rirA was identified as a regulon of Irr and it also plays a role in iron metabolism of Brucella. Collectively, these results provide valuable insights for the exploration of Brucella iron metabolism.
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Affiliation(s)
- Huan Zhang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Tianhao Sun
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xudong Cao
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- School of Medicine, HeXi University, Zhangye City, Gansu, China
| | - Yifan Wang
- State key Laboratory of Agricultural Microbiology/College of Veterinary Medicine Huazhong Agricultural University 1 Wuhan, China
| | - Zhongchen Ma
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Yueli Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Ningning Yang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Mingguo Xu
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xiaoyu Deng
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Honghuan Li
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Benben Wang
- School of Life Science, Shihezi University, Shihezi City, Xinjiang, China
| | - Jihai Yi
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Zhen Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Qian Zhang
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agriculture and Reclamation Science,Shihezi, Xinjiang, China
| | - Chuangfu Chen
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
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7
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Zhang G, Dong H, Feng Y, Jiang H, Wu T, Sun J, Wang X, Liu M, Peng X, Zhang Y, Zhang X, Zhu L, Ding J, Shen X. The Pseudogene BMEA_B0173 Deficiency in Brucella melitensis Contributes to M-epitope Formation and Potentiates Virulence in a Mice Infection Model. Curr Microbiol 2022; 79:378. [DOI: 10.1007/s00284-022-03078-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022]
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8
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Borghesan E, Smith EP, Myeni S, Binder K, Knodler LA, Celli J. A Brucella effector modulates the Arf6-Rab8a GTPase cascade to promote intravacuolar replication. EMBO J 2021; 40:e107664. [PMID: 34423453 PMCID: PMC8488576 DOI: 10.15252/embj.2021107664] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 01/15/2023] Open
Abstract
Remodeling of host cellular membrane transport pathways is a common pathogenic trait of many intracellular microbes that is essential to their intravacuolar life cycle and proliferation. The bacterium Brucella abortus generates a host endoplasmic reticulum‐derived vacuole (rBCV) that supports its intracellular growth, via VirB Type IV secretion system‐mediated delivery of effector proteins, whose functions and mode of action are mostly unknown. Here, we show that the effector BspF specifically promotes Brucella replication within rBCVs by interfering with vesicular transport between the trans‐Golgi network (TGN) and recycling endocytic compartment. BspF targeted the recycling endosome, inhibited retrograde traffic to the TGN, and interacted with the Arf6 GTPase‐activating Protein (GAP) ACAP1 to dysregulate Arf6‐/Rab8a‐dependent transport within the recycling endosome, which resulted in accretion of TGN‐associated vesicles by rBCVs and enhanced bacterial growth. Altogether, these findings provide mechanistic insight into bacterial modulation of membrane transport used to promote their own proliferation within intracellular vacuoles.
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Affiliation(s)
- Elizabeth Borghesan
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Erin P Smith
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Sebenzile Myeni
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Kelsey Binder
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Leigh A Knodler
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Jean Celli
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, USA.,Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
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9
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Sun J, Dong H, Peng X, Liu Y, Jiang H, Feng Y, Li Q, Zhu L, Qin Y, Ding J. Deletion of the Transcriptional Regulator MucR in Brucella canis Affects Stress Responses and Bacterial Virulence. Front Vet Sci 2021; 8:650942. [PMID: 34250056 PMCID: PMC8267065 DOI: 10.3389/fvets.2021.650942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
The transcriptional regulator MucR is related to normal growth, stress responses and Brucella virulence, and affects the expression of various virulence-related genes in smooth-type Brucella strains. However, the function of MucR in the rough-type Brucella canis remains unknown. In this study, we discovered that MucR protein was involved in resistance to heat stress, iron-limitation, and various antibiotics in B. canis. In addition, the expression level of various bacterial flagellum-related genes was altered in mucR mutant strain. Deletion of this transcriptional regulator in B. canis significantly affected Brucella virulence in RAW264.7 macrophage and mice infection model. To gain insight into the genetic basis for distinctive phenotypic properties exhibited by mucR mutant strain, RNA-seq was performed and the result showed that various genes involved in translation, ribosomal structure and biogenesis, signal transduction mechanisms, energy production, and conversion were significantly differently expressed in ΔmucR strain. Overall, these studies have not only discovered the phenotype of mucR mutant strain but also preliminarily uncovered the molecular mechanism between the transcriptional regulator MucR, stress response and bacterial virulence in B. canis.
