1
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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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2
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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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3
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Manik MK, Shi Y, Li S, Zaydman MA, Damaraju N, Eastman S, Smith TG, Gu W, Masic V, Mosaiab T, Weagley JS, Hancock SJ, Vasquez E, Hartley-Tassell L, Kargios N, Maruta N, Lim BYJ, Burdett H, Landsberg MJ, Schembri MA, Prokes I, Song L, Grant M, DiAntonio A, Nanson JD, Guo M, Milbrandt J, Ve T, Kobe B. Cyclic ADP ribose isomers: Production, chemical structures, and immune signaling. Science 2022; 377:eadc8969. [PMID: 36048923 DOI: 10.1126/science.adc8969] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cyclic adenosine diphosphate (ADP)-ribose (cADPR) isomers are signaling molecules produced by bacterial and plant Toll/interleukin-1 receptor (TIR) domains via nicotinamide adenine dinucleotide (oxidized form) (NAD+) hydrolysis. We show that v-cADPR (2'cADPR) and v2-cADPR (3'cADPR) isomers are cyclized by O-glycosidic bond formation between the ribose moieties in ADPR. Structures of 2'cADPR-producing TIR domains reveal conformational changes that lead to an active assembly that resembles those of Toll-like receptor adaptor TIR domains. Mutagenesis reveals a conserved tryptophan that is essential for cyclization. We show that 3'cADPR is an activator of ThsA effector proteins from the bacterial antiphage defense system termed Thoeris and a suppressor of plant immunity when produced by the effector HopAM1. Collectively, our results reveal the molecular basis of cADPR isomer production and establish 3'cADPR in bacteria as an antiviral and plant immunity-suppressing signaling molecule.
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Affiliation(s)
- Mohammad K Manik
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Yun Shi
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Sulin Li
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mark A Zaydman
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
| | - Neha Damaraju
- Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
| | - Samuel Eastman
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Thomas G Smith
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Weixi Gu
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Veronika Masic
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Tamim Mosaiab
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - James S Weagley
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Steven J Hancock
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Eduardo Vasquez
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | | | - Nestoras Kargios
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Natsumi Maruta
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bryan Y J Lim
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Hayden Burdett
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Michael J Landsberg
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ivan Prokes
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Lijiang Song
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Murray Grant
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Aaron DiAntonio
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
- Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ming Guo
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Jeffrey Milbrandt
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63100, USA
| | - Thomas Ve
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD 4072, Australia
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4
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Ma Z, Deng X, Li R, Hu R, Miao Y, Xu Y, Zheng W, Yi J, Wang Z, Wang Y, Chen C. Crosstalk of Brucella abortus nucleomodulin BspG and host DNA replication process/mitochondrial respiratory pathway promote anti-apoptosis and infection. Vet Microbiol 2022; 268:109414. [DOI: 10.1016/j.vetmic.2022.109414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/18/2022] [Accepted: 03/26/2022] [Indexed: 01/18/2023]
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5
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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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6
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Ma Z, Yu S, Cheng K, Miao Y, Xu Y, Hu R, Zheng W, Yi J, Zhang H, Li R, Li Z, Wang Y, Chen C. Nucleomodulin BspJ as an effector promotes the colonization of Brucella abortus in the host. J Vet Sci 2021; 23:e8. [PMID: 34841746 PMCID: PMC8799945 DOI: 10.4142/jvs.21224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/21/2021] [Accepted: 10/04/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Brucella infection induces brucellosis, a zoonotic disease. The intracellular circulation process and virulence of Brucella mainly depend on its type IV secretion system (T4SS) expressing secretory effectors. Secreted protein BspJ is a nucleomodulin of Brucella that invades the host cell nucleus. BspJ mediates host energy synthesis and apoptosis through interaction with proteins. However, the mechanism of BspJ as it affects the intracellular survival of Brucella remains to be clarified. OBJECTIVES To verify the functions of nucleomodulin BspJ in Brucella's intracellular infection cycles. METHODS Constructed Brucella abortus BspJ gene deletion strain (B. abortus ΔBspJ) and complement strain (B. abortus pBspJ) and studied their roles in the proliferation of Brucella both in vivo and in vitro. RESULTS BspJ gene deletion reduced the survival and intracellular proliferation of Brucella at the replicating Brucella-containing vacuoles (rBCV) stage. Compared with the parent strain, the colonization ability of the bacteria in mice was significantly reduced, causing less inflammatory infiltration and pathological damage. We also found that the knockout of BspJ altered the secretion of cytokines (interleukin [IL]-6, IL-1β, IL-10, tumor necrosis factor-α, interferon-γ) in host cells and in mice to affect the intracellular survival of Brucella. CONCLUSIONS BspJ is extremely important for the circulatory proliferation of Brucella in the host, and it may be involved in a previously unknown mechanism of Brucella's intracellular survival.
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Affiliation(s)
- Zhongchen Ma
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Shuifa Yu
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Kejian Cheng
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Yuhe Miao
- Fujian Sunvet Biological Technology Co., Ltd, Nanping 354100, Fujian, China
| | - Yimei Xu
- Xinjiang Center for Disease Control and Prevention, Urumqi 830002, Xinjiang, China
| | - Ruirui Hu
- College of Life Sciences, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Wei Zheng
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Jihai Yi
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Huan Zhang
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Ruirui Li
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan, China
| | - Yong Wang
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.
| | - Chuangfu Chen
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.,Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.
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7
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Tang HP, Huang C, Hu CB, Li H, Shao T, Ji JF, Bai J, Fan DD, Lin AF, Xiang LX, Shao JZ. Inhibitory Role of an Aeromonas hydrophila TIR Domain Effector in Antibacterial Immunity by Targeting TLR Signaling Complexes in Zebrafish. Front Microbiol 2021; 12:694081. [PMID: 34305858 PMCID: PMC8297594 DOI: 10.3389/fmicb.2021.694081] [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: 04/12/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022] Open
Abstract
The Toll/interleukin-1 receptor (TIR) domain is a structural unit responsible for the assembly of signal protein complexes in Toll-like receptor (TLR) and interleukin-1 receptor signaling pathways. TIR domain homologs are found in a considerable number of bacteria and enhance bacterial infection and survival in host organisms. However, whether TIR domain homologs exist in Aeromonas hydrophila, a ubiquitous waterborne bacterium in aquatic environments, remains poorly understood. In this study, a TIR domain protein (TcpAh) was identified from A. hydrophila JBN2301. TIR domain of TcpAh is highly homologous to the counterpart domains in TLRs and myeloid differentiation factor 88 (MyD88). The zebrafish infected with mutant A. hydrophila with tcpAh deletion had a remarkably lower mortality than those infected with the wild-type strain. This result suggests that TcpAh is a crucial virulence factor for A. hydrophila infection. TcpAh exhibited a strong ability to associate with MyD88, tumor necrosis factor receptor-associated factor 3 (TRAF3) and TRAF-associated NF-κB activator-binding kinase 1 (TBK1) in TIR-TIR, TIR-Death domain (DD), and other alternative interactions. This finding suggests that TcpAh extensively interferes with MyD88 and TIR domain-containing adapter inducing interferon (IFN)-β (TRIF) signaling pathways downstream of TLRs. Consequently, CD80/86 expression was suppressed by TcpAh via attenuating TLR-stimulated NF-κB activation, which ultimately led to the impairment of the major costimulatory signal essential for the initiation of adaptive humoral immunity against A. hydrophila infection. We believe that this study is the first to show a previously unrecognized mechanism underlying A. hydrophila evades from host antibacterial defense by intervening CD80/86 signal, which bridges innate and adaptive immunity. The mechanism will benefit the development of therapeutic interventions for A. hydrophila infection and septicemia by targeting TcpAh homologs.
