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Guo WH, Zhu YJ, Haimiti G, Xie XR, Niu C, Li M, Shi J, Yin ZW, Yu MK, Ding JB, Zhang FB. Bioinformatics-based design of a fusion vaccine with CTLA-4 variable region to combat Brucella. Braz J Med Biol Res 2023; 56:e12938. [PMID: 37493775 PMCID: PMC10361638 DOI: 10.1590/1414-431x2023e12938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/16/2023] [Indexed: 07/27/2023] Open
Abstract
Brucellosis has become a global zoonotic disease, seriously endangering the health of people all over the world. Vaccination is an effective strategy for protection against Brucella infection in livestock in developed countries. However, current vaccines are pathogenic to humans and pregnant animals, which limits their use. Therefore, it is very important to improve the safety and immune protection of Brucella vaccine. In this study, different bioinformatics approaches were carried out to predict the physicochemical properties, T/B epitope, and tertiary structure of Omp2b and Omp31. Then, these two proteins were sequentially linked, and the Cytotoxic T lymphocyte associated antigen-4 (CTLA-4) variable region was fused to the N-terminal of the epitope sequence. In addition, molecular docking was performed to show that the structure of the fusion protein vaccine had strong affinity with B7 (B7-1, B7-2). This study showed that the designed vaccine containing CTLA-4 had high potency against Brucella, which could provide a reference for the future development of efficient brucellosis vaccines.
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Affiliation(s)
- W H Guo
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Y J Zhu
- Department of Reproductive Assistance, Center for Reproductive Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - G Haimiti
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - X R Xie
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - C Niu
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - M Li
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - J Shi
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Z W Yin
- The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - M K Yu
- School of Life Science and Technology, Southeast University, Nanjing, China
| | - J B Ding
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - F B Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
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2
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Hans R, Thavaselvam D. Immunoassay-based evaluation of rOmp28 protein as a candidate for the identification of Brucella species. J Med Microbiol 2023; 72. [PMID: 37367949 DOI: 10.1099/jmm.0.001718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023] Open
Abstract
Introduction. Brucellosis is an important bacterial zoonosis, re-emerging as a serious public health concern in developing countries. Two major species, Brucella melitensis and Brucella abortus, cause recurrent facile infection in human. Therefore, rapid and accurate diagnosis for early disease control and prevention is needed in areas with low disease burden.Hypothesis. This study evaluated the sandwich enzyme-linked immunosorbent assay (ELISA) (S-ELISA) immunoassay for potential use of whole-cell (WC) and recombinant outer-membrane protein (rOmp28)-derived IgG polyclonals in sensitive detection of Brucella.Aim. Immunoassay-based WC detection of Brucella species in important sub-clinical matrices at lower limits of detection.Methodology. We purified recombinant rOmp28 with Ni-NTA gel affinity chromatography and produced IgG polyclonal antibodies (pAbs) using BALB/c mice and New Zealand white female rabbits against different antigens (Ags) of Brucella. Checkerboard sandwich ELISA and P/N ratio (optical density of 'P' positive test sample to 'N' negative control) were used for evaluation and optimization of the study. The pAbs were characterized using Western blot analysis and different matrices were spiked with WC Ag of Brucella.Results. Double-antibody S-ELISA was developed using WC Ag-derived rabbit IgG (capture antibody at 10 µg ml-1) and rOmp28-derived mice IgG (detection antibody at 100 µg ml-1) with a detection range of 102 to 108 cells ml-1 and a limit of detection at 102 cells ml-1. A P/N ratio of 1.1 was obtained with WC pAbs as compared to 0.6 and 0.9 ratios with rOmp28-derived pAbs for detecting B. melitensis 16M and B. abortus S99, respectively. An increased P/N ratio of 4.4 was obtained with WC Ag-derived rabbit IgG as compared to 4.2>4.1>2.4 ratios obtained with rabbit IgGs derived against cell envelope (CE), rOmp28 and sonicated antigen (SA) of Brucella with high affinity for rOmp28 Ag analysed on immunoblots. The rOmp28-derived mice IgG revealed two Brucella species at P/N ratios of 11.8 and 6.3, respectively. Upon validation, S-ELISA detected Brucella WCs in human whole blood and sera samples with no cross-reactivity to other related bacteria.Conclusion. The developed S-ELISA is specific and sensitive in early detection of Brucella from different matrices of clinical and non-clinical disease presentation.