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Affiliation(s)
- Jiali Sun
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Hao Dong
- Veterinary Diagnostic Laboratory, China Animal Disease Control Center, Beijing, China.,Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing, China
| | - Xiaowei Peng
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Yufu Liu
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Hui Jiang
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Yu Feng
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Qiaoling Li
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Liangquan Zhu
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Yuming Qin
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
| | - Jiabo Ding
- National Reference Laboratory for Animal Brucellosis, China Institute of Veterinary Drug Control, Beijing, China
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10
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Comparative proteomic analysis of outer membrane vesicles from Brucella suis, Brucella ovis, Brucella canis and Brucella neotomae. Arch Microbiol 2021; 203:1611-1626. [PMID: 33432377 PMCID: PMC7799404 DOI: 10.1007/s00203-020-02170-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 10/22/2020] [Accepted: 12/27/2020] [Indexed: 01/18/2023]
Abstract
Gram-negative bacteria release nanovesicles, called outer membrane vesicles (OMVs), from their outer membrane. Proteomics has been used to determine their composition. OMVs contain proteins able to elicit an immune response, so they have been proposed as a model to develop acellular vaccines. In this study, OMVs of Brucella suis, B. ovis, B. canis, and B. neotomae were purified and analyzed by SDS-PAGE, transmission electron microscopy and liquid chromatography coupled to mass spectrometry to determine the pan-proteome of these vesicles. In addition, antigenic proteins were detected by western blot with anti-Brucella sera. The in silico analysis of the pan-proteome revealed many homologous proteins, such as Omp16, Omp25, Omp31, SodC, Omp2a, and BhuA. Proteins contained in the vesicles from different Brucella species were detected by anti-Brucella sera. The occurrence of previously described immunogenic proteins derived from OMVs supports the use of these vesicles as candidates to be evaluated as an acellular brucellosis vaccine.
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11
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Liu Y, Dong H, Peng X, Gao Q, Jiang H, Xu G, Qin Y, Niu J, Sun S, Li P, Ding J, Chen R. RNA-seq reveals the critical role of Lon protease in stress response and Brucella virulence. Microb Pathog 2019; 130:112-119. [DOI: 10.1016/j.micpath.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 11/16/2022]
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12
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The Manganese-Dependent Pyruvate Kinase PykM Is Required for Wild-Type Glucose Utilization by Brucella abortus 2308 and Its Virulence in C57BL/6 Mice. J Bacteriol 2018; 200:JB.00471-18. [PMID: 30275278 DOI: 10.1128/jb.00471-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/18/2018] [Indexed: 12/14/2022] Open
Abstract
Pyruvate kinase plays a central role in glucose catabolism in bacteria, and efficient utilization of this hexose has been linked to the virulence of Brucella strains in mice. The brucellae produce a single pyruvate kinase which is an ortholog of the Bradyrhizobium manganese (Mn)-dependent pyruvate kinase PykM. A biochemical analysis of the Brucella pyruvate kinase and phenotypic analysis of a Brucella abortus mutant defective in high-affinity Mn import indicate that this enzyme is an authentic PykM ortholog which functions as a Mn-dependent enzyme in vivo The loss of PykM has a negative impact on the capacity of the parental 2308 strain to utilize glucose, fructose, and galactose but not on its ability to utilize ribose, xylose, arabinose, or erythritol, and a pykM mutant displays significant attenuation in C57BL/6 mice. Although the enzyme pyruvate phosphate dikinase (PpdK) can substitute for the loss of pyruvate kinase in some bacteria and is also an important virulence determinant in Brucella, a phenotypic analysis of B. abortus 2308 and isogenic pykM, ppdK, and pykM ppdK mutants indicates that PykM and PpdK make distinctly different contributions to carbon metabolism and virulence in these bacteria.IMPORTANCE Mn plays a critical role in the physiology and virulence of Brucella strains, and the results presented here suggest that one of the important roles that the high-affinity Mn importer MntH plays in the pathogenesis of these strains is supporting the function of the Mn-dependent kinase PykM. A better understanding of how the brucellae adapt their physiology and metabolism to sustain their intracellular persistence in host macrophages will provide knowledge that can be used to design improved strategies for preventing and treating brucellosis, a disease that has a significant impact on both the veterinary and public health communities worldwide.
