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Zhao C, Porter JM, Burke PC, Arnberg N, Smith JG. Alpha-defensin binding expands human adenovirus tropism. PLoS Pathog 2024; 20:e1012317. [PMID: 38900833 PMCID: PMC11230588 DOI: 10.1371/journal.ppat.1012317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/08/2024] [Accepted: 06/04/2024] [Indexed: 06/22/2024] Open
Abstract
Mammalian α-defensins are a family of abundant effector peptides of the mucosal innate immune system. Although primarily considered to be antimicrobial, α-defensins can increase rather than block infection by certain prominent bacterial and viral pathogens in cell culture and in vivo. We have shown previously that exposure of mouse and human adenoviruses (HAdVs) to α-defensins is able to overcome competitive inhibitors that block cell binding, leading us to hypothesize a defensin-mediated binding mechanism that is independent of known viral receptors. To test this hypothesis, we used genetic approaches to demonstrate that none of several primary receptors nor integrin co-receptors are needed for human α-defensin-mediated binding of HAdV to cells; however, infection remains integrin dependent. Thus, our studies have revealed a novel pathway for HAdV binding to cells that bypasses viral primary receptors. We speculate that this pathway functions in parallel with receptor-mediated entry and contributes to α-defensin-enhanced infection of susceptible cells. Remarkably, we also found that in the presence of α-defensins, HAdV tropism is expanded to non-susceptible cells, even when viruses are exposed to a mixture of both susceptible and non-susceptible cells. Therefore, we propose that in the presence of sufficient concentrations of α-defensins, such as in the lung or gut, integrin expression rather than primary receptor expression will dictate HAdV tropism in vivo. In summary, α-defensins may contribute to tissue tropism not only through the neutralization of susceptible viruses but also by allowing certain defensin-resistant viruses to bind to cells independently of previously described mechanisms.
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Affiliation(s)
- Cheng Zhao
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Jessica M. Porter
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Phillip C. Burke
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Niklas Arnberg
- Department of Clinical Microbiology, Division of Virology and Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Jason G. Smith
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
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Zhao C, Porter JM, Burke PC, Arnberg N, Smith JG. Alpha-defensin binding expands human adenovirus tropism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596681. [PMID: 38854108 PMCID: PMC11160700 DOI: 10.1101/2024.05.30.596681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Mammalian α-defensins are a family of abundant effector peptides of the mucosal innate immune system. Although primarily considered to be antimicrobial, α-defensins can increase rather than block infection by certain prominent bacterial and viral pathogens in cell culture and in vivo . We have shown previously that exposure of mouse and human adenoviruses (HAdVs) to α-defensins is able to overcome competitive inhibitors that block cell binding, leading us to hypothesize a defensin-mediated binding mechanism that is independent of known viral receptors. To test this hypothesis, we used genetic approaches to demonstrate that none of several primary receptors nor integrin co-receptors are needed for human α-defensin-mediated binding of HAdV to cells; however, infection remains integrin dependent. Thus, our studies have revealed a novel pathway for HAdV binding to cells that bypasses viral primary receptors. We speculate that this pathway functions in parallel with receptor-mediated entry and contributes to α-defensin-enhanced infection of susceptible cells. Remarkably, we also found that in the presence of α-defensins, HAdV tropism is expanded to non-susceptible cells, even when viruses are exposed to a mixture of both susceptible and non-susceptible cells. Therefore, we propose that in the presence of sufficient concentrations of α-defensins, such as in the lung or gut, integrin expression rather than primary receptor expression will dictate HAdV tropism in vivo . In summary, α-defensins may contribute to tissue tropism not only through the neutralization of susceptible viruses but also by allowing certain defensin-resistant viruses to bind to cells independently of previously described mechanisms. Author Summary In this study, we demonstrate a novel mechanism for binding of human adenoviruses (HAdVs) to cells that is dependent upon interactions with α-defensin host defense peptides but is independent of known viral receptors and co-receptors. To block normal receptor-mediated HAdV infection, we made genetic changes to both host cells and HAdVs. Under these conditions, α-defensins restored cell binding; however, infection still required the function of HAdV integrin co-receptors. This was true for multiple types of HAdVs that use different primary receptors and for cells that are either naturally devoid of HAdV receptors or were engineered to be receptor deficient. These observations suggest that in the presence of concentrations of α-defensins that would be found naturally in the lung or intestine, there are two parallel pathways for HAdV binding to cells that converge on integrins for productive infection. Moreover, these binding pathways function independently, and both operate in mixed culture. Thus, we have found that viruses can co-opt host defense molecules to expand their tropism.
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Gerlach RG, Wittmann I, Heinrich L, Pinkenburg O, Meyer T, Elpers L, Schmidt C, Hensel M, Schnare M. Subversion of a family of antimicrobial proteins by Salmonella enterica. Front Cell Infect Microbiol 2024; 14:1375887. [PMID: 38505286 PMCID: PMC10948614 DOI: 10.3389/fcimb.2024.1375887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 02/19/2024] [Indexed: 03/21/2024] Open
Abstract
Salmonella enterica is a food-borne pathogen able to cause a wide spectrum of diseases ranging from mild gastroenteritis to systemic infections. During almost all stages of the infection process Salmonella is likely to be exposed to a wide variety of host-derived antimicrobial peptides (AMPs). AMPs are important components of the innate immune response which integrate within the bacterial membrane, thus forming pores which lead ultimately to bacterial killing. In contrast to other AMPs Bactericidal/Permeability-increasing Protein (BPI) displayed only weak bacteriostatic or bactericidal effects towards Salmonella enterica sv. Typhimurium (STM) cultures. Surprisingly, we found that sub-antimicrobial concentrations of BPI fold-containing (BPIF) superfamily members mediated adhesion of STM depending on pre-formed type 1 fimbriae. BPIF proteins directly bind to type 1 fimbriae through mannose-containing oligosaccharide modifications. Fimbriae decorated with BPIF proteins exhibit extended binding specificity, allowing for bacterial adhesion on a greater variety of abiotic and biotic surfaces likely promoting host colonization. Further, fimbriae significantly contributed to the resistance against BPI, probably through sequestration of the AMP before membrane interaction. In conclusion, functional subversion of innate immune proteins of the BPIF family through binding to fimbriae promotes Salmonella virulence by survival of host defense and promotion of host colonization.
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Affiliation(s)
- Roman G. Gerlach
- Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital of Erlangen and Friedrich-Alexander-University (FAU) Erlangen-Nuremberg, Erlangen, Germany
- Robert Koch Institute, Wernigerode, Germany
| | - Irene Wittmann
- Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital of Erlangen and Friedrich-Alexander-University (FAU) Erlangen-Nuremberg, Erlangen, Germany
| | | | - Olaf Pinkenburg
- Institute for Immunology, Philipps-University Marburg, Marburg, Germany
| | - Torben Meyer
- Institute for Immunology, Philipps-University Marburg, Marburg, Germany
| | - Laura Elpers
- Division of Microbiology and CellNanOs – Center of Cellular Nanoanalytics Osnabrück, School of Biology/Chemistry, University Osnabrück, Osnabrück, Germany
| | | | - Michael Hensel
- Division of Microbiology and CellNanOs – Center of Cellular Nanoanalytics Osnabrück, School of Biology/Chemistry, University Osnabrück, Osnabrück, Germany
| | - Markus Schnare
- Institute for Immunology, Philipps-University Marburg, Marburg, Germany
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4
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Zheng R, Li W, Yin W, Qiao L, Song S, An Y, Ling Z, Bai L, Yang H, Shen J, Dong Y, Wang Y. PEtN-Modified O-Antigen Enhances Shigella Pathogenesis by Promoting Epithelial Cell Invasion and Inhibiting Complement Binding. ACS Infect Dis 2024; 10:377-383. [PMID: 38252850 DOI: 10.1021/acsinfecdis.3c00602] [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] [Indexed: 01/24/2024]
Abstract
Shigellosis poses an ongoing global public health threat. The presence and length of the O-antigen in lipopolysaccharide play critical roles in Shigella pathogenesis. The plasmid-mediated opt gene encodes a phosphoethanolamine (PEtN) transferase that catalyzes the addition of PEtN to the O-antigen of Shigella flexneri serotype X and Y strains, converting them into serotype Xv and Yv strains, respectively. Since 2002, these modified strains have become prevalent in China. Here we demonstrate that PEtN-mediated O-antigen modification in S. flexneri increase the severity of corneal infection in guinea pigs without any adaptive cost. This heightened virulence is associated with epithelial cell adhesion and invasion, as well as an enhanced inflammatory response of macrophage. Notably, PEtN addition allow S. flexneri to attenuate the binding of complement C3 and better resist phagocytosis, potentially contributing to the retention of S. flexneri in the host environment.