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Affiliation(s)
- Richa Hans
- Division of Biodetector Development Test and Evaluation, Defence Research and Development Establishment, Defence Research and Development Organisation, Jhansi Road, Gwalior - 474002, India
| | - Duraipandian Thavaselvam
- Director (PM) O/o Director General Life Sciences (DGLS), Defence Research and Development Organization (DRDO) Headquarters, Ministry of Defence, SSPL Campus, Timarpur, New Delhi - 110011, India
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3
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Richter P, Melzer B, Müller FD. Interacting bactofilins impact cell shape of the MreB-less multicellular Rhodomicrobium vannielii. PLoS Genet 2023; 19:e1010788. [PMID: 37256900 DOI: 10.1371/journal.pgen.1010788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 05/16/2023] [Indexed: 06/02/2023] Open
Abstract
Most non-spherical bacteria rely on the actin-like MreB cytoskeleton to control synthesis of a cell-shaping and primarily rod-like cell wall. Diverging from simple rod shape generally requires accessory cytoskeletal elements, which locally interfere with the MreB-guided cell wall synthesis. Conserved and widespread representatives of this accessory cytoskeleton are bactofilins that polymerize into static, non-polar bundles of filaments. Intriguingly, many species of the Actinobacteria and Rhizobiales manage to grow rod-like without MreB by tip extension, yet some of them still possess bactofilin genes, whose function in cell morphogenesis is unknown. An intricate representative of these tip-growing bacteria is Rhodomicrobium vannielii; a member of the hitherto genetically not tractable and poorly studied Hyphomicrobiaceae within the MreB-less Rhizobiales order. R. vannielii displays complex asymmetric cell shapes and differentiation patterns including filamentous hyphae to produce offspring and to build dendritic multicellular arrays. Here, we introduce techniques to genetically access R. vannielii, and we elucidate the role of bactofilins in its sophisticated morphogenesis. By targeted mutagenesis and fluorescence microscopy, protein interaction studies and peptidoglycan incorporation analysis we show that the R. vannielii bactofilins are associated with the hyphal growth zones and that one of them is essential to form proper hyphae. Another paralog is suggested to represent a novel hybrid and co-polymerizing bactofilin. Notably, we present R. vannielii as a powerful new model to understand prokaryotic cell development and control of multipolar cell growth in the absence of the conserved cytoskeletal element, MreB.
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Affiliation(s)
- Pia Richter
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
- Faculty of Biology, University of Marburg, Marburg, Germany
| | - Brigitte Melzer
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
- Max Rubner-Institute, Federal Research Institute of Nutrition and Food, Kulmbach, Germany
| | - Frank D Müller
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
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4
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Pascual DW, Goodwin ZI, Bhagyaraj E, Hoffman C, Yang X. Activation of mucosal immunity as a novel therapeutic strategy for combating brucellosis. Front Microbiol 2022; 13:1018165. [PMID: 36620020 PMCID: PMC9814167 DOI: 10.3389/fmicb.2022.1018165] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Brucellosis is a disease of livestock that is commonly asymptomatic until an abortion occurs. Disease in humans results from contact of infected livestock or consumption of contaminated milk or meat. Brucella zoonosis is primarily caused by one of three species that infect livestock, Bacillus abortus in cattle, B. melitensis in goats and sheep, and B. suis in pigs. To aid in disease prophylaxis, livestock vaccines are available, but are only 70% effective; hence, improved vaccines are needed to mitigate disease, particularly in countries where disease remains pervasive. The absence of knowing which proteins confer complete protection limits development of subunit vaccines. Instead, efforts are focused on developing new and improved live, attenuated Brucella vaccines, since these mimic attributes of wild-type Brucella, and stimulate host immune, particularly T helper 1-type responses, required for protection. In considering their development, the new mutants must address Brucella's defense mechanisms normally active to circumvent host immune detection. Vaccination approaches should also consider mode and route of delivery since disease transmission among livestock and humans is believed to occur via the naso-oropharyngeal tissues. By arming the host's mucosal immune defenses with resident memory T cells (TRMs) and by expanding the sources of IFN-γ, brucellae dissemination from the site of infection to systemic tissues can be prevented. In this review, points of discussion focus on understanding the various immune mechanisms involved in disease progression and which immune players are important in fighting disease.