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Affiliation(s)
- Huai-Ping Tang
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Chen Huang
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Chong-Bin Hu
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Hao Li
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Tong Shao
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Jian-Fei Ji
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Jun Bai
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Dong-Dong Fan
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Ai-Fu Lin
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Li-Xin Xiang
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China
| | - Jian-Zhong Shao
- College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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8
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Ma Z, Yu S, Cheng K, Miao Y, Xu Y, Hu R, Zheng W, Yi J, Zhang H, Li R, Li Z, Wang Y, Chen C. Nucleomodulin BspJ as an effector promotes the colonization of Brucella abortus in the host. J Vet Sci 2021. [DOI: 10.4142/jvs.2021.22.e94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Zhongchen Ma
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Shuifa Yu
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Kejian Cheng
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Yuhe Miao
- Fujian Sunvet Biological Technology Co., Ltd, Nanping 354100, Fujian, China
| | - Yimei Xu
- Xinjiang Center for Disease Control and Prevention, Urumqi 830002, Xinjiang, China
| | - Ruirui Hu
- College of Life Sciences, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Wei Zheng
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Jihai Yi
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Huan Zhang
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Ruirui Li
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan, China
| | - Yong Wang
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Chuangfu Chen
- International Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China
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Liu T, Yang Q, Wei W, Wang K, Wang E. Toll/IL-1 receptor-containing proteins STIR-1, STIR-2 and STIR-3 synergistically assist Yersinia ruckeri SC09 immune escape. FISH & SHELLFISH IMMUNOLOGY 2020; 103:357-365. [PMID: 32461169 DOI: 10.1016/j.fsi.2020.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/29/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Immune escape is a common feature of bacteria, viruses, parasites and even cancer cells. Our earlier work on an integrative and conjugative element (ICEr2) of Yersinia ruckeri SC09 demonstrated contributory roles of stir-1, stir-2 and stir-3 in bacterial toxicity and ability to code for immune evasion. Here, we further examined the ability of stir-4 in ICE (r2) and its encoded STIR-4 protein to mediate immune evasion using comparative genomic analysis. Additionally, the mechanisms underlying the synergistic activities of STIR-1, STIR-2, STIR-3 and STIR-4 in immune evasion were examined. Our results showed that STIR-4 did not contribute to bacterial toxicity, either in vivo nor in vitro, or show the ability to assist in bacterial immune escape. STIR-1, STIR-2, and STIR-3 formed heterotrimers in bacteria while facilitating immune evasion, which we speculate may be essential to maintain their stability. This discovery also partially explains the previous finding that a single gene can mediate immune evasion. Our data provide further knowledge on the distribution of ICE (r2)-like elements in bacteria, validating the prevalence of large-scale gene transfer in pathogens and its potential for enhancing virulence levels. Further studies are necessary to establish the biological significance of the ICE (r2) component.
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Affiliation(s)
- Tao Liu
- Department of Basic Veterinary, Veterinary Medicine College, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qian Yang
- Department of Basic Veterinary, Veterinary Medicine College, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Wenyan Wei
- Institute of Fisheries of Chengdu Agriculture and Forestry Academy, Chengdu, China
| | - Kaiyu Wang
- Department of Basic Veterinary, Veterinary Medicine College, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China.
| | - Erlong Wang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China
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The TIR-domain containing effectors BtpA and BtpB from Brucella abortus impact NAD metabolism. PLoS Pathog 2020; 16:e1007979. [PMID: 32298382 PMCID: PMC7188309 DOI: 10.1371/journal.ppat.1007979] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 04/28/2020] [Accepted: 03/26/2020] [Indexed: 12/20/2022] Open
Abstract
Brucella species are facultative intracellular Gram-negative bacteria relevant to animal and human health. Their ability to establish an intracellular niche and subvert host cell pathways to their advantage depends on the delivery of bacterial effector proteins through a type IV secretion system. Brucella Toll/Interleukin-1 Receptor (TIR)-domain-containing proteins BtpA (also known as TcpB) and BtpB are among such effectors. Although divergent in primary sequence, they interfere with Toll-like receptor (TLR) signaling to inhibit the innate immune responses. However, the molecular mechanisms implicated still remain unclear. To gain insight into the functions of BtpA and BtpB, we expressed them in the budding yeast Saccharomyces cerevisiae as a eukaryotic cell model. We found that both effectors were cytotoxic and that their respective TIR domains were necessary and sufficient for yeast growth inhibition. Growth arrest was concomitant with actin depolymerization, endocytic block and a general decrease in kinase activity in the cell, suggesting a failure in energetic metabolism. Indeed, levels of ATP and NAD+ were low in yeast cells expressing BtpA and BtpB TIR domains, consistent with the recently described enzymatic activity of some TIR domains as NAD+ hydrolases. In human epithelial cells, both BtpA and BtpB expression reduced intracellular total NAD levels. In infected cells, both BtpA and BtpB contributed to reduction of total NAD, indicating that their NAD+ hydrolase functions are active intracellularly during infection. Overall, combining the yeast model together with mammalian cells and infection studies our results show that BtpA and BtpB modulate energy metabolism in host cells through NAD+ hydrolysis, assigning a novel role for these TIR domain-containing effectors in Brucella pathogenesis. Brucella is a genus of zoonotic bacteria that cause severe disease in a variety of mammals, ranging from farm animals (as bovines, swine and ovine) to marine mammals. Transmission to humans, often by ingestion of non-treated dairy products, leads to serious systemic infection. Brucella abortus invades host cells and replicates intracellularly. Such behavior relies on the injection of bacterial proteins into the host cytoplasm via specialized secretion systems. Our work focuses on the study of two of these factors, BtpA and BtpB, previously described to contain Toll/Interleukin-1 Receptor (TIR)-domains that modulate innate immunity. We use here two biological models: the yeast Saccharomyces cerevisiae and human cell lines. We found that the TIR domains of both Brucella proteins were necessary and sufficient to collapse energy metabolism in yeast by depleting ATP and NAD+. This result was translatable to higher cells and consistent with the recently described NADase activity of some TIR domains both in mammalian and bacterial proteins. Importantly, we demonstrate that Brucella down-regulates total NAD levels in host cells by using both BtpA and BtpB effectors. Our results show that NAD+ is targeted by Brucella during infection, which may constitute a novel mechanism for its pathogenicity.
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Liu T, Li L, Wei W, Wang K, Yang Q, Wang E. Yersinia ruckeri strain SC09 disrupts proinflammatory activation via Toll/IL-1 receptor-containing protein STIR-3. FISH & SHELLFISH IMMUNOLOGY 2020; 99:424-434. [PMID: 32087278 DOI: 10.1016/j.fsi.2020.02.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/11/2020] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
Virulent pathogenic microorganisms often enhance their infectivity through immune evasion mechanisms. Our research on the integrative and conjugative element (ICE(r2)) of the virulent fish pathogen Yersinia ruckeri SC09 led to the identification of genes related to immune evasion (designated stir-1, stir-2, stir-3 and stir-4), among which stir-1 and stir-2 were determined as the key contributors to bacterial toxicity and immune evasion. Here, we further examined the ability of stir-3 to mediate immune evasion based on detailed bioinformatic analysis of ICE(r2) from Y. ruckeri SC09. Interactions among the translated STIR-1, STIR-2, STIR-3 and STIR-4 proteins in the secretory process were additionally explored. STIR-3 was positively correlated with bacterial toxicity and inhibited host toll-like receptor (TLR) signaling by interacting with MyD88, thereby facilitating bacterial survival in host cells. Importantly, our data showed co-secretion of STIR-1, STIR-2 and STIR-3 as a complex, with secretion failure occurring in the absence of any one of these proteins. While stir-1, stir-2, stir-3 and stir-4 genes werespecific to Y. ruckeri SC09, the ICE(r2) region where these genes were located is a mobile component widely distributed in bacteria. Therefore, the potential transmission risk of these immune evasion genes requires further research attention.
