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Peng Y, Wu J, Sun Y, Zhang Y, Wang Q, Shao S. Contrastive-learning of language embedding and biological features for cross modality encoding and effector prediction. Nat Commun 2025; 16:1299. [PMID: 39900608 PMCID: PMC11791096 DOI: 10.1038/s41467-025-56526-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2024] [Accepted: 01/15/2025] [Indexed: 02/05/2025] Open
Abstract
Identifying and characterizing virulence proteins secreted by Gram-negative bacteria are fundamental for deciphering microbial pathogenicity as well as aiding the development of therapeutic strategies. Effector predictors utilizing pre-trained protein language models (PLMs) have shown sound performance by leveraging extensive evolutionary and sequential protein features. However, the accuracy and sensitivity of effector prediction remain challenging. Here, we introduce a model named Contrastive-learning of Language Embedding and Biological Features (CLEF) leveraging contrastive learning to integrate PLM representations with supplementary biological features. Biologically information is captured in learned contextualized embeddings to yield meaningful representations. With cross-modality biological features, CLEF outperforms state-of-the-art (SOTA) models in predicting type III, type IV, and type VI secreted effectors (T3SEs/T4SEs/T6SEs) in enteric pathogens. All experimentally verified effectors in Enterohemorrhagic Escherichia coli and 41 of 43 experimentally verified T3SEs of Salmonella Typhimurium are recognized. Moreover, 12 predicted T3SEs and 11 predicted T6SEs are validated by extensive experiments in Edwardsiella piscicida. Furthermore, integrating omics data via CLEF framework enhances protein representations to illustrate effector-effector interactions and determine in vivo colonization-essential genes. Collectively, CLEF provides a blueprint to bridge the gap between in silico PLM's capacity and experimental biological information to fulfill complicated tasks.
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Affiliation(s)
- Yue Peng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Junze Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yi Sun
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yuanxing Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519000, Zhuhai, China
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
- Laboratory of Aquatic Animal Diseases of MOA, Shanghai, China
| | - Shuai Shao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China.
- Laboratory of Aquatic Animal Diseases of MOA, Shanghai, China.
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Dias MKHM, Jayathilaka ET, Jayasinghe JNC, Tennakoon N, Nikapitiya C, Whang I, De Zoysa M. Exploring the Proteomic Landscape and Immunomodulatory Functions of Edwardsiella piscicida Derived Extracellular Vesicles. J Microbiol Biotechnol 2024; 35:e2410001. [PMID: 39849936 PMCID: PMC11813346 DOI: 10.4014/jmb.2410.10001] [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: 10/02/2024] [Revised: 11/24/2024] [Accepted: 12/02/2024] [Indexed: 01/25/2025]
Abstract
Extracellular vesicles (EVs) have garnered attention in research for their potential as biochemical transporters and immune modulators, crucial for regulating the host immune system. The present study was conducted to isolate and characterize EVs from Gram negative bacteria Edwardsiella piscicida (EpEVs) and investigate their proteomic profile and immune responses. Isolation of EpEVs was carried out using ultracentrifugation method. Transmission electron microscopy results confirmed the spherical shape of EpEVs. The average size and zeta potential were 85.3 ± 1.8 nm and -8.28 ± 0.41 mV, respectively. EpEVs consisted of 1,487 distinct proteins. Subcellular localization analysis revealed that "cell" and "cell part" were the most predominant areas for protein localization. Proteins associated with virulence, along with several chaperones that facilitate protein folding and stability, were also present. No toxicity was detected when EpEVs were treated to fathead minnow (FHM) cells up to 100 μg/ml. Fluorescent-labeled EpEVs showed cellular internalization in FHM cells at 24 h post treatment (hpt). In-vitro gene expression in Raw 264.7 cells showed upregulation of interleukin (Il)6, Il1β, and interferon (Ifn)β with simultaneous upregulation of anti-inflammatory Il10. In vivo, gene expression revealed that except for heat shock protein (hsp)70, all other genes were upregulated suggesting that EpEVs induced the expression of immune-related genes. Western blot analysis showed increased protein levels of tumor necrosis factor (Tnf)α in EpEVs-treated spleen tissue of zebrafish. Our results confirm that EpEVs can be successfully isolated using the ultracentrifugation method. Furthermore, exploring immunomodulatory mechanism of EpEVs is essential for their potential use as novel therapeutics in fish medicine.