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13
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Dong H, Peng X, Liu Y, Wu T, Wang X, De Y, Han T, Yuan L, Ding J, Wang C, Wu Q. BASI74, a Virulence-Related sRNA in Brucella abortus. Front Microbiol 2018; 9:2173. [PMID: 30271397 PMCID: PMC6146029 DOI: 10.3389/fmicb.2018.02173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/24/2018] [Indexed: 11/13/2022] Open
Abstract
Brucella spp. are intracellular pathogens that infect a wide variety of mammals including humans, posing threats to the livestock industry and human health in developing countries. A number of genes associated with the intracellular trafficking and multiplication have so far been identified in Brucella spp. However, the sophisticated post-transcriptional regulation and coordination of gene expression that enable Brucella spp. to adapt to changes in environment and to evade host cell defenses are not fully understood. Bacteria small RNAs (sRNAs) play a significant role in post-transcriptional regulation, which has already been confirmed in a number of bacteria but the role of sRNAs in Brucella remains elusive. In this study, we identified several different sRNAs in Brucella spp., and found that over-expression of a sRNA, tentatively termed BASI74, led to alternation in virulence of Brucella in macrophage infection model. The expression level of BASI74 increased while Brucella abortus 2308 was grown in acidic media. In addition, BASI74 affected the growth ratio of the Brucella cells in minimal media and iron limiting medium. Using a two-plasmid reporter system, we identified four genes as the target of BASI74. One target gene, BABI1154, was predicted to encode a cytosine-N4-specific DNA methyltransferase, which protects cellular DNA from the restriction endonuclease in Brucella. These results show that BASI74 plays an important role in Brucella survival in macrophage infection model, speculatively by its connection with stress response or impact on restriction-modification system. Our study promotes the understanding of Brucella sRNAs, as well as the mechanism by which sRNAs use to influence Brucella physiology and pathogenesis.
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Affiliation(s)
- Hao Dong
- China Animal Disease Control Center, Beijing, China
| | - Xiaowei Peng
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | - Yufu Liu
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China.,College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Tonglei Wu
- Key Laboratory of Preventive Veterinary Medicine of Hebei Province, Hebei Normal University of Science and Technology, Qinhuangdao, China
| | - Xiaolei Wang
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yanyan De
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Tao Han
- China Animal Disease Control Center, Beijing, China
| | - Lin Yuan
- China Animal Disease Control Center, Beijing, China
| | - Jiabo Ding
- Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing, China
| | | | - Qingmin Wu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Budnick JA, Prado-Sanchez E, Caswell CC. Defining the regulatory mechanism of NikR, a nickel-responsive transcriptional regulator, in Brucella abortus. MICROBIOLOGY-SGM 2018; 164:1320-1325. [PMID: 30062985 DOI: 10.1099/mic.0.000702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Metals are essential micronutrients for virtually all forms of life, but metal acquisition is a double-edged sword, because high concentrations of divalent cations can be toxic to the cell. Therefore, the genes involved in metal acquisition, storage and efflux are tightly regulated. The present study characterizes a nickel-responsive transcriptional regulator in the intracellular mammalian pathogen, Brucella abortus. Deletion of bab2_0432 (nikR) in B. abortus led to alterations in the nickel-responsive expression of the genes encoding the putative nickel importer NikABCDE and, moreover, NikR binds directly to a specific DNA sequence within the promoter region of nikA in a metal-dependent manner to control gene expression. While NikR is involved in controlling the expression of nikA, nikR is not required for the infection of macrophages or mice by B. abortus. Overall, this work characterizes the role of NikR in nickel-responsive gene expression, as well as the dispensability of nikR for Brucella virulence.