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Affiliation(s)
- Ruicheng Zheng
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Wan Li
- School of Basic Medicine, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Wenjuan Yin
- School of Basic Medicine, Hebei University, Baoding, Hebei 071000, China
| | - Lu Qiao
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Shikai Song
- Poultry Institute, Shandong Academy of Agricultural Science, Jinan, Shandong 250100, China
| | - Yina An
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhuoren Ling
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Li Bai
- NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Hui Yang
- NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Jianzhong Shen
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yanjun Dong
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yang Wang
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
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Fu J, Zong X, Jin M, Min J, Wang F, Wang Y. Mechanisms and regulation of defensins in host defense. Signal Transduct Target Ther 2023; 8:300. [PMID: 37574471 PMCID: PMC10423725 DOI: 10.1038/s41392-023-01553-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/11/2023] [Accepted: 06/26/2023] [Indexed: 08/15/2023] Open
Abstract
As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.
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Affiliation(s)
- Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Junxia Min
- The First Affiliated Hospital, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Fudi Wang
- The Second Affiliated Hospital, School of Public Health, State Key Laboratory of Experimental Hematology, Zhejiang University School of Medicine, Hangzhou, China.
- The First Affiliated Hospital, Basic Medical Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, China.
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China.
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China.
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Boero E, Vezzani G, Micoli F, Pizza M, Rossi O. Functional assays to evaluate antibody-mediated responses against Shigella: a review. Front Cell Infect Microbiol 2023; 13:1171213. [PMID: 37260708 PMCID: PMC10227456 DOI: 10.3389/fcimb.2023.1171213] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/27/2023] [Indexed: 06/02/2023] Open
Abstract
Shigella is a major global pathogen and the etiological agent of shigellosis, a diarrheal disease that primarily affects low- and middle-income countries. Shigellosis is characterized by a complex, multistep pathogenesis during which bacteria use multiple invasion proteins to manipulate and invade the intestinal epithelium. Antibodies, especially against the O-antigen and some invasion proteins, play a protective role as titres against specific antigens inversely correlate with disease severity; however, the context of antibody action during pathogenesis remains to be elucidated, especially with Shigella being mostly an intracellular pathogen. In the absence of a correlate of protection, functional assays rebuilding salient moments of Shigella pathogenesis can improve our understanding of the role of protective antibodies in blocking infection and disease. In vitro assays are important tools to build correlates of protection. Only recently animal models to recapitulate human pathogenesis, often not in full, have been established. This review aims to discuss in vitro assays to evaluate the functionality of anti-Shigella antibodies in polyclonal sera in light of the multistep and multifaced Shigella infection process. Indeed, measurement of antibody level alone may limit the evaluation of full vaccine potential. Serum bactericidal assay (SBA), and other functional assays such as opsonophagocytic killing assays (OPKA), and adhesion/invasion inhibition assays (AIA), are instead physiologically relevant and may provide important information regarding the role played by these effector mechanisms in protective immunity. Ultimately, the review aims at providing scientists in the field with new points of view regarding the significance of functional assays of choice which may be more representative of immune-mediated protection mechanisms.
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Affiliation(s)
- Elena Boero
- GSK Vaccines Institute for Global Health (GVGH) S.r.l., Siena, Italy
| | - Giacomo Vezzani
- GSK Vaccines Institute for Global Health (GVGH) S.r.l., Siena, Italy
| | - Francesca Micoli
- GSK Vaccines Institute for Global Health (GVGH) S.r.l., Siena, Italy
| | - Mariagrazia Pizza
- GSK Vaccines Institute for Global Health (GVGH) S.r.l., Siena, Italy
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Omar Rossi
- GSK Vaccines Institute for Global Health (GVGH) S.r.l., Siena, Italy
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Mouse α-Defensins: Structural and Functional Analysis of the 17 Cryptdin Isoforms Identified from a Single Jejunal Crypt. Infect Immun 2023; 91:e0036122. [PMID: 36472443 PMCID: PMC9872612 DOI: 10.1128/iai.00361-22] [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] [Indexed: 12/12/2022] Open
Abstract
Mouse α-defensins, better known as cryptdins, are host protective antimicrobial peptides produced in the intestinal crypt by Paneth cells. To date, more than 20 cryptdin mRNAs have been identified from mouse small intestine, of which the first six cryptdins (Crp1 to Crp6) have been isolated and characterized at the peptide level. We quantified bactericidal activities against Escherichia coli and Staphylococcus aureus of the 17 cryptdin isoforms identified by Ouellette and colleagues from a single jejunal crypt (A. J. Ouellette et al., Infect Immun 62:5040-5047, 1994), along with linearized analogs of Crp1, Crp4, and Crp14. In addition, we analyzed the most potent and weakest cryptdins in the panel with respect to their ability to self-associate in solution. Finally, we solved, for the first time, the high-resolution crystal structure of a cryptdin, Crp14, and performed molecular dynamics simulation on Crp14 and a hypothetical mutant, T14K-Crp14. Our results indicate that mutational effects are highly dependent on cryptdin sequence, residue position, and bacterial strain. Crp14 adopts a disulfide-stabilized, three-stranded β-sheet core structure and forms a noncanonical dimer stabilized by asymmetrical interactions between the two β1 strands in parallel. The killing of E. coli by cryptdins is generally independent of their tertiary and quaternary structures that are important for the killing of S. aureus, which is indicative of two distinct mechanisms of action. Importantly, sequence variations impact the bactericidal activity of cryptdins by influencing their ability to self-associate in solution. This study expands our current understanding of how cryptdins function at the molecular level.
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Liu Y, Xu T, Wang Q, Huang J, Zhu Y, Liu X, Liu R, Yang B, Zhou K. Vibrio cholerae senses human enteric α-defensin 5 through a CarSR two-component system to promote bacterial pathogenicity. Commun Biol 2022; 5:559. [PMID: 35676416 PMCID: PMC9178039 DOI: 10.1038/s42003-022-03525-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 05/23/2022] [Indexed: 11/09/2022] Open
Abstract
Vibrio cholerae (V. cholerae) is an aquatic bacterium responsible for acute and fatal cholera outbreaks worldwide. When V. cholerae is ingested, the bacteria colonize the epithelium of the small intestine and stimulate the Paneth cells to produce large amounts of cationic antimicrobial peptides (CAMPs). Human defensin 5 (HD-5) is the most abundant CAMPs in the small intestine. However, the role of the V. cholerae response to HD-5 remains unclear. Here we show that HD-5 significantly upregulates virulence gene expression. Moreover, a two-component system, CarSR (or RstAB), is essential for V. cholerae virulence gene expression in the presence of HD-5. Finally, phosphorylated CarR can directly bind to the promoter region of TcpP, activating transcription of tcpP, which in turn activates downstream virulence genes to promote V. cholerae colonization. In conclusion, this study reveals a virulence-regulating pathway, in which the CarSR two-component regulatory system senses HD-5 to activate virulence genes expression in V. cholerae.
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Affiliation(s)
- Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, TEDA, Nankai University, Tianjin, PR China
| | - Tingting Xu
- The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, PR China
| | - Qian Wang
- TEDA Institute of Biological Sciences and Biotechnology, TEDA, Nankai University, Tianjin, PR China
| | - Junxi Huang
- The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, PR China
| | - Yangfei Zhu
- The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Laboratory Department, Shenzhen People's Hospital, Shenzhen, Guangdong, PR China
| | - Xingmei Liu
- TEDA Institute of Biological Sciences and Biotechnology, TEDA, Nankai University, Tianjin, PR China
| | - Ruiying Liu
- TEDA Institute of Biological Sciences and Biotechnology, TEDA, Nankai University, Tianjin, PR China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, TEDA, Nankai University, Tianjin, PR China.
| | - Kai Zhou
- The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, PR China.
