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Saposnik L, Coria LM, Bruno L, Guaimas FF, Pandolfi J, Pol M, Urga ME, Sabbione F, McClelland M, Trevani A, Pasquevich KA, Cassataro J. Ecotin protects Salmonella Typhimurium against the microbicidal activity of host proteases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594389. [PMID: 38798423 PMCID: PMC11118277 DOI: 10.1101/2024.05.15.594389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Salmonella enterica serovar Typhimurium causes acute diarrhea upon oral infection in humans. The harsh and proteolytic environment found in the gastrointestinal tract is the first obstacle that these bacteria face after infection. However, the mechanisms that allow Salmonella to survive the hostile conditions of the gut are poorly understood. The ecotin gene is found in an extensive range of known phyla of bacteria and it encodes a protein that has been shown to inhibit serine proteases. Thus, in the present work we studied the role of ecotin of Salmonella Typhimurium in host-pathogen interactions. We found that Salmonella Typhimurium Δ ecotin strain exhibited lower inflammation in a murine model of Salmonella induced colitis. The Δ ecotin mutant was more susceptible to the action of pancreatin and purified pancreatic elastase. In addition, the lack of ecotin led to impaired adhesion to Caco-2 and HT-29 cell lines, related to the proteolytic activity of brush border enzymes. Besides, Δ ecotin showed higher susceptibility to lysosomal proteolytic content and intracellular replication defects in macrophages. In addition, we found Ecotin to have a crucial role in Salmonella against the microbicide action of granules released and neutrophil extracellular traps from human polymorphonuclear leukocytes. Thus, the work presented here highlights the importance of ecotin in Salmonella as countermeasures against the host proteolytic defense system. IMPORTANCE The gastrointestinal tract is a very complex and harsh environment. Salmonella is a successful food borne pathogen, but little is known about its capacity to survive against the proteolysis of the gut lumen and intracellular proteases. Here, we show that Ecotin, a serine protease inhibitor, plays an important role in protecting Salmonella against proteases present at different sites encountered during oral infection. Our results indicate that Ecotin is an important virulence factor in Salmonella , adding another tool to the wide range of features this pathogen uses during oral infection.
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Yu H, Gu X, Wang D, Wang Z. Brucella infection and Toll-like receptors. Front Cell Infect Microbiol 2024; 14:1342684. [PMID: 38533384 PMCID: PMC10963510 DOI: 10.3389/fcimb.2024.1342684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/17/2024] [Indexed: 03/28/2024] Open
Abstract
Brucella consists of gram-negative bacteria that have the ability to invade and replicate in professional and non-professional phagocytes, and its prolonged persistence in the host leads to brucellosis, a serious zoonosis. Toll-like receptors (TLRs) are the best-known sensors of microorganisms implicated in the regulation of innate and adaptive immunity. In particular, TLRs are transmembrane proteins with a typical structure of an extracellular leucine-rich repeat (LRR) region and an intracellular Toll/interleukin-1 receptor (TIR) domain. In this review, we discuss Brucella infection and the aspects of host immune responses induced by pathogens. Furthermore, we summarize the roles of TLRs in Brucella infection, with substantial emphasis on the molecular insights into its mechanisms of action.
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Affiliation(s)
- Hui Yu
- Inner Mongolia Key Laboratory of Disease-Related Biomarkers, The Second Affiliated Hospital, Baotou Medical College, Baotou, China
- School of Basic Medicine, Baotou Medical College, Baotou, China
| | - Xinyi Gu
- The College of Medical Technology, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Danfeng Wang
- The College of Medical Technology, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Zhanli Wang
- Inner Mongolia Key Laboratory of Disease-Related Biomarkers, The Second Affiliated Hospital, Baotou Medical College, Baotou, China
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Yang J, Wang Y, Hou Y, Sun M, Xia T, Wu X. Evasion of host defense by Brucella. CELL INSIGHT 2024; 3:100143. [PMID: 38250017 PMCID: PMC10797155 DOI: 10.1016/j.cellin.2023.100143] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 01/23/2024]
Abstract
Brucella , an adept intracellular pathogen, causes brucellosis, a zoonotic disease leading to significant global impacts on animal welfare and the economy. Regrettably, there is currently no approved and effective vaccine for human use. The ability of Brucella to evade host defenses is essential for establishing chronic infection and ensuring stable intracellular growth. Brucella employs various mechanisms to evade and undermine the innate and adaptive immune responses of the host through modulating the activation of pattern recognition receptors (PRRs), inflammatory responses, or the activation of immune cells like dendritic cells (DCs) to inhibit antigen presentation. Moreover, it regulates multiple cellular processes such as apoptosis, pyroptosis, and autophagy to establish persistent infection within host cells. This review summarizes the recently discovered mechanisms employed by Brucella to subvert host immune responses and research progress on vaccines, with the aim of advancing our understanding of brucellosis and facilitating the development of more effective vaccines and therapeutic approaches against Brucella .