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Affiliation(s)
- James A Budnick
- Department of Biomedical Sciences and Pathobiology, Center for One Health Research, VA-MD College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24060, USA
| | - Evymarie Prado-Sanchez
- Department of Biomedical Sciences and Pathobiology, Center for One Health Research, VA-MD College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24060, USA
| | - Clayton C Caswell
- Department of Biomedical Sciences and Pathobiology, Center for One Health Research, VA-MD College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24060, USA
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15
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Hop HT, Arayan LT, Huy TXN, Reyes AWB, Baek EJ, Min W, Lee HJ, Rhee MH, Watanabe K, Chang HH, Kim S. Lipocalin 2 (Lcn2) interferes with iron uptake by Brucella abortus and dampens immunoregulation during infection of RAW 264.7 macrophages. Cell Microbiol 2017; 20. [PMID: 29168343 DOI: 10.1111/cmi.12813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 01/19/2023]
Abstract
Lipocalin 2 (Lcn2) is an important innate immunity component against bacterial pathogens. In this study, we report that Lcn2 is induced by Brucella (B.) abortus infection and significantly contributes to the restriction of intracellular survival of Brucella in macrophages. We found that Lcn2 prevented iron uptake by B. abortus through two distinct mechanisms. First, Lcn2 is secreted to capture bacterial siderophore(s) and abrogate iron import by Brucella. Second, Lcn2 decreases the intracellular iron levels during Brucella infection, which probably deprives the invading Brucella of the iron source needed for growth. Suppression of Lcn2 signalling resulted in a marked induction of anti-inflammatory cytokine, interleukin 10, which was shown to play a major role in Lcn2-induced antibrucella immunity. Similarly, interleukin 6 was also found to be increased when Lcn2 signalling is abrogated; however, this induction was thought to be an alternative pathway that rescues the cell from infection when the effective Lnc2 pathway is repressed. Furthermore, Lcn2 deficiency also caused a marked decrease in brucellacidal effectors, such as reactive oxygen species and nitric oxide but not the phagolysosome fusion. Taken together, our results indicate that Lcn2 is required for the efficient restriction of intracellular B. abortus growth that is through limiting iron acquisition and shifting cells to pro-inflammatory brucellacidal activity in murine macrophages.