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Xu D, Xiao J, Jiang D, Liu Y, Gou Z, Li J, Shi M, Wang X, Guo Y, Ma L, Yin H, Guo L, Zhu C, Zhang Y, Guo H. Inhibitory effects of a water-soluble jujube polysaccharide against biofilm-forming oral pathogenic bacteria. Int J Biol Macromol 2022; 208:1046-1062. [PMID: 35378158 DOI: 10.1016/j.ijbiomac.2022.03.196] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 01/08/2023]
Abstract
Oral diseases caused by infectious pathogens raises significant concerns in public health. In the light of side effects of current antibiotics therapy and growing drug resistance of pathogenic bacteria, natural products have become attractive alternatives for antibiotics agents in dental practice. This current study investigated the effects of polysaccharides extracted from Zizyphus jujuba Mill. on three major oral biofilm-forming pathogenic bacteria including caries-inducing Streptococcus mutans, lesions-causing MRSA, and periodontitis-related Porphyromonas gingivalis, as well as general oral microbiota. Our results demonstrated that jujube polysaccharide prepared in this study was mainly composed by galacturonic acid with an average molecular weight 242 kDa, which were further characterized for structural features by FT-IR spectra and NMR spectroscopy analysis. This jujube polysaccharide was shown to exhibit remarkable inhibitory effects against all the tested oral bacterial pathogens through various mechanisms including growth inhibition, biofilm prevention and disruption, intervention of bacterial infection (adhesion and invasion), attenuation of cytotoxicity, modulation of excessive inflammatory response of LPS-stimulated and MRSA-infected macrophages as well as positive regulation of oral microbiota. The present study paves the way to explore jujube polysaccharides for the prevention and treatment of oral infectious diseases. Graphic Abstract.
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Affiliation(s)
- Dan Xu
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China.
| | - Jiu Xiao
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Dazhao Jiang
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yaxin Liu
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Zhuolun Gou
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Jing Li
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Mingyao Shi
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xinyi Wang
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yaxuan Guo
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Lingyan Ma
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Hong Yin
- Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi'an, China
| | - Li Guo
- State Key Laboratory of Electrical Insulation and Power Equipment, Center for Plasma Biomedicine, Xi'an Jiaotong University, Xi'an, China
| | - Chunhui Zhu
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Yali Zhang
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China.
| | - Hui Guo
- Department of Endocrinology, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, China.
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Abstract
We report the development of peptidomimetic antibiotics derived from a natural antimicrobial peptide, human α-defensin 5. By engaging multiple bacterial targets, the lead compound is efficacious in vitro and in vivo against bacteria with highly inducible antibiotic resistance, promising a useful therapeutic agent for the treatment of infections caused by antibiotic-resistant bacteria. Antibiotics with multiple mechanisms of action and broad-spectrum are urgently required to combat the growing health threat posed by resistant pathogenic microorganisms. Combining computational and medicinal chemistry tools, we used the structure of human α-defensin 5 (HD5) to design a class of peptidomimetic antibiotics with improved activity against both gram-negative and gram-positive bacteria. The most promising lead, compound 10, showed potent killing of multiple drug-resistant gram-negative bacteria isolated from patients. Compound 10 exhibited a multiplex mechanism of action through targeting membrane components—outer membrane protein A and lipopolysaccharide, as well as a potential intracellular target—70S ribosome, thus causing membrane perturbation and inhibition of protein synthesis. In vivo efficacy, stability, and safety of compound 10 were also validated. This human defensin-inspired synthetic peptidomimetic could help solve the serious problem of drug resistance to conventional antibiotics.
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Gao X, Ding J, Liao C, Xu J, Liu X, Lu W. Defensins: The natural peptide antibiotic. Adv Drug Deliv Rev 2021; 179:114008. [PMID: 34673132 DOI: 10.1016/j.addr.2021.114008] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/28/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022]
Abstract
Defensins are a family of cationic antimicrobial peptides active against a broad range of infectious microbes including bacteria, viruses and fungi, playing important roles as innate effectors and immune modulators in immunological control of microbial infection. Their antibacterial properties and unique mechanisms of action have garnered considerable interest in developing defensins into a novel class of natural antibiotic peptides to fend off pathogenic infection by bacteria, particularly those resistant to conventional antibiotics. However, serious pharmacological and technical obstacles, some of which are unique to defensins and others are common to peptide drugs in general, have hindered the development and clinical translation of defensins as anti-infective therapeutics. To overcome them, several technologies have been developed, aiming for improved functionality, prolonged circulation time, enhanced proteolytic stability and bioavailability, and efficient and controlled delivery and release of defensins to the site of infection. Additional challenges include the alleviation of potential toxicity of defensins and their cost-effective manufacturing. In this review, we briefly introduce defensin biology, focus on various transforming strategies and practical techniques developed for defensins and their derivatives as antibacterial therapeutics, and conclude with a summation of future challenges and possible solutions.
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Wu Y, Jiang W, Huo S, Li S, Xu Y, Ding S, Zhou J, Liu H, Lv W, Wang Y. Nano-metal-organic-frameworks for treating H 2O 2-Secreting bacteria alleviate pulmonary injury and prevent systemic sepsis. Biomaterials 2021; 279:121237. [PMID: 34749071 DOI: 10.1016/j.biomaterials.2021.121237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/19/2021] [Accepted: 11/01/2021] [Indexed: 02/06/2023]
Abstract
As a vital bacteria-secreted toxin, hydrogen peroxide (H2O2) can destroy infected tissues and increase vascular permeability, leading to life-threatening systemic bacteremia or sepsis. No strategy that can alleviate H2O2-induced injury and prevent systemic sepsis has been reported. Herein, as a proof of concept, we demonstrate the use of H2O2-reactive metal-organic framework nanosystems (MOFs) for treating H2O2-secreting bacteria. In mice infected with Streptococcus pneumoniae (S. pneumoniae) isolated from patients, MOFs efficiently accumulate in the lungs after systemic administration due to infection-induced alveolar-capillary barrier dysfunction. Moreover, MOFs sequester pneumococcal H2O2, reduce endothelial DNA damage, and prevent systemic dissemination of bacteria. In addition, this nanosystem exhibits excellent chemodynamic bactericidal effects against drug-resistant bacteria. Through synergistic therapy with the antibiotic ampicillin, MOFs eliminate over 98% of invading S. pneumoniae, resulting in a survival rate of greater than 90% in mice infected with a lethal dose of S. pneumoniae. This work opens up new paths for the clinical treatment of toxin-secreting bacteria.
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Affiliation(s)
- Yi Wu
- Department of Radiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, 230001, PR China
| | - Wei Jiang
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China
| | - Shaohu Huo
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, PR China
| | - Shuya Li
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China
| | - Youcui Xu
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China
| | - Shenggang Ding
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, PR China
| | - Jing Zhou
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China
| | - Hang Liu
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China.
| | - Weifu Lv
- Department of Radiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, 230001, PR China.
| | - Yucai Wang
- Department of Radiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, 230001, PR China; Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, PR China.
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13
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Qiao Q, Bai R, Song W, Gao H, Zhang M, Lu J, Hong M, Zhang X, Sun P, Zhang Q, Zhao P. Human α-defensin 5 suppressed colon cancer growth by targeting PI3K pathway. Exp Cell Res 2021; 407:112809. [PMID: 34487729 DOI: 10.1016/j.yexcr.2021.112809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 08/23/2021] [Accepted: 09/01/2021] [Indexed: 01/06/2023]
Abstract
Defensins are highly conserved antimicrobial peptides, which ubiquitously expressed in different species. In addition to the functions in host defense, their aberrant expression have also been documented in cancerous tissue including breast cancer, lung caner and renal carcinoma etc. Whereas, roles of Defensin Alpha 5 (DEFA5) in colon cancer has not been explored. Bioinformatic analysis was used to study the expression of DEFA5 and its correlation with clinical outcomes; Western blot, qPCR, Co-immunoprecipitation, xenograft models were used to the study the molecular mechanism. Decreased expression of DEFA5 at protein level was observed in colon tissues. Colon cancer cell lines proliferation and colony formation capacity were significantly suppressed by DEFA5 overexpression. Moreover, in vivo tumor growth in nude mice was also suppressed by DEFA5 overexpression, suggesting a tumor suppressor role of DEFA5 in colon cancer. Mechanistically, DEFA5 directly binds to the subunits of PI3K complex, thus attenuates the downstream signaling transduction, leads to delayed cell growth and metastasis. Collectively, we concluded that DEFA5 showed an inhibitory effect in colon cancer cell growth and may serve as a potential tumor suppressor in colon cancer.
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Affiliation(s)
- Qiao Qiao
- Department of Obstetrics and Gynecology, Affiliated Hospital of Inner Mongolia Medical University, No.1, Tongdao North Street, Huimin District, Hohhot, 010050, PR China.
| | - Ruixia Bai
- Department of Clinical Laboratory, Inner Mongolia People's Hospital, Zhaowuda Road, Hohhot, 010018, PR China.
| | - Wanying Song
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Haining Gao
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Minyu Zhang
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Jingkun Lu
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Mei Hong
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Xuan Zhang
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Peng Sun
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
| | - Qian Zhang
- Pediatric Intensive Care Unit, Affiliated Hospital of Inner Mongolia Medical University, 1#, Xinhua Street, Hohhot, 010050, PR China.
| | - Pengwei Zhao
- Laboratory of Microbiology and Immunology, School of Basic Medical Science, Inner Mongolia Medical University, Xinhua Street, Hohhot, 010059, PR China.