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Affiliation(s)
- Tao Liu
- Department of Basic Veterinary, Veterinary Medicine College, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Liangyu Li
- Institute of Fisheries of Chengdu Agriculture and Forestry Academy, Chengdu, China
| | - Wenyan Wei
- Institute of Fisheries of Chengdu Agriculture and Forestry Academy, Chengdu, China
| | - Kaiyu Wang
- Department of Basic Veterinary, Veterinary Medicine College, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China.
| | - Qian Yang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Erlong Wang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China
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12
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Avila-Calderón ED, Flores-Romo L, Sharon W, Donis-Maturano L, Becerril-García MA, Arreola MGA, Reynoso BA, Güemes FS, Contreras-Rodríguez A. Dendritic cells and Brucella spp. interaction: the sentinel host and the stealthy pathogen. Folia Microbiol (Praha) 2020; 65:1-16. [PMID: 30783994 PMCID: PMC7224029 DOI: 10.1007/s12223-019-00691-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/06/2019] [Indexed: 01/18/2023]
Abstract
As dendritic cells (DCs) are among the first cells to encounter antigens, these cells trigger both innate and T cell responses, and are the most potent antigen-presenting cells. Brucella spp., which is an intracellular facultative and stealthy pathogen, is able to evade the bactericidal activities of professional phagocytes. Several studies have demonstrated that Brucella can survive and replicate intracellularly, thereby provoking impaired maturation of DCs. Therefore, the interaction between DCs and Brucella becomes an interesting model to study the immune response. In this review, we first will describe the most common techniques for DCs differentiation in vitro as well as general features of brucellosis. Then, the interaction of DCs and Brucella, including pathogen recognition, molecular mechanisms of bacterial pathogenesis, and intracellular trafficking of Brucella to subvert innate response, will be reviewed. Finally, we will debate diversity in immunological DC response and the controversial role of DC activation against Brucella infection.
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Affiliation(s)
- Eric Daniel Avila-Calderón
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, CINVESTAV-IPN, Av. IPN No 2508, Zacatenco, C.P 07330, Mexico city, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Santo Tomás, 11340, Mexico city, Mexico
| | - Leopoldo Flores-Romo
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, CINVESTAV-IPN, Av. IPN No 2508, Zacatenco, C.P 07330, Mexico city, Mexico
| | - Witonsky Sharon
- Center for Molecular Medicine and Infectious Diseases/Center for One Health, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061-0442, USA
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061-0442, USA
| | - Luis Donis-Maturano
- Departamento de Innovación Biomédica, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada-Tijuana 3918, Zona Playitas, 22860, Ensenada, Baja California, Mexico
| | - Miguel Angel Becerril-García
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Avenida Francisco I Madero y Dr. Aguirre Pequeño S/N Mitras Centro, 64460, Monterrey, Nuevo León, Mexico
| | - Ma Guadalupe Aguilera Arreola
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Santo Tomás, 11340, Mexico city, Mexico
| | - Beatriz Arellano Reynoso
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán, 04510, Mexico city, Mexico
| | - Francisco Suarez Güemes
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán, 04510, Mexico city, Mexico
| | - Araceli Contreras-Rodríguez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Santo Tomás, 11340, Mexico city, Mexico.
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13
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Głowacka P, Żakowska D, Naylor K, Niemcewicz M, Bielawska-Drózd A. Brucella - Virulence Factors, Pathogenesis and Treatment. Pol J Microbiol 2019; 67:151-161. [PMID: 30015453 PMCID: PMC7256693 DOI: 10.21307/pjm-2018-029] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2018] [Indexed: 12/27/2022] Open
Abstract
Brucellae are Gram-negative, small rods infecting mammals and capable of causing disease called brucellosis. The infection results in abortion and sterility in domestic animals (sheeps, pigs, rams etc). Especially dangerous for humans are: Brucella melitensis, Brucella suis, Brucella abortus, and Brucella canis that trigger unspecific symptoms (flu-like manifestation). Brucella rods are introduced via host cells, by inhalation, skin abrasions, ingestion or mucosal membranes. The most important feature of Brucella is the ability to survive and multiply within both phagocytic and non-phagocytic cells. Brucella does not produce classical virulence factors: exotoxin, cytolisins, exoenzymes, plasmids, fimbria, and drug resistant forms. Major virulence factors are: lipopolysaccharide (LPS), T4SS secretion system and BvrR/BvrS system, which allow interaction with host cell surface, formation of an early, late BCV (Brucella Containing Vacuole) and interaction with endoplasmic reticulum (ER) when the bacteria multiply. The treatment of brucellosis is based on two-drug therapy, the most common combinations of antibiotics are: doxycycline with rifampicin or fluoroquinolones with rifampicin. Currently, also other methods are used to disrupt Brucella intracellular replication (tauroursodeoxycholic acid or ginseng saponin fraction A).
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Affiliation(s)
- Patrycja Głowacka
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology,Puławy,Poland
| | - Dorota Żakowska
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology,Puławy,Poland
| | - Katarzyna Naylor
- Lublin Medical University, Department of Didactics and Medical Simulation,Lublin,Poland
| | - Marcin Niemcewicz
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology,Puławy,Poland
| | - Agata Bielawska-Drózd
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology,Puławy,Poland
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14
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Dehio C, Tsolis RM. Type IV Effector Secretion and Subversion of Host Functions by Bartonella and Brucella Species. Curr Top Microbiol Immunol 2019. [PMID: 29536363 DOI: 10.1007/978-3-319-75241-9_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2023]
Abstract
Bartonella and Brucella species comprise closely related genera of the order Rhizobiales within the class α-proteobacteria. Both groups of bacteria are mammalian pathogens with a facultative intracellular lifestyle and are capable of causing chronic infections, but members of each genus have evolved broadly different infection and transmission strategies. While Brucella spp. transmit in general via the reproductive tract in their natural hosts, the Bartonella spp. have evolved to transmit via arthropod vectors. However, a shared feature of both groups of pathogens is their reliance on type IV secretion systems (T4SSs) to interact with cells in their mammalian hosts. The genomes of Bartonella spp. encode three types of T4SS, Trw, Vbh/TraG, and VirB/VirD4, whereas those of Brucella spp. uniformly contain a single T4SS of the VirB type. The VirB systems of Bartonella and Brucella are associated with distinct groups of effector proteins that collectively mediate interactions with host cells. This chapter discusses recent findings on the role of T4SS in the biology of Bartonella spp. and Brucella spp. with emphasis on effector repertoires, on recent advances in our understanding of their evolution, how individual effectors function at the molecular level, and on the consequences of these interactions for cellular and immune responses in the host.
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Affiliation(s)
| | - Renée M Tsolis
- Medical Microbiology and Immunology, University of California at Davis, Davis, CA, 95616, USA.
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Abstract
Bacteria of the genus Brucella colonize a wide variety of mammalian hosts, in which their infectious cycle and ability to cause disease predominantly rely on an intracellular lifestyle within phagocytes. Upon entry into host cells, Brucella organisms undergo a complex, multistage intracellular cycle in which they sequentially traffic through, and exploit functions of, the endocytic, secretory, and autophagic compartments via type IV secretion system (T4SS)-mediated delivery of bacterial effectors. These effectors modulate an array of host functions and machineries to first promote conversion of the initial endosome-like Brucella-containing vacuole (eBCV) into a replication-permissive organelle derived from the host endoplasmic reticulum (rBCV) and then to an autophagy-related vacuole (aBCV) that mediates bacterial egress. Here we detail and discuss our current knowledge of cellular and molecular events of the Brucella intracellular cycle. We discuss the importance of the endosomal stage in determining T4SS competency, the roles of autophagy in rBCV biogenesis and aBCV formation, and T4SS-driven mechanisms of modulation of host secretory traffic in rBCV biogenesis and bacterial egress.