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Affiliation(s)
- Huynh Tan Hop
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | - Lauren Togonon Arayan
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | - Tran Xuan Ngoc Huy
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | | | - Eun Jin Baek
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | - Wongi Min
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | - Hu Jang Lee
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
| | - Man Hee Rhee
- College of Veterinary Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Kenta Watanabe
- The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Hong Hee Chang
- Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Suk Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea.,Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Republic of Korea
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16
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Zai X, Yang Q, Yin Y, Li R, Qian M, Zhao T, Li Y, Zhang J, Fu L, Xu J, Chen W. Relative Quantitative Proteomic Analysis of Brucella abortus Reveals Metabolic Adaptation to Multiple Environmental Stresses. Front Microbiol 2017; 8:2347. [PMID: 29238329 PMCID: PMC5712581 DOI: 10.3389/fmicb.2017.02347] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/15/2017] [Indexed: 11/19/2022] Open
Abstract
Brucella spp. are facultative intracellular pathogens that cause chronic brucellosis in humans and animals. The virulence of Brucella primarily depends on its successful survival and replication in host cells. During invasion of the host tissue, Brucella is simultaneously subjected to a variety of harsh conditions, including nutrient limitation, low pH, antimicrobial defenses, and extreme levels of reactive oxygen species (ROS) via the host immune response. This suggests that Brucella may be able to regulate its metabolic adaptation in response to the distinct stresses encountered during its intracellular infection of the host. An investigation into the differential proteome expression patterns of Brucella grown under the relevant stress conditions may contribute toward a better understanding of its pathogenesis and adaptive response. Here, we utilized a mass spectrometry-based label-free relative quantitative proteomics approach to investigate and compare global proteomic changes in B. abortus in response to eight different stress treatments. The 3 h short-term in vitro single-stress and multi-stress conditions mimicked the in vivo conditions of B. abortus under intracellular infection, with survival rates ranging from 3.17 to 73.17%. The proteomic analysis identified and quantified a total of 2,272 proteins and 74% of the theoretical proteome, thereby providing wide coverage of the B. abortus proteome. By including eight distinct growth conditions and comparing these with a control condition, we identified a total of 1,221 differentially expressed proteins (DEPs) that were significantly changed under the stress treatments. Pathway analysis revealed that most of the proteins were involved in oxidative phosphorylation, ABC transporters, two-component systems, biosynthesis of secondary metabolites, the citrate cycle, thiamine metabolism, and nitrogen metabolism; constituting major response mechanisms toward the reconstruction of cellular homeostasis and metabolic balance under stress. In conclusion, our results provide a better understanding of the global metabolic adaptations of B. abortus associated with distinct environmental stresses. The identification of proteins necessary for stress resistance is crucial toward elucidating the infectious process in order to control brucellosis, and may facilitate the discovery of novel therapeutic targets and effective vaccines.
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Affiliation(s)
- Xiaodong Zai
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Qiaoling Yang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ruihua Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Mengying Qian
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Taoran Zhao
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yaohui Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ling Fu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
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17
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Hop HT, Arayan LT, Reyes AWB, Huy TXN, Min W, Lee HJ, Son JS, Kim S. Simultaneous RNA-seq based transcriptional profiling of intracellular Brucella abortus and B. abortus-infected murine macrophages. Microb Pathog 2017; 113:57-67. [PMID: 29054743 DOI: 10.1016/j.micpath.2017.10.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 10/15/2017] [Accepted: 10/16/2017] [Indexed: 02/06/2023]
Abstract
Brucella is a zoonotic pathogen that survives within macrophages; however the replicative mechanisms involved are not fully understood. We describe the isolation of sufficient Brucella abortus RNA from primary host cell environment using modified reported methods for RNA-seq analysis, and simultaneously characterize the transcriptional profiles of intracellular B. abortus and bone marrow-derived macrophages (BMM) from BALB/c mice at 24 h (replicative phase) post-infection. Our results revealed that 25.12% (801/3190) and 16.16% (515/3190) of the total B. abortus genes were up-regulated and down-regulated at >2-fold, respectively as compared to the free-living B. abortus. Among >5-fold differentially expressed genes, the up-regulated genes are mostly involved in DNA, RNA manipulations as well as protein biosynthesis and secretion while the down-regulated genes are mainly involved in energy production and metabolism. On the other hand, the host responses during B. abortus infection revealed that 14.01% (6071/43,346) of BMM genes were reproducibly transcribed at >5-fold during infection. Transcription of cytokines, chemokines and transcriptional factors, such as tumor necrosis factor (Tnf), interleukin-1α (Il1α), interleukin-1β (Il1β), interleukin-6 (Il6), interleukin-12 (Il12), chemokine C-X-C motif (CXCL) family, nuclear factor kappa B (Nf-κb), signal transducer and activator of transcription 1 (Stat1), that may contribute to host defense were markedly induced while transcription of various genes involved in cell proliferation and metabolism were suppressed upon B. abortus infection. In conclusion, these data suggest that Brucella modulates gene expression in hostile intracellular environment while simultaneously alters the host pathways that may lead to the pathogen's intracellular survival and infection.