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14
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Awang T, Pongprayoon P. The penetration of human defensin 5 (HD5) through bacterial outer membrane: simulation studies. J Mol Model 2021; 27:291. [PMID: 34546425 DOI: 10.1007/s00894-021-04915-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/13/2021] [Indexed: 11/24/2022]
Abstract
Human α-defensin 5 (HD5) is one of cationic antimicrobial peptides which plays a crucial role in an innate immune system in human body. HD5 shows the killing activity against a broad spectrum of pathogenic bacteria by making a pore in a bacterial membrane and penetrating into a cytosol. Nonetheless, its pore-forming mechanisms remain unclear. Thus, in this work, the constant-velocity steered molecular dynamics (SMD) simulation was used to simulate the permeation of a dimeric HD5 into a gram-negative lipopolysaccharide (LPS) membrane model. Arginine-rich HD5 is found to strongly interact with a LPS surface. Upon arrival, arginines on HD5 interact with lipid A head groups (a top part of LPS) and then drag these charged moieties down into a hydrophobic core resulting in the formation of water-filled pore. Although all arginines are found to interact with a membrane, Arg13 and Arg32 appear to play a dominant role in the HD5 adsorption on a gram-negative membrane. Furthermore, one chain of a dimeric HD5 is required for HD5 adhesion. The interactions of arginine-lipid A head groups play a major role in adhering a cationic HD5 on a membrane surface and retarding a HD5 passage in the meantime.
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Affiliation(s)
- Tadsanee Awang
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Prapasiri Pongprayoon
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand. .,Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, KU Institute for Advanced Studies, Kasetsart University, Bangkok, 10900, Thailand.
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15
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Zhang QY, Yan ZB, Meng YM, Hong XY, Shao G, Ma JJ, Cheng XR, Liu J, Kang J, Fu CY. Antimicrobial peptides: mechanism of action, activity and clinical potential. Mil Med Res 2021; 8:48. [PMID: 34496967 PMCID: PMC8425997 DOI: 10.1186/s40779-021-00343-2] [Citation(s) in RCA: 196] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022] Open
Abstract
The management of bacterial infections is becoming a major clinical challenge due to the rapid evolution of antibiotic resistant bacteria. As an excellent candidate to overcome antibiotic resistance, antimicrobial peptides (AMPs) that are produced from the synthetic and natural sources demonstrate a broad-spectrum antimicrobial activity with the high specificity and low toxicity. These peptides possess distinctive structures and functions by employing sophisticated mechanisms of action. This comprehensive review provides a broad overview of AMPs from the origin, structural characteristics, mechanisms of action, biological activities to clinical applications. We finally discuss the strategies to optimize and develop AMP-based treatment as the potential antimicrobial and anticancer therapeutics.
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Affiliation(s)
- Qi-Yu Zhang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Zhi-Bin Yan
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Yue-Ming Meng
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Xiang-Yu Hong
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Gang Shao
- Department of Oncology, The 903rd Hospital of PLA, Hangzhou, 310013, Zhejiang, China
| | - Jun-Jie Ma
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Xu-Rui Cheng
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China
| | - Jun Liu
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd. South, San Francisco, CA, 94158, USA
| | - Jian Kang
- Oncogenic Signaling and Growth Control Program, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC, 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Cai-Yun Fu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, No. 928, Street 2, Xiasha Higher Education Zone, Hangzhou, 310018, Zhejiang, China.
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16
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Gan BH, Gaynord J, Rowe SM, Deingruber T, Spring DR. The multifaceted nature of antimicrobial peptides: current synthetic chemistry approaches and future directions. Chem Soc Rev 2021; 50:7820-7880. [PMID: 34042120 PMCID: PMC8689412 DOI: 10.1039/d0cs00729c] [Citation(s) in RCA: 175] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Indexed: 12/13/2022]
Abstract
Bacterial infections caused by 'superbugs' are increasing globally, and conventional antibiotics are becoming less effective against these bacteria, such that we risk entering a post-antibiotic era. In recent years, antimicrobial peptides (AMPs) have gained significant attention for their clinical potential as a new class of antibiotics to combat antimicrobial resistance. In this review, we discuss several facets of AMPs including their diversity, physicochemical properties, mechanisms of action, and effects of environmental factors on these features. This review outlines various chemical synthetic strategies that have been applied to develop novel AMPs, including chemical modifications of existing peptides, semi-synthesis, and computer-aided design. We will also highlight novel AMP structures, including hybrids, antimicrobial dendrimers and polypeptides, peptidomimetics, and AMP-drug conjugates and consider recent developments in their chemical synthesis.
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Affiliation(s)
- Bee Ha Gan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Josephine Gaynord
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Sam M Rowe
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Tomas Deingruber
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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17
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Protective effect of glutamine and alanyl-glutamine against zearalenone-induced intestinal epithelial barrier dysfunction in IPEC-J2 cells. Res Vet Sci 2021; 137:48-55. [PMID: 33932823 DOI: 10.1016/j.rvsc.2021.04.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 04/13/2021] [Accepted: 04/22/2021] [Indexed: 12/22/2022]
Abstract
Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, has a negative effect on porcine intestine. Glutamine (Gln) and alanyl-glutamine (Ala-Gln) are nutrients with potential preservation functions similar to those of the intestinal epithelial barrier. The protective role of Gln and Ala-Gln on ZEN-induced intestinal barrier dysfunction was evaluated in this study. Additionally, the ability of Gln and Ala-Gln to protect the intestinal barrier was investigated. Our results showed that lactate dehydrogenase (LDH) activity, paracellular permeability and reactive oxygen species (ROS) level were increased by ZEN, while the glutathione (GSH) level was decreased by ZEN. Gln and Ala-Gln promoted the proliferation of cells and attenuated the ZEN-induced increase in cytotoxicity, cell apoptosis and paracellular permeability. Gln and Ala-Gln alleviated barrier function damage, which was additionally induced by ZEN by increasing the antioxidant capacity of cells. In addition, Gln and Ala-Gln upregulated intestinal barrier associated gene expressions including pBD-1, pBD-2, MUC-2, ZO-1, occludin and claudin-3. This study revealed that Gln and Ala-Gln had similar effects in protecting intestinal epithelial barrier function against ZEN exposure in IPEC-J2 cells. A new treatment for alleviating ZEN-induced injury to the intestine through nutritional intervention is provided.
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18
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Li Y, Liu M, Liu H, Sui X, Liu Y, Wei X, Liu C, Cheng Y, Ye W, Gao B, Wang X, Lu Q, Cheng H, Zhang L, Yuan J, Li M. The Anti-Inflammatory Effect and Mucosal Barrier Protection of Clostridium butyricum RH2 in Ceftriaxone-Induced Intestinal Dysbacteriosis. Front Cell Infect Microbiol 2021; 11:647048. [PMID: 33842393 PMCID: PMC8027357 DOI: 10.3389/fcimb.2021.647048] [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: 02/26/2021] [Indexed: 12/12/2022] Open
Abstract
This study aimed at determining the beneficial effect of Clostridium butyricum (CB) RH2 on ceftriaxone-induced dysbacteriosis. To this purpose, BALB/c mice were exposed to ceftriaxone (400 mg/ml) or not (control) for 7 days, and administered a daily oral gavage of low-, and high-dose CB RH2 (108 and 1010 CFU/ml, respectively) for 2 weeks. CB RH2 altered the diversity of gut microbiota, changed the composition of gut microbiota in phylum and genus level, decreased the F/B ratio, and decreased the pro-inflammatory bacteria (Deferribacteres, Oscillibacter, Desulfovibrio, Mucispirillum and Parabacteroides) in ceftriaxone-treated mice. Additionally, CB RH2 improved colonic architecture and intestinal integrity by improving the mucous layer and the tight junction barrier. Furthermore, CB RH2 also mitigated intestinal inflammation through decreasing proinflammatory factors (TNF-α and COX-2) and increasing anti-inflammatory factors (IL-10). CB RH2 had direct effects on the expansion of CD4+ T cells in Peyer’s patches (PPs) in vitro, which in turn affected their immune response upon challenge with ceftriaxone. All these data suggested that CB RH2 possessed the ability to modulate the intestinal mucosal and systemic immune system in limiting intestinal alterations to relieve ceftriaxone-induced dysbacteriosis.