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16
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Saqib U, Baig MS. Scaffolding role of TcpB in disrupting TLR4‐Mal interactions: Three to tango. J Cell Biochem 2018; 120:3455-3458. [DOI: 10.1002/jcb.27619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/10/2018] [Accepted: 08/14/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Uzma Saqib
- Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology, Indore Indore Madhya Pradesh India
| | - Mirza S Baig
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore (IITI) Madhya Pradesh India
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17
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Boggiatto PM, Fitzsimmons D, Bayles DO, Alt D, Vrentas CE, Olsen SC. Coincidence cloning recovery of Brucella melitensis RNA from goat tissues: advancing the in vivo analysis of pathogen gene expression in brucellosis. BMC Mol Biol 2018; 19:10. [PMID: 30068312 PMCID: PMC6071331 DOI: 10.1186/s12867-018-0111-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 07/24/2018] [Indexed: 11/10/2022] Open
Abstract
Background Brucella melitensis bacteria cause persistent, intracellular infections in small ruminants as well as in humans, leading to significant morbidity and economic loss worldwide. The majority of experiments on the transcriptional responses of Brucella to conditions inside the host have been performed following invasion of cultured mammalian cells, and do not address gene expression patterns during long-term infection. Results Here, we examine the application of the previously developed coincidence cloning methodology to recover and characterize B. melitensis RNA from the supramammary lymph node of experimentally-infected goats. Using coincidence cloning, we successfully recovered Brucella RNA from supramammary lymph nodes of B. melitensis-infected goats at both short-term (4 weeks) and long-term (38 weeks) infection time points. Amplified nucleic acid levels were sufficient for analysis of Brucella gene expression patterns by RNA-sequencing, providing evidence of metabolic activity in both the short-term and the long-term samples. We developed a workflow for the use of sequence polymorphism analysis to confirm recovery of the inoculated strain in the recovered reads, and utilized clustering analysis to demonstrate a distinct transcriptional profile present in samples recovered in long-term infection. In this first look at B. melitensis gene expression patterns in vivo, the subset of Brucella genes that was highly upregulated in long-term as compared to short-term infection included genes linked to roles in murine infection, such as genes involved in proline utilization and signal transduction. Finally, we demonstrated the challenges of qPCR validation of samples with very low ratios of pathogen:host RNA, as is the case during in vivo brucellosis, and alternatively characterized intermediate products of the coincidence cloning reaction. Conclusions Overall, this study provides the first example of recovery plus characterization of B. melitensis RNA from in vivo lymph node infection, and demonstrates that the coincidence cloning technique is a useful tool for characterizing in vivo transcriptional changes in Brucella species. Genes upregulated in long-term infection in this data set, including many genes not previously demonstrated to be virulence factors in mice or macrophage experiments, are candidates of future interest for potential roles in Brucella persistence in natural host systems. Electronic supplementary material The online version of this article (10.1186/s12867-018-0111-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paola M Boggiatto
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Daniel Fitzsimmons
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - David Alt
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Catherine E Vrentas
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA.
| | - Steven C Olsen
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
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18
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Conde-Álvarez R, Palacios-Chaves L, Gil-Ramírez Y, Salvador-Bescós M, Bárcena-Varela M, Aragón-Aranda B, Martínez-Gómez E, Zúñiga-Ripa A, de Miguel MJ, Bartholomew TL, Hanniffy S, Grilló MJ, Vences-Guzmán MÁ, Bengoechea JA, Arce-Gorvel V, Gorvel JP, Moriyón I, Iriarte M. Identification of lptA, lpxE, and lpxO, Three Genes Involved in the Remodeling of Brucella Cell Envelope. Front Microbiol 2018; 8:2657. [PMID: 29375522 PMCID: PMC5767591 DOI: 10.3389/fmicb.2017.02657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/20/2017] [Indexed: 12/19/2022] Open
Abstract
The brucellae are facultative intracellular bacteria that cause a worldwide extended zoonosis. One of the pathogenicity mechanisms of these bacteria is their ability to avoid rapid recognition by innate immunity because of a reduction of the pathogen-associated molecular pattern (PAMP) of the lipopolysaccharide (LPS), free-lipids, and other envelope molecules. We investigated the Brucella homologs of lptA, lpxE, and lpxO, three genes that in some pathogens encode enzymes that mask the LPS PAMP by upsetting the core-lipid A charge/hydrophobic balance. Brucella lptA, which encodes a putative ethanolamine transferase, carries a frame-shift in B. abortus but not in other Brucella spp. and phylogenetic neighbors like the opportunistic pathogen Ochrobactrum anthropi. Consistent with the genomic evidence, a B. melitensis lptA mutant lacked lipid A-linked ethanolamine and displayed increased sensitivity to polymyxin B (a surrogate of innate immunity bactericidal peptides), while B. abortus carrying B. melitensis lptA displayed increased resistance. Brucella lpxE encodes a putative phosphatase acting on lipid A or on a free-lipid that is highly conserved in all brucellae and O. anthropi. Although we found no evidence of lipid A dephosphorylation, a B. abortus lpxE mutant showed increased polymyxin B sensitivity, suggesting the existence of a hitherto unidentified free-lipid involved in bactericidal peptide resistance. Gene lpxO putatively encoding an acyl hydroxylase carries a frame-shift in all brucellae except B. microti and is intact in O. anthropi. Free-lipid analysis revealed that lpxO corresponded to olsC, the gene coding for the ornithine lipid (OL) acyl hydroxylase active in O. anthropi and B. microti, while B. abortus carrying the olsC of O. anthropi and B. microti synthesized hydroxylated OLs. Interestingly, mutants in lptA, lpxE, or olsC were not attenuated in dendritic cells or mice. This lack of an obvious effect on virulence together with the presence of the intact homolog genes in O. anthropi and B. microti but not in other brucellae suggests that LptA, LpxE, or OL β-hydroxylase do not significantly alter the PAMP properties of Brucella LPS and free-lipids and are therefore not positively selected during the adaptation to intracellular life.
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Affiliation(s)
- Raquel Conde-Álvarez
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Leyre Palacios-Chaves
- Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas - Universidad Pública de Navarra - Gobierno de Navarra, Pamplona, Spain
| | - Yolanda Gil-Ramírez
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Miriam Salvador-Bescós
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Marina Bárcena-Varela
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Beatriz Aragón-Aranda
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Estrella Martínez-Gómez
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Amaia Zúñiga-Ripa
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - María J de Miguel
- Unidad de Producción y Sanidad Animal, Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón - Universidad de Zaragoza, Zaragoza, Spain
| | - Toby Leigh Bartholomew
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Sean Hanniffy
- Institut National de la Santé et de la Recherche Médicale, U1104, Centre National de la Recherche Scientifique UMR7280, Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University UM2, Marseille, France
| | - María-Jesús Grilló
- Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas - Universidad Pública de Navarra - Gobierno de Navarra, Pamplona, Spain
| | | | - José A Bengoechea
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Vilma Arce-Gorvel
- Institut National de la Santé et de la Recherche Médicale, U1104, Centre National de la Recherche Scientifique UMR7280, Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University UM2, Marseille, France
| | - Jean-Pierre Gorvel
- Institut National de la Santé et de la Recherche Médicale, U1104, Centre National de la Recherche Scientifique UMR7280, Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University UM2, Marseille, France
| | - Ignacio Moriyón
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
| | - Maite Iriarte
- Universidad de Navarra, Facultad de Medicina, Departamento de Microbiología y Parasitología, Instituto de Salud Tropical (ISTUN) e Instituto de Investigación Sanitaria de Navarra (IdISNA), Pamplona, Spain
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19
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Imbert PR, Louche A, Luizet JB, Grandjean T, Bigot S, Wood TE, Gagné S, Blanco A, Wunderley L, Terradot L, Woodman P, Garvis S, Filloux A, Guery B, Salcedo SP. A Pseudomonas aeruginosa TIR effector mediates immune evasion by targeting UBAP1 and TLR adaptors. EMBO J 2017; 36:1869-1887. [PMID: 28483816 PMCID: PMC5494471 DOI: 10.15252/embj.201695343] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/11/2022] Open
Abstract
Bacterial pathogens often subvert the innate immune system to establish a successful infection. The direct inhibition of downstream components of innate immune pathways is particularly well documented but how bacteria interfere with receptor proximal events is far less well understood. Here, we describe a Toll/interleukin 1 receptor (TIR) domain‐containing protein (PumA) of the multi‐drug resistant Pseudomonas aeruginosa PA7 strain. We found that PumA is essential for virulence and inhibits NF‐κB, a property transferable to non‐PumA strain PA14, suggesting no additional factors are needed for PumA function. The TIR domain is able to interact with the Toll‐like receptor (TLR) adaptors TIRAP and MyD88, as well as the ubiquitin‐associated protein 1 (UBAP1), a component of the endosomal‐sorting complex required for transport I (ESCRT‐I). These interactions are not spatially exclusive as we show UBAP1 can associate with MyD88, enhancing its plasma membrane localization. Combined targeting of UBAP1 and TLR adaptors by PumA impedes both cytokine and TLR receptor signalling, highlighting a novel strategy for innate immune evasion.