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Affiliation(s)
- Huynh Tan Hop
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Lauren Togonon Arayan
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | | | - Tran Xuan Ngoc Huy
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - WonGi Min
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Hu Jang Lee
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Jee Soo Son
- iNtRON Biotechnology, Inc., Room 903, JungAng Induspia, 137, Sagimakgol-ro, Jungwon-gu, Seongnam, Gyeonggi-do 13202, Republic of Korea
| | - Suk Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea; Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Republic of Korea.
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18
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A dual-targeting approach to inhibit Brucella abortus replication in human cells. Sci Rep 2016; 6:35835. [PMID: 27767061 PMCID: PMC5073326 DOI: 10.1038/srep35835] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022] Open
Abstract
Brucella abortus is an intracellular bacterial pathogen and an etiological agent of the zoonotic disease known as brucellosis. Brucellosis can be challenging to treat with conventional antibiotic therapies and, in some cases, may develop into a debilitating and life-threatening chronic illness. We used multiple independent assays of in vitro metabolism and intracellular replication to screen a library of 480 known bioactive compounds for novel B. abortus anti-infectives. Eighteen non-cytotoxic compounds specifically inhibited B. abortus replication in the intracellular niche, which suggests these molecules function by targeting host cell processes. Twenty-six compounds inhibited B. abortus metabolism in axenic culture, thirteen of which are non-cytotoxic to human host cells and attenuate B. abortus replication in the intracellular niche. The most potent non-cytotoxic inhibitors of intracellular replication reduce B. abortus metabolism in axenic culture and perturb features of mammalian cellular biology including mitochondrial function and receptor tyrosine kinase signaling. The efficacy of these molecules as inhibitors of B. abortus replication in the intracellular niche suggests “dual-target” compounds that coordinately perturb host and pathogen are promising candidates for development of improved therapeutics for intracellular infections.
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19
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Peng X, Dong H, Wu Q. A new cis-encoded sRNA, BsrH, regulating the expression of hemH gene in Brucella abortus 2308. FEMS Microbiol Lett 2014; 362:1-7. [DOI: 10.1093/femsle/fnu017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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20
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Muraille E, Leo O, Moser M. TH1/TH2 paradigm extended: macrophage polarization as an unappreciated pathogen-driven escape mechanism? Front Immunol 2014; 5:603. [PMID: 25505468 PMCID: PMC4244692 DOI: 10.3389/fimmu.2014.00603] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/10/2014] [Indexed: 02/04/2023] Open
Abstract
The classical view of the Th1/Th2 paradigm posits that the pathogen nature, infectious cycle, and persistence represent key parameters controlling the choice of effector mechanisms operating during an immune response. Thus, efficient Th1 responses are triggered by replicating intracellular pathogens, while Th2 responses would control helminth infection and promote tissue repair during the resolution phase of an infectious event. However, this vision does not account for a growing body of data describing how pathogens exploit the polarization of the host immune response to their own benefit. Recently, the study of macrophages has illustrated a novel aspect of this arm race between pathogens and the immune system, and the central role of macrophages in homeostasis, repair and defense of all tissues is now fully appreciated. Like T lymphocytes, macrophages differentiate into distinct effectors including classically (M1) and alternatively (M2) activated macrophages. Interestingly, in addition to represent immune effectors, M1/M2 cells have been shown to represent potential reservoir cells to a wide range of intracellular pathogens. Subversion of macrophage cell metabolism by microbes appears as a recently uncovered immune escape strategy. Upon infection, several microbial agents have been shown to activate host metabolic pathways leading to the production of nutrients necessary to their long-term persistence in host. The purpose of this review is to summarize and discuss the strategies employed by pathogens to manipulate macrophage differentiation, and in particular their basic cell metabolism, to favor their own growth while avoiding immune control.