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Affiliation(s)
- Yuyuan Li
- Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
| | - Man Liu
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - He Liu
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Xue Sui
- Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
| | - Yinhui Liu
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Xiaoqing Wei
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Chunzheng Liu
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Yiqin Cheng
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Weikang Ye
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Binbin Gao
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Xin Wang
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Qiao Lu
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Hao Cheng
- Marketing Department, Hangzhou Grand Biologic Pharmaceutical Inc., Hangzhou, China
| | - Lu Zhang
- Marketing Department, Hangzhou Grand Biologic Pharmaceutical Inc., Hangzhou, China
| | - Jieli Yuan
- College of Basic Medical Science, Dalian Medical University, Dalian, China
| | - Ming Li
- College of Basic Medical Science, Dalian Medical University, Dalian, China
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19
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Luo G, Sun Y, Zhang J, Xu Z, Lu W, Wang H, Zhang Y, Li H, Mao Z, Ye S, Cheng B, Fang X. Nanodefensin-encased hydrogel with dual bactericidal and pro-regenerative functions for advanced wound therapy. Am J Cancer Res 2021; 11:3642-3660. [PMID: 33664853 PMCID: PMC7914350 DOI: 10.7150/thno.53089] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/31/2020] [Indexed: 12/25/2022] Open
Abstract
Background: Host defense peptides (HDPs) have emerged as a novel therapeutic paradigm for wound management; however, their clinical applications remain a challenge owing to their poor pharmacological properties and lack of suitable pharmaceutical formulations. Nanodefensin (ND), a nanoengineered human α-defensin 5 (HD5), has shown improved pharmacological properties relative to the parent compound. In this study, we engineered a nanodefensin-encased hydrogel (NDEFgel), investigated the effects of NDEFgel on wound healing, and elucidated underlying mechanisms. Method: ND was chemically synthesized and tested functions by in vitro antimicrobial and scratch assays and western blotting. Different NDEFgels were evaluated by in vitro characterizations including degradation, drug release and antimicrobial activity. In full-thickness excisional murine models, the optimal NDEFgel was directly applied onto wound sites, and the efficacy was assessed. Moreover, the underlying mechanisms of pro-regenerative effect developed by NDEFgel were also explored. Results: Apart from bactericidal effects, ND modulated fibroblast behaviors by promoting migration and differentiation. Among the tested hydrogels, the Pluronic F127 (Plu) hydrogel represented the most desirable carrier for ND delivery owing to its favorable controlled release and compatibility with ND. Local treatment of NDEFgel on the wound bed resulted in accelerated wound regeneration and attenuated bacterial burden. We further demonstrated that NDEFgel therapy significantly upregulated genes related to collagen deposition and fibroblasts, and increased the expression of myofibroblasts and Rac1. We therefore found that Rac1 is a critical factor in the ND-induced modulation of fibroblast behaviors in vitro through a Rac1-dependent cytoskeletal rearrangement. Conclusion: Our results indicate that NDEFgel may be a promising dual-action therapeutic option for advanced wound management in the future.
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20
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Bajunaid W, Haidar-Ahmad N, Kottarampatel AH, Ourida Manigat F, Silué N, F. Tchagang C, Tomaro K, Campbell-Valois FX. The T3SS of Shigella: Expression, Structure, Function, and Role in Vacuole Escape. Microorganisms 2020; 8:microorganisms8121933. [PMID: 33291504 PMCID: PMC7762205 DOI: 10.3390/microorganisms8121933] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022] Open
Abstract
Shigella spp. are one of the leading causes of infectious diarrheal diseases. They are Escherichia coli pathovars that are characterized by the harboring of a large plasmid that encodes most virulence genes, including a type III secretion system (T3SS). The archetypal element of the T3SS is the injectisome, a syringe-like nanomachine composed of approximately 20 proteins, spanning both bacterial membranes and the cell wall, and topped with a needle. Upon contact of the tip of the needle with the plasma membrane, the injectisome secretes its protein substrates into host cells. Some of these substrates act as translocators or effectors whose functions are key to the invasion of the cytosol and the cell-to-cell spread characterizing the lifestyle of Shigella spp. Here, we review the structure, assembly, function, and methods to measure the activity of the injectisome with a focus on Shigella, but complemented with data from other T3SS if required. We also present the regulatory cascade that controls the expression of T3SS genes in Shigella. Finally, we describe the function of translocators and effectors during cell-to-cell spread, particularly during escape from the vacuole, a key element of Shigella’s pathogenesis that has yet to reveal all of its secrets.
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Affiliation(s)
- Waad Bajunaid
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Nathaline Haidar-Ahmad
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Anwer Hasil Kottarampatel
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - France Ourida Manigat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Navoun Silué
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Caetanie F. Tchagang
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Kyle Tomaro
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - François-Xavier Campbell-Valois
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Correspondence:
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21
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Diaz K, Hu CT, Sul Y, Bromme BA, Myers ND, Skorohodova KV, Gounder AP, Smith JG. Defensin-driven viral evolution. PLoS Pathog 2020; 16:e1009018. [PMID: 33232373 PMCID: PMC7723274 DOI: 10.1371/journal.ppat.1009018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 12/08/2020] [Accepted: 10/02/2020] [Indexed: 01/06/2023] Open
Abstract
Enteric alpha-defensins are potent effectors of innate immunity that are abundantly expressed in the small intestine. Certain enteric bacteria and viruses are resistant to defensins and even appropriate them to enhance infection despite neutralization of closely related microbes. We therefore hypothesized that defensins impose selective pressure during fecal-oral transmission. Upon passaging a defensin-sensitive serotype of adenovirus in the presence of a human defensin, mutations in the major capsid protein hexon accumulated. In contrast, prior studies identified the vertex proteins as important determinants of defensin antiviral activity. Infection and biochemical assays suggest that a balance between increased cell binding and a downstream block in intracellular trafficking mediated by defensin interactions with all of the major capsid proteins dictates the outcome of infection. These results extensively revise our understanding of the interplay between defensins and non-enveloped viruses. Furthermore, they provide a feasible rationale for defensins shaping viral evolution, resulting in differences in infection phenotypes of closely related viruses. Defensins are potent antimicrobial peptides that are found on human mucosal surfaces and can directly neutralize viruses. They are abundant in the small intestine, which is constantly challenged by ingested viral pathogens. Interestingly, non-enveloped viruses, such as adenovirus, that infect the gastrointestinal system are unaffected by defensins or can even appropriate defensins to enhance their infection. In contrast, respiratory adenoviruses are neutralized by the same defensins. How enteric viruses overcome defensin neutralization is not well understood. Our studies are the first to show that defensins can drive the evolution of non-enveloped viruses. Furthermore, we identify important components within human adenovirus that dictate sensitivity to defensins. This new insight into defensin-virus interactions informs our understanding of mucosal immunity to viral infections.
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Affiliation(s)
- Karina Diaz
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Ciara T. Hu
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Youngmee Sul
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Beth A. Bromme
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Nicolle D. Myers
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Ksenia V. Skorohodova
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Anshu P. Gounder
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Jason G. Smith
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
- * E-mail:
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22
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Panwar H, Rokana N, Aparna SV, Kaur J, Singh A, Singh J, Singh KS, Chaudhary V, Puniya AK. Gastrointestinal stress as innate defence against microbial attack. J Appl Microbiol 2020; 130:1035-1061. [PMID: 32869386 DOI: 10.1111/jam.14836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/09/2020] [Accepted: 08/21/2020] [Indexed: 12/13/2022]
Abstract
The human gastrointestinal (GI) tract has been bestowed with the most difficult task of protecting the underlying biological compartments from the resident commensal flora and the potential pathogens in transit through the GI tract. It has a unique environment in which several defence tactics are at play while maintaining homeostasis and health. The GI tract shows myriad number of environmental extremes, which includes pH variations, anaerobic conditions, nutrient limitations, elevated osmolarity etc., which puts a check to colonization and growth of nonfriendly microbial strains. The GI tract acts as a highly selective barrier/platform for ingested food and is the primary playground for balance between the resident and uninvited organisms. This review focuses on antimicrobial defense mechanisms of different sections of human GI tract. In addition, the protective mechanisms used by microbes to combat the human GI defence systems are also discussed. The ability to survive this innate defence mechanism determines the capability of probiotic or pathogen strains to confer health benefits or induce clinical events respectively.
