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Cobe BL, Dey S, Minasov G, Inniss N, Satchell KJF, Cianciotto NP. Bactericidal effectors of the Stenotrophomonas maltophilia type IV secretion system: functional definition of the nuclease TfdA and structural determination of TfcB. mBio 2024:e0119824. [PMID: 38832773 DOI: 10.1128/mbio.01198-24] [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: 04/18/2024] [Accepted: 04/28/2024] [Indexed: 06/05/2024] Open
Abstract
Stenotrophomonas maltophilia expresses a type IV protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria and does so partly by secreting the effector TfcB. Here, we report the structure of TfcB, comprising an N-terminal domain similar to the catalytic domain of glycosyl hydrolase (GH-19) chitinases and a C-terminal domain for recognition and translocation by the T4SS. Utilizing a two-hybrid assay to measure effector interactions with the T4SS coupling protein VirD4, we documented the existence of five more T4SS substrates. One of these was protein 20845, an annotated nuclease. A S. maltophilia mutant lacking the gene for 20845 was impaired for killing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Moreover, the cloned 20845 gene conferred robust toxicity, with the recombinant E. coli being rescued when 20845 was co-expressed with its cognate immunity protein. The 20845 effector was an 899 amino-acid protein, comprised of a GHH-nuclease domain in its N-terminus, a large central region of indeterminant function, and a C-terminus for secretion. Engineered variants of the 20845 gene that had mutations in the predicted catalytic site did not impede E. coli, indicating that the antibacterial effect of 20845 involves its nuclease activity. Using flow cytometry with DNA staining, we determined that 20845, but not its mutant variants, confers a loss in DNA content of target bacteria. Database searches revealed that uncharacterized homologs of 20845 occur within a range of bacteria. These data indicate that the S. maltophilia T4SS promotes interbacterial competition through the action of multiple toxic effectors, including a potent, novel DNase.IMPORTANCEStenotrophomonas maltophilia is a multi-drug-resistant, Gram-negative bacterium that is an emerging pathogen of humans. Patients with cystic fibrosis are particularly susceptible to S. maltophilia infection. In hospital water systems and various types of infections, S. maltophilia co-exists with other bacteria, including other pathogens such as Pseudomonas aeruginosa. We previously demonstrated that S. maltophilia has a functional VirB/D4 type VI protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria. Since most work on antibacterial systems involves the type VI secretion system, this observation remains noteworthy. Moreover, S. maltophilia currently stands alone as a model for a human pathogen expressing an antibacterial T4SS. Using biochemical, genetic, and cell biological approaches, we now report both the discovery of a novel antibacterial nuclease (TfdA) and the first structural determination of a bactericidal T4SS effector (TfcB).
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Affiliation(s)
- Brandi L Cobe
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Supratim Dey
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - George Minasov
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Nicole Inniss
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Nicholas P Cianciotto
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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2
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Marchesini MI, Spera JM, Comerci DJ. The 'ins and outs' of Brucella intracellular journey. Curr Opin Microbiol 2024; 78:102427. [PMID: 38309247 DOI: 10.1016/j.mib.2024.102427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/27/2023] [Accepted: 01/04/2024] [Indexed: 02/05/2024]
Abstract
Members of the genus Brucella are the causative agents of brucellosis, a worldwide zoonosis affecting wild and domestic animals and humans. These facultative intracellular pathogens cause long-lasting chronic infections by evolving sophisticated strategies to counteract, evade, or subvert host bactericidal mechanisms in order to establish a secure replicative niche necessary for their survival. In this review, we present recent findings on selected Brucella effectors to illustrate how this pathogen modulates host cell signaling pathways to gain control of the vacuole, promote the formation of a safe intracellular replication niche, alter host cell metabolism to its advantage, and exploit various cellular pathways to ensure egress from the infected cell.
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Affiliation(s)
- María I Marchesini
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Juan M Spera
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Diego J Comerci
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina; Comisión Nacional de Energía Atómica, Grupo Pecuario, Centro Atómico Ezeiza, Buenos Aires, Argentina.