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Affiliation(s)
- Jinke Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Yue Wang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Yuanpan Hou
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Mengyao Sun
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Tian Xia
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Xin Wu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
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Wang S, Yin Y, Zai X, Gu Y, Guo F, Shao F, Zhang Y, Li Y, Li R, Zhang J, Xu J, Chen W. A novel Galleria mellonella experimental model for zoonotic pathogen Brucella. Virulence 2023; 14:2268496. [PMID: 37817444 PMCID: PMC10599192 DOI: 10.1080/21505594.2023.2268496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/04/2023] [Indexed: 10/12/2023] Open
Abstract
Brucellosis is a major threat to public health and animal husbandry. Several in vivo vertebrate models, such as mice, guinea pigs, and nonhuman primates, have been used to study Brucella pathogenesis, bacteria-host interactions, and vaccine efficacy. However, these models have limitations whereas the invertebrate Galleria mellonella model is a cost-effective and ethical alternative. The aim of the present study was to examine the invertebrate G. mellonella as an in vivo infection model for Brucella. Infection assays were employed to validate the fitness of the larval model for Brucella infection and virulence evaluation. The protective efficacy of immune sera was evaluated by pre-incubated with a lethal dose of bacteria before infection. The consistency between the mouse model and the larval model was confirmed by assessing the protective efficacy of two Brucella vaccine strains. The results show that G. mellonella could be infected by Brucella strains, in a dose- and temperature-dependent way. Moreover, this larval model can effectively evaluate the virulence of Brucella strains in a manner consistent with that of mammalian infection models. Importantly, this model can assess the protective efficacy of vaccine immune sera within a day. Further investigation implied that haemolymph played a crucial role in the protective efficacy of immune sera. In conclusion, G. mellonella could serve as a quick, efficient, and reliable model for evaluating the virulence of Brucella strains and efficacy of immune sera in an ethical manner.
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Affiliation(s)
- Shuyi Wang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Xiaodong Zai
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yanfei Gu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Fengyu Guo
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Fangze Shao
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yue Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yaohui Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ruihua Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
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Wu A, Wang Y, Ali A, Xu Z, Zhang D, Zhumanov K, Sheng J, Yi J. Design of a multi-epitope vaccine against brucellosis fused to IgG-fc by an immunoinformatics approach. Front Vet Sci 2023; 10:1238634. [PMID: 37937155 PMCID: PMC10625910 DOI: 10.3389/fvets.2023.1238634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/27/2023] [Indexed: 11/09/2023] Open
Abstract
Introduction Brucella, a type of intracellular Gram-negative bacterium, has unique features and acts as a zoonotic pathogen. It can lead to abortion and infertility in animals. Eliminating brucellosis becomes very challenging once it spreads among both humans and animals, putting a heavy burden on livestock and people worldwide. Given the increasing spread of brucellosis, it is crucial to develop improved vaccines for susceptible animals to reduce the disease's impact. Methods In this study, we effectively used an immunoinformatics approach with advanced computer software to carefully identify and analyze important antigenic parts of Brucella abortus. Subsequently, we skillfully designed chimeric peptides to enhance the vaccine's strength and effectiveness. We used computer programs to find four important parts of the Brucella bacteria that our immune system recognizes. Then, we carefully looked for eight parts that are recognized by a type of white blood cell called cytotoxic T cells, six parts recognized by T helper cells, and four parts recognized by B cells. We connected these parts together using a special link, creating a strong new vaccine. To make the vaccine even better, we added some extra parts called molecular adjuvants. These included something called human β-defensins 3 (hBD-3) that we found in a database, and another part that helps the immune system called PADRE. We attached these extra parts to the beginning of the vaccine. In a new and clever way, we made the vaccine even stronger by attaching a part from a mouse's immune system to the end of it. This created a new kind of vaccine called MEV-Fc. We used advanced computer methods to study how well the MEV-Fc vaccine interacts with certain receptors in the body (TLR-2 and TLR-4). Results In the end, Immunosimulation predictions showed that the MEV-Fc vaccine can make the immune system respond strongly, both in terms of cells and antibodies. Discussion In summary, our results provide novel insights for the development of Brucella vaccines. Although further laboratory experiments are required to assess its protective effect.