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Affiliation(s)
- H Panwar
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - N Rokana
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - S V Aparna
- Department of Dairy Microbiology, College of Dairy Science and Technology, Kerala Veterinary and Animal Science University, Mannuthy, Thrissur, India
| | - J Kaur
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - A Singh
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - J Singh
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - K S Singh
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - V Chaudhary
- Department of Microbiology, Punjab Agriculture University, Ludhiana, Punjab, India
| | - A K Puniya
- Dairy Microbiology Division, ICAR-National Dairy Research Institute, Karnal, Haryana, India
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23
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Ou J, Liang S, Guo XK, Hu X. α-Defensins Promote Bacteroides Colonization on Mucosal Reservoir to Prevent Antibiotic-Induced Dysbiosis. Front Immunol 2020; 11:2065. [PMID: 33013873 PMCID: PMC7509133 DOI: 10.3389/fimmu.2020.02065] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
In addition to their established functions in host defense, accumulating evidence has suggested an emerging role for antimicrobial proteins (AMPs) in shaping commensal microbiota. However, the role of α-defensins, the most abundant AMPs of intestine, in regulating microbial ecology remains inconclusive. Here, we report that α-defensins promote commensal Bacteroides colonization by enhancing bacterial adhesion to the mucosal reservoir. Experiments utilizing mice deficient in matrix metalloproteinase 7 (MMP7), the α-defensin–activating enzyme, with rigorous littermate controls showed that α-defensin deficiency did not significantly influence steady-state intestinal microbiota. In contrast, α-defensins are essential for replenishment of commensal Bacteroides from the mucosal reservoir following antibiotics-induced dysbiosis, shown by markedly compromised recovery of Bacteroides in Mmp7−/− animals. Mechanistically, α-defensins promote Bacteroides colonization on epithelial surfaces in vivo and adhesion to epithelial cells in vitro. Moreover, α-defensins unexpectedly does not show any microbicidal activities against Bacteroides. Together, we propose that α-defensins promote commensal bacterial colonization and recovery to maintain microbial diversity upon environmental challenges.
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Affiliation(s)
- Jiayao Ou
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
| | - Shaonan Liang
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
| | - Xue-Kun Guo
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
| | - Xiaoyu Hu
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
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24
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Abstract
Defensins are a major family of host defense peptides expressed predominantly in neutrophils and epithelial cells. Their broad antimicrobial activities and multifaceted immunomodulatory functions have been extensively studied, cementing their role in innate immunity as a core host-protective component against bacterial, viral and fungal infections. More recent studies, however, paint defensins in a bad light such that they are "alleged" to promote viral and bacterial infections in certain biological settings. This mini review summarizes the latest findings on the potential pathogenic properties of defensins against the backdrop of their protective roles in antiviral and antibacterial immunity. Further, a succinct description of both tumor-proliferative and -suppressive activities of defensins is also given to highlight their functional and mechanistic complexity in antitumor immunity. We posit that given an enabling environment defensins, widely heralded as the "Swiss army knife," can function as a "double-edged sword" in host immunity.
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Affiliation(s)
- Dan Xu
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
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25
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Panjeta A, Preet S. Anticancer potential of human intestinal defensin 5 against 1, 2-dimethylhydrazine dihydrochloride induced colon cancer: A therapeutic approach. Peptides 2020; 126:170263. [PMID: 31981594 DOI: 10.1016/j.peptides.2020.170263] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 12/12/2022]
Abstract
The escalating predicament of multidrug resistant cancer cells and associated side effects of conventional chemotherapy necessitates the exploration of alternative anticancer therapies. The present study evaluated anticancer therapeutic potential of human defensin 5 (HD-5) against colon cancer. The in vivo anticancer efficacy of HD-5 against 1,2-dimethylhydrazine (DMH) induced colon cancer was elucidated in terms of tumor biostatistics, number of aberrant crypt foci (ACF), in situ apoptosis assay,changes in morphological as well as histological architecture of colon(s). The direct interaction of peptide was investigated by incubating peptide with normal and/or cancerous colonocytes followed by phase contrast, Hoechst 3342 and AO/PI staining as well as confocal microscopy. Changes in membrane dynamics were evaluated by MC 540 and N-NBD-PE staining. In vivo decrease(s) in tumor parameters, number of aberrant crypt foci along with marked increase in the rate of apoptosis was observed.H&E staining revealed neutrophils infiltration and restoration of normal architecture in treated colon(s) which was consistent with scanning electron microscopic observations. Furthermore, non-membranolytic mechanism was found to be acquired by peptide as it could traverse cell membrane gaining access to nucleus and cytoplasm thereby disintegrating cellular architecture. MC 540 and NBD-PE staining revealed that peptide could bind to cancerous cells by taking advantage of altered fluidity levels. Our results indicated that HD-5 exhibited strong cancer cell killing and does not affect normal host cells. The peptide can be exploited as promising option to combat developing menace of colon cancer and/or can at least be used as an adjunct to present day chemotherapies.
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Affiliation(s)
- Anshul Panjeta
- Department of Biophysics, Basic Medical Sciences, Block II, Panjab University, Sector 25, Chandigarh, 160014, India
| | - Simran Preet
- Department of Biophysics, Basic Medical Sciences, Block II, Panjab University, Sector 25, Chandigarh, 160014, India.
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26
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Duperthuy M. Antimicrobial Peptides: Virulence and Resistance Modulation in Gram-Negative Bacteria. Microorganisms 2020; 8:microorganisms8020280. [PMID: 32092866 PMCID: PMC7074834 DOI: 10.3390/microorganisms8020280] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 02/03/2023] Open
Abstract
Growing resistance to antibiotics is one of the biggest threats to human health. One of the possibilities to overcome this resistance is to use and develop alternative molecules such as antimicrobial peptides (AMPs). However, an increasing number of studies have shown that bacterial resistance to AMPs does exist. Since AMPs are immunity molecules, it is important to ensure that their potential therapeutic use is not harmful in the long term. Recently, several studies have focused on the adaptation of Gram-negative bacteria to subinhibitory concentrations of AMPs. Such concentrations are commonly found in vivo and in the environment. It is therefore necessary to understand how bacteria detect and respond to low concentrations of AMPs. This review focuses on recent findings regarding the impact of subinhibitory concentrations of AMPs on the modulation of virulence and resistance in Gram-negative bacteria.
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Affiliation(s)
- Marylise Duperthuy
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
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27
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Kuehl CJ, D'Gama JD, Warr AR, Waldor MK. An Oral Inoculation Infant Rabbit Model for Shigella Infection. mBio 2020; 11:e03105-19. [PMID: 31964739 PMCID: PMC6974573 DOI: 10.1128/mbio.03105-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 02/07/2023] Open
Abstract
Shigella species cause diarrheal disease globally. Shigellosis is typically characterized by bloody stools and colitis with mucosal damage and is the leading bacterial cause of diarrheal death worldwide. After the pathogen is orally ingested, it invades and replicates within the colonic epithelium through mechanisms that rely on its type III secretion system (T3SS). Currently, oral infection-based small animal models to study the pathogenesis of shigellosis are lacking. Here, we found that orogastric inoculation of infant rabbits with Shigella flexneri resulted in diarrhea and colonic pathology resembling that found in human shigellosis. Fasting animals prior to S. flexneri inoculation increased the frequency of disease. The pathogen colonized the colon, where both luminal and intraepithelial foci were observed. The intraepithelial foci likely arise through S. flexneri spreading from cell to cell. Robust S. flexneri intestinal colonization, invasion of the colonic epithelium, and epithelial sloughing all required the T3SS as well as IcsA, a factor required for bacterial spreading and adhesion in vitro Expression of the proinflammatory chemokine interleukin 8 (IL-8), detected with in situ mRNA labeling, was higher in animals infected with wild-type S. flexneri versus mutant strains deficient in icsA or T3SS, suggesting that epithelial invasion promotes expression of this chemokine. Collectively, our findings suggest that oral infection of infant rabbits offers a useful experimental model for studies of the pathogenesis of shigellosis and for testing of new therapeutics.IMPORTANCEShigella species are the leading bacterial cause of diarrheal death globally. The pathogen causes bacillary dysentery, a bloody diarrheal disease characterized by damage to the colonic mucosa and is usually spread through the fecal-oral route. Small animal models of shigellosis that rely on the oral route of infection are lacking. Here, we found that orogastric inoculation of infant rabbits with S. flexneri led to a diarrheal disease and colonic pathology reminiscent of human shigellosis. Diarrhea, intestinal colonization, and pathology in this model were dependent on the S. flexneri type III secretion system and IcsA, canonical Shigella virulence factors. Thus, oral infection of infant rabbits offers a feasible model to study the pathogenesis of shigellosis and to develop and test new therapeutics.