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3
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Bastidas RJ, Kędzior M, Davidson RK, Walsh SC, Dolat L, Sixt BS, Pruneda JN, Coers J, Valdivia RH. The acetylase activity of Cdu1 regulates bacterial exit from infected cells by protecting Chlamydia effectors from degradation. eLife 2024; 12:RP87386. [PMID: 38358795 PMCID: PMC10942603 DOI: 10.7554/elife.87386] [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] [Indexed: 02/16/2024] Open
Abstract
Many cellular processes are regulated by ubiquitin-mediated proteasomal degradation. Pathogens can regulate eukaryotic proteolysis through the delivery of proteins with de-ubiquitinating (DUB) activities. The obligate intracellular pathogen Chlamydia trachomatis secretes Cdu1 (ChlaDUB1), a dual deubiquitinase and Lys-acetyltransferase, that promotes Golgi remodeling and survival of infected host cells presumably by regulating the ubiquitination of host and bacterial proteins. Here, we determined that Cdu1's acetylase but not its DUB activity is important to protect Cdu1 from ubiquitin-mediated degradation. We further identified three C. trachomatis proteins on the pathogen-containing vacuole (InaC, IpaM, and CTL0480) that required Cdu1's acetylase activity for protection from degradation and determined that Cdu1 and these Cdu1-protected proteins are required for optimal egress of Chlamydia from host cells. These findings highlight a non-canonical mechanism of pathogen-mediated protection of virulence factors from degradation after their delivery into host cells and the coordinated regulation of secreted effector proteins.
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Affiliation(s)
- Robert J Bastidas
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Mateusz Kędzior
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Robert K Davidson
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Stephen C Walsh
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Lee Dolat
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Barbara S Sixt
- Deparment of Molecular Biology, Umeå UniversityUmeåSweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå UniversityUmeåSweden
- Umeå Centre for Microbial Research (UCMR), Umeå UniversityUmeåSweden
| | - Jonathan N Pruneda
- Department of Molecular Microbiology & Immunology, Oregon Health & Science UniversityPortlandUnited States
| | - Jorn Coers
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Raphael H Valdivia
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
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4
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Joshi K, Mazumdar V, Nandi BR, Radhakrishnan GK. Brucella targets the host ubiquitin-specific protease, Usp8, through the effector protein, TcpB, for facilitating infection of macrophages. Infect Immun 2024; 92:e0028923. [PMID: 38174929 PMCID: PMC10863413 DOI: 10.1128/iai.00289-23] [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: 07/26/2023] [Accepted: 11/12/2023] [Indexed: 01/05/2024] Open
Abstract
Brucella species are Gram-negative intracellular bacterial pathogens that cause the worldwide zoonotic disease brucellosis. Brucella can infect many mammals, including humans and domestic and wild animals. Brucella manipulates various host cellular processes to invade and multiply in professional and non-professional phagocytic cells. However, the host targets and their modulation by Brucella to facilitate the infection process remain obscure. Here, we report that the host ubiquitin-specific protease, USP8, negatively regulates the invasion of Brucella into macrophages through the plasma membrane receptor, CXCR4. Upon silencing or chemical inhibition of USP8, the membrane localization of the CXCR4 receptor was enriched, which augmented the invasion of Brucella into macrophages. Activation of USP8 through chemical inhibition of 14-3-3 protein affected the invasion of Brucella into macrophages. Brucella suppressed the expression of Usp8 at its early stage of infection in the infected macrophages. Furthermore, we found that only live Brucella could negatively regulate the expression of Usp8, suggesting the role of secreted effector protein of Brucella in modulating the gene expression. Subsequent studies revealed that the Brucella effector protein, TIR-domain containing protein from Brucella, TcpB, plays a significant role in downregulating the expression of Usp8 by targeting the cyclic-AMP response element-binding protein pathway. Treatment of mice with USP8 inhibitor resulted in enhanced survival of B. melitensis, whereas mice treated with CXCR4 or 14-3-3 antagonists showed a diminished bacterial load. Our experimental data demonstrate a novel role of Usp8 in the host defense against microbial intrusion. The present study provides insights into the microbial subversion of host defenses, and this information may ultimately help to develop novel therapeutic interventions for infectious diseases.