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Affiliation(s)
- Eric Muraille
- Laboratory of Parasitology, Faculty of Medicine, Université Libre de Bruxelles , Brussels , Belgium
| | - Oberdan Leo
- Laboratory of Immunobiology, Faculty of Sciences, Université Libre de Bruxelles , Gosselies , Belgium
| | - Muriel Moser
- Laboratory of Immunobiology, Faculty of Sciences, Université Libre de Bruxelles , Gosselies , Belgium
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21
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Zhu Y, Wang H, Li X, Hu C, Yang M, Qu J. Characterization of biofilm and corrosion of cast iron pipes in drinking water distribution system with UV/Cl2 disinfection. WATER RESEARCH 2014; 60:174-181. [PMID: 24859195 DOI: 10.1016/j.watres.2014.04.035] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/10/2014] [Accepted: 04/21/2014] [Indexed: 06/03/2023]
Abstract
The effect of UV/Cl2 disinfection on the biofilm and corrosion of cast iron pipes in drinking water distribution system were studied using annular reactors (ARs). Passivation occurred more rapidly in the AR with UV/Cl2 than in the one with Cl2 alone, decreasing iron release for higher corrosivity of water. Based on functional gene, pyrosequencing assays and principal component analysis, UV disinfection not only reduced the required initial chlorine dose, but also enhanced denitrifying functional bacteria advantage in the biofilm of corrosion scales. The nitrate-reducing bacteria (NRB) Dechloromonas exhibited the greatest corrosion inhibition by inducing the redox cycling of iron to enhance the precipitation of iron oxides and formation of Fe3O4 in the AR with UV/Cl2, while the rhizobia Bradyrhizobium and Rhizobium, and the NRB Sphingomonas, Brucella producing siderophores had weaker corrosion-inhibition effect by capturing iron in the AR with Cl2. These results indicated that the microbial redox cycling of iron was possibly responsible for higher corrosion inhibition and lower effect of water Larson-Skold Index (LI) changes on corrosion. This finding could be applied toward the control of water quality in drinking water distribution systems.
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Affiliation(s)
- Ying Zhu
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Haibo Wang
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaoxiao Li
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chun Hu
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Min Yang
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jiuhui Qu
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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22
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Nydam SD, Shah DH, Call DR. Transcriptome analysis of Vibrio parahaemolyticus in type III secretion system 1 inducing conditions. Front Cell Infect Microbiol 2014; 4:1. [PMID: 24478989 PMCID: PMC3895804 DOI: 10.3389/fcimb.2014.00001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/02/2014] [Indexed: 12/16/2022] Open
Abstract
Vibrio parahaemolyticus is an emerging bacterial pathogen capable of causing inflammatory gastroenteritis, wound infections, and septicemia. As a food-borne illness, infection is most frequently associated with the consumption of raw or undercooked seafood, particularly shellfish. It is the primary cause of Vibrio-associated food-borne illness in the United States and the leading cause of food-borne illness in Japan. The larger of its two chromosomes harbors a set of genes encoding type III section system 1 (T3SS1), a virulence factor present in all V. parahaemolyticus strains that is similar to the Yersinia ysc T3SS. T3SS1 translocates effector proteins into eukaryotic cells where they induce changes to cellular physiology and modulate host-pathogen interactions. T3SS1 is also responsible for cytotoxicity toward several different cultured cell lines as well as mortality in a mouse model. Herein we used RNA-seq to obtain global transcriptome patterns of V. parahaemolyticus under conditions that either induce [growth in Dulbecco's Modified Eagle Medium (DMEM) media, in trans expression of transcriptional regulator exsA] or repress T3SS1 expression (growth in LB-S media, in trans exsD expression) and during infection of HeLa cells over time. Comparative transcriptomic analysis demonstrated notable differences in the expression patterns under inducing conditions and was also used to generate an expression profile of V. parahaemolyticus during infection of HeLa cells. In addition, we identified several new genes that are associated with T3SS1 expression and may warrant further study.