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Affiliation(s)
- Aodi Wu
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Yueli Wang
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Adnan Ali
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Zhenyu Xu
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Dongsheng Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Kairat Zhumanov
- College of Veterinary Medicine, Kazakhstan Kazakh State Agricultural University, Almaty, Kazakhstan
| | - Jinliang Sheng
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Jihai Yi
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
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Zhi F, Fang J, Zheng W, Li J, Zhang G, Zhou D, Jin Y, Wang A. A Brucella Omp16 Conditional Deletion Strain Is Attenuated in BALB/c Mice. J Microbiol Biotechnol 2022; 32:6-14. [PMID: 34675138 PMCID: PMC9628832 DOI: 10.4014/jmb.2107.07016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/26/2021] [Accepted: 10/18/2021] [Indexed: 01/18/2023]
Abstract
Brucella spp. are facultative intracellular pathogens that invade, survive and proliferate in numerous phagocytic and non-phagocytic cell types, thereby leading to human and animal brucellosis. Outer membrane proteins (Omps) are major immunogenic and protective antigens that are implicated in Brucella virulence. A strain deleted of the omp16 gene has not been obtained which suggests that the Omp16 protein is vital for Brucella survival. Nevertheless, we previously constructed an omp16 conditional deletion strain of Brucella, ΔOmp16. Here, the virulence and immune response elicted by this strain were assessed in a mouse model of infection. Splenomegaly was significantly reduced at two weeks post-infection in ΔOmp16-infected mice compared to infection with the parental strain. The bacterial load in the spleen also was significantly decreased at this post-infection time point in ΔOmp16-infected mice. Histopathological changes in the spleen were observed via hematoxylineosin staining and microscopic examination which showed that infection with the ΔOmp16 strain alleviated spleen histopathological alterations compared to mice infected with the parental strain. Moreover, the levels of humoral and cellular immunity were similar in both ΔOmp16-infected mice and parental strain-infected mice. The results overall show that the virulence of ΔOmp16 is attenuated markedly, but that the immune responses mediated by the deletion and parental strains in mice are indistinguishable. The data provide important insights that illuminate the pathogenic strategies adopted by Brucella.
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Affiliation(s)
- Feijie Zhi
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China
| | - Jiaoyang Fang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China
| | - Weifang Zheng
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China
| | - Junmei Li
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China
| | - Guangdong Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China
| | - Dong Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, P.R. China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, P.R. China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, P.R. China,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, P.R. China,Corresponding author Phone: +862987082869 E-mail:
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Laura Darriba M, Castro CP, Coria LM, Bruno L, Laura Cerutti M, Otero LH, Chemes LB, Rasia RM, Klinke S, Cassataro J, Pasquevich KA. A disordered region retains the full protease inhibitor activity and the capacity to induce CD8+ T cells in vivo of the oral vaccine adjuvant U-Omp19. Comput Struct Biotechnol J 2022; 20:5098-5114. [PMID: 36187929 PMCID: PMC9486555 DOI: 10.1016/j.csbj.2022.08.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 01/18/2023] Open
Affiliation(s)
- M. Laura Darriba
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Celeste Pueblas Castro
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Lorena M. Coria
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Laura Bruno
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - M. Laura Cerutti
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Lisandro H. Otero
- Fundación Instituto Leloir, IIBBA-CONICET, and Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Lucía B. Chemes
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Rodolfo M. Rasia
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Santa Fe, Argentina and Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir, IIBBA-CONICET, and Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Juliana Cassataro
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Karina A. Pasquevich
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, Buenos Aires, Argentina
- Corresponding author.