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Affiliation(s)
- Kiranmai Joshi
- Laboratory of Immunology and Microbial Pathogenesis, National Institute of Animal Biotechnology (NIAB), Hyderabad, Telangana, India
- Regional Centre for Biotechnology (RCB), Faridabad, India
| | - Varadendra Mazumdar
- Laboratory of Immunology and Microbial Pathogenesis, National Institute of Animal Biotechnology (NIAB), Hyderabad, Telangana, India
- Regional Centre for Biotechnology (RCB), Faridabad, India
| | - Binita Roy Nandi
- Laboratory of Immunology and Microbial Pathogenesis, National Institute of Animal Biotechnology (NIAB), Hyderabad, Telangana, India
- Regional Centre for Biotechnology (RCB), Faridabad, India
| | - Girish K. Radhakrishnan
- Laboratory of Immunology and Microbial Pathogenesis, National Institute of Animal Biotechnology (NIAB), Hyderabad, Telangana, India
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5
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Zheng M, Lin R, Zhu J, Dong Q, Chen J, Jiang P, Zhang H, Liu J, Chen Z. Effector Proteins of Type IV Secretion System: Weapons of Brucella Used to Fight Against Host Immunity. Curr Stem Cell Res Ther 2024; 19:145-153. [PMID: 36809969 DOI: 10.2174/1574888x18666230222124529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 11/15/2022] [Accepted: 12/29/2022] [Indexed: 02/24/2023]
Abstract
Brucella is an intracellular bacterial pathogen capable of long-term persistence in the host, resulting in chronic infections in livestock and wildlife. The type IV secretion system (T4SS) is an important virulence factor of Brucella and is composed of 12 protein complexes encoded by the VirB operon. T4SS exerts its function through its secreted 15 effector proteins. The effector proteins act on important signaling pathways in host cells, inducing host immune responses and promoting the survival and replication of Brucella in host cells to promote persistent infection. In this article, we describe the intracellular circulation of Brucella-infected cells and survey the role of Brucella VirB T4SS in regulating inflammatory responses and suppressing host immune responses during infection. In addition, the important mechanisms of these 15 effector proteins in resisting the host immune response during Brucella infection are elucidated. For example, VceC and VceA assist in achieving sustained survival of Brucella in host cells by affecting autophagy and apoptosis. BtpB, together with BtpA, controls the activation of dendritic cells during infection, induces inflammatory responses, and controls host immunity. This article reviews the effector proteins secreted by Brucella T4SS and their involvement in immune responses, which can provide a reliable theoretical basis for the subsequent mechanism of hijacking the host cell signaling pathway by bacteria and contribute to the development of better vaccines to effectively treat Brucella bacterial infection.
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Affiliation(s)
- Min Zheng
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Ruiqi Lin
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Jinying Zhu
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Qiao Dong
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Jingjing Chen
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Pengfei Jiang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Huan Zhang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Jinling Liu
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
| | - Zeliang Chen
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China
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6
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Bastidas RJ, Kędzior M, Davidson RK, Walsh SC, Dolat L, Sixt BS, Pruneda JN, Coers J, Valdivia RH. The acetylase activity of Cdu1 regulates bacterial exit from infected cells by protecting Chlamydia effectors from degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.28.530337. [PMID: 36909574 PMCID: PMC10002621 DOI: 10.1101/2023.02.28.530337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Many cellular processes are regulated by ubiquitin-mediated proteasomal degradation. Pathogens can regulate eukaryotic proteolysis through the delivery of proteins with de-ubiquitinating (DUB) activities. The obligate intracellular pathogen Chlamydia trachomatis secretes Cdu1 (ChlaDUB1), a dual deubiquitinase and Lys-acetyltransferase, that promotes Golgi remodeling and survival of infected host cells presumably by regulating the ubiquitination of host and bacterial proteins. Here we determined that Cdu1's acetylase but not its DUB activity is important to protect Cdu1 from ubiquitin-mediated degradation. We further identified three C. trachomatis proteins on the pathogen-containing vacuole (InaC, IpaM, and CTL0480) that required Cdu1's acetylase activity for protection from degradation and determined that Cdu1 and these Cdu1-protected proteins are required for optimal egress of Chlamydia from host cells. These findings highlight a non-canonical mechanism of pathogen-mediated protection of virulence factors from degradation after their delivery into host cells and the coordinated regulation of secreted effector proteins.
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Affiliation(s)
- Robert J. Bastidas
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Mateusz Kędzior
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Robert K. Davidson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Stephen C. Walsh
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Lee Dolat
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Barbara S. Sixt
- Deparment of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Jonathan N. Pruneda
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jörn Coers
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Raphael H. Valdivia
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
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7
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Lin R, Li A, Li Y, Shen R, Du F, Zheng M, Zhu J, Chen J, Jiang P, Zhang H, Liu J, Chen X, Chen Z. The Brucella Effector Protein BspF Regulates Apoptosis through the Crotonylation of p53. Microorganisms 2023; 11:2322. [PMID: 37764165 PMCID: PMC10534853 DOI: 10.3390/microorganisms11092322] [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: 08/09/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
The Brucella type IV secretion system (T4SS) can promote the intracellular survival and reproduction of Brucella. T4SS secretes effector proteins to act on cellular signaling pathways to inhibit the host's innate immune response and cause a chronic, persistent Brucella infection. Brucella can survive in host cells for a long time by inhibiting macrophage apoptosis and avoiding immune recognition. The effector protein, BspF, secreted by T4SS, can regulate host secretory transport and accelerate the intracellular replication of Brucella. BspF has an acetyltransferase domain of the GNAT (GCN5-related N-acetyltransferases) family, and in our previous crotonylation proteomics data, we have found that BspF has crotonyl transferase activity and crotonylation regulation of host cell protein in the proteomics data. Here, we found that BspF attenuates the crotonylation modification of the interacting protein p53, which reduces the p53 expression through the GNAT domain. BspF can inhibit the transcription and protein expression of downstream apoptotic genes, thereby inhibiting host cell apoptosis. Additionally, the Brucella ΔbspF mutant stain promotes apoptosis and reduces the survival rate of Brucella in the cells. In conclusion, we identified that the T4SS effector protein BspF can regulate host cell apoptosis to assist Brucella in its long-term survival by attenuating crotonylation modification of p53 and decreasing p53 expression. Our findings reveal a unique mechanism of elucidating how Brucella regulates host cell apoptosis and promotes its proliferation through the secretion of effector proteins.
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Affiliation(s)
- Ruiqi Lin
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Ang Li
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Yuzhuo Li
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Ruitong Shen
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Fangyuan Du
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Min Zheng
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Jinying Zhu
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Jingjing Chen
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Pengfei Jiang
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Huan Zhang
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Jinling Liu
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Xiaoyue Chen
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Zeliang Chen
- Key Laboratory of Livestock Infectious Disease, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; (R.L.); (A.L.); (R.S.); (F.D.); (M.Z.); (J.Z.); (J.C.); (P.J.); (J.L.); (X.C.)
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510275, China
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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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9
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Kambarev S, Borghesan E, Miller CN, Myeni S, Celli J. The Brucella abortus Type IV Effector BspA Inhibits MARCH6-Dependent ERAD To Promote Intracellular Growth. Infect Immun 2023; 91:e0013023. [PMID: 37129527 PMCID: PMC10187129 DOI: 10.1128/iai.00130-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 05/03/2023] Open
Abstract
Brucella abortus, the intracellular causative agent of brucellosis, relies on type IV secretion system (T4SS) effector-mediated modulation of host cell functions to establish a replicative niche, the Brucella-containing vacuole (BCV). Brucella exploits the host's endocytic, secretory, and autophagic pathways to modulate the nature and function of its vacuole from an endocytic BCV (eBCV) to an endoplasmic reticulum (ER)-derived replicative BCV (rBCV) to an autophagic egress BCV (aBCV). A role for the host ER-associated degradation pathway (ERAD) in the B. abortus intracellular cycle was recently uncovered, as it is enhanced by the T4SS effector BspL to control the timing of aBCV-mediated egress. Here, we show that the T4SS effector BspA also interferes with ERAD, yet to promote B. abortus intracellular proliferation. BspA was required for B. abortus replication in bone marrow-derived macrophages and interacts with membrane-associated RING-CH-type finger 6 (MARCH6), a host E3 ubiquitin ligase involved in ERAD. Pharmacological inhibition of ERAD and small interfering RNA (siRNA) depletion of MARCH6 did not affect the replication of wild-type B. abortus but rescued the replication defect of a bspA deletion mutant, while depletion of the ERAD component UbxD8 affected replication of B. abortus and rescued the replication defect of the bspA mutant. BspA affected the degradation of ERAD substrates and destabilized the MARCH6 E3 ligase complex. Taken together, these findings indicate that BspA inhibits the host ERAD pathway via targeting of MARCH6 to promote B. abortus intracellular growth. Our data reveal that targeting ERAD components by type IV effectors emerges as a multifaceted theme in Brucella pathogenesis.
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Affiliation(s)
- Stanimir Kambarev
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
| | - Elizabeth Borghesan
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
| | - Cheryl N. Miller
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
| | - Sebenzile Myeni
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Jean Celli
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
- Department of Microbiology and Molecular Genetics, Larner College of Medicine at the University of Vermont, Burlington, Vermont, USA
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10
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Karimitabar Z, Chegini Z, Shokoohizadeh L, Moez NM, Arabestani MR, Hosseini SM. Use of the quantum dot-labeled solid lipid nanoparticles for delivery of streptomycin and hydroxychloroquine: A new therapeutic approach for treatment of intracellular Brucella abortus infection. Biomed Pharmacother 2023; 158:114116. [PMID: 36527846 DOI: 10.1016/j.biopha.2022.114116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/19/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Brucellosis is considered one of the most important infectious diseases affecting any tissue and organ in the human body. Due to the intracellular pathogenesis of Brucella species, the use of conventional antibiotics for managing chronic brucellosis has several limitations. Therefore, the study focused on the use of solid lipid nanoparticles (SLN) to deliver streptomycin (STR) for intracellular infection, with or without the combination of hydroxychloroquine (HCQ) to evaluate if there might be a boost in the antibiotic effect when using the STR or STR-NPs alone. We used the double emulsion technique to synthesize Nano drug carriers; afterward, the physicochemical characteristics of synthesized Nano drug carriers were determined. The in vitro antibacterial activity of free drugs and Nano drug carriers were evaluated using well diffusion, broth microdilution assays (BMD), and murine macrophage-like cells cell line J774A.1. Additionally, acute and chronic phases of brucellosis were inducted into Wistar rats, and healing capacity of Nano drug carriers on liver and spleen tissues was compared with free drugs. The zeta potential of nanoparticles, means of size, Polydispersity Index (PDI), drugs loading, and encapsulation efficiency were 15.2 mV, 312.5 ± 26 nm, 0.433 ± 0.09, 16.6% and 89.5%, respectively. Well diffusion and BMD methods did not show a significantly differ between free drugs and nano drug carriers. However, the Nano drug carriers remarkably decreased the number of bacteria in the cell line compared to the free drugs. STR/HCQ-SLN enhanced the healing processes of the liver and spleen after brucellosis induction. STR/HCQ-SLN showed better inhibitory effects against the chronic phase of B. abortus infection in comparison to the STR-SLN, but this difference was not statistically significant. Using nanoplatforms to enhance conventional anti-brucellosis agents is promising, green and safe. Due to the continuous release of drugs, drugs increase their accumulation at the site of infection, causing a more significant effect on the chronic and acute phases of brucellosis.