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Bialer MG, Ferrero MC, Delpino MV, Ruiz-Ranwez V, Posadas DM, Baldi PC, Zorreguieta A. Adhesive Functions or Pseudogenization of Type Va Autotransporters in Brucella Species. Front Cell Infect Microbiol 2021; 11:607610. [PMID: 33987105 PMCID: PMC8111173 DOI: 10.3389/fcimb.2021.607610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 04/01/2021] [Indexed: 01/18/2023] Open
Abstract
Adhesion to host cells is a key step for successful infection of many bacterial pathogens and may define tropism to different host tissues. To do so, bacteria display adhesins on their surfaces. Brucella is an intracellular pathogen capable of proliferating in a wide variety of cell types. It has been described that BmaC, a large protein that belongs to the classical (type Va) autotransporter family, is required for efficient adhesion of Brucella suis strain 1330 to epithelial cells and fibronectin. Here we show that B. suis 1330 harbors two other type Va autotransporters (BmaA and BmaB), which, although much smaller, share significant sequence similarities with BmaC and contain the essential domains to mediate proper protein translocation to the bacterial surface. Gain and loss of function studies indicated that BmaA, BmaB, and BmaC contribute, to a greater or lesser degree, to adhesion of B. suis 1330 to different cells such as synovial fibroblasts, osteoblasts, trophoblasts, and polarized epithelial cells as well as to extracellular matrix components. It was previously shown that BmaC localizes to a single bacterial pole. Interestingly, we observed here that, similar to BmaC, the BmaB adhesin is localized mostly at a single cell pole, reinforcing the hypothesis that Brucella displays an adhesive pole. Although Brucella species have strikingly similar genomes, they clearly differ in their host preferences. Mainly, the differences identified between species appear to be at loci encoding surface proteins. A careful in silico analysis of the putative type Va autotransporter orthologues from several Brucella strains showed that the bmaB locus from Brucella abortus and both, the bmaA and bmaC loci from Brucella melitensis are pseudogenes in all strains analyzed. Results reported here evidence that all three autotransporters play a role in the adhesion properties of B. suis 1330. However, Brucella spp. exhibit extensive variations in the repertoire of functional adhesins of the classical autotransporter family that can be displayed on the bacterial surface, making them an interesting target for future studies on host preference and tropism.
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Affiliation(s)
- Magalí G Bialer
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina
| | - Mariana C Ferrero
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Victoria Delpino
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Diana M Posadas
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina
| | - Pablo C Baldi
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Angeles Zorreguieta
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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6
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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7
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Bialer MG, Sycz G, Muñoz González F, Ferrero MC, Baldi PC, Zorreguieta A. Adhesins of Brucella: Their Roles in the Interaction with the Host. Pathogens 2020; 9:E942. [PMID: 33198223 PMCID: PMC7697752 DOI: 10.3390/pathogens9110942] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 01/30/2023] Open
Abstract
A central aspect of Brucella pathogenicity is its ability to invade, survive, and replicate in diverse phagocytic and non-phagocytic cell types, leading to chronic infections and chronic inflammatory phenomena. Adhesion to the target cell is a critical first step in the invasion process. Several Brucella adhesins have been shown to mediate adhesion to cells, extracellular matrix components (ECM), or both. These include the sialic acid-binding proteins SP29 and SP41 (binding to erythrocytes and epithelial cells, respectively), the BigA and BigB proteins that contain an Ig-like domain (binding to cell adhesion molecules in epithelial cells), the monomeric autotransporters BmaA, BmaB, and BmaC (binding to ECM components, epithelial cells, osteoblasts, synoviocytes, and trophoblasts), the trimeric autotransporters BtaE and BtaF (binding to ECM components and epithelial cells) and Bp26 (binding to ECM components). An in vivo role has also been shown for the trimeric autotransporters, as deletion mutants display decreased colonization after oral and/or respiratory infection in mice, and it has also been suggested for BigA and BigB. Several adhesins have shown unipolar localization, suggesting that Brucella would express an adhesive pole. Adhesin-based vaccines may be useful to prevent brucellosis, as intranasal immunization in mice with BtaF conferred high levels of protection against oral challenge with B. suis.
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Affiliation(s)
- Magalí G. Bialer
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires 1405, Argentina; (M.G.B.); (G.S.)
| | - Gabriela Sycz
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires 1405, Argentina; (M.G.B.); (G.S.)
| | - Florencia Muñoz González
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires 1113, Argentina; (F.M.G.); (M.C.F.)
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires 1113, Argentina
| | - Mariana C. Ferrero
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires 1113, Argentina; (F.M.G.); (M.C.F.)
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires 1113, Argentina
| | - Pablo C. Baldi
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires 1113, Argentina; (F.M.G.); (M.C.F.)
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires 1113, Argentina
| | - Angeles Zorreguieta
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires 1405, Argentina; (M.G.B.); (G.S.)