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Affiliation(s)
- Paul Rc Imbert
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Arthur Louche
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Jean-Baptiste Luizet
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Teddy Grandjean
- EA 7366 Recherche Translationelle Relations Hôte-Pathogènes, Faculté de Médecine Pôle Recherche, Université Lille 2, Lille, France
| | - Sarah Bigot
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Thomas E Wood
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Stéphanie Gagné
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Amandine Blanco
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Lydia Wunderley
- School of Biological Sciences, Faculty of Biology Medicine and Health University of Manchester Manchester Academic Health Science Centre, Manchester, UK†
| | - Laurent Terradot
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
| | - Philip Woodman
- School of Biological Sciences, Faculty of Biology Medicine and Health University of Manchester Manchester Academic Health Science Centre, Manchester, UK†
| | - Steve Garvis
- Laboratoire de Biologie et Modelisation, Ecole Normal Supérieur, UMR5239, Lyon, France
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Benoit Guery
- EA 7366 Recherche Translationelle Relations Hôte-Pathogènes, Faculté de Médecine Pôle Recherche, Université Lille 2, Lille, France
| | - Suzana P Salcedo
- Laboratory of Molecular Microbiology and Structural Biochemistry, Centre National de la Recherche Scientifique, University of Lyon, Lyon, France
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20
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Brucella TIR-like protein TcpB/Btp1 specifically targets the host adaptor protein MAL/TIRAP to promote infection. Biochem Biophys Res Commun 2016; 477:509-14. [PMID: 27311859 DOI: 10.1016/j.bbrc.2016.06.064] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/13/2016] [Indexed: 02/06/2023]
Abstract
Brucella spp. are known to avoid host immune recognition and weaken the immune response to infection. Brucella like accomplish this by employing two clever strategies, called the stealth strategy and hijacking strategy. The TIR domain-containing protein (TcpB/Btp1) of Brucella melitensis is thought to be involved in inhibiting host NF-κB activation by binding to adaptors downstream of Toll-like receptors. However, of the five TIR domain-containing adaptors conserved in mammals, whether MyD88 or MAL, even other three adaptors, are specifically targeted by TcpB has not been identified. Here, we confirmed the effect of TcpB on B.melitensis virulence in mice and found that TcpB selectively targets MAL. By using siRNA against MAL, we found that TcpB from B.melitensis is involved in intracellular survival and that MAL affects intracellular replication of B.melitensis. Our results confirm that TcpB specifically targets MAL/TIRAP to disrupt downstream signaling pathways and promote intra-host survival of Brucella spp.
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21
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Ke Y, Li W, Wang Y, Yang M, Guo J, Zhan S, Du X, Wang Z, Yang M, Li J, Li W, Chen Z. Inhibition of TLR4 signaling by Brucella TIR-containing protein TcpB-derived decoy peptides. Int J Med Microbiol 2016; 306:391-400. [PMID: 27289452 DOI: 10.1016/j.ijmm.2016.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 05/04/2016] [Accepted: 05/08/2016] [Indexed: 02/06/2023] Open
Abstract
Brucella spp. avoid host immune recognition and thus, weaken the immune response to infection. The Toll/interleukin-1 receptor (TIR) domain-containing protein (TcpB/Btp1) of Brucella spp. is thought to be involved in blocking host innate immune responses by binding to adaptors downstream of Toll-like receptors. In this study, based on the observation that TcpB binds to the host target proteins, MAL, through the TIR domain, we examined decoy peptides from TcpB TIR domains and found that TB-8 and TB-9 substantially inhibit lipopolysaccharide (LPS)-induced signaling in vitro and in vivo. Both these peptides share a common loop, the DD loop, indicating a novel structural region mediating TIR interactions. The inhibition of LPS signaling by TB-8 and TB-9 shows no preference to MyD88-dependent cytokines, such as TNF-α and IL-1β or TRIF-dependent cytokines including IFN-β and IL-6. Furthermore, these two peptides rescue the virulence of Brucella ΔtcpB mutants at the cellular level, indicating key roles of the DD loop in Brucella pathogenesis. In conclusion, identification of inhibitors from the bacterial TIR domains is helpful not only for illustrating interacting mechanisms between TIR domains and bacterial pathogenesis, but also for developing novel signaling inhibitors and therapeutics for human inflammatory diseases.
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Affiliation(s)
- Yuehua Ke
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Wenna Li
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China; School of Public Health, Jilin University, Changchun 130021, People's Republic of China
| | - Yufei Wang
- General Hospital of People's Armed Police Forces, Beijing 100039, People's Republic of China
| | - Mingjuan Yang
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Jinpeng Guo
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Shaoxia Zhan
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Xinying Du
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Zhoujia Wang
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China
| | - Min Yang
- Construction Engineering Research Institute, Xi'an 71000, Shanxi Province, People's Republic of China
| | - Juan Li
- School of Public Health, Jilin University, Changchun 130021, People's Republic of China.
| | - Wenfeng Li
- Department of Orthopedics, The First Affiliated Hospital of General Hospital of People's Liberation Army, Beijing 100048, People's Republic of China.
| | - Zeliang Chen
- Institute of Disease Control and Prevention, AMMS, Beijing 100071, People's Republic of China; College of Medicine, Shihezi University, Shihezi, People's Republic of China; Research Center of Molecular Biology, Inner Mongolia Medical University, Hohhot, People's Republic of China.
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22
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de Figueiredo P, Ficht TA, Rice-Ficht A, Rossetti CA, Adams LG. Pathogenesis and immunobiology of brucellosis: review of Brucella-host interactions. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1505-17. [PMID: 25892682 DOI: 10.1016/j.ajpath.2015.03.003] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 02/10/2015] [Accepted: 03/02/2015] [Indexed: 01/18/2023]
Abstract
This review of Brucella-host interactions and immunobiology discusses recent discoveries as the basis for pathogenesis-informed rationales to prevent or treat brucellosis. Brucella spp., as animal pathogens, cause human brucellosis, a zoonosis that results in worldwide economic losses, human morbidity, and poverty. Although Brucella spp. infect humans as an incidental host, 500,000 new human infections occur annually, and no patient-friendly treatments or approved human vaccines are reported. Brucellae display strong tissue tropism for lymphoreticular and reproductive systems with an intracellular lifestyle that limits exposure to innate and adaptive immune responses, sequesters the organism from the effects of antibiotics, and drives clinical disease manifestations and pathology. Stealthy brucellae exploit strategies to establish infection, including i) evasion of intracellular destruction by restricting fusion of type IV secretion system-dependent Brucella-containing vacuoles with lysosomal compartments, ii) inhibition of apoptosis of infected mononuclear cells, and iii) prevention of dendritic cell maturation, antigen presentation, and activation of naive T cells, pathogenesis lessons that may be informative for other intracellular pathogens. Data sets of next-generation sequences of Brucella and host time-series global expression fused with proteomics and metabolomics data from in vitro and in vivo experiments now inform interactive cellular pathways and gene regulatory networks enabling full-scale systems biology analysis. The newly identified effector proteins of Brucella may represent targets for improved, safer brucellosis vaccines and therapeutics.
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Affiliation(s)
- Paul de Figueiredo
- Department of Veterinary Pathobiology, Texas A&M University and Texas AgriLife Research, College Station, Texas; Norman Borlaug Center, Texas A&M University, College Station, Texas; Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas
| | - Thomas A Ficht
- Department of Veterinary Pathobiology, Texas A&M University and Texas AgriLife Research, College Station, Texas
| | - Allison Rice-Ficht
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, Bryan, Texas
| | - Carlos A Rossetti
- Institute of Pathobiology, CICVyA-CNIA, National Institute of Animal Agriculture Technology (INTA), Buenos Aires, Argentina
| | - L Garry Adams
- Department of Veterinary Pathobiology, Texas A&M University and Texas AgriLife Research, College Station, Texas.
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23
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Bacteria, the endoplasmic reticulum and the unfolded protein response: friends or foes? Nat Rev Microbiol 2014; 13:71-82. [PMID: 25534809 DOI: 10.1038/nrmicro3393] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The unfolded protein response (UPR) is a cytoprotective response that is aimed at restoring cellular homeostasis following physiological stress exerted on the endoplasmic reticulum (ER), which also invokes innate immune signalling in response to invading microorganisms. Although it has been known for some time that the UPR is modulated by various viruses, recent evidence indicates that it also has multiple roles during bacterial infections. In this Review, we describe how bacteria interact with the ER, including how bacteria induce the UPR, how subversion of the UPR promotes bacterial proliferation and how the UPR contributes to innate immune responses against invading bacteria.
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24
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Felix C, Kaplan Türköz B, Ranaldi S, Koelblen T, Terradot L, O'Callaghan D, Vergunst AC. The Brucella TIR domain containing proteins BtpA and BtpB have a structural WxxxE motif important for protection against microtubule depolymerisation. Cell Commun Signal 2014; 12:53. [PMID: 25304327 PMCID: PMC4203976 DOI: 10.1186/s12964-014-0053-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 08/27/2014] [Indexed: 01/12/2023] Open
Abstract
Background The TIR domain-containing proteins BtpA/Btp1/TcpB and BtpB are translocated into host cells by the facultative intracellular bacterial pathogen Brucella. Here, they interfere with Toll like receptor signalling to temper the host inflammatory response. BtpA has also been found to modulate microtubule dynamics. In both proteins we identified a WxxxE motif, previously shown to be an essential structural component in a family of bacterial type III secretion system effectors that modulate host actin dynamics by functioning as guanine nucleotide exchange factors of host GTPases. We analysed a role for the WxxxE motif in association of BtpA and BtpB with the cytoskeleton. Results Unlike BtpA, ectopically expressed BtpB did not show a tubular localisation, but was found ubiquitously in the cytoplasm and the nucleus, and often appeared in discrete punctae in HeLa cells. BtpB was able to protect microtubules from drug-induced destabilisation similar to BtpA. The WxxxE motif was important for the ability of BtpA and BtpB to protect microtubules against destabilising drugs. Surprisingly, ectopic expression of BtpA, although not BtpB, in HeLa cells induced the formation of filopodia. This process was invariably dependent of the WxxxE motif. Our recent resolution of the crystal structure of the BtpA TIR domain reveals that the motif positions a glycine residue that has previously been shown to be essential for interaction of BtpA with microtubules. Conclusions Our results suggest a structural role for the WxxxE motif in the association of BtpA and BtpB with microtubules, as with the WxxxE GEF family proteins where the motif positions an adjacent catalytic loop important for interaction with specific Rho GTPases. In addition, the ability of ectopically expressed BtpA to induce filopodia in a WxxxE-dependent manner suggests a novel property for BtpA. A conserved WxxxE motif is found in most bacterial and several eukaryotic TIR domain proteins. Despite the similarity between ectopically expressed BtpA and WxxxE GEFs to modulate host actin dynamics, our results suggest that BtpA is not part of this WxxxE GEF family. The WxxxE motif may therefore be a more common structural motif than thus far described. BtpA may provide clues to cross-talk between the TLR and GTPase signalling pathways. Electronic supplementary material The online version of this article (doi:10.1186/s12964-014-0053-y) contains supplementary material, which is available to authorized users.
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25
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Azad T, Tashakor A, Hosseinkhani S. Split-luciferase complementary assay: applications, recent developments, and future perspectives. Anal Bioanal Chem 2014; 406:5541-60. [DOI: 10.1007/s00216-014-7980-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/22/2014] [Accepted: 06/16/2014] [Indexed: 12/19/2022]
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26
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Affiliation(s)
- Jean-Pierre Gorvel
- Centre d'Immunologie de Marseille-Luminy; Aix-Marseille University; Marseille, France; CNRS UMR7280; Marseille, France; INSERM U1104; Marseille, France
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27
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Wattam AR, Foster JT, Mane SP, Beckstrom-Sternberg SM, Beckstrom-Sternberg JM, Dickerman AW, Keim P, Pearson T, Shukla M, Ward DV, Williams KP, Sobral BW, Tsolis RM, Whatmore AM, O'Callaghan D. Comparative phylogenomics and evolution of the Brucellae reveal a path to virulence. J Bacteriol 2014; 196:920-30. [PMID: 24336939 PMCID: PMC3957692 DOI: 10.1128/jb.01091-13] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/04/2013] [Indexed: 11/20/2022] Open
Abstract
Brucella species include important zoonotic pathogens that have a substantial impact on both agriculture and human health throughout the world. Brucellae are thought of as "stealth pathogens" that escape recognition by the host innate immune response, modulate the acquired immune response, and evade intracellular destruction. We analyzed the genome sequences of members of the family Brucellaceae to assess its evolutionary history from likely free-living soil-based progenitors into highly successful intracellular pathogens. Phylogenetic analysis split the genus into two groups: recently identified and early-dividing "atypical" strains and a highly conserved "classical" core clade containing the major pathogenic species. Lateral gene transfer events brought unique genomic regions into Brucella that differentiated them from Ochrobactrum and allowed the stepwise acquisition of virulence factors that include a type IV secretion system, a perosamine-based O antigen, and systems for sequestering metal ions that are absent in progenitors. Subsequent radiation within the core Brucella resulted in lineages that appear to have evolved within their preferred mammalian hosts, restricting their virulence to become stealth pathogens capable of causing long-term chronic infections.
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Affiliation(s)
- Alice R. Wattam
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Jeffrey T. Foster
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
| | | | - Stephen M. Beckstrom-Sternberg
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - James M. Beckstrom-Sternberg
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - Allan W. Dickerman
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Paul Keim
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - Talima Pearson
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
| | - Maulik Shukla
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Doyle V. Ward
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Kelly P. Williams
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Bruno W. Sobral
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Renee M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, California, USA
| | - Adrian M. Whatmore
- Department of Bacteriology, Animal Health & Veterinary Laboratories Agency, Addlestone, United Kingdom
| | - David O'Callaghan
- INSERM U1047, UFR Médecine, Nîmes, France
- Université Montpellier 1, UFR Médecine, Nîmes, France
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28
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Snyder GA, Deredge D, Waldhuber A, Fresquez T, Wilkins DZ, Smith PT, Durr S, Cirl C, Jiang J, Jennings W, Luchetti T, Snyder N, Sundberg EJ, Wintrode P, Miethke T, Xiao TS. Crystal structures of the Toll/Interleukin-1 receptor (TIR) domains from the Brucella protein TcpB and host adaptor TIRAP reveal mechanisms of molecular mimicry. J Biol Chem 2013; 289:669-79. [PMID: 24275656 DOI: 10.1074/jbc.m113.523407] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Toll/IL-1 receptor (TIR) domains are crucial innate immune signaling modules. Microbial TIR domain-containing proteins inhibit Toll-like receptor (TLR) signaling through molecular mimicry. The TIR domain-containing protein TcpB from Brucella inhibits TLR signaling through interaction with host adaptor proteins TIRAP/Mal and MyD88. To characterize the microbial mimicry of host proteins, we have determined the X-ray crystal structures of the TIR domains from the Brucella protein TcpB and the host adaptor protein TIRAP. We have further characterized homotypic interactions of TcpB using hydrogen/deuterium exchange mass spectrometry and heterotypic TcpB and TIRAP interaction by co-immunoprecipitation and NF-κB reporter assays. The crystal structure of the TcpB TIR domain reveals the microtubule-binding site encompassing the BB loop as well as a symmetrical dimer mediated by the DD and EE loops. This dimerization interface is validated by peptide mapping through hydrogen/deuterium exchange mass spectrometry. The human TIRAP TIR domain crystal structure reveals a unique N-terminal TIR domain fold containing a disulfide bond formed by Cys(89) and Cys(134). A comparison between the TcpB and TIRAP crystal structures reveals substantial conformational differences in the region that encompasses the BB loop. These findings underscore the similarities and differences in the molecular features found in the microbial and host TIR domains, which suggests mechanisms of bacterial mimicry of host signaling adaptor proteins, such as TIRAP.
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Affiliation(s)
- Greg A Snyder
- From the Laboratory of Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892
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29
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Alaidarous M, Ve T, Casey LW, Valkov E, Ericsson DJ, Ullah MO, Schembri MA, Mansell A, Sweet MJ, Kobe B. Mechanism of bacterial interference with TLR4 signaling by Brucella Toll/interleukin-1 receptor domain-containing protein TcpB. J Biol Chem 2013; 289:654-68. [PMID: 24265315 DOI: 10.1074/jbc.m113.523274] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Upon activation of Toll-like receptors (TLRs), cytoplasmic Toll/interleukin-1 receptor (TIR) domains of the receptors undergo homo- or heterodimerization. This in turn leads to the recruitment of adaptor proteins, activation of transcription factors, and the secretion of pro-inflammatory cytokines. Recent studies have described the TIR domain-containing protein from Brucella melitensis, TcpB (BtpA/Btp1), to be involved in virulence and suppression of host innate immune responses. TcpB interferes with TLR4 and TLR2 signaling pathways by a mechanism that remains controversial. In this study, we show using co-immunoprecipitation analyses that TcpB interacts with MAL, MyD88, and TLR4 but interferes only with the MAL-TLR4 interaction. We present the crystal structure of the TcpB TIR domain, which reveals significant structural differences in the loop regions compared with other TIR domain structures. We demonstrate that TcpB forms a dimer in solution, and the crystal structure reveals the dimerization interface, which we validate by mutagenesis and biophysical studies. Our study advances the understanding of the molecular mechanisms of host immunosuppression by bacterial pathogens.
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30
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Alaidarous M, Ve T, Ullah MO, Valkov E, Mansell A, Schembri MA, Sweet MJ, Kobe B. Cloning, expression, purification, crystallization and preliminary X-ray crystallographic analysis of the TIR domain from the Brucella melitensis TIR-domain-containing protein TcpB. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1167-70. [PMID: 24100574 PMCID: PMC3792682 DOI: 10.1107/s1744309113024408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 09/02/2013] [Indexed: 01/23/2023]
Abstract
In mammals, Toll-like receptors (TLRs) recognize conserved microbial molecular signatures and induce an early innate immune response in the host. TLR signalling is mediated by interactions between the cytosolic TIR (Toll/interleukin-1 receptor) domains of the receptor and the adaptor proteins. Increasingly, it is apparent that pathogens target this interaction via pathogen-expressed TIR-domain-containing proteins to modulate immune responses. A TIR-domain-containing protein TcpB has been reported in the pathogenic bacterium Brucella melitensis. Studies have shown that TcpB interferes with the TLR2 and TLR4 signalling pathways to inhibit TLR-mediated inflammatory responses. Such interference may involve TIR-TIR-domain interactions between bacterial and mammalian proteins, but there is a lack of information about these interactions at the molecular level. In this study, the cloning, expression, purification, crystallization and preliminary X-ray crystallographic analysis of the protein construct corresponding to the TIR domain of TcpB (residues 120-250) are reported. The crystals diffracted to 2.6 Å resolution, have the symmetry of the monoclinic space group P2₁ and are most likely to contain four molecules in the asymmetric unit. The structure should help in understanding the molecular basis of how TcpB affects the innate immunity of the host.
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Affiliation(s)
- Mohammed Alaidarous
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - Thomas Ve
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - M. Obayed Ullah
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - Eugene Valkov
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, England
| | - Ashley Mansell
- Centre for Innate Immunity and Infectious Diseases, Monash Institute of Medical Research, Monash University, Melbourne, VIC 3168, Australia
| | - Mark A. Schembri
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - Matthew J. Sweet
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
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31
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Kaplan-Türköz B, Koelblen T, Felix C, Candusso MP, O'Callaghan D, Vergunst AC, Terradot L. Structure of the Toll/interleukin 1 receptor (TIR) domain of the immunosuppressive Brucella effector BtpA/Btp1/TcpB. FEBS Lett 2013; 587:3412-6. [PMID: 24076024 DOI: 10.1016/j.febslet.2013.09.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 11/15/2022]
Abstract
BtpA/Btp1/TcpB is a virulence factor produced by Brucella species that possesses a Toll interleukin-1 receptor (TIR) domain. Once delivered into the host cell, BtpA interacts with MyD88 to interfere with TLR signalling and modulates microtubule dynamics. Here the crystal structure of the BtpA TIR domain at 3.15 Å is presented. The structure shows a dimeric arrangement of a canonical TIR domain, similar to the Paracoccus denitrificans Tir protein but secured by a unique long N-terminal α-tail that packs against the TIR:TIR dimer. Structure-based mutations and multi-angle light scattering experiments characterized the BtpA dimer conformation in solution. The structure of BtpA will help with studies to understand the mechanisms involved in its interactions with MyD88 and with microtubules.
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Affiliation(s)
- Burcu Kaplan-Türköz
- UMR 5086, BMSSI, CNRS - Université Lyon 1, Institut de Biologie et Chimie des Protéines, 7 passage du Vercors, F-69367, France
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32
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Ben-Tekaya H, Gorvel JP, Dehio C. Bartonella and Brucella--weapons and strategies for stealth attack. Cold Spring Harb Perspect Med 2013; 3:3/8/a010231. [PMID: 23906880 DOI: 10.1101/cshperspect.a010231] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Bartonella spp. and Brucella spp. are closely related α-proteobacterial pathogens that by distinct stealth-attack strategies cause chronic infections in mammals including humans. Human infections manifest by a broad spectrum of clinical symptoms, ranging from mild to fatal disease. Both pathogens establish intracellular replication niches and subvert diverse pathways of the host's immune system. Several virulence factors allow them to adhere to, invade, proliferate, and persist within various host-cell types. In particular, type IV secretion systems (T4SS) represent essential virulence factors that transfer effector proteins tailored to recruit host components and modulate cellular processes to the benefit of the bacterial intruders. This article puts the remarkable features of these two pathogens into perspective, highlighting the mechanisms they use to hijack signaling and trafficking pathways of the host as the basis for their stealthy infection strategies.
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Affiliation(s)
- Houchaima Ben-Tekaya
- Focal Area Infection Biology, Biozentrum, University of Basel, 4052 Basel, Switzerland
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33
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Salcedo SP, Marchesini MI, Degos C, Terwagne M, Von Bargen K, Lepidi H, Herrmann CK, Santos Lacerda TL, Imbert PRC, Pierre P, Alexopoulou L, Letesson JJ, Comerci DJ, Gorvel JP. BtpB, a novel Brucella TIR-containing effector protein with immune modulatory functions. Front Cell Infect Microbiol 2013; 3:28. [PMID: 23847770 PMCID: PMC3703528 DOI: 10.3389/fcimb.2013.00028] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/18/2013] [Indexed: 12/29/2022] Open
Abstract
Several bacterial pathogens have TIR domain-containing proteins that contribute to their pathogenesis. We identified a second TIR-containing protein in Brucella spp. that we have designated BtpB. We show it is a potent inhibitor of TLR signaling, probably via MyD88. BtpB is a novel Brucella effector that is translocated into host cells and interferes with activation of dendritic cells. In vivo mouse studies revealed that BtpB is contributing to virulence and control of local inflammatory responses with relevance in the establishment of chronic brucellosis. Together, our results show that BtpB is a novel Brucella effector that plays a major role in the modulation of host innate immune response during infection.
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Affiliation(s)
- Suzana P Salcedo
- Aix-Marseille Univ UM 2, Centre d'Immunologie de Marseille-Luminy Marseille, France
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34
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Gomez G, Adams LG, Rice-Ficht A, Ficht TA. Host-Brucella interactions and the Brucella genome as tools for subunit antigen discovery and immunization against brucellosis. Front Cell Infect Microbiol 2013; 3:17. [PMID: 23720712 PMCID: PMC3655278 DOI: 10.3389/fcimb.2013.00017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 04/26/2013] [Indexed: 01/18/2023] Open
Abstract
Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development.
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Affiliation(s)
- Gabriel Gomez
- Department of Veterinary Pathobiology, Texas A&M University College Station, TX 77843, USA.