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Affiliation(s)
- Carole J Kuehl
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Jonathan D D'Gama
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Alyson R Warr
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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28
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Inhibitory Activity of a Scorpion Defensin BmKDfsin3 against Hepatitis C Virus. Antibiotics (Basel) 2020; 9:antibiotics9010033. [PMID: 31963532 PMCID: PMC7168052 DOI: 10.3390/antibiotics9010033] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 12/26/2022] Open
Abstract
Hepatitis C virus (HCV) infection is a major worldwide health problem which can cause chronic hepatitis, liver fibrosis and hepatocellular carcinoma (HCC). There is still no vaccine to prevent HCV infection. Currently, the clinical treatment of HCV infection mainly relies on the use of direct-acting antivirals (DAAs) which are expensive and have side effects. Here, BmKDfsin3, a scorpion defensin from the venom of Mesobuthus martensii Karsch, is found to dose-dependently inhibit HCV infection at noncytotoxic concentrations and affect viral attachment and post-entry in HCV life cycle. Further experimental results show that BmKDfsin3 not only suppresses p38 mitogen-activated protein kinase (MAPK) activation of HCV-infected Huh7.5.1 cells, but also inhibits p38 activation of Huh7.5.1 cells stimulated by tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) or lipopolysaccharide (LPS). BmKDfsin3 is also revealed to enter into cells. Using an upstream MyD88 dimerization inhibitor ST2345 or kinase IRAK-1/4 inhibitor I, the inhibition of p38 activation represses HCV replication in vitro. Taken together, a scorpion defensin BmKDfsin3 inhibits HCV replication, related to regulated p38 MAPK activation.
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29
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Wu J, Ma N, Johnston LJ, Ma X. Dietary Nutrients Mediate Intestinal Host Defense Peptide Expression. Adv Nutr 2020; 11:92-102. [PMID: 31204774 PMCID: PMC7442325 DOI: 10.1093/advances/nmz057] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/14/2019] [Accepted: 05/17/2019] [Indexed: 02/06/2023] Open
Abstract
The intestinal tract is the shared locus of intestinal epithelial cells, immune cells, nutrient digestion and absorption, and microbial survival. The gut in animals faces continuous challenges in communicating with the external environment. Threats from endogenous imbalance and exogenous feeds, especially pathogens, could trigger a disorder of homeostasis, leading to intestinal disease and even systematic disease risk. As a part of the intestinal protective barrier, endogenous host defense peptides (HDPs) play multiple beneficial physiological roles in the gut mucosa. Moreover, enhancing endogenous HDPs is being developed as a new strategy for resisting pathogens and commensal microbes, and to maintain intestinal health and reduce antibiotic use. In recent years, multiple nutrients such as branched-chain amino acids, SCFAs, lactose, zinc, and cholecalciferol (vitamin D3) have been reported to significantly increase HDP expression. Nutritional intervention has received more attention and is viewed as a promising means to defend against pathogenic infections and intestinal inflammation. The present review focuses on current discoveries surrounding HDP expression and nutritional regulation of mechanisms in the gut. Our aim is to provide a comprehensive overview, referable tactics, and novel opinions.
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Affiliation(s)
- Jianmin Wu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Ning Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Lee J Johnston
- Swine Nutrition and Production, West Central Research and Outreach Center, University of Minnesota, Morris, MN, USA
| | - Xi Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
- Department of Internal Medicine, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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30
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31
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Human Enteric Defensin 5 Promotes Shigella Infection of Macrophages. Infect Immun 2019; 88:IAI.00769-19. [PMID: 31611271 DOI: 10.1128/iai.00769-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 10/06/2019] [Indexed: 01/13/2023] Open
Abstract
Human α-defensins are 3- to 5-kDa disulfide-bridged peptides with a multitude of antimicrobial activities and immunomodulatory functions. Recent studies show that human enteric α-defensin 5 (HD5), a host defense peptide important for intestinal homeostasis and innate immunity, aids the highly infectious enteropathogen Shigella in breaching the intestinal epithelium in vitro and in vivo Whether and how HD5 influences Shigella infection of resident macrophages following its invasion of the intestinal epithelium remain poorly understood. Here, we report that HD5 greatly promoted phagocytosis of Shigella by macrophages by targeting the bacteria to enhance bacterium-to-cell contacts in a structure- and sequence-dependent fashion. Subsequent intracellular multiplication of phagocytosed Shigella led to massive necrotic cell death and release of the bacteria. HD5-promoted phagocytosis of Shigella was independent of the status of the type 3 secretion system. Furthermore, HD5 neither inhibited nor enhanced phagosomal escape of Shigella Collectively, these findings confirm a potential pathogenic role of HD5 in Shigella infection of not only epithelial cells but also macrophages, illuminating how an enteropathogen exploits a host protective factor for virulence and infection.
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32
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Oral Microbiota Composition and Antimicrobial Antibody Response in Patients with Recurrent Aphthous Stomatitis. Microorganisms 2019; 7:microorganisms7120636. [PMID: 31805744 PMCID: PMC6955784 DOI: 10.3390/microorganisms7120636] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 02/06/2023] Open
Abstract
Recurrent aphthous stomatitis (RAS) is the most common disease of the oral mucosa, and it has been recently associated with bacterial and fungal dysbiosis. To study this link further, we investigated microbial shifts during RAS manifestation at an ulcer site, in its surroundings, and at an unaffected site, compared with healed mucosa in RAS patients and healthy controls. We sampled microbes from five distinct sites in the oral cavity. The one site with the most pronounced differences in microbial alpha and beta diversity between RAS patients and healthy controls was the lower labial mucosa. Detailed analysis of this particular oral site revealed strict association of the genus Selenomonas with healed mucosa of RAS patients, whereas the class Clostridia and genera Lachnoanaerobaculum, Cardiobacterium, Leptotrichia, and Fusobacterium were associated with the presence of an active ulcer. Furthermore, active ulcers were dominated by Malassezia, which were negatively correlated with Streptococcus and Haemophilus and positively correlated with Porphyromonas species. In addition, RAS patients showed increased serum levels of IgG against Mogibacterium timidum compared with healthy controls. Our study demonstrates that the composition of bacteria and fungi colonizing healthy oral mucosa is changed in active RAS ulcers, and that this alteration persists to some extent even after the ulcer is healed.
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33
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Hotinger JA, May AE. Animal Models of Type III Secretion System-Mediated Pathogenesis. Pathogens 2019; 8:pathogens8040257. [PMID: 31766664 PMCID: PMC6963218 DOI: 10.3390/pathogens8040257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 01/22/2023] Open
Abstract
The type III secretion system (T3SS) is a conserved virulence factor used by many Gram-negative pathogenic bacteria and has become an important target for anti-virulence drugs. Most T3SS inhibitors to date have been discovered using in vitro screening assays. Pharmacokinetics and other important characteristics of pharmaceuticals cannot be determined with in vitro assays alone. In vivo assays are required to study pathogens in their natural environment and are an important step in the development of new drugs and vaccines. Animal models are also required to understand whether T3SS inhibition will enable the host to clear the infection. This review covers selected animal models (mouse, rat, guinea pig, rabbit, cat, dog, pig, cattle, primates, chicken, zebrafish, nematode, wax moth, flea, fly, and amoeba), where T3SS activity and infectivity have been studied in relation to specific pathogens (Escherichia coli, Salmonella spp., Pseudomonas spp., Shigella spp., Bordetella spp., Vibrio spp., Chlamydia spp., and Yersinia spp.). These assays may be appropriate for those researching T3SS inhibition.