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An ArsR Transcriptional Regulator Facilitates Brucella sp. Survival via Regulating Self and Outer Membrane Protein. Int J Mol Sci 2021; 22:ijms221910860. [PMID: 34639201 PMCID: PMC8509827 DOI: 10.3390/ijms221910860] [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: 09/02/2021] [Revised: 09/21/2021] [Accepted: 09/26/2021] [Indexed: 12/30/2022] Open
Abstract
The arsenic acid-resistant (ArsR) family transcriptional regulators are widely distributed in microorganisms, including in the facultative intracellular pathogen Brucella spp. ArsR proteins are implicated in numerous biological processes. However, the specific roles of ArsR family members in Brucella remain obscure. Here, we show that ArsR6 (BSS2_RS07325) is required for Brucella survival both under heat, oxidative, and osmotic stress and in a murine infection model in vivo. RNA-seq and ChIP-seq reveal that 34 potential target genes for ArsR6 protein were identified, among which eight genes were up-regulated and 26 genes were down-regulated, including outer membrane protein 25D (Omp25D). ArsR6 autoregulates its own expression to maintain bacterial intracellular Cu/Ni homeostasis to benefit bacterial survival in hostile environments. Moreover, ArsR6 also regulates the production of virulence factor Omp25D, which is important for the survival of Brucella under stress conditions. Significantly, Omp25D deletion strain attenuated in a murine infection model in vivo. Altogether, our findings reveal a unique mechanism in which the ArsR family member ArsR6 autoregulates its expression and also modulates Omp25D expression to maintain metal ion homeostasis and virulence in Brucella.
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Li R, Liu W, Yin X, Zheng F, Wang Z, Wu X, Zhang X, Du Q, Huang Y, Tong D. Brucella spp. Omp25 Promotes Proteasome-Mediated cGAS Degradation to Attenuate IFN-β Production. Front Microbiol 2021; 12:702881. [PMID: 34394047 PMCID: PMC8358459 DOI: 10.3389/fmicb.2021.702881] [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: 04/30/2021] [Accepted: 06/22/2021] [Indexed: 11/13/2022] Open
Abstract
Type I interferons (IFN), a family of cytokines widely expressed in various tissues, play important roles in anti-infection immunity. Nevertheless, it is not known whether Brucella spp. could interfere with IFN-I production induced by other pathogens. This study investigated the regulatory roles of Brucella outer membrane protein (Omp)25 on the IFN-I signaling pathway and found that Omp25 inhibited the production of IFN-β and its downstream IFN-stimulated genes induced by various DNA viruses or IFN-stimulatory DNA in human, murine, porcine, bovine, and ovine monocyte/macrophages or peripheral blood mononuclear cells. Brucella Omp25 suppressed the phosphorylation of stimulator of IFN genes (STINGs) and IFN regulatory factor 3 and nuclear translocation of phosphorylated IFN regulatory factor 3 in pseudorabies virus- or herpes simplex virus-1-infected murine, human, or porcine macrophages. Furthermore, we found that Brucella Omp25 promoted cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) degradation via the proteasome-dependent pathway, resulting in a decreased cyclic guanosine monophosphate-adenosine monophosphate production and downstream signaling activation upon DNA virus infection or IFN-stimulatory DNA stimulation. Mapping the predominant function domain of Omp25 showed that the amino acids 161 to 184 of Omp25 were required for Omp25-induced cGAS degradation, among which five amino acid residues (R176, Y179, R180, Y181, and Y184) were required for the inhibitory effect of Omp25 on IFN-β induction. Altogether, our results demonstrated that Brucella Omp25 inhibits cGAS STING signaling pathway-induced IFN-β via facilitating the ubiquitin-proteasome-dependent degradation of cGAS in various mammalian monocyte/macrophages.
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Affiliation(s)
- Ruizhen Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Wenli Liu
- School Hospital, Northwest A&F University, Yangling, China
| | - Xiangrui Yin
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fangfang Zheng
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Zhenyu Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xingchen Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xiaohua Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Qian Du
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Yong Huang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Dewen Tong
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
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Zai X, Yin Y, Guo F, Yang Q, Li R, Li Y, Zhang J, Xu J, Chen W. Screening of potential vaccine candidates against pathogenic Brucella spp. using compositive reverse vaccinology. Vet Res 2021; 52:75. [PMID: 34078437 PMCID: PMC8170439 DOI: 10.1186/s13567-021-00939-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/04/2021] [Indexed: 11/25/2022] Open
Abstract
Brucella spp. are Gram-negative, facultative intracellular bacteria that cause brucellosis in humans and various animals. The threat of brucellosis has increased, yet currently available live attenuated vaccines still have drawbacks. Therefore, subunit vaccines, produced using protein antigens and having the advantage of being safe, cost-effective and efficacious, are urgently needed. In this study, we used core proteome analysis and a compositive RV methodology to screen potential broad-spectrum antigens against 213 pathogenic strains of Brucella spp. with worldwide geographic distribution. Candidate proteins were scored according to six biological features: subcellular localization, antigen similarity, antigenicity, mature epitope density, virulence, and adhesion probability. In the RV analysis, a total 32 candidate antigens were picked out. Of these, three proteins were selected for assessment of immunogenicity and preliminary protection in a mouse model: outer membrane protein Omp19 (used as a positive control), type IV secretion system (T4SS) protein VirB8, and type I secretion system (T1SS) protein HlyD. These three antigens with a high degree of conservation could induce specific humoral and cellular immune responses. Omp19, VirB8 and HlyD could substantially reduce the organ bacterial load of B. abortus S19 in mice and provide varying degrees of protection. In this study, we demonstrated the effectiveness of this unique strategy for the screening of potential broad-spectrum antigens against Brucella. Further evaluation is needed to identify the levels of protection conferred by the vaccine antigens against wild-type pathogenic Brucella species challenge.
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Affiliation(s)
- Xiaodong Zai
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Fengyu Guo
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Qiaoling Yang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ruihua Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yaohui Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China.
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China.
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Zhou D, Zhi F, Fang J, Zheng W, Li J, Zhang G, Chen L, Jin Y, Wang A. RNA-Seq Analysis Reveals the Role of Omp16 in Brucella-Infected RAW264.7 Cells. Front Vet Sci 2021; 8:646839. [PMID: 33748220 PMCID: PMC7970042 DOI: 10.3389/fvets.2021.646839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
Brucellosis is an endemic zoonotic infectious disease in the majority of developing countries, which causes huge economic losses. As immunogenic and protective antigens at the surface of Brucella spp., outer membrane proteins (Omps) are particularly attractive for developing vaccine and could have more relevant role in host–pathogen interactions. Omp16, a homolog to peptidoglycan-associated lipoproteins (Pals), is essential for Brucella survival in vitro. At present, the functions of Omp16 have been poorly studied. Here, the gene expression profile of RAW264.7 cells infected with Brucella suis vaccine strain 2 (B. suis S2) and ΔOmp16 was analyzed by RNA-seq to investigate the cellular response immediately after Brucella entry. The RNA-sequence analysis revealed that a total of 303 genes were significantly regulated by B. suis S2 24 h post-infection. Of these, 273 differentially expressed genes (DEGs) were upregulated, and 30 DEGs were downregulated. These DEGs were mainly involved in innate immune signaling pathways, including pattern recognition receptors (PRRs), proinflammatory cytokines, and chemokines by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In ΔOmp16-infected cells, the expression of 52 total cells genes was significantly upregulated and that of 9 total cells genes were downregulated compared to B. suis S2-infected RAW264.7 cells. The KEGG pathway analysis showed that several upregulated genes were proinflammatory cytokines and chemokines, such as interleukin (IL)-6, IL-11, IL-12β, C–C motif chemokine (CCL2), and CCL22. All together, we clearly demonstrate that ΔOmp16 can alter macrophage immune-related pathways to increase proinflammatory cytokines and chemokines, which provide insights into illuminating the Brucella pathogenic strategies.