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
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8
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Zhu L, Wang Q, Wang Y, Xu Y, Peng D, Huang H, Hu L, Wei K, Zhu R. Comparison of Immune Effects Between Brucella Recombinant Omp10-Omp28-L7/L12 Proteins Expressed in Eukaryotic and Prokaryotic Systems. Front Vet Sci 2020; 7:576. [PMID: 33195494 PMCID: PMC7531237 DOI: 10.3389/fvets.2020.00576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023] Open
Abstract
Brucella, a genus of bacteria that causes brucellosis, infects and threatens domestic animals, and humans in endemic areas. Presently, some live attenuated vaccines of Brucella are used to immunize livestock; however, these vaccines are pathogenic to humans, can provoke abortion when administered to pregnant livestock, and induce antibodies in vaccinated livestock that affect the diagnosis of field infection. It is, therefore, very important for improving the safety and immune protection effects of Brucella vaccine. Currently, recombinant protein-based subunit vaccines are considered promising safe and effective alternatives against brucellosis. Here, we separately expressed the recombinant Omp10-Omp28-L7/L12 proteins of Brucella using eukaryotic and prokaryotic expression systems, which were then used as immunogens for evaluating their immune responses. Taishan Pinus massoniana pollen polysaccharides (TPPPS), an already verified natural adjuvant, was utilized to evaluate the immune conditioning effect on the recombinant proteins. Antibody levels, spleen lymphocyte proliferation, percentages of CD4+ and CD8+ T cells, and cytokine secretion in mice were examined after three successive immunizations. The protective effects against Brucella challenge were also evaluated in mice, and used a live vaccine as a positive control. The results indicated that the immune responses of the recombinant Omp10-Omp28-L7/L12 protein groups were significantly higher than those of the PBS control group. The recombinant Omp10-Omp28-L7/L12 protein expressed in Pichia pastoris (P. pastoris) exhibited a slightly higher expression level and immunogenicity than that expressed in Escherichia coli (E. coli), and the Omp10-Omp28-L7/L12 (P. pastoris) + TPPPS group provided the most pronounced immune effect. The protective results showed that the recombinant Omp10-Omp28-L7/L12 proteins expressed in the two expression systems had significantly better protective effects against Brucella melitensis challenge compared with the negative control, and the addition of TPPPS adjuvant could significantly improve the protective effects of subunit vaccines. However, we also noticed that all of the evaluated subunit vaccines induced less protection than the B. melitensis M5 live vaccine. These results indicate that the combination of recombinant Omp10-Omp28-L7/L12 antigen and TPPPS adjuvant shows potential as an effective brucellosis subunit vaccine, and P. pastoris is a preferred expression system to prepare this recombinant subunit antigen.
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Affiliation(s)
- Lin Zhu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
| | - Qiuju Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
| | - Yujian Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
| | - Yulin Xu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
| | - Duo Peng
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - He Huang
- Shandong New Hope Liuhe Co., Ltd., New Hope Group, Qingdao, China
| | - Liping Hu
- Animal Disease Prevention and Control Center of Shandong Province, Animal Husbandry and Veterinary Bureau of Shandong Province, Jinan, China
| | - Kai Wei
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
| | - Ruiliang Zhu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an, China
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9
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Omp16, a conserved peptidoglycan-associated lipoprotein, is involved in Brucella virulence in vitro. J Microbiol 2020; 58:793-804. [PMID: 32870485 DOI: 10.1007/s12275-020-0144-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/02/2020] [Accepted: 07/09/2020] [Indexed: 01/31/2023]
Abstract
Brucella, the bacterial agent of common zoonotic brucellosis, primarily infects specific animal species. The Brucella outer membrane proteins (Omps) are particularly attractive for developing vaccine and improving diagnostic tests and are associated with the virulence of smooth Brucella strains. Omp16 is a homologue to peptidoglycan-associated lipoproteins (Pals), and an omp16 mutant has not been generated in any Brucella strain until now. Very little is known about the functions and pathogenic mechanisms of Omp16 in Brucella. Here, we confirmed that Omp16 has a conserved Pal domain and is highly conserved in Brucella. We attempted to delete omp16 in Brucella suis vaccine strain 2 (B. suis S2) without success, which shows that Omp16 is vital for Brucella survival. We acquired a B. suis S2 Omp16 mutant via conditional complementation. Omp16 deficiency impaired Brucella outer membrane integrity and activity in vitro. Moreover, inactivation of Omp16 decreased bacterial intracellular survival in macrophage RAW 264.7 cells. B. suis S2 and its derivatives induced marked expression of IL-1β, IL-6, and TNF-a mRNA in Raw 264.7 cells. Whereas inactivation of Omp16 in Brucella enhanced IL-1β and IL-6 expression in Raw 264.7 cells. Altogether, these findings show that the Brucella Omp16 mutant was obtained via conditional complementation and confirmed that Omp16 can maintain outer membrane integrity and be involved in bacterial virulence in Brucella in vitro and in vivo. These results will be important in uncovering the pathogenic mechanisms of Brucella.