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Affiliation(s)
- Zahra Karimitabar
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Zahra Chegini
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Leili Shokoohizadeh
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Narjes Morovati Moez
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Reza Arabestani
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Seyed Mostafa Hosseini
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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11
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Guo J, Deng X, Zhang Y, Song S, Zhao T, Zhu D, Cao S, Baryshnikov PI, Cao G, Blair HT, Chen C, Gu X, Liu L, Zhang H. The Flagellar Transcriptional Regulator FtcR Controls Brucella melitensis 16M Biofilm Formation via a betI-Mediated Pathway in Response to Hyperosmotic Stress. Int J Mol Sci 2022; 23:ijms23179905. [PMID: 36077302 PMCID: PMC9456535 DOI: 10.3390/ijms23179905] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022] Open
Abstract
The expression of flagellar proteins in Brucella species likely evolved through genetic transference from other microorganisms, and contributed to virulence, adaptability, and biofilm formation. Despite significant progress in defining the molecular mechanisms behind flagellar gene expression, the genetic program controlling biofilm formation remains unclear. The flagellar transcriptional factor (FtcR) is a master regulator of the flagellar system’s expression, and is critical for B. melitensis 16M’s flagellar biogenesis and virulence. Here, we demonstrate that FtcR mediates biofilm formation under hyperosmotic stress. Chromatin immunoprecipitation with next-generation sequencing for FtcR and RNA sequencing of ftcR-mutant and wild-type strains revealed a core set of FtcR target genes. We identified a novel FtcR-binding site in the promoter region of the osmotic-stress-response regulator gene betI, which is important for the survival of B. melitensis 16M under hyperosmotic stress. Strikingly, this site autoregulates its expression to benefit biofilm bacteria’s survival under hyperosmotic stress. Moreover, biofilm reduction in ftcR mutants is independent of the flagellar target gene fliF. Collectively, our study provides new insights into the extent and functionality of flagellar-related transcriptional networks in biofilm formation, and presents phenotypic and evolutionary adaptations that alter the regulation of B. melitensis 16M to confer increased tolerance to hyperosmotic stress.
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Affiliation(s)
- Jia Guo
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Xingmei Deng
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Yu Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Shengnan Song
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Tianyi Zhao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Dexin Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Shuzhu Cao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Peter Ivanovic Baryshnikov
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- College of Veterinary, Altai State Agricultural University, 656000 Barnaul, Russia
| | - Gang Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430000, China
| | - Hugh T. Blair
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- International Sheep Research Center, School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand
| | - Chuangfu Chen
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Xinli Gu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Liangbo Liu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- Correspondence: (L.L.); (H.Z.); Tel.: +86-0993-2057971 (L.L. & H.Z.)
| | - Hui Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- Correspondence: (L.L.); (H.Z.); Tel.: +86-0993-2057971 (L.L. & H.Z.)
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12
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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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13
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Hosseini SM, Farmany A, Alikhani MY, Taheri M, Asl SS, Alamian S, Arabestani MR. Co-Delivery of Doxycycline and Hydroxychloroquine Using CdTe-Labeled Solid Lipid Nanoparticles for Treatment of Acute and Chronic Brucellosis. Front Chem 2022; 10:890252. [PMID: 35646816 PMCID: PMC9130827 DOI: 10.3389/fchem.2022.890252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 04/07/2022] [Indexed: 12/15/2022] Open
Abstract
Brucellosis is a systemic disease in both acute and chronic forms which can affect any organ or tissue in the body. One of the biggest issues in treating this disease is its relapse. In this study, a complete treatment of brucellosis was evaluated using enhanced performance of doxycycline and hydroxychloroquine drugs by using solid lipid nanoparticles (SLN) conjugated cadmium-telluride quantum dots. The double emulsion method was used to prepare SLN and cadmium-telluride quantum dots. The physicochemical properties of NPs were determined. The effect of nanoparticle-loaded antibiotics against Brucella melitensis was determined by well diffusion, minimum inhibitory concentration (MIC), cell culture, and animal studies. The means of particle size, PDI, zeta potential, drugs loading, and encapsulation efficiency were 214 ± 25 nm, 0.385 ± 0.022, −18.7 ± 2.3 mV, 17.7 ± 1.5%, and 94.15 ± 2.6%, respectively. The results of FTIR and DSC showed that no chemical reaction occurred between the components of the NPs. The effect of free drug and NPs on bacteria was the same by well diffusion and MIC method. Drug-loaded NPs significantly reduced the number of CFUs in the cell line and acute and chronic brucellosis compared to the free drug. In conclusion, the synthesized nanoparticles were safe and green. With the slow release of the drug (100 h), the accumulation of the drug at the bacterial site increases and causes a greater effect on the B. melitensis and improves the disease of brucellosis. The use of synthesized nanodrugs in this study had promising therapeutic results.
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Affiliation(s)
- Seyed Mostafa Hosseini
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abbas Farmany
- Dental Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Yousef Alikhani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Taheri
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Sara Soleimani Asl
- Department of Anatomical Sciences, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Saeed Alamian
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Mohammad Reza Arabestani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Brucellosis Research Center, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- *Correspondence: Mohammad Reza Arabestani,
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14
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Xiong X, Li B, Zhou Z, Gu G, Li M, Liu J, Jiao H. The VirB System Plays a Crucial Role in Brucella Intracellular Infection. Int J Mol Sci 2021; 22:ijms222413637. [PMID: 34948430 PMCID: PMC8707931 DOI: 10.3390/ijms222413637] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/09/2021] [Accepted: 12/15/2021] [Indexed: 01/18/2023] Open
Abstract
Brucellosis is a highly prevalent zoonotic disease caused by Brucella. Brucella spp. are gram-negative facultative intracellular parasitic bacteria. Its intracellular survival and replication depend on a functional virB system, an operon encoded by VirB1–VirB12. Type IV secretion system (T4SS) encoded by the virB operon is an important virulence factor of Brucella. It can subvert cellular pathway and induce host immune response by secreting effectors, which promotes Brucella replication in host cells and induce persistent infection. Therefore, this paper summarizes the function and significance of the VirB system, focusing on the structure of the VirB system where VirB T4SS mediates biogenesis of the endoplasmic reticulum (ER)-derived replicative Brucella-containing vacuole (rBCV), the effectors of T4SS and the cellular pathways it subverts, which will help better understand the pathogenic mechanism of Brucella and provide new ideas for clinical vaccine research and development.
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Affiliation(s)
- Xue Xiong
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
| | - Bowen Li
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
| | - Zhixiong Zhou
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
| | - Guojing Gu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
| | - Mengjuan Li
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
| | - Jun Liu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Yujinxiang Street 573, Changchun 130122, China
- Correspondence: (J.L.); (H.J.)
| | - Hanwei Jiao
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (X.X.); (B.L.); (Z.Z.); (G.G.); (M.L.)
- National Center of Technology Innovation for Pigs, Chongqing 402460, China
- Veterinary Scientific Engineering Research Center, Chongqing 402460, China
- Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, China
- Correspondence: (J.L.); (H.J.)
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15
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Vaughn B, Abu Kwaik Y. Idiosyncratic Biogenesis of Intracellular Pathogens-Containing Vacuoles. Front Cell Infect Microbiol 2021; 11:722433. [PMID: 34858868 PMCID: PMC8632064 DOI: 10.3389/fcimb.2021.722433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
While most bacterial species taken up by macrophages are degraded through processing of the bacteria-containing vacuole through the endosomal-lysosomal degradation pathway, intravacuolar pathogens have evolved to evade degradation through the endosomal-lysosomal pathway. All intra-vacuolar pathogens possess specialized secretion systems (T3SS-T7SS) that inject effector proteins into the host cell cytosol to modulate myriad of host cell processes and remodel their vacuoles into proliferative niches. Although intravacuolar pathogens utilize similar secretion systems to interfere with their vacuole biogenesis, each pathogen has evolved a unique toolbox of protein effectors injected into the host cell to interact with, and modulate, distinct host cell targets. Thus, intravacuolar pathogens have evolved clear idiosyncrasies in their interference with their vacuole biogenesis to generate a unique intravacuolar niche suitable for their own proliferation. While there has been a quantum leap in our knowledge of modulation of phagosome biogenesis by intravacuolar pathogens, the detailed biochemical and cellular processes affected remain to be deciphered. Here we discuss how the intravacuolar bacterial pathogens Salmonella, Chlamydia, Mycobacteria, Legionella, Brucella, Coxiella, and Anaplasma utilize their unique set of effectors injected into the host cell to interfere with endocytic, exocytic, and ER-to-Golgi vesicle traffic. However, Coxiella is the main exception for a bacterial pathogen that proliferates within the hydrolytic lysosomal compartment, but its T4SS is essential for adaptation and proliferation within the lysosomal-like vacuole.