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Affiliation(s)
- Seth D Nydam
- Department of Veterinary Microbiology and Pathology, Washington State University Pullman, WA, USA ; Paul G. Allen School for Global Animal Health, Washington State University Pullman, WA, USA
| | - Devendra H Shah
- Department of Veterinary Microbiology and Pathology, Washington State University Pullman, WA, USA ; Paul G. Allen School for Global Animal Health, Washington State University Pullman, WA, USA
| | - Douglas R Call
- Department of Veterinary Microbiology and Pathology, Washington State University Pullman, WA, USA ; Paul G. Allen School for Global Animal Health, Washington State University Pullman, WA, USA
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23
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Herrou J, Crosson S. Molecular structure of the Brucella abortus metalloprotein RicA, a Rab2-binding virulence effector. Biochemistry 2013; 52:9020-8. [PMID: 24251537 DOI: 10.1021/bi401373r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Gram-negative intracellular pathogen Brucella abortus is the causative agent of brucellosis, which is among the most common zoonoses globally. The B. abortus RicA protein binds the host-expressed guanosine nucleotide-binding protein, Rab2, and modulates B. abortus infection biology. We have solved the first X-ray crystal structure of RicA to 2.7 Å resolution and have quantified the affinity of RicA binding to human Rab2 in its GDP-bound and nucleotide-free forms. RicA adopts a classic γ-carbonic anhydrase (γ-CA) fold containing a left-handed β-helix followed by a C-terminal α-helix. Two homotrimers of RicA occupy the crystallographic asymmetric unit. Though no zinc was included in the purification or crystallization buffers, zinc is contained within the RicA crystals, as demonstrated by X-ray fluorescence spectroscopy. Electron density for a Zn(2+) ion coordinated by three histidine residues is evident in the putative active site of RicA. However, purified RicA preparations do not exhibit carbonic anhydrase activity, suggesting that Zn(2+) may not be the physiologically relevant metal cofactor or that RicA is not a bona fide carbonic anhydrase enzyme. Isothermal titration calorimetry (ITC) measurements of purified RicA binding to purified human Rab2 and GDP-Rab2 revealed similar equilibrium affinities (Kd ≈ 35 and 40 μM, respectively). This study thus defines RicA as a Zn(2+)-binding γ-carbonic anhydrase-like protein that binds the human membrane fusion/trafficking protein Rab2 with low micromolar affinity in vitro. These results support a model in which γ-CA family proteins may evolve unique cellular functions while retaining many of the structural hallmarks of archetypal γ-CA enzymes.
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Affiliation(s)
- Julien Herrou
- Department of Biochemistry and Molecular Biology, University of Chicago , Chicago, Illinois 60637, United States
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24
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Dong H, Liu W, Peng X, Jing Z, Wu Q. The effects of MucR on expression of type IV secretion system, quorum sensing system and stress responses in Brucella melitensis. Vet Microbiol 2013; 166:535-42. [PMID: 23932078 DOI: 10.1016/j.vetmic.2013.06.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 06/24/2013] [Accepted: 06/25/2013] [Indexed: 01/21/2023]
Abstract
MucR is a transcriptional regulator in many bacterial pathogens and is required for virulence in mice and macrophages, resistance to stress responses, and modification of the cell envelope in Brucella spp. To determine why the mucR deleted mutant is attenuated in vivo and in vitro, we performed RNA-seq analysis using Brucella melitensis RNA obtained from B. melitensis 16M and 16MΔmucR grown under the same conditions. We found 442 differentially expressed genes; 310 were over expressed, and 132 were less expressed in 16MΔmucR. Many genes identified are involved in metabolism, cell wall/envelope biogenesis, replication, and translation. Notably, genes involved in type IV secretion system and quorum sensing system were down-regulated in 16MΔmucR. In addition, genes involved in tolerance to acid and iron-limitation were also affected and experimentally verified in this study. The effects of MucR on Brucella survival and persistence in mice and macrophages were related to type IV secretion system, quorum sensing system, and stress tolerance, which also provide added insight to the MucR regulon.
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Affiliation(s)
- Hao Dong
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China
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