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10
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Sulkowski NI, Hardy GG, Brun YV, Bharat TAM. A Multiprotein Complex Anchors Adhesive Holdfast at the Outer Membrane of Caulobacter crescentus. J Bacteriol 2019; 201:e00112-19. [PMID: 31061167 PMCID: PMC6707917 DOI: 10.1128/jb.00112-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/26/2019] [Indexed: 01/11/2023] Open
Abstract
Adhesion allows microbes to colonize surfaces and is the first stage in biofilm formation. Stable attachment of the freshwater alphaproteobacterium Caulobacter crescentus to surfaces requires an adhesive polysaccharide called holdfast, which is synthesized at a specific cell pole and ultimately found at the tip of cylindrical extensions of the cell envelope called stalks. Secretion and anchoring of holdfast to the cell surface are governed by proteins HfsDAB and HfaABD, respectively. The arrangement and organization of these proteins with respect to each other and the cell envelope, and the mechanism by which the holdfast is anchored on cells, are unknown. In this study, we have imaged a series of C. crescentus mutants using electron cryotomography, revealing the architecture and arrangement of the molecular machinery involved in holdfast anchoring in cells. We found that the holdfast is anchored to cells by a defined complex made up of the HfaABD proteins and that the HfsDAB secretion proteins are essential for proper assembly and localization of the HfaABD anchor. Subtomogram averaging of cell stalk tips showed that the HfaABD complex spans the outer membrane. The anchor protein HfaB is the major component of the anchor complex located on the periplasmic side of the outer membrane, while HfaA and HfaD are located on the cell surface. HfaB is the critical component of the complex, without which no HfaABD complex was observed in cells. These results allow us to propose a working model of holdfast anchoring, laying the groundwork for further structural and cell biological investigations.IMPORTANCE Adhesion and biofilm formation are fundamental processes that accompany bacterial colonization of surfaces, which are of critical importance in many infections. Caulobacter crescentus biofilm formation proceeds via irreversible adhesion mediated by a polar polysaccharide called holdfast. Mechanistic and structural details of how the holdfast is secreted and anchored on cells are still lacking. Here, we have assigned the location and described the arrangement of the holdfast anchor complex. This work increases our knowledge of the relatively underexplored field of polysaccharide-mediated adhesion by identifying structural elements that anchor polysaccharides to the cell envelope, which is important in a variety of bacterial species.
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Affiliation(s)
- Nina I Sulkowski
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- Central Oxford Structural and Molecular Imaging Centre, Oxford, United Kingdom
| | - Gail G Hardy
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Yves V Brun
- Department of Biology, Indiana University, Bloomington, Indiana, USA
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Tanmay A M Bharat
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- Central Oxford Structural and Molecular Imaging Centre, Oxford, United Kingdom
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11
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Zhou D, Zhi FJ, Qi MZ, Bai FR, Zhang G, Li JM, Liu H, Chen HT, Lin PF, Tang KQ, Liu W, Jin YP, Wang AH. Brucella induces unfolded protein response and inflammatory response via GntR in alveolar macrophages. Oncotarget 2017; 9:5184-5196. [PMID: 29435171 PMCID: PMC5797042 DOI: 10.18632/oncotarget.23706] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/04/2017] [Indexed: 01/18/2023] Open
Abstract
Brucella is an intracellular bacterium that causes the zoonosis brucellosis worldwide. Alveolar macrophages (AM) constitute the main cell target of inhaled Brucella. Brucella thwarts immune surveillance and evokes endoplasmic reticulum (ER) stress to replicate in macrophages via virulence factors. The GntR regulators family was concentrated as an important virulence factor in controlling virulence and intracellular survival of Brucella. However, the detailed underlying mechanism for the host-pathogen interaction is poorly understood. In this study the BSS2_II0438 mutant (ΔGntR) was constructed. The type IV secretion system (T4SS) virulence factor genes (VirB2, VirB6, and VirB8) were down-expression in ΔGntR. ΔGntR could infect and proliferate to high titers in GAMs without a significant difference compared with the parental strain. ΔGntR infection increased the expression of ER stress marker genes GRP78, ATF6, and PERK in the early stages of its intracellular cycle but decreased the expression of these genes in the late stages. ΔGntR increased greatly the number of Brucella CFUs in the inactive ER stress state in GAMs. Meanwhile, ΔGntR infection increased the levels of IFN-γ, IL-1β, and TNF-α, indicating ΔGntR could induce the secretion of inflammatory but not anti-inflammatory cytokines IL-10. Taken together, our results clarified the role of the GntR in B. suis. S2 virulence expression and elucidated that GntR is potentially involved in the signaling pathway of the Brucella-induced UPR and inflammatory response in GAMs.
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Affiliation(s)
- Dong Zhou
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fei-Jie Zhi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Mao-Zhen Qi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fu-Rong Bai
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Guangdong Zhang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Jun-Mei Li
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Huan Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Hua-Tao Chen
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Peng-Fei Lin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ke-Qiong Tang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Wei Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ya-Ping Jin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ai-Hua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
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12
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Pascual DW, Yang X, Wang H, Goodwin Z, Hoffman C, Clapp B. Alternative strategies for vaccination to brucellosis. Microbes Infect 2017; 20:599-605. [PMID: 29287984 DOI: 10.1016/j.micinf.2017.12.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/11/2017] [Indexed: 01/18/2023]
Abstract
Brucellosis remains burdensome for livestock and humans worldwide. Better vaccines for protection are needed to reduce disease incidence. Immunity to brucellosis and barriers to protection are discussed. The benefits and limitations of conventional and experimental brucellosis vaccines are outlined, and novel vaccination strategies needed to ultimately protect against brucellosis are introduced.