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Affiliation(s)
| | - E.H.T. Thulshan Jayathilaka
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | | | - Nipuna Tennakoon
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Chamilani Nikapitiya
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Ilson Whang
- National Marine Biodiversity Institute of Korea (MABIK), Janghang-eup, Seocheon 33662, Republic of Korea
| | - Mahanama De Zoysa
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
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Xia F, Liu Y, Wei L, Shao S, Zhang Y, Ma Y, Wang Q. Long-chain unsaturated fatty acids sensor controlling the type III/VI secretion system is essential for Edwardsiella piscicida infection. Microbiol Res 2024; 285:127770. [PMID: 38788352 DOI: 10.1016/j.micres.2024.127770] [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: 04/21/2024] [Revised: 05/07/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
Edwardsiella piscicida is an acute marine pathogen that causes severe damage to the aquaculture industry worldwide. The pathogenesis of E. piscicida is dependent mainly on the type III secretion system (T3SS) and type VI secretion system (T6SS), both of which are critically regulated by EsrB and EsrC. In this study, we revealed that fatty acids influence T3SS expression. Unsaturated fatty acids (UFAs), but not saturated fatty acids (SFAs), directly interact with EsrC, which abolishes the function of EsrC and results in the turn-off of T3/T6SS. Moreover, during the in vivo colonization of E. piscicida, host fatty acids were observed to be transported into E. piscicida through FadL and to modulate the expression of T3/T6SS. Furthermore, the esrCR38G mutant blocked the interaction between EsrC and UFAs, leading to dramatic growth defects in DMEM and impaired colonization in HeLa cells and zebrafish. In conclusion, this study revealed that the interaction between UFAs and EsrC to turn off T3/T6SS expression is essential for E. piscicida infection.
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Affiliation(s)
- Feng Xia
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yihan Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Lifan Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Shuai Shao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China; Laboratory of Aquatic Animal Diseases of MOA, Shanghai 200237, China
| | - Yuanxing Zhang
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China; Laboratory of Aquatic Animal Diseases of MOA, Shanghai 200237, China
| | - Yue Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China; Laboratory of Aquatic Animal Diseases of MOA, Shanghai 200237, China.
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China; Laboratory of Aquatic Animal Diseases of MOA, Shanghai 200237, China; Shanghai Haosi Marine Biotechnology Co., Ltd, China.
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Secreted in a Type III Secretion System-Dependent Manner, EsaH and EscE Are the Cochaperones of the T3SS Needle Protein EsaG of Edwardsiella piscicida. mBio 2022; 13:e0125022. [PMID: 35861543 PMCID: PMC9426511 DOI: 10.1128/mbio.01250-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular EscE protein tightly controls the secretion of the type III secretion system (T3SS) middle and late substrates in Edwardsiella piscicida. However, the regulation of secretion by EscE is incompletely understood. In this work, we reveal that EscE interacts with EsaH and EsaG. The crystal structures of the EscE-EsaH complex and EscE-EsaG-EsaH complex were resolved at resolutions of 1.4 Å and 1.8 Å, respectively. EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG (56 to 73 amino acids [aa]), serving as the cochaperones of T3SS needle protein EsaG in E. piscicida. V61, K62, M64, and M65 of EsaG play a pivotal role in maintaining the conformation of the ternary complex of EscE-EsaG-EsaH, thereby maintaining the stability of EsaG. An in vivo experiment revealed that EscE and EsaH stabilize each other, and both of them stabilize EsaG. Meanwhile, either EscE or EsaH can be secreted through the T3SS. The secondary structure of EsaH lacks the fourth and fifth α helices presented in its homologs PscG, YscG, and AscG. Insertion of the α4 and α5 helices of PscG or swapping the N-terminal 25 aa of PscG with those of EsaH starkly decreases the protein level of the chimeric EsaH, resulting in instability of EsaG and deactivation of the T3SS. To the best of our knowledge, these data represent the first reported structure of the T3SS needle complex of pathogens from Enterobacteriaceae and the first evidence for the secretion of T3SS needle chaperones. IMPORTANCE Edwardsiella piscicida causes severe hemorrhagic septicemia in fish. Inactivation of the type III secretion system (T3SS) increases its 50% lethal dose (LD50) by ~10 times. The secretion of T3SS middle and late substrates in E. piscicida is tightly controlled by the intracellular steady-state protein level of EscE, but the mechanism is incompletely understood. In this study, EscE was found to interact with and stabilize EsaH in E. piscicida. The EscE-EsaH complex is structurally analogous to T3SS needle chaperones. Further study revealed that EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG, serving as the cochaperones stabilizing the T3SS needle protein EsaG. Interestingly, both EscE and EsaH are secreted. Our study reveals that the EscE-EsaH complex controls T3SS protein secretion by stabilizing EsaG, whose secretion in turn leads to the secretion of the middle and late T3SS substrates.