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Affiliation(s)
- Bethany Vaughn
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY, United States
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16
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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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17
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Effectors of the Stenotrophomonas maltophilia Type IV Secretion System Mediate Killing of Clinical Isolates of Pseudomonas aeruginosa. mBio 2021; 12:e0150221. [PMID: 34182776 PMCID: PMC8262851 DOI: 10.1128/mbio.01502-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Previously, we documented that Stenotrophomonas maltophilia encodes a type IV secretion system (T4SS) that allows the organism to kill, in contact-dependent fashion, heterologous bacteria, including wild-type Pseudomonas aeruginosa. Bioinformatic screens based largely on the presence of both a C-terminal consensus sequence and an adjacent gene encoding a cognate immunity protein identified 13 potential antibacterial effectors, most of which were highly conserved among sequenced strains of S. maltophilia. The immunity proteins of two of these proved especially capable of protecting P. aeruginosa and Escherichia coli against attack from the Stenotrophomonas T4SS. In turn, S. maltophilia mutants lacking the putative effectors RS14245 and RS14255 were impaired for killing not only laboratory E. coli but clinical isolates of P. aeruginosa, including ones isolated from the lungs of cystic fibrosis patients. That complemented mutants behaved as wild type did confirmed that RS14245 and RS14255 are required for the bactericidal activity of the S. maltophilia T4SS. Moreover, a mutant lacking both of these proteins was as impaired as a mutant lacking the T4SS apparatus, indicating that RS14245 and RS14255 account for (nearly) all of the bactericidal effects seen. Utilizing an interbacterial protein translocation assay, we determined that RS14245 and RS14255 are bona fide substrates of the T4SS, a result confirmed by examination of mutants lacking both the T4SS and the individual effectors. Delivery of the cloned 14245 protein (alone) into the periplasm resulted in the killing of target bacteria, indicating that this effector, a putative lipase, is both necessary and sufficient for bactericidal activity.
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18
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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19
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González-Espinoza G, Arce-Gorvel V, Mémet S, Gorvel JP. Brucella: Reservoirs and Niches in Animals and Humans. Pathogens 2021; 10:pathogens10020186. [PMID: 33572264 PMCID: PMC7915599 DOI: 10.3390/pathogens10020186] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 01/18/2023] Open
Abstract
Brucella is an intracellular bacterium that causes abortion, reproduction failure in livestock and leads to a debilitating flu-like illness with serious chronic complications if untreated in humans. As a successful intracellular pathogen, Brucella has developed strategies to avoid recognition by the immune system of the host and promote its survival and replication. In vivo, Brucellae reside mostly within phagocytes and other cells including trophoblasts, where they establish a preferred replicative niche inside the endoplasmic reticulum. This process is central as it gives Brucella the ability to maintain replicating-surviving cycles for long periods of time, even at low bacterial numbers, in its cellular niches. In this review, we propose that Brucella takes advantage of the environment provided by the cellular niches in which it resides to generate reservoirs and disseminate to other organs. We will discuss how the favored cellular niches for Brucella infection in the host give rise to anatomical reservoirs that may lead to chronic infections or persistence in asymptomatic subjects, and which may be considered as a threat for further contamination. A special emphasis will be put on bone marrow, lymph nodes, reproductive and for the first time adipose tissues, as well as wildlife reservoirs.
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