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Affiliation(s)
- David W Pascual
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA.
| | - Xinghong Yang
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Hongbin Wang
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Zakia Goodwin
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Carol Hoffman
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Beata Clapp
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
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13
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Pathogens of Food Animals: Sources, Characteristics, Human Risk, and Methods of Detection. ADVANCES IN FOOD AND NUTRITION RESEARCH 2017; 82:277-365. [PMID: 28427535 DOI: 10.1016/bs.afnr.2016.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pathogens associated with food production (livestock) animals come in many forms causing a multitude of disease for humans. For the purpose of this review, these infectious agents can be divided into three broad categories: those that are associated with bacterial disease, those that are associated with viruses, and those that are parasitic in nature. The goal of this chapter is to provide the reader with an overview of the most common pathogens that cause disease in humans through exposure via the food chain and the consequence of this exposure as well as risk and detection methods. We have also included a collection of unusual pathogens that although rare have still caused disease, and their recognition is warranted in light of emerging and reemerging diseases. These provide the reader an understanding of where the next big outbreak could occur. The influence of the global economy, the movement of people, and food makes understanding production animal-associated disease paramount to being able to address new diseases as they arise.
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14
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Francis N, Poncin K, Fioravanti A, Vassen V, Willemart K, Ong TAP, Rappez L, Letesson JJ, Biondi EG, De Bolle X. CtrA controls cell division and outer membrane composition of the pathogenBrucella abortus. Mol Microbiol 2017; 103:780-797. [DOI: 10.1111/mmi.13589] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Nayla Francis
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Katy Poncin
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Antonella Fioravanti
- Unité de Glycobiologie Structurale et Fonctionnelle; UMR 8576 CNRS - Université de Lille; 50 Avenue Halley Villeneuve d'Ascq France
| | - Victoria Vassen
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Kevin Willemart
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Thi Anh Phuong Ong
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Luca Rappez
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Jean-Jacques Letesson
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
| | - Emanuele G. Biondi
- Unité de Glycobiologie Structurale et Fonctionnelle; UMR 8576 CNRS - Université de Lille; 50 Avenue Halley Villeneuve d'Ascq France
- Laboratoire de Chimie Bactérienne; Institut de Microbiologie de la Méditerranée, Aix-Marseille Université, CNRS; UMR 7283 Marseille France
| | - Xavier De Bolle
- Microorganisms Biology Research Unit (URBM); Narilis, University of Namur; Namur Belgium
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15
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Yin D, Li L, Song D, Liu Y, Ju W, Song X, Wang J, Pang B, Xu K, Li J. A novel recombinant multi-epitope protein against Brucella melitensis infection. Immunol Lett 2016; 175:1-7. [DOI: 10.1016/j.imlet.2016.04.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/16/2016] [Accepted: 04/26/2016] [Indexed: 01/22/2023]
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16
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Short-Stalked Prosthecomicrobium hirschii Cells Have a Caulobacter-Like Cell Cycle. J Bacteriol 2016; 198:1149-59. [PMID: 26833409 DOI: 10.1128/jb.00896-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/24/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The dimorphic alphaproteobacterium Prosthecomicrobium hirschii has both short-stalked and long-stalked morphotypes. Notably, these morphologies do not arise from transitions in a cell cycle. Instead, the maternal cell morphology is typically reproduced in daughter cells, which results in microcolonies of a single cell type. In this work, we further characterized the short-stalked cells and found that these cells have a Caulobacter-like life cycle in which cell division leads to the generation of two morphologically distinct daughter cells. Using a microfluidic device and total internal reflection fluorescence (TIRF) microscopy, we observed that motile short-stalked cells attach to a surface by means of a polar adhesin. Cells attached at their poles elongate and ultimately release motile daughter cells. Robust biofilm growth occurs in the microfluidic device, enabling the collection of synchronous motile cells and downstream analysis of cell growth and attachment. Analysis of a draft P. hirschii genome sequence indicates the presence of CtrA-dependent cell cycle regulation. This characterization of P. hirschii will enable future studies on the mechanisms underlying complex morphologies and polymorphic cell cycles. IMPORTANCE Bacterial cell shape plays a critical role in regulating important behaviors, such as attachment to surfaces, motility, predation, and cellular differentiation; however, most studies on these behaviors focus on bacteria with relatively simple morphologies, such as rods and spheres. Notably, complex morphologies abound throughout the bacteria, with striking examples, such as P. hirschii, found within the stalked Alphaproteobacteria. P. hirschii is an outstanding candidate for studies of complex morphology generation and polymorphic cell cycles. Here, the cell cycle and genome of P. hirschii are characterized. This work sets the stage for future studies of the impact of complex cell shapes on bacterial behaviors.