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Edwardsiella piscicida Interferes with Classical Endocytic Trafficking and Replicates in a Specialized Replication-Permissive Niche in Nonphagocytic Cells. J Bacteriol 2021; 203:e0050520. [PMID: 34060905 DOI: 10.1128/jb.00505-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Edwardsiella piscicida is an intracellular pathogen within a broad spectrum of hosts. Essential to E. piscicida's virulence is its ability to invade and replicate inside host cells, yet the survival mechanisms and the nature of the replicative compartment remain unknown. Here, we characterized its intracellular lifestyle in nonphagocytic cells and showed that the intracellular replication of E. piscicida in nonphagocytic cells is dependent on its type III secretion system (T3SS) but not its type VI secretion system. Following internalization, E. piscicida is contained in vacuoles that transiently mature into early endosomes but subsequently bypasses the classical endosome pathway and fusion with lysosomes, which depend on its T3SS. Following rapid escape from the degradative pathway, E. piscicida was found to create a specialized replication-permissive niche characterized by endoplasmic reticulum (ER) markers. Furthermore, we found that a T3SS effector, EseJ, is responsible for the intracellular replication of E. piscicida by preventing endosome/lysosome fusion. In vivo experiments also confirmed that EseJ is necessary for bacterial colonization by E. piscicida in the epithelial layer, followed by systemic dissemination in both zebrafish and mice. Thus, this work elucidates the tactics used by E. piscicida to survive and proliferate within host nonphagocytic cells. IMPORTANCE E. piscicida is a facultative intracellular bacterium associated with septicemia and fatal infections in many animals, including fish and humans. However, little is known about its intracellular life, which is important for successful invasion of the host. The present study is the first comprehensive characterization of E. piscicida's intracellular lifestyle in host cells. Upon internalization, E. piscicida is transiently contained in Rab5-positive vacuoles, but the pathogen prevents further endosome maturation and fusion with lysosomes by utilizing a T3SS effector, EseJ. In addition, the bacterium creates a specialized replication niche for rapid growth via an interaction with the ER. Our study provides new insights into the strategies used by E. piscicida to successfully establish an intracellular lifestyle that contributes to its survival and dissemination during infection.
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Li J, Tang L, Wang P, Li G, Jin H, Mo Z. Identification and application of T3SS translocation signal in Edwardsiella piscicida attenuated carrier as a bivalent vaccine. JOURNAL OF FISH DISEASES 2021; 44:513-520. [PMID: 33682163 DOI: 10.1111/jfd.13338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/03/2021] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Type III secretion system (T3SS)-dependent translocation has been used to deliver heterologous antigens by vaccine carriers into host cells. In this research, we identified the translocation signal of Edwardsiella piscicida T3SS effector EseG and constructed an antibiotic resistance-free balanced-lethal system as attenuated vaccine carrier to present antigens by T3SS. Edwardsiella piscicida LSE40 asd gene deletion mutant was constructed and complemented with pYA3342 harbouring the asd (aspartate β-semialdehyde dehydrogenase) gene from Salmonella. Fusion proteins composed of EseG N-terminal 1-108 amino acids and the TEM1-β-lactamase reporter were inserted in plasmid pYA3342. The fusion protein could secrete into the cell culture, translocate into HeLa cells, and localize in the membrane fraction. Then, the double gene deletion mutant LSE40ΔasdΔpurA was constructed as an attenuated vaccine carrier, and Aeromonas hydrophila GapA (glyceraldehyde-3-phosphate dehydrogenase) was fused with the translocation signal, instead of the TEM1-β-lactamase reporter. The bivalent vaccine could protect blue gourami (Trichogaster trichopterus) against E. piscicida and A. hydrophila, with the relative per cent survival of 80.77% and 63.83%, respectively. These results indicated that EseG N-terminal 1-108 amino acid peptide was the translocation signal of E. piscicida T3SS, which could be used to construct bivalent vaccines based on an attenuated E. piscicida carrier.