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Affiliation(s)
- Dong Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Feijie Zhi
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Jiaoyang Fang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Weifang Zheng
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Junmei Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Guangdong Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Lei Chen
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
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12
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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13
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Nikam PS, Kingston JJ, Belagal Motatis AK. Oral co-administration of bivalent protein r-BL with U-Omp19 elicits mucosal immune responses and reduces S. Typhimurium shedding in BALB/c mice. Immunol Lett 2021; 231:61-67. [PMID: 33460704 DOI: 10.1016/j.imlet.2021.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 12/15/2020] [Accepted: 01/11/2021] [Indexed: 01/18/2023]
Abstract
The increase in international food trade and travel has dramatically increased the global incidences of Salmonellosis. In the light of widespread resistance to frontline antibiotics, oral vaccines remain the most reliable alternative. In this study, the fusion protein, r-BL was rationally constructed by splicing the Salmonella Typhimurium sseB and ompL genes through G4S linker by over-lap extension PCR. The oral coadministration of r-BL with B. abortus U-Omp19 protein with known protease inhibitor activity resulted in significant increase of mucosal IgA titres to antilog 4.5051 (p < 0.0001) and 4.806 (p < 0.0001) in the fecal samples and intestinal washes respectively. Antibody isotyping of the intestinal washes demonstrated increase in mucosal IgM, IgG1 and IgG2a isotypes also and demonstrated a significant reduction in fecal shedding of S. Typhimurium in challenge study. The r-BL + U-Omp19 treated mice demonstrated a complete termination of Salmonella fecal shedding by the 12th day of challenge as compared to other study groups. In summary, the bivalent protein r-BL when administered with the mucosal adjuvant U-Omp19 was successful in triggering mucosal arm of the immune system which forms the first line of defence in combating the infections caused by the enteric pathogen like Salmonella.
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Affiliation(s)
- Pradnya Sukhadev Nikam
- Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysuru, Karnataka, 570011, India.
| | - Joseph J Kingston
- Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysuru, Karnataka, 570011, India.
| | - Anil Kumar Belagal Motatis
- Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysuru, Karnataka, 570011, India.
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14
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The Role of ST2 Receptor in the Regulation of Brucella abortus Oral Infection. Pathogens 2020; 9:pathogens9050328. [PMID: 32353980 PMCID: PMC7281115 DOI: 10.3390/pathogens9050328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/15/2020] [Accepted: 04/25/2020] [Indexed: 01/18/2023] Open
Abstract
The ST2 receptor plays an important role in the gut such as permeability regulation, epithelium regeneration, and promoting intestinal immune modulation. Here, we studied the role of ST2 receptor in a murine model of oral infection with Brucella abortus, its influence on gut homeostasis and control of bacterial replication. Balb/c (wild-type, WT) and ST2 deficient mice (ST2−/−) were infected by oral gavage and the results were obtained at 3 and 14 days post infection (dpi). Our results suggest that ST2−/− are more resistant to B. abortus infection, as a lower bacterial colony-forming unit (CFU) was detected in the livers and spleens of knockout mice, when compared to WT. Additionally, we observed an increase in intestinal permeability in WT-infected mice, compared to ST2−/− animals. Breakage of the intestinal epithelial barrier and bacterial dissemination might be associated with the presence of the ST2 receptor; since, in the knockout mice no change in intestinal permeability was observed after infection. Together with enhanced resistance to infection, ST2−/− produced greater levels of IFN-γ and TNF-α in the small intestine, compared to WT mice. Nevertheless, in the systemic model of infection ST2 plays no role in controlling Brucella replication in vivo. Our results suggest that the ST2 receptor is involved in the invasion process of B. abortus by the mucosa in the oral infection model.
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15
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Abstract
Brucella spp. are Gram negative intracellular bacteria responsible for brucellosis, a worldwide distributed zoonosis. A prominent aspect of the Brucella life cycle is its ability to invade, survive and multiply within host cells. Comprehensive approaches, such as proteomics, have aided in unravelling the molecular mechanisms underlying Brucella pathogenesis. Technological and methodological advancements such as increased instrument performance and multiplexed quantification have broadened the range of proteome studies, enabling new and improved analyses, providing deeper and more accurate proteome coverage. Indeed, proteomics has demonstrated its contribution to key research questions in Brucella biology, i.e., immunodominant proteins, host-cell interaction, stress response, antibiotic targets and resistance, protein secretion. Here, we review the proteomics of Brucella with a focus on more recent works and novel findings, ranging from reconfiguration of the intracellular bacterial proteome and studies on proteomic profiles of Brucella infected tissues, to the identification of Brucella extracellular proteins with putative roles in cell signaling and pathogenesis. In conclusion, proteomics has yielded copious new candidates and hypotheses that require future verification. It is expected that proteomics will continue to be an invaluable tool for Brucella and applications will further extend to the currently ill-explored aspects including, among others, protein processing and post-translational modification.
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