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17
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Kang YX, Li XM, Piao DR, Tian GZ, Jiang H, Jia EH, Lin L, Cui BY, Chang YF, Guo XK, Zhu YZ. Typing Discrepancy Between Phenotypic and Molecular Characterization Revealing an Emerging Biovar 9 Variant of Smooth Phage-Resistant B. abortus Strain 8416 in China. Front Microbiol 2015; 6:1375. [PMID: 26696984 PMCID: PMC4672676 DOI: 10.3389/fmicb.2015.01375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/19/2015] [Indexed: 11/23/2022] Open
Abstract
A newly isolated smooth colony morphology phage-resistant strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of Brucella melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 could not be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella sp. is subject to variation and the routine Brucella biovar typing needs further studies.
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Affiliation(s)
- Yao-Xia Kang
- Department of Immunology and Microbiology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China ; Baotou Municipal Center for Disease Control and Prevention Baotou, China
| | - Xu-Ming Li
- Department of Immunology and Microbiology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Dong-Ri Piao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention Beijing, China
| | - Guo-Zhong Tian
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention Beijing, China
| | - Hai Jiang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention Beijing, China
| | - En-Hou Jia
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention Beijing, China
| | - Liang Lin
- Baotou Municipal Center for Disease Control and Prevention Baotou, China
| | - Bu-Yun Cui
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention Beijing, China
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca NY, USA
| | - Xiao-Kui Guo
- Department of Immunology and Microbiology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Yong-Zhang Zhu
- Department of Immunology and Microbiology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China ; Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca NY, USA
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18
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De Bolle X, Crosson S, Matroule JY, Letesson JJ. Brucella abortus Cell Cycle and Infection Are Coordinated. Trends Microbiol 2015; 23:812-821. [PMID: 26497941 DOI: 10.1016/j.tim.2015.09.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 09/09/2015] [Accepted: 09/24/2015] [Indexed: 12/29/2022]
Abstract
Brucellae are facultative intracellular pathogens. The recent development of methods and genetically engineered strains allowed the description of cell-cycle progression of Brucella abortus, including unipolar growth and the ordered initiation of chromosomal replication. B. abortus cell-cycle progression is coordinated with intracellular trafficking in the endosomal compartments. Bacteria are first blocked at the G1 stage, growth and chromosome replication being resumed shortly before reaching the intracellular proliferation compartment. The control mechanisms of cell cycle are similar to those reported for the bacterium Caulobacter crescentus, and they are crucial for survival in the host cell. The development of single-cell analyses could also be applied to other bacterial pathogens to investigate their cell-cycle progression during infection.
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Affiliation(s)
- Xavier De Bolle
- University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium.
| | - Sean Crosson
- University of Chicago, Gordon Center for Integrative Science W125, 929 E. 57th Street, Chicago, IL 60637, USA
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19
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Interaction network and localization of Brucella abortus membrane proteins involved in the synthesis, transport, and succinylation of cyclic β-1,2-glucans. J Bacteriol 2015; 197:1640-8. [PMID: 25733613 DOI: 10.1128/jb.00068-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 02/22/2015] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Cyclic β-1,2-glucans (CβG) are periplasmic homopolysaccharides that play an important role in the virulence and interaction of Brucella with the host. Once synthesized in the cytoplasm by the CβG synthase (Cgs), CβG are transported to the periplasm by the CβG transporter (Cgt) and succinylated by the CβG modifier enzyme (Cgm). Here, we used a bacterial two-hybrid system and coimmunoprecipitation techniques to study the interaction network between these three integral inner membrane proteins. Our results indicate that Cgs, Cgt, and Cgm can form both homotypic and heterotypic interactions. Analyses carried out with Cgs mutants revealed that the N-terminal region of the protein (Cgs region 1 to 418) is required to sustain the interactions with Cgt and Cgm as well as with itself. We demonstrated by single-cell fluorescence analysis that in Brucella, Cgs and Cgt are focally distributed in the membrane, particularly at the cell poles, whereas Cgm is mostly distributed throughout the membrane with a slight accumulation at the poles colocalizing with the other partners. In summary, our results demonstrate that Cgs, Cgt, and Cgm form a membrane-associated biosynthetic complex. We propose that the formation of a membrane complex could serve as a mechanism to ensure the fidelity of CβG biosynthesis by coordinating their synthesis with the transport and modification. IMPORTANCE In this study, we analyzed the interaction and localization of the proteins involved in the synthesis, transport, and modification of Brucella abortus cyclic β-1,2-glucans (CβG), which play an important role in the virulence and interaction of Brucella with the host. We demonstrate that these proteins interact, forming a complex located mainly at the cell poles; this is the first experimental evidence of the existence of a multienzymatic complex involved in the metabolism of osmoregulated periplasmic glucans in bacteria and argues for another example of pole differentiation in Brucella. We propose that the formation of this membrane complex could serve as a mechanism to ensure the fidelity of CβG biosynthesis by coordinating synthesis with the transport and modification.
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20
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The essential features and modes of bacterial polar growth. Trends Microbiol 2015; 23:347-53. [PMID: 25662291 DOI: 10.1016/j.tim.2015.01.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/19/2014] [Accepted: 01/07/2015] [Indexed: 01/25/2023]
Abstract
Polar growth represents a surprising departure from the canonical dispersed cell growth model. However, we know relatively little of the underlying mechanisms governing polar growth or the requisite suite of factors that direct polar growth. Underscoring how classic doctrine can be turned on its head, the peptidoglycan layer of polar-growing bacteria features unusual crosslinks and in some species the quintessential cell division proteins FtsA and FtsZ are recruited to the growing poles. Remarkably, numerous medically important pathogens utilize polar growth, accentuating the need for intensive research in this area. Here we review models of polar growth in bacteria based on recent research in the Actinomycetales and Rhizobiales, with emphasis on Mycobacterium and Agrobacterium species.
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21
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Ronneau S, Moussa S, Barbier T, Conde-Álvarez R, Zuniga-Ripa A, Moriyon I, Letesson JJ. Brucella, nitrogen and virulence. Crit Rev Microbiol 2014; 42:507-25. [PMID: 25471320 DOI: 10.3109/1040841x.2014.962480] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.
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Affiliation(s)
| | - Simon Moussa
- a UNamur, URBM 61 rue de Bruxelles , Namur , Belgium and
| | | | - Raquel Conde-Álvarez
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Amaia Zuniga-Ripa
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Ignacio Moriyon
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
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22
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Ghasemi A, Jeddi-Tehrani M, Mautner J, Salari MH, Zarnani AH. Immunization of mice with a novel recombinant molecular chaperon confers protection against Brucella melitensis infection. Vaccine 2014; 32:6659-66. [DOI: 10.1016/j.vaccine.2014.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 01/21/2023]
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23
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Deghelt M, Mullier C, Sternon JF, Francis N, Laloux G, Dotreppe D, Van der Henst C, Jacobs-Wagner C, Letesson JJ, De Bolle X. G1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus. Nat Commun 2014; 5:4366. [PMID: 25006695 PMCID: PMC4104442 DOI: 10.1038/ncomms5366] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 06/10/2014] [Indexed: 12/15/2022] Open
Abstract
Several intracellular pathogens, such as Brucella abortus, display a biphasic infection process starting with a non-proliferative stage of unclear nature. Here, we study the cell cycle of B. abortus at the single-cell level, in culture and during infection of HeLa cells and macrophages. The localization of segregation and replication loci of the two bacterial chromosomes indicates that, immediately after being engulfed by host-cell endocytic vacuoles, most bacterial cells are newborn. These bacterial cells do not initiate DNA replication for the next 4 to 6 h, indicating a G1 arrest. Moreover, growth is completely stopped during that time, reflecting a global cell cycle block. Growth and DNA replication resume later, although bacteria still reside within endosomal-like compartments. We hypothesize that the predominance of G1-arrested bacteria in the infectious population, and the bacterial cell cycle arrest following internalization, may constitute a widespread strategy among intracellular pathogens to colonize new proliferation niches. Certain pathogenic bacteria such as Brucella abortus undergo a temporary non-proliferative stage after infecting host cells. Here, the authors study chromosomal replication and segregation in B. abortus during infection, showing that the non-proliferative stage consists of G1-arrested newborn cells.
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Affiliation(s)
- Michaël Deghelt
- 1] Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium [2]
| | - Caroline Mullier
- 1] Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium [2]
| | - Jean-François Sternon
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
| | - Nayla Francis
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
| | - Géraldine Laloux
- 1] Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA [2] Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520, USA [3] Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Delphine Dotreppe
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
| | - Charles Van der Henst
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
| | - Christine Jacobs-Wagner
- 1] Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA [2] Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520, USA [3] Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Jean-Jacques Letesson
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
| | - Xavier De Bolle
- Microorganisms biology research unit (URBM), University of Namur (UNamur), Namur, Belgium
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24
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Ojcius DM. Another year of microbial pathogens and the host immune response. Microbes Infect 2014; 16:1. [PMID: 24434009 DOI: 10.1016/j.micinf.2013.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Affiliation(s)
- David M Ojcius
- Health Sciences Research Institute, University of California, Merced, USA.
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25
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Greub G. Pathogenesis and cell corruption by intracellular bacteria. Microbes Infect 2013; 15:969-70. [DOI: 10.1016/j.micinf.2013.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 10/10/2013] [Indexed: 12/19/2022]
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