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Affiliation(s)
- Jie Li
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Lei Tang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Pengmei Wang
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Guiyang Li
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Huaiyuan Jin
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
- College of Aquaculture, Tianjin Agricultural University, Tianjin, China
| | - Zhaolan Mo
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
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Isolation and genomic characterization of a pathogenic Providencia rettgeri strain G0519 in turtle Trachemys scripta. Antonie van Leeuwenhoek 2020; 113:1633-1662. [PMID: 32951105 DOI: 10.1007/s10482-020-01469-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/31/2020] [Indexed: 02/08/2023]
Abstract
Providencia rettgeri infection has occurred occasionally in aquaculture, but is rare in turtles. Here, a pathogenic P. rettgeri strain G0519 was isolated from a diseased slider turtle (Trachemys scripta) in China, and qPCR assay was established for the RTX toxin (rtxD) gene. Histopathological examination showed that many inflammatory cells were infiltrated into heart, liver and intestine, as well as the necrosis of liver, kidney and spleen. The genome consisted of one circular chromosome (4.493 Mb) and one plasmid (18.8 kb), and predicted to contain 4170 and 19 protein-coding genes, respectively. Multiple pathogenic and virulence factors (e.g., fimbria, adhesion, invasion, toxin, hemolysin, chemotaxis, secretion system), multidrug-resistant genes (e.g., ampC, per-1, oxa-1, sul1, tetR) and a novel genomic resistance island PRI519 were identified. Comparative genome analysis revealed the closest relationship was with P. rettgeri, and with P. heimbachae closer than with other Providencia spp. To our knowledge, this was first report on genomic characterization of multidrug-resistant pathogenic P. rettgeri in cultured turtles.
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Chen H, Ding S, Tan J, Yang D, Zhang Y, Liu Q. Characterization of the Japanese flounder NLRP3 inflammasome in restricting Edwardsiella piscicida colonization in vivo. FISH & SHELLFISH IMMUNOLOGY 2020; 103:169-180. [PMID: 32387560 DOI: 10.1016/j.fsi.2020.04.063] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/08/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
NLRP3 inflammasome is one of the most well-known inflammasomes in mammals, which plays critical roles in innate immunity. However, knowledge about this inflammasome in non-mammalian species, especially in teleost fish, remains rarely known. Herein, we established an Edwardsiella piscicida-head-kidney macrophages (HKMs) infection model in Japanese flounder, and found a robust caspase-1 activation and IL-1β maturation. To characterize the upstream receptor, we established a bioinformatic screening analysis, and found an NLRP3 homolog (JfNLRP3) from Japanese flounder, which shares an overall conservative structure architecture to human NLRP3. Moreover, the JfNLRP3 can assemble JfASC through PYD-PYD domain interaction and trigger JfCaspase-1 activation and JfIL-1β maturation. Meanwhile, the classical inflammasome activation stimulators, including nigericin, ATP or MSU, can trigger the JfCaspase-1 activation and JfIL-1β maturation in Japanese flounder HKMs. During intraperitoneal infection of E. piscicida in Japanese flounder, we found a dynamic up-regulated transcription of JfNLRP3 and JfCaspase-1 in vivo. Furthermore, knockdown of either JfNLRP3 or JfCaspase-1 reduces the serum JfIL-1β level, and promotes the bacterial colonization in systemic immune organs at 2 day-post infection, while overexpression of JfNLRP3 or JfCaspase-1 hampers the bacterial colonization in these organs of Japanese flounder. Taken together, our results identified the NLRP3 inflammasome paradigm in Japanese flounder, which not only providing new insight into the molecular mechanisms of teleost NLRP3 inflammasome and revealing its role in restricting bacterial infection in vivo, but also shedding light on the evolutionary of NLRP3 inflammasome in teleost.
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Affiliation(s)
- Hao Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Shuangfei Ding
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Jinchao Tan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Dahai Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, 200237, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, 200237, China
| | - Qin Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, 200237, China.
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He TT, Zhou Y, Liu YL, Li DY, Nie P, Li AH, Xie HX. Edwardsiella piscicida
type III protein EseJ suppresses apoptosis through down regulating type 1 fimbriae, which stimulate the cleavage of caspase‐8. Cell Microbiol 2020; 22:e13193. [DOI: 10.1111/cmi.13193] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/24/2020] [Accepted: 02/10/2020] [Indexed: 01/13/2023]
Affiliation(s)
- Tian Tian He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
- University of Chinese Academy of Sciences Beijing China
| | - Ying Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
- University of Chinese Academy of Sciences Beijing China
| | - Ying Li Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
- University of Chinese Academy of Sciences Beijing China
| | - Duan You Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
- University of Chinese Academy of Sciences Beijing China
| | - Pin Nie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao) Qingdao China
- School of Marine Science and EngineeringQingdao Agricultural University Qingdao China
| | - Ai Hua Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
| | - Hai Xia Xie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of Sciences Wuhan China
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The Edwardsiella piscicida Type III Effector EseJ Suppresses Expression of Type 1 Fimbriae, Leading to Decreased Bacterial Adherence to Host Cells. Infect Immun 2019; 87:IAI.00187-19. [PMID: 30988056 DOI: 10.1128/iai.00187-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/09/2019] [Indexed: 12/28/2022] Open
Abstract
The type III secretion system (T3SS) of Edwardsiella piscicida plays a crucial role in its pathogenesis. Our previous study indicated that the T3SS effector protein EseJ inhibits the bacterium's adhesion to epithelioma papillosum cyprini (EPC) cells, while the mechanism of the inhibition remains elusive. In this study, we revealed that EseJ negatively regulates the fimA gene, as demonstrated by comparative transcription analysis of ΔeseJ and wild-type (WT) strains. As well, the dramatically increased production of FimA was detected in the absence of EseJ compared to that by the WT strain. The adherence of the ΔeseJ strain decreased far below that of the WT strain in the absence of FimA, demonstrating that FimA plays a pivotal role in the hyperadhesion of the ΔeseJ strain. Adherence analysis with a strain with truncated eseJ demonstrated that the C-terminal region of EseJ (Gly1191 to Ile1359) is necessary to inhibit the transcription of the type 1 fimbrial operon. Binding between the EseJ fragment from amino acid residues 1191 to 1359 and the DNA fragment upstream of fimA was not detected, indicating that EseJ might indirectly regulate the type 1 fimbrial operon. Our study reveals that EseJ controls E. piscicida adherence to EPC cells by negatively regulating the type 1 fimbrial operon.
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The Edwardsiella piscicida Type III Translocon Protein EseC Inhibits Biofilm Formation by Sequestering EseE. Appl Environ Microbiol 2019; 85:AEM.02133-18. [PMID: 30770403 DOI: 10.1128/aem.02133-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 02/04/2019] [Indexed: 11/20/2022] Open
Abstract
The type III secretion system (T3SS) is one of the most important virulence factors of the fish pathogen Edwardsiella piscicida It contains three translocon proteins, EseB, EseC, and EseD, required for translocation of effector proteins into host cells. We have previously shown that EseB forms filamentous appendages on the surface of E. piscicida, and these filamentous structures mediate bacterial cell-cell interactions promoting autoaggregation and biofilm formation. In the present study, we show that EseC, but not EseD, inhibits the autoaggregation and biofilm formation of E. piscicida At 18 h postsubculture, a ΔeseC strain developed strong autoaggregation and mature biofilm formation, accompanied by enhanced formation of EseB filamentous appendages. This is in contrast to the weak autoaggregation and immature biofilm formation seen in the E. piscicida wild-type strain. EseE, a protein that directly binds to EseC and also positively regulates the transcription of the escC-eseE operon, was liberated and showed increased levels in the absence of EseC. This led to augmented transcription of the escC-eseE operon, thereby increasing the steady-state protein levels of intracellular EseB, EseD, and EseE, as well as biofilm formation. Notably, the levels of intracellular EseB and EseD produced by the ΔeseE and ΔeseC ΔeseE strains were similar but remarkably lower than those produced by the wild-type strain at 18 h postsubculture. Taken together, we have shown that the translocon protein EseC inhibits biofilm formation through sequestering EseE, a positive regulator of the escC-eseE operon.IMPORTANCE Edwardsiella piscicida, previously known as Edwardsiella tarda, is a Gram-negative intracellular pathogen that mainly infects fish. The type III secretion system (T3SS) plays a pivotal role in its pathogenesis. The T3SS translocon protein EseB is required for the assembly of filamentous appendages on the surface of E. piscicida The interactions between the appendages facilitate autoaggregation and biofilm formation. In this study, we explored the role of the other two translocon proteins, EseC and EseD, in biofilm formation. We have demonstrated that EseC, but not EseD, inhibits the autoaggregation and biofilm formation of E. piscicida, providing new insights into the regulatory mechanism involved in E. piscicida biofilm formation.
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Chen S, Yang D, Wen Y, Jiang Z, Zhang L, Jiang J, Chen Y, Hu T, Wang Q, Zhang Y, Liu Q. Dysregulated hemolysin liberates bacterial outer membrane vesicles for cytosolic lipopolysaccharide sensing. PLoS Pathog 2018; 14:e1007240. [PMID: 30138458 PMCID: PMC6124777 DOI: 10.1371/journal.ppat.1007240] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/05/2018] [Accepted: 07/25/2018] [Indexed: 01/22/2023] Open
Abstract
Inflammatory caspase-11/4/5 recognize cytosolic LPS from invading Gram-negative bacteria and induce pyroptosis and cytokine release, forming rapid innate antibacterial defenses. Since extracellular or vacuole-constrained bacteria are thought to rarely access the cytoplasm, how their LPS are exposed to the cytosolic sensors is a critical event for pathogen recognition. Hemolysin is a pore-forming bacterial toxin, which was generally accepted to rupture cell membrane, leading to cell lysis. Whether and how hemolysin participates in non-canonical inflammasome signaling remains undiscovered. Here, we show that hemolysin-overexpressed enterobacteria triggered significantly increased caspase-4 activation in human intestinal epithelial cell lines. Hemolysin promoted LPS cytosolic delivery from extracellular bacteria through dynamin-dependent endocytosis. Further, we revealed that hemolysin was largely associated with bacterial outer membrane vesicles (OMVs) and induced rupture of OMV-containing vacuoles, subsequently increasing LPS exposure to the cytosolic sensor. Accordingly, overexpression of hemolysin promoted caspase-11 dependent IL-18 secretion and gut inflammation in mice, which was associated with restricting bacterial colonization in vivo. Together, our work reveals a concept that hemolysin promotes noncanonical inflammasome activation via liberating OMVs for cytosolic LPS sensing, which offers insights into innate immune surveillance of dysregulated hemolysin via caspase-11/4 in intestinal antibacterial defenses. Sensing of lipopolysaccharide (LPS) in the cytosol triggers non-canonical inflammasome-mediated innate responses. Recent work revealed that bacterial outer membrane vesicles (OMVs) enables LPS to access the cytosol for extracellular bacteria. However, since intracellular OMVs are generally constrained in endosomes, how OMV-derived LPS gain access to the cytosol remains unknown. Here, we reported that hemolysin largely bound with OMVs and entered cells through dynamin-dependent endocytosis. Intracellular hemolysin significantly impaired OMVs-constrained vacuole integrity and increased OMV-derived LPS exposure to the cytosolic sensor, which promoted non-canonical inflammasome activation and restricted bacterial gut infections. This work reveals that dysregulated hemolysin promotes non-canonical inflammasome activation and alerts host immune recognition, providing insights into the more sophisticated biological functions of hemolysin upon infection.
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Affiliation(s)
- Shouwen Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Dahai Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Ying Wen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Zhiwei Jiang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Lingzhi Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Department of Pathology and Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jiatiao Jiang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yaozhen Chen
- Department of Transfusion Medicine, Xijing hospital, Xi’an, China
| | - Tianjian Hu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Qin Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- * E-mail:
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Edwardsiella piscicida Type III Secretion System Effector EseK Inhibits Mitogen-Activated Protein Kinase Phosphorylation and Promotes Bacterial Colonization in Zebrafish Larvae. Infect Immun 2018; 86:IAI.00233-18. [PMID: 29986890 DOI: 10.1128/iai.00233-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/01/2018] [Indexed: 12/21/2022] Open
Abstract
Bacteria utilize type III secretion systems (T3SS) to deliver effectors directly into host cells. Hence, it is very important to identify the functions of bacterial (T3SS) effectors to understand host-pathogen interactions. Edwardsiella piscicida encodes a functional T3SS effector, EseK, which can be translocated into host cells and affect bacterial loads. Here, it was demonstrated that an eseK mutant (the ΔeseK mutant) significantly increased the phosphorylation levels of p38α, c-Jun NH2-terminal kinases (JNK), and extracellular signal-regulated protein kinases 1/2 (ERK1/2) in HeLa cells. Overexpression of EseK directly inhibited mitogen-activated protein kinase (MAPK) signaling pathways in HEK293T cells. The ΔeseK mutant consistently promoted the phosphorylation of MAPKs in zebrafish larva infection models. Further, it was shown that the ΔeseK mutant increased the expression of tumor necrosis factor alpha (TNF-α) in an MAPK-dependent manner. Importantly, the EseK-mediated inhibition of MAPKs in vivo attenuated bacterial clearance in larvae. Taken together, this work reveals that the E. piscicida T3SS effector EseK promotes bacterial infection by inhibiting MAPK activation, which provides insights into the molecular pathogenesis of E. piscicida in fish.
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14
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Zhang L, Jiang Z, Fang S, Huang Y, Yang D, Wang Q, Zhang Y, Liu Q. Systematic Identification of Intracellular-Translocated Candidate Effectors in Edwardsiella piscicida. Front Cell Infect Microbiol 2018; 8:37. [PMID: 29503811 PMCID: PMC5820615 DOI: 10.3389/fcimb.2018.00037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/29/2018] [Indexed: 12/31/2022] Open
Abstract
Many bacterial pathogens inject effectors directly into host cells to target a variety of host cellular processes and promote bacterial dissemination and survival. Identifying the bacterial effectors and elucidating their functions are central to understanding the molecular pathogenesis of these pathogens. Edwardsiella piscicida is a pathogen with a wide host range, and very few of its effectors have been identified to date. Here, based on the genes significantly regulated by macrophage infection, we identified 25 intracellular translocation-positive candidate effectors, including all five previously reported effectors, namely EseG, EseJ, EseH, EseK, and EvpP. A subsequent secretion analysis revealed diverse secretion patterns for the 25 effector candidates, suggesting that multiple transport pathways were involved in the internalization of these candidate effectors. Further, we identified two novel type VI secretion system (T6SS) putative effectors and three outer membrane vesicles (OMV)-dependent putative effectors among the candidate effectors described above, and further analyzed their contribution to bacterial virulence in a zebrafish model. This work demonstrates an effective approach for screening bacterial effectors and expands the effectors repertoire in E. piscicida.
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Affiliation(s)
- Lingzhi Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Zhiwei Jiang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Shan Fang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yajun Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Dahai Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.,Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China.,Shanghai Collaborative Innovation Center for Bio-Manufacturing Technology, Shanghai, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.,Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China.,Shanghai Collaborative Innovation Center for Bio-Manufacturing Technology, Shanghai, China
| | - Qin Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.,Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China.,Shanghai Collaborative Innovation Center for Bio-Manufacturing Technology, Shanghai, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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15
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Castiblanco LF, Triplett LR, Sundin GW. Regulation of Effector Delivery by Type III Secretion Chaperone Proteins in Erwinia amylovora. Front Microbiol 2018; 9:146. [PMID: 29472907 PMCID: PMC5809446 DOI: 10.3389/fmicb.2018.00146] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/23/2018] [Indexed: 11/16/2022] Open
Abstract
Type III secretion (TTS) chaperones are critical for the delivery of many effector proteins from Gram-negative bacterial pathogens into host cells, functioning in the stabilization and hierarchical delivery of the effectors to the type III secretion system (TTSS). The plant pathogen Erwinia amylovora secretes at least four TTS effector proteins: DspE, Eop1, Eop3, and Eop4. DspE specifically interacts with the TTS chaperone protein DspF, which stabilizes the effector protein in the cytoplasm and promotes its efficient translocation through the TTSS. However, the role of E. amylovora chaperones in regulating the delivery of other secreted effectors is unknown. In this study, we identified functional interactions between the effector proteins DspE, Eop1, and Eop3 with the TTS chaperones DspF, Esc1 and Esc3 in yeast. Using site-directed mutagenesis, secretion, and translocation assays, we demonstrated that the three TTS chaperones have additive roles for the secretion and translocation of DspE into plant cells whereas DspF negatively affects the translocation of Eop1 and Eop3. Collectively, these results indicate that TTS chaperone proteins exhibit a cooperative behavior to orchestrate the effector secretion and translocation dynamics in E. amylovora.
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Affiliation(s)
- Luisa F Castiblanco
- Department of Plant, Soil and Microbial Sciences, Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI, United States
| | - Lindsay R Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, United States
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI, United States
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