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34
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Gulati NM, Miyagi M, Wiens ME, Smith JG, Stewart PL. α-Defensin HD5 Stabilizes Human Papillomavirus 16 Capsid/Core Interactions. Pathog Immun 2019; 4:196-234. [PMID: 31583330 PMCID: PMC6755940 DOI: 10.20411/pai.v4i2.314] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 08/17/2019] [Indexed: 12/17/2022] Open
Abstract
Background: Human papillomavirus (HPV) is linked to nearly all cases of cervical cancer. Despite available vaccines, a deeper understanding of the immune response to HPV is needed. Human α-defensin 5 (HD5), an innate immune effector peptide, blocks infection of multiple sero-types of HPV, including high-risk HPV16. While a common mechanism of α-defensin anti-viral activity against nonenveloped viruses such as HPV has emerged, there is limited understanding of how α-defensins bind to viral capsids to block infection. Methods: We have used cryo-electron microscopy (cryoEM), mass spectrometry (MS) crosslinking and differential lysine modification studies, and molecular dynamics (MD) simulations to probe the interaction of HPV16 pseudovirions (PsVs) with HD5. Results: CryoEM single particle reconstruction did not reveal HD5 density on the capsid surface. Rather, increased density was observed under the capsid shell in the presence of HD5. MS studies indicate that HD5 binds near the L1 and L2 capsid proteins and specifically near the C-terminal region of L1. MD simulations indicate that favorable electrostatic interactions can be formed between HD5 and the L1 C-terminal tail. Conclusions: A model is presented for how HD5 affects HPV16 structure and cell entry. In this model, HD5 binds to disordered regions of L1 and L2 protruding from the icosahedrally ordered capsid. HD5 acts to cement interactions between L1 and L2 and leads to a closer association of the L2/genome core with the L1 capsid. This model provides a structural rationale for our prior observation that HD5 interferes with the separation of L1 from the L2/genome complex during cell entry. Graphical Abstract
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Affiliation(s)
- Neetu M Gulati
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, Ohio
| | - Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Mayim E Wiens
- Department of Microbiology, University of Washington, Seattle, Washington
| | - Jason G Smith
- Department of Microbiology, University of Washington, Seattle, Washington
| | - Phoebe L Stewart
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, Ohio
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35
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Liao C, Fang K, Xiao J, Zhang W, Zhang B, Yuan W, Lu W, Xu D. Critical determinants of human neutrophil peptide 1 for enhancing host epithelial adhesion of Shigella flexneri. Cell Microbiol 2019; 21:e13069. [PMID: 31218775 DOI: 10.1111/cmi.13069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/17/2019] [Accepted: 06/04/2019] [Indexed: 11/27/2022]
Abstract
Human neutrophil peptides (HNPs), also known as human myeloid α-defensins degranulated by infiltrating neutrophils at bacterial infection loci, exhibit broad antomicrobial activities against bacteria, fungi, and viruses. We have made a surprising recent finding that Shigella, a highly contagious, yet poorly adhesive enteric pathogen, exploits human α-defensins including HNP1 to enhance its adhesion to and invasion of host epithelial cells. However, the critical molecular determinants responsible for HNP1-enhanced Shigella adhesion and invasion have yet to be investigated. Using cultured epithelial cells and polarised Caco2 cells as an in vitro infection model, we demonstrated that HNP1 promoted Shigella infection in a structure- and sequence-dependent manner, with two bulky hydrophobic residues, Trp26 and Phe28 important for HNP1 self-assembly, being most critical. The functional importance of hydrophobicity for HNP1-enhanced Shigella infection was further verified by substitutions for Trp26 of a series of unnatural amino acids with straight aliphatic side chains of different lengths. Dissection of the Shigella infection process revealed that bacteria-rather than host cells-bound HNP1 contributed most to the enhancement. Further, mutagenesis analysis of bacterial surface components, while precluding the involvement of lipopolysaccharides (LPS) in the interaction with HNP1, identified outer membrane proteins and the Type 3 secretion apparatus as putative binding targets of HNP1 involved in enhanced Shigella adhesion and invasion. Our findings provide molecular and mechanistic insights into the mode of action of HNP1 in promoting Shigella infection, thus showcasing another example of how innate immune factors may serve as a double-edged sword in health and disease.
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Affiliation(s)
- Chongbing Liao
- Center for Translational Medicine Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kun Fang
- Department of Internal Medicine, Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jiu Xiao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Wei Zhang
- Center for Translational Medicine Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Bing Zhang
- Center for Translational Medicine Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Weirong Yuan
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Dan Xu
- Center for Translational Medicine Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
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Brunner K, Samassa F, Sansonetti PJ, Phalipon A. Shigella-mediated immunosuppression in the human gut: subversion extends from innate to adaptive immune responses. Hum Vaccin Immunother 2019; 15:1317-1325. [PMID: 30964713 PMCID: PMC6663138 DOI: 10.1080/21645515.2019.1594132] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/13/2019] [Accepted: 02/27/2019] [Indexed: 02/07/2023] Open
Abstract
The enteropathogen, Shigella, is highly virulent and remarkably adjusted to the intestinal environment of its almost exclusive human host. Key for Shigella pathogenicity is the injection of virulence effectors into the host cell via its type three secretion system (T3SS), initiating disease onset and progression by the vast diversity of the secreted T3SS effectors and their respective cellular targets. The multifaceted modulation of host signaling pathways exerted by Shigella T3SS effectors, which include the subversion of host innate immune defenses and the promotion of intracellular bacterial survival and dissemination, have been extensively reviewed in the recent past. This review focuses on the human species specificity of Shigella by discussing some possible evasion mechanisms towards the human, but not non-human or rodent gut innate defense barrier, leading to the lack of a relevant animal infection model. In addition, subversion mechanisms of the adaptive immune response are highlighted summarizing research advances of the recent years. In particular, the new paradigm of Shigella pathogenicity constituted of invasion-independent T3SS effector-mediated targeting of activated, human lymphocytes is discussed. Along with consequences on vaccine development, these findings offer new directions for future research endeavors towards a better understanding of immunity to Shigella infection.
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Affiliation(s)
- Katja Brunner
- Molecular Microbial Pathogenesis Unit, Department of Cellular Biology of Infection, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
| | - Fatoumata Samassa
- Molecular Microbial Pathogenesis Unit, Department of Cellular Biology of Infection, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
| | - Philippe J. Sansonetti
- Molecular Microbial Pathogenesis Unit, Department of Cellular Biology of Infection, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
- Chaire de Microbiologie et Maladies Infectieuses, Collège de France, Paris, France
| | - Armelle Phalipon
- Molecular Microbial Pathogenesis Unit, Department of Cellular Biology of Infection, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
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Abstract
ABSTRACT
Shigella
is a genus of Gram-negative enteropathogens that have long been, and continue to be, an important public health concern worldwide. Over the past several decades,
Shigella
spp. have also served as model pathogens in the study of bacterial pathogenesis, and
Shigella flexneri
has become one of the best-studied pathogens on a molecular, cellular, and tissue level. In the arms race between
Shigella
and the host immune system,
Shigella
has developed highly sophisticated mechanisms to subvert host cell processes in order to promote infection, escape immune detection, and prevent bacterial clearance. Here, we give an overview of
Shigella
pathogenesis while highlighting innovative techniques and methods whose application has significantly advanced our understanding of
Shigella
pathogenesis in recent years.
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Koestler BJ, Ward CM, Fisher CR, Rajan A, Maresso AW, Payne SM. Human Intestinal Enteroids as a Model System of Shigella Pathogenesis. Infect Immun 2019; 87:e00733-18. [PMID: 30642906 PMCID: PMC6434139 DOI: 10.1128/iai.00733-18] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/06/2019] [Indexed: 01/01/2023] Open
Abstract
The enteric bacterium and intracellular human pathogen Shigella causes hundreds of millions of cases of the diarrheal disease shigellosis per year worldwide. Shigella is acquired by ingestion of contaminated food or water; upon reaching the colon, the bacteria invade colonic epithelial cells, replicate intracellularly, spread to adjacent cells, and provoke an intense inflammatory response. There is no animal model that faithfully recapitulates human disease; thus, cultured cells have been used to model Shigella pathogenesis. However, the use of transformed cells in culture does not provide the same environment to the bacteria as the normal human intestinal epithelium. Recent advances in tissue culture now enable the cultivation of human intestinal enteroids (HIEs), which are derived from human intestinal stem cells, grown ex vivo, and then differentiated into "mini-intestines." Here, we demonstrate that HIEs can be used to model Shigella pathogenesis. We show that Shigella flexneri invades polarized HIE monolayers preferentially via the basolateral surface. After S. flexneri invades HIE monolayers, S. flexneri replicates within HIE cells and forms actin tails. S. flexneri also increases the expression of HIE proinflammatory signals and the amino acid transporter SLC7A5. Finally, we demonstrate that disruption of HIE tight junctions enables S. flexneri invasion via the apical surface.
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Affiliation(s)
- Benjamin J Koestler
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Cara M Ward
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA
| | - C R Fisher
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Anubama Rajan
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Anthony W Maresso
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Shelley M Payne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA
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Murphy AG, Maloy KJ. Defens-IN! Human α-Defensin 5 Acts as an Unwitting Double Agent to Promote Shigella Infection. Immunity 2019; 48:1070-1072. [PMID: 29924970 DOI: 10.1016/j.immuni.2018.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Shigella pathogenesis has confounded researchers for years because of its narrow host selectivity and extraordinary infectious capability. In this issue of Immunity, Xu et al. (2018) identify a cunning mechanism whereby Shigella hijacks human α-defensin 5 to enhance its adhesion and subsequent invasion.
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Affiliation(s)
- Alison G Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Kevin J Maloy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
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