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35
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Dimitrakopoulos O, Liopeta K, Dimitracopoulos G, Paliogianni F. Replication of Brucella melitensis inside primary human monocytes depends on mitogen activated protein kinase signaling. Microbes Infect 2013; 15:450-60. [PMID: 23628412 DOI: 10.1016/j.micinf.2013.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 02/12/2013] [Accepted: 04/18/2013] [Indexed: 01/18/2023]
Abstract
The clinical course of infections caused by Brucella is linked to its capacity to modulate the initial immune response of macrophages in order to ensure its intracellular replication. Signal transduction pathways implicated in the survival of Brucella in human cells are not completely elucidated. We herein investigated the involvement of the TLR-MAPK-dependent signaling pathways in the survival of Brucella in primary human monocytes using live clinical strains of Brucella melitensis. B. melitensis caused a delayed, TLR2 dependent MAPK activation. Specific MAPK inhibitors for p38 (SB203580), ERK1/2 (PD98059) and JNK (SP600125) or the anti-TLR2 blocking Ab inhibited both inflammatory and anti-inflammatory responses characterized by TNF-α, IL-6 and IL-10 production. Intracellular replication of B. melitensis was mainly dependent on p38 and JNK activation and not affected by IL-10 levels. These are the first evidence to support that survival of B. melitensis inside human monocytes depends on interplay among the different MAPK family members, activated through TLR2, in spite of an initial pro-inflammatory response.
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36
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Molecular mechanisms for the subversion of MyD88 signaling by TcpC from virulent uropathogenic Escherichia coli. Proc Natl Acad Sci U S A 2013; 110:6985-90. [PMID: 23569230 DOI: 10.1073/pnas.1215770110] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The Toll/IL-1 receptor (TIR) domains are crucial signaling modules during innate immune responses involving the Toll-like receptors (TLRs) and IL-1 receptor (IL-1R). Myeloid differential factor 88 (MyD88) is a central TIR domain-containing adapter molecule responsible for nearly all TLR-mediated signaling and is targeted by a TIR domain-containing protein C (TcpC) from virulent uropathogenic Escherichia coli, a common human pathogen. The mechanism of such molecular antagonism has remained elusive. We present the crystal structure of the MyD88 TIR domain with distinct loop conformations that underscore the functional specialization of the adapter, receptor, and microbial TIR domains. Our structural analyses shed light on the genetic mutations at these loops as well as the Poc site. We demonstrate that TcpC directly associates with MyD88 and TLR4 through its predicted DD and BB loops to impair the TLR-induced cytokine induction. Furthermore, NMR titration experiments identify the unique CD, DE, and EE loops from MyD88 at the TcpC-interacting surface, suggesting that TcpC specifically engages these MyD88 structural elements for immune suppression. These findings thus provide a molecular basis for the subversion of TLR signaling by the uropathogenic E. coli virulence factor TcpC and furnish a framework for the design of novel therapeutic agents that modulate immune activation.
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37
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Lacerda TLS, Salcedo SP, Gorvel JP. Brucella T4SS: the VIP pass inside host cells. Curr Opin Microbiol 2013; 16:45-51. [PMID: 23318140 DOI: 10.1016/j.mib.2012.11.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/11/2012] [Accepted: 11/26/2012] [Indexed: 02/07/2023]
Abstract
For many Gram-negative bacteria, like Brucella, the type IV secretion system (T4SS) has a critical role in bacterial virulence. In Brucella, the VirB T4SS permits the injection of bacterial effectors inside host cells, leading to subversion of signaling pathways and favoring bacterial growth and pathogenesis. The virB operon promoter is tightly regulated by a combination of transcriptional activators and repressors that are expressed according to the environmental conditions encountered by Brucella. Recent advances have shed light on the Brucella T4SS regulatory mechanisms and also its substrates. Characterization of the targets and functions of these translocated effectors is underway and will help understand the role of the T4SS in the establishment of a replication niche inside host cells.
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Wiesemann K, Groß LE, Sommer M, Schleiff E, Sommer MS. self-assembling GFP: a versatile tool for plant (membrane) protein analyses. Methods Mol Biol 2013; 1033:131-144. [PMID: 23996175 DOI: 10.1007/978-1-62703-487-6_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The investigation of cellular processes on the molecular level is important to understand the functional network within plant cells. self-assembling GFP has evolved to be a versatile tool for (membrane) protein analyses. Based on the autocatalytical reassembling property of the nonfluorescent strands 1-10 and 11, protein distribution and membrane protein topology can be analyzed in vivo. Here, we provide basic protocols to determine membrane protein topology in Arabidopsis thaliana protoplasts.
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Affiliation(s)
- Katharina Wiesemann
- Cluster of Excellence Frankfurt, Center for Membrane Proteomics, Department of Biosciences, Molecular Cell Biology, Goethe University, Frankfurt, Germany
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39
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Pei J, Ding X, Fan Y, Rice-Ficht A, Ficht TA. Toll-like receptors are critical for clearance of Brucella and play different roles in development of adaptive immunity following aerosol challenge in mice. Front Cell Infect Microbiol 2012; 2:115. [PMID: 22973560 PMCID: PMC3435510 DOI: 10.3389/fcimb.2012.00115] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 08/15/2012] [Indexed: 01/18/2023] Open
Abstract
Brucella spp. cause undulant fever in humans and brucellosis in variety of other animals. Both innate and adaptive immunity have been shown to be important in controlling Brucella infection. Toll-like receptors (TLRs) represent a group of pattern recognition receptors (PRRs) that play critical roles in the host innate immune response, as well as development of adaptive immunity. In the current report, we investigated the role of TLR signaling in the clearance of Brucella and development of adaptive immunity in TLR2(-/-), TLR4(-/-), or MyD88(-/-) mice following aerosol exposure to B. melitensis 16 M. Consistent with previous reports, MyD88 is required for efficient clearance of Brucella from all three organs (lung, spleen, and liver). The results reveal Th2-skewed immune responses in TLR2(-/-) mice late in infection and support a TLR2 requirement for efficient clearance of Brucella from the lungs, but not from the spleen or liver. Similarly, TLR4 is required for efficient clearance of Brucella from the lung, but exhibits a minor contribution to clearance from the spleen and no demonstrable contribution to clearance from the liver. Lymphocyte proliferation assays suggest that the TLRs are not involved in the development of cell-mediated memory response to Brucella antigen. Antibody detection reveals that TLR2 and 4 are required to generate early antigen-specific IgG, but not during the late stages of infection. TLR2 and 4 are only transiently required for IgM production and not at all for IgA production. In contrast, MyD88 is essential for antigen specific IgG production late in infection, but is not required for IgM generation over the course of infection. Surprisingly, despite the prominent role for MyD88 in clearance from all tissues, MyD88-knockout mice express significantly higher levels of serum IgA. These results confirm the important role of MyD88 in controlling infection in the spleen while providing evidence of a prominent contribution to protection in other tissues. In addition, although TLR4 and TLR2 contribute little to control of spleen infection, a significant contribution to clearance of lung infection is described.
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Affiliation(s)
- Jianwu Pei
- Department of Veterinary Pathobiology, Texas A&M University, College Station TX, USA.
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40
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von Bargen K, Gorvel JP, Salcedo SP. Internal affairs: investigating the Brucella intracellular lifestyle. FEMS Microbiol Rev 2012; 36:533-62. [PMID: 22373010 DOI: 10.1111/j.1574-6976.2012.00334.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 01/10/2012] [Accepted: 02/16/2012] [Indexed: 01/18/2023] Open
Abstract
Bacteria of the genus Brucella are Gram-negative pathogens of several animal species that cause a zoonotic disease in humans known as brucellosis or Malta fever. Within their hosts, brucellae reside within different cell types where they establish a replicative niche and remain protected from the immune response. The aim of this article is to discuss recent advances in the field in the specific context of the Brucella intracellular 'lifestyle'. We initially discuss the different host cell targets and their relevance during infection. As it represents the key to intracellular replication, the focus is then set on the maturation of the Brucella phagosome, with particular emphasis on the Brucella factors that are directly implicated in intracellular trafficking and modulation of host cell signalling pathways. Recent data on the role of the type IV secretion system are discussed, novel effector molecules identified and how some of them impact on trafficking events. Current knowledge on Brucella gene regulation and control of host cell death are summarized, as they directly affect intracellular persistence. Understanding how Brucella molecules interplay with their host cell targets to modulate cellular functions and establish the intracellular niche will help unravel how this pathogen causes disease.
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Affiliation(s)
- Kristine von Bargen
- Faculté de Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université, UM 2, Marseille Cedex, France
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