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Benyamini P. Phylogenetic Tracing of Evolutionarily Conserved Zonula Occludens Toxin Reveals a "High Value" Vaccine Candidate Specific for Treating Multi-Strain Pseudomonas aeruginosa Infections. Toxins (Basel) 2024; 16:271. [PMID: 38922165 PMCID: PMC11209546 DOI: 10.3390/toxins16060271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/09/2024] [Accepted: 06/12/2024] [Indexed: 06/27/2024] Open
Abstract
Extensively drug-resistant Pseudomonas aeruginosa infections are emerging as a significant threat associated with adverse patient outcomes. Due to this organism's inherent properties of developing antibiotic resistance, we sought to investigate alternative strategies such as identifying "high value" antigens for immunotherapy-based purposes. Through extensive database mining, we discovered that numerous Gram-negative bacterial (GNB) genomes, many of which are known multidrug-resistant (MDR) pathogens, including P. aeruginosa, horizontally acquired the evolutionarily conserved gene encoding Zonula occludens toxin (Zot) with a substantial degree of homology. The toxin's genomic footprint among so many different GNB stresses its evolutionary importance. By employing in silico techniques such as proteomic-based phylogenetic tracing, in conjunction with comparative structural modeling, we discovered a highly conserved intermembrane associated stretch of 70 amino acids shared among all the GNB strains analyzed. The characterization of our newly identified antigen reveals it to be a "high value" vaccine candidate specific for P. aeruginosa. This newly identified antigen harbors multiple non-overlapping B- and T-cell epitopes exhibiting very high binding affinities and can adopt identical tertiary structures among the least genetically homologous P. aeruginosa strains. Taken together, using proteomic-driven reverse vaccinology techniques, we identified multiple "high value" vaccine candidates capable of eliciting a polarized immune response against all the P. aeruginosa genetic variants tested.
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Affiliation(s)
- Payam Benyamini
- Department of Health Sciences at Extension, University of California Los Angeles, 1145 Gayley Ave., Los Angeles, CA 90024, USA
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2
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Veres-Székely A, Szász C, Pap D, Szebeni B, Bokrossy P, Vannay Á. Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions. Int J Mol Sci 2023; 24:ijms24087548. [PMID: 37108711 PMCID: PMC10139156 DOI: 10.3390/ijms24087548] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/05/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.
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Affiliation(s)
- Apor Veres-Székely
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
- ELKH-SE Pediatrics and Nephrology Research Group, 1052 Budapest, Hungary
| | - Csenge Szász
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
| | - Domonkos Pap
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
- ELKH-SE Pediatrics and Nephrology Research Group, 1052 Budapest, Hungary
| | - Beáta Szebeni
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
- ELKH-SE Pediatrics and Nephrology Research Group, 1052 Budapest, Hungary
| | - Péter Bokrossy
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
| | - Ádám Vannay
- Pediatric Center, MTA Center of Excellence, Semmelweis University, 1083 Budapest, Hungary
- ELKH-SE Pediatrics and Nephrology Research Group, 1052 Budapest, Hungary
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3
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Mittal M, Tripathi S, Saini A, Mani I. Phage for treatment of Vibrio cholerae infection. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 201:21-39. [PMID: 37770173 DOI: 10.1016/bs.pmbts.2023.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Bacteriophages (or "phages") are ubiquitous and the amplest biological entities on our planet. It is a natural enemy of bacteria. Cholera is one of the most known diseases to cause multiple pandemics around the world, killing millions of people. The pathogen of cholera is Vibrio species. Up until the emergence of multidrug resistance, preventive therapeutics like antibiotics were the most effective means of battling bacteria. Globally, one of the most significant challenges in treating microbial infections is the development of drug-resistant strains. Based on their antibacterial properties and unique characteristics, phages are being comprehensively evaluated taxonomically. Moreover, phage-based vaccination is evolving as one of the most encouraging preventive approaches. Due to this, its related research got remarkable recognition. However, due to the rapid emergence of bacterial resistance to antibiotics, the use of phages (phage therapy) could be a major motive for research because the most promising solution lies in bacteriophages. This chapter briefly highlights the promising use of bacteriophages to combat Vibrio-related infectious diseases.
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Affiliation(s)
- Milky Mittal
- Dr. B.R. Ambedkar Centre for Biomedical Research, University of Delhi, New Delhi, India
| | - Surbhi Tripathi
- Dr. B.R. Ambedkar Centre for Biomedical Research, University of Delhi, New Delhi, India
| | - Ashok Saini
- Department of Microbiology, Institute of Home Economics, University of Delhi, New Delhi, India.
| | - Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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4
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Kim D, Jin L, Park EJ, Na DH. Peptide permeation enhancers for improving oral bioavailability of macromolecules. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2022. [DOI: 10.1007/s40005-022-00609-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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5
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In Vitro and In Vivo Inhibitory Activities of Selected Traditional Medicinal Plants against Toxin-Induced Cyto- and Entero- Toxicities in Cholera. Toxins (Basel) 2022; 14:toxins14100649. [PMID: 36287918 PMCID: PMC9611792 DOI: 10.3390/toxins14100649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 12/02/2022] Open
Abstract
Careya arborea, Punica granatum, Psidium guajava, Holarrhena antidysenterica, Aegle marmelos, and Piper longum are commonly used traditional medicines against diarrhoeal diseases in India. This study investigated the inhibitory activity of these plants against cytotoxicity and enterotoxicity induced by toxins secreted by Vibrio cholerae. Cholera toxin (CT) and non-membrane damaging cytotoxin (NMDCY) in cell free culture filtrate (CFCF) of V. cholerae were quantified using GM1 ELISA and cell-based assays, respectively. Hydro-alcoholic extracts of these plants and lyophilized juice of P. granatum were tested against CT-induced elevation of cAMP levels in CHO cell line, binding of CT to ganglioside GM1 receptor and NMDCY-induced cytotoxicity. Significant reduction of cAMP levels in CFCF treated CHO cell line was observed for all extracts except P. longum. C. arborea, P. granatum, H. antidysenterica and A. marmelos showed >50% binding inhibition of CT to GM1 receptor. C. arborea, P. granatum, and P. guajava effectively decreased cytotoxicity and morphological alterations caused by NMDCY in CHO cell line. Further, the efficacy of these three plants against CFCF-induced enterotoxicity was seen in adult mice ligated-ileal loop model as evidenced by decrease in volume of fluid accumulation, cAMP levels in ligated-ileal tissues, and histopathological changes in intestinal mucosa. Therefore, these plants can be further validated for their clinical use against cholera.
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6
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Ramamurthy T, Nandy RK, Mukhopadhyay AK, Dutta S, Mutreja A, Okamoto K, Miyoshi SI, Nair GB, Ghosh A. Virulence Regulation and Innate Host Response in the Pathogenicity of Vibrio cholerae. Front Cell Infect Microbiol 2020; 10:572096. [PMID: 33102256 PMCID: PMC7554612 DOI: 10.3389/fcimb.2020.572096] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
The human pathogen Vibrio cholerae is the causative agent of severe diarrheal disease known as cholera. Of the more than 200 "O" serogroups of this pathogen, O1 and O139 cause cholera outbreaks and epidemics. The rest of the serogroups, collectively known as non-O1/non-O139 cause sporadic moderate or mild diarrhea and also systemic infections. Pathogenic V. cholerae circulates between nutrient-rich human gut and nutrient-deprived aquatic environment. As an autochthonous bacterium in the environment and as a human pathogen, V. cholerae maintains its survival and proliferation in these two niches. Growth in the gastrointestinal tract involves expression of several genes that provide bacterial resistance against host factors. An intricate regulatory program involving extracellular signaling inputs is also controlling this function. On the other hand, the ability to store carbon as glycogen facilitates bacterial fitness in the aquatic environment. To initiate the infection, V. cholerae must colonize the small intestine after successfully passing through the acid barrier in the stomach and survive in the presence of bile and antimicrobial peptides in the intestinal lumen and mucus, respectively. In V. cholerae, virulence is a multilocus phenomenon with a large functionally associated network. More than 200 proteins have been identified that are functionally linked to the virulence-associated genes of the pathogen. Several of these genes have a role to play in virulence and/or in functions that have importance in the human host or the environment. A total of 524 genes are differentially expressed in classical and El Tor strains, the two biotypes of V. cholerae serogroup O1. Within the host, many immune and biological factors are able to induce genes that are responsible for survival, colonization, and virulence. The innate host immune response to V. cholerae infection includes activation of several immune protein complexes, receptor-mediated signaling pathways, and other bactericidal proteins. This article presents an overview of regulation of important virulence factors in V. cholerae and host response in the context of pathogenesis.
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Affiliation(s)
| | - Ranjan K Nandy
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish K Mukhopadhyay
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ankur Mutreja
- Global Health-Infectious Diseases, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Keinosuke Okamoto
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.,Collaborative Research Center of Okayama University for Infectious Diseases in India, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shin-Ichi Miyoshi
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - G Balakrish Nair
- Microbiome Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Amit Ghosh
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
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7
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Pérez-Reytor D, Pavón A, Lopez-Joven C, Ramírez-Araya S, Peña-Varas C, Plaza N, Alegría-Arcos M, Corsini G, Jaña V, Pavez L, Del Pozo T, Bastías R, Blondel CJ, Ramírez D, García K. Analysis of the Zonula occludens Toxin Found in the Genome of the Chilean Non-toxigenic Vibrio parahaemolyticus Strain PMC53.7. Front Cell Infect Microbiol 2020; 10:482. [PMID: 33072618 PMCID: PMC7541967 DOI: 10.3389/fcimb.2020.00482] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/04/2020] [Indexed: 12/13/2022] Open
Abstract
Vibrio parahaemolyticus non-toxigenic strains are responsible for about 10% of acute gastroenteritis associated with this species, suggesting they harbor unique virulence factors. Zonula occludens toxin (Zot), firstly described in Vibrio cholerae, is a secreted toxin that increases intestinal permeability. Recently, we identified Zot-encoding genes in the genomes of highly cytotoxic Chilean V. parahaemolyticus strains, including the non-toxigenic clinical strain PMC53.7. To gain insights into a possible role of Zot in V. parahaemolyticus, we analyzed whether it could be responsible for cytotoxicity. However, we observed a barely positive correlation between Caco-2 cell membrane damage and Zot mRNA expression during PMC53.7 infection and non-cytotoxicity induction in response to purified PMC53.7-Zot. Unusually, we observed a particular actin disturbance on cells infected with PMC53.7. Based on this observation, we decided to compare the sequence of PMC53.7-Zot with Zot of human pathogenic species such as V. cholerae, Campylobacter concisus, Neisseria meningitidis, and other V. parahaemolyticus strains, using computational tools. The PMC53.7-Zot was compared with other toxins and identified as an endotoxin with conserved motifs in the N-terminus and a variable C-terminal region and without FCIGRL peptide. Notably, the C-terminal diversity among Zots meant that not all of them could be identified as toxins. Structurally, PMC53.7-Zot was modeled as a transmembrane protein. Our results suggested that it has partial 3D structure similarity with V. cholerae-Zot. Probably, the PMC53.7-Zot would affect the actin cytoskeletal, but, in the absence of FCIGRL, the mechanisms of actions must be elucidated.
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Affiliation(s)
- Diliana Pérez-Reytor
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Alequis Pavón
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Carmen Lopez-Joven
- Facultad de Ciencias Veterinarias, Instituto de Medicina Preventiva Veterinaria, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastián Ramírez-Araya
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Carlos Peña-Varas
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Nicolás Plaza
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Melissa Alegría-Arcos
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Gino Corsini
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Víctor Jaña
- Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Santiago, Chile
| | - Leonardo Pavez
- Departamento de Ciencias Químicas y Biológicas, Universidad Bernardo O'Higgins, Santiago, Chile.,Instituto de Ciencias Naturales, Universidad de Las Américas, Santiago, Chile
| | - Talia Del Pozo
- Centro Tecnológico de Recursos Vegetales, Escuela de Agronomía, Universidad Mayor, Huechuraba, Chile
| | - Roberto Bastías
- Laboratorio de Microbiología, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Carlos J Blondel
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.,Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andrés Bello, Santiago, Chile
| | - David Ramírez
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Katherine García
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
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8
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Pérez-Reytor D, Jaña V, Pavez L, Navarrete P, García K. Accessory Toxins of Vibrio Pathogens and Their Role in Epithelial Disruption During Infection. Front Microbiol 2018; 9:2248. [PMID: 30294318 PMCID: PMC6158335 DOI: 10.3389/fmicb.2018.02248] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/03/2018] [Indexed: 01/21/2023] Open
Abstract
Gastrointestinal episodes associated with Vibrio species have been rising worldwide in the last few years. Consequently, it is important to comprehend how occurs the production of diarrhea, to establish new preventive and therapeutic measures. Besides the classical CT and TCP toxins, Zot, RTX, and Ace among others have been deeply studied in V. cholerae. However, in other Vibrio species of clinical interest, where some of these toxins have been reported, there is practically no information. Zot activates a cascade of signals inside of the cell that increase the permeability of epithelial barrier, while RTX causes depolymerization of the actin cytoskeleton and Ace increases the permeability of intestinal cell monolayers. The goal of this study is to acquire information about the distribution of these toxins in human pathogenic Vibrios and to review the progress in the study of their role in the intestinal epithelium during infection.
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Affiliation(s)
- Diliana Pérez-Reytor
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Victor Jaña
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago, Chile
| | - Leonardo Pavez
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago, Chile.,Departamento de Ciencias Químicas y Biológicas, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Paola Navarrete
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Katherine García
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
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9
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Anvari S, Najar-Peerayeh S, Behmanesh M, Bakhshi B. Cumulative protective efficacy of rZot and rAce combination in challenge experiments with wild type Vibrio cholerae in mouse model. Hum Vaccin Immunother 2018; 14:2323-2328. [PMID: 29852089 DOI: 10.1080/21645515.2018.1469593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
The aim of this study was to assess the cumulative immunogenicity properties of rZot and rAce combination and their potential ability to increase the clearance rate of pathogenic standard Vibrio cholerae strain in challenge experiments in mice model. The recombinant Zot and Ace proteins were produced and used to raise polyclonal antibodies of anti-Zot and anti-Ace recombinant proteins in rabbit. Six-week female BALB/c mice were immunized with different antigens via oral route. Blood samples were collected, and the total amount of IgG and IgA antibodies against rZot and rAce were measured in blood and stool samples of each immunized mouse. Challenge experiments were done with toxigenic V. cholerae strain. The anti-Zot and anti-Ace IgG titers were significantly higher in immunized mice in comparison with control group. The IgG and IgA titers were higher in the sera of mice immunized by recombinant Ace than in group immunized by rZot, indicating the higher immunogenicity of rAce than rZot. The use of rAce and rZot mixture led to synergistic activities in increasing the level of IgG and IgA in comparison with the use of each protein separately. The clearance rate was significantly higher in different challenge groups than in the control group, and the coherence between rZot and rAce reduced the bacterial shedding significantly. In conclusion, the use of recombinant Zot and Ace mixture can produce the proper amount of IgA and IgG against to toxigenic V. cholerae, reduce bacterial shedding in immunized mice significantly, and be used as a potent candidate in cholera vaccine research.
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Affiliation(s)
- Shaghayegh Anvari
- a Department of Bacteriology , Faculty of Medical Sciences, Tarbiat Modares University , Tehran , Iran
| | - Shahin Najar-Peerayeh
- a Department of Bacteriology , Faculty of Medical Sciences, Tarbiat Modares University , Tehran , Iran
| | - Mehrdad Behmanesh
- b Department of Genetic , Faculty of Basic Science, Tarbiat Modares University , Tehran , Iran
| | - Bita Bakhshi
- a Department of Bacteriology , Faculty of Medical Sciences, Tarbiat Modares University , Tehran , Iran
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10
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Sturgeon C, Fasano A. Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue Barriers 2016; 4:e1251384. [PMID: 28123927 DOI: 10.1080/21688370.2016.1251384] [Citation(s) in RCA: 264] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/14/2016] [Accepted: 10/14/2016] [Indexed: 12/15/2022] Open
Abstract
Beside digesting nutrients and absorbing solutes and electrolytes, the intestinal epithelium with its barrier function is in charge of a tightly controlled antigen trafficking from the intestinal lumen to the submucosa. This trafficking dictates the delicate balance between tolerance and immune response causing inflammation. Loss of barrier function secondary to upregulation of zonulin, the only known physiological modulator of intercellular tight junctions, leads to uncontrolled influx of dietary and microbial antigens. Additional insights on zonulin mechanism of action and the recent appreciation of the role that altered intestinal permeability can play in the development and progression of chronic inflammatory disorders has increased interest of both basic scientists and clinicians on the potential role of zonulin in the pathogenesis of these diseases. This review focuses on the recent research implicating zonulin as a master regulator of intestinal permeability linked to the development of several chronic inflammatory disorders.
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Affiliation(s)
- Craig Sturgeon
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Boston, MA, USA; Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alessio Fasano
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Boston, MA, USA; European Biomedical Research Institute of Salerno (EBRIS), Salerno, Italy
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11
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Mooney PD, Hadjivassiliou M, Sanders DS. Emerging drugs for coeliac disease. Expert Opin Emerg Drugs 2014; 19:533-44. [DOI: 10.1517/14728214.2014.959490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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12
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Pathogenesis of human enterovirulent bacteria: lessons from cultured, fully differentiated human colon cancer cell lines. Microbiol Mol Biol Rev 2014; 77:380-439. [PMID: 24006470 DOI: 10.1128/mmbr.00064-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hosts are protected from attack by potentially harmful enteric microorganisms, viruses, and parasites by the polarized fully differentiated epithelial cells that make up the epithelium, providing a physical and functional barrier. Enterovirulent bacteria interact with the epithelial polarized cells lining the intestinal barrier, and some invade the cells. A better understanding of the cross talk between enterovirulent bacteria and the polarized intestinal cells has resulted in the identification of essential enterovirulent bacterial structures and virulence gene products playing pivotal roles in pathogenesis. Cultured animal cell lines and cultured human nonintestinal, undifferentiated epithelial cells have been extensively used for understanding the mechanisms by which some human enterovirulent bacteria induce intestinal disorders. Human colon carcinoma cell lines which are able to express in culture the functional and structural characteristics of mature enterocytes and goblet cells have been established, mimicking structurally and functionally an intestinal epithelial barrier. Moreover, Caco-2-derived M-like cells have been established, mimicking the bacterial capture property of M cells of Peyer's patches. This review intends to analyze the cellular and molecular mechanisms of pathogenesis of human enterovirulent bacteria observed in infected cultured human colon carcinoma enterocyte-like HT-29 subpopulations, enterocyte-like Caco-2 and clone cells, the colonic T84 cell line, HT-29 mucus-secreting cell subpopulations, and Caco-2-derived M-like cells, including cell association, cell entry, intracellular lifestyle, structural lesions at the brush border, functional lesions in enterocytes and goblet cells, functional and structural lesions at the junctional domain, and host cellular defense responses.
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13
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Escherichia coli heat-stable toxin b impairs intestinal epithelial barrier function by altering tight junction proteins. Infect Immun 2013; 81:2819-27. [PMID: 23716609 DOI: 10.1128/iai.00455-13] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Escherichia coli heat-stable toxin b (STb) causes diarrhea in animals. STb binds to sulfatide, its receptor, and is then internalized. In the cytoplasm, through a cascade of events, STb triggers the opening of ion channels, allowing ion secretion and water loss and leading to diarrhea. Tight junctions (TJs) are well known for controlling paracellular traffic of ions and water by forming a physical intercellular barrier in epithelial cells, and some bacterial toxins are known to affect adversely TJs. The present study aimed at determining the effect of STb on TJs. T84 cells were treated for 24 h with purified STb and a nontoxic STb mutant (D30V). Transepithelial resistance (TER), paracellular flux marker, and confocal microscopy were used to analyze the effect of STb on TJs. Purified STb caused a significant reduction of TER parallel to an increase in paracellular permeability compared to the results seen in untreated cells or mutant D30V. The increased paracellular permeability was associated with a marked alteration of F-actin stress fibers. F-actin filament dissolution and condensation were accompanied by redistribution and/or fragmentation of ZO-1, claudin-1, and occludin. These changes were also observed following treatment of T84 cells with an 8-amino-acid peptide found in the STb sequence corresponding to a consensus sequence of Vibrio cholerae Zot toxin. These effects were not observed with a scrambled peptide or mutant D30V. Our findings indicate that STb induces epithelial barrier dysfunction through changes in TJ proteins that could contribute to diarrhea.
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14
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Fasano A. Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiol Rev 2011; 91:151-75. [PMID: 21248165 DOI: 10.1152/physrev.00003.2008] [Citation(s) in RCA: 567] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The primary functions of the gastrointestinal tract have traditionally been perceived to be limited to the digestion and absorption of nutrients and to electrolytes and water homeostasis. A more attentive analysis of the anatomic and functional arrangement of the gastrointestinal tract, however, suggests that another extremely important function of this organ is its ability to regulate the trafficking of macromolecules between the environment and the host through a barrier mechanism. Together with the gut-associated lymphoid tissue and the neuroendocrine network, the intestinal epithelial barrier, with its intercellular tight junctions, controls the equilibrium between tolerance and immunity to non-self antigens. Zonulin is the only physiological modulator of intercellular tight junctions described so far that is involved in trafficking of macromolecules and, therefore, in tolerance/immune response balance. When the finely tuned zonulin pathway is deregulated in genetically susceptible individuals, both intestinal and extraintestinal autoimmune, inflammatory, and neoplastic disorders can occur. This new paradigm subverts traditional theories underlying the development of these diseases and suggests that these processes can be arrested if the interplay between genes and environmental triggers is prevented by reestablishing the zonulin-dependent intestinal barrier function. This review is timely given the increased interest in the role of a "leaky gut" in the pathogenesis of several pathological conditions targeting both the intestine and extraintestinal organs.
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Affiliation(s)
- Alessio Fasano
- Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Zhang XH, He KW, Zhang SX, Lu WC, Zhao PD, Luan XT, Ye Q, Wen LB, Li B, Guo RL, Wang XM, Lv LX, Zhou JM, Yu ZY, Mao AH. Subcutaneous and intranasal immunization with Stx2B-Tir-Stx1B-Zot reduces colonization and shedding of Escherichia coli O157:H7 in mice. Vaccine 2011; 29:3923-9. [PMID: 21338683 DOI: 10.1016/j.vaccine.2011.02.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 01/13/2011] [Accepted: 02/06/2011] [Indexed: 11/28/2022]
Abstract
The type III secretion system of Escherichia coli O157:H7 is involved in colonization of mammalian hosts by the organism. The translocated intimin receptor (Tir) is inserted into the mammalian host cell plasma membrane in a hairpin loop topology with the central loop of the molecule exposed to the host cell surface and accessible for interaction with an LEE-encoded bacterial outer membrane adhesin called intimin. Shiga toxin type 1 and 2 produced by E. coli O157:H7 are responsible for hemolytic uremic syndrome and able to promote intestinal colonization. Zonula occludens toxin (Zot) is a single polypeptide chain encoded by the filamentous bacteriophage CTXφ of Vibrio cholerae. Zot binds a receptor on intestinal epithelial cells and increases mucosal permeability by affecting the structure of epithelial tight junctions. Because of these properties, Zot is a promising tool for mucosal drug and antigen (Ag) delivery. In the current study, we constructed a novel fusion protein carrying both of the immunogenic B subunits derived from the two toxins, Tir and Zot, designated Stx2B-Tir-Stx1B-Zot, expressed in the E. coli BL21 and harvested the purified protein by a simple GST·Bind Resin chromatography method. We used a streptomycin-treated mouse model to evaluate the efficacy of subcutaneous vs. intranasal administration of the vaccine. Following immunization, mice were infected with E. coli O157:H7 and feces were monitored for shedding. Immune responses against Stx2B-Tir-Stx1B-Zot, Stx2B-Tir-Stx1B and control agent (GST/PBS) were also monitored. Subcutaneous immunization of mice with Stx2B-Tir-Stx1B-Zot induced significant Stx2B-Tir-Stx1B-Zot-specific serum IgG antibodies but did not significantly induce any antigen-specific IgA in feces, whereas intranasal immunization elicited significant Stx2B-Tir-Stx1B-Zot-specific serum IgG antibodies with some animals developing antigen-specific IgA in feces. Mice that were immunized intranasally with Stx2B-Tir-Stx1B-Zot showed dramatically decreased E. coli O157:H7 shedding compared to those of Stx2B-Tir-Stx1B and control agent following experimental infection. Mice immunized subcutaneously with Stx2B-Tir-Stx1B-Zot or Stx2B-Tir-Stx1B both showed reduced shedding in feces, moreover, Stx2B-Tir-Stx1B-Zot did better. These results demonstrate the perspective for the use of Stx2B-Tir-Stx1B-Zot to prevent colonization and shedding of E. coli O157:H7.
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Affiliation(s)
- Xue-Han Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Tongwei Road 6#, Nanjing 210095, China
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16
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Schuppan D, Junker Y, Barisani D. Celiac disease: from pathogenesis to novel therapies. Gastroenterology 2009; 137:1912-33. [PMID: 19766641 DOI: 10.1053/j.gastro.2009.09.008] [Citation(s) in RCA: 408] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/02/2009] [Accepted: 09/11/2009] [Indexed: 02/08/2023]
Abstract
Celiac disease has become one of the best-understood HLA-linked disorders. Although it shares many immunologic features with inflammatory bowel disease, celiac disease is uniquely characterized by (1) a defined trigger (gluten proteins from wheat and related cereals), (2) the necessary presence of HLA-DQ2 or HLA-DQ8, and (3) the generation of circulating autoantibodies to the enzyme tissue transglutaminase (TG2). TG2 deamidates certain gluten peptides, increasing their affinity to HLA-DQ2 or HLA-DQ8. This generates a more vigorous CD4(+) T-helper 1 T-cell activation, which can result in intestinal mucosal inflammation, malabsorption, and numerous secondary symptoms and autoimmune diseases. Moreover, gluten elicits innate immune responses that act in concert with the adaptive immunity. Exclusion of gluten from the diet reverses many disease manifestations but is usually not or less efficient in patients with refractory celiac disease or associated autoimmune diseases. Based on the advanced understanding of the pathogenesis of celiac disease, targeted nondietary therapies have been devised, and some of these are already in phase 1 or 2 clinical trials. Examples are modified flours that have been depleted of immunogenic gluten epitopes, degradation of immunodominant gliadin peptides that resist intestinal proteases by exogenous endopeptidases, decrease of intestinal permeability by blockage of the epithelial ZOT receptor, inhibition of intestinal TG2 activity by transglutaminase inhibitors, inhibition of gluten peptide presentation by HLA-DQ2 antagonists, modulation or inhibition of proinflammatory cytokines, and induction of oral tolerance to gluten. These and other experimental therapies will be discussed critically.
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Affiliation(s)
- Detlef Schuppan
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
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17
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Visser J, Rozing J, Sapone A, Lammers K, Fasano A. Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms. Ann N Y Acad Sci 2009; 1165:195-205. [PMID: 19538307 PMCID: PMC2886850 DOI: 10.1111/j.1749-6632.2009.04037.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autoimmune diseases are characterized by tissue damage and loss of function due to an immune response that is directed against specific organs. This review is focused on celiac disease (CD), an autoimmune enteropathy, and type 1 diabetes (T1D), a hyperglycosaemia caused by a destructive autoimmune process targeting the insulin-producing pancreatic islet cells. Even if environmental factors and genetic susceptibility are clearly involved in the pathogenesis of autoimmunity, for most autoimmune disorders there is no or little knowledge about the causing agent or genetic makeup underlying the disease. In this respect, CD represents a unique autoimmune disorder because a close genetic association with HLA-DQ2 or HLA-DQ8 haplotypes and, more importantly, the environmental trigger (the gliadin fraction of gluten-containing grains wheat, barley, and rye) are known. Conversely, the trigger for autoimmune destruction of pancreatic ss cells in T1D is unclear. Interestingly, recent data suggest that gliadin is also involved in the pathogenesis of T1D. There is growing evidence that increased intestinal permeability plays a pathogenic role in various autoimmune diseases including CD and T1D. Therefore, we hypothesize that besides genetic and environmental factors, loss of intestinal barrier function is necessary to develop autoimmunity. In this review, each of these components will be briefly reviewed.
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Affiliation(s)
- Jeroen Visser
- Department of Cell Biology, Section Immunology and Histology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jan Rozing
- Department of Cell Biology, Section Immunology and Histology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Anna Sapone
- Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, MD
| | - Karen Lammers
- Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, MD
| | - Alessio Fasano
- Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, MD
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18
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Fasano A. Physiological, pathological, and therapeutic implications of zonulin-mediated intestinal barrier modulation: living life on the edge of the wall. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 173:1243-52. [PMID: 18832585 DOI: 10.2353/ajpath.2008.080192] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The anatomical and functional arrangement of the gastrointestinal tract suggests that this organ, beside its digestive and absorptive functions, regulates the trafficking of macromolecules between the environment and the host through a barrier mechanism. Under physiological circumstances, this trafficking is safeguarded by the competency of intercellular tight junctions, structures whose physiological modulation is mediated by, among others, the recently described protein zonulin. To prevent harm and minimize inflammation, the same paracellular pathway, in concert with the gut-associated lymphoid tissue and the neuroendocrine network, controls the equilibrium between tolerance and immunity to nonself antigens. The zonulin pathway has been exploited to deliver drugs, macromolecules, or vaccines that normally would not be absorbed through the gastrointestinal mucosal barrier. However, if the tightly regulated trafficking of macromolecules is jeopardized secondary to prolonged zonulin up-regulation, the excessive flow of nonself antigens in the intestinal submucosa can cause both intestinal and extraintestinal autoimmune disorders in genetically susceptible individuals. This new paradigm subverts traditional theories underlying the development of autoimmunity, which are based on molecular mimicry and/or the bystander effect, and suggests that the autoimmune process can be arrested if the interplay between genes and environmental triggers is prevented by re-establishing intestinal barrier competency. Understanding the role of zonulin-dependent intestinal barrier dysfunction in the pathogenesis of autoimmune diseases is an area of translational research that encompasses many fields.
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Affiliation(s)
- Alessio Fasano
- University of Maryland School of Medicine, Mucosal Biology Research Center, Health Science Facility II, Baltimore, MD 21201, USA.
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MOTLEKAR NUSRATA, FASANO ALESSIO, WACHTEL MITCHELLS, YOUAN BIBOTTIC. Zonula occludens toxin synthetic peptide derivative AT1002 enhances in vitro and in vivo intestinal absorption of low molecular weight heparin. J Drug Target 2006; 14:321-9. [PMID: 16882552 PMCID: PMC1994914 DOI: 10.1080/10611860600613316] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Zonula occludens toxin (Zot) is an enterotoxin obtained from the bacterium vibrio cholerae that has been shown to reversibly and safely open the tight junctions and enhance paracellular transport. AT1002 is a novel synthetic hexapeptide derived from Zot. The hypothesis to be tested in this study is that AT1002 enhances the oral absorption of ardeparin, a low molecular weight heparin (LMWH). To test this hypothesis, drug transport through Caco-2 cell monolayers was monitored in the presence and absence of AT1002. Regional permeability studies using rat intestine were performed. Cell viability in the presence of various concentrations of enhancer was determined. The absorption of ardeparin after oral administration in rats was measured by anti-factor Xa assay. Furthermore, the eventual mucosal and epithelial damage was histologically evaluated. Higher ardeparin permeability (approximately 2-fold) compared to control was observed in the presence of 0.025% of AT1002. Regional permeability studies revealed that the permeability of ardeparin across the duodenal membrane was improved by the AT1002. Cell viability studies showed no significant cytotoxicity below 0.0028% of AT1002. In the presence of 100 microg/kg of AT1002, ardeparin oral bioavailability was significantly increased (F(relative/s.c) approximately 20.5%). Furthermore, AT1002 at a dose of 100 microg/kg did not induce any observable morphological damage on gastrointestinal (GI) tissues in vivo. These in vivo and in vitro results suggest that the co-administration of LMWH with AT1002 may be a useful delivery strategy to increase its permeability and hence oral absorption.
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Affiliation(s)
- NUSRAT A. MOTLEKAR
- Department of Pharmaceutical Sciences, Texas Tech University
Health Sciences Center, School of Pharmacy, Amarillo, TX, USA
| | - ALESSIO FASANO
- Division of Pediatric Gastroenterology and Nutrition,
Department of Pediatrics, University of Maryland School of Medicine, Baltimore,
MD, USA, and
| | - MITCHELL S. WACHTEL
- Divisions of Anatomic Pathology and Research, Department of
Pathology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - BI-BOTTI C. YOUAN
- Department of Pharmaceutical Sciences, Texas Tech University
Health Sciences Center, School of Pharmacy, Amarillo, TX, USA
- Correspondence: B.-B. C. Youan, Texas Tech University Health
Sciences Center, School of Pharmacy, 1300 Coulter Drive, Amarillo, TX 79106,
USA. Tel: 1 806 356 4015. Ext. 236. Fax: 1 806 354 4034. E-mail:
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20
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Drago S, El Asmar R, Di Pierro M, Grazia Clemente M, Tripathi A, Sapone A, Thakar M, Iacono G, Carroccio A, D'Agate C, Not T, Zampini L, Catassi C, Fasano A. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scand J Gastroenterol 2006; 41:408-19. [PMID: 16635908 DOI: 10.1080/00365520500235334] [Citation(s) in RCA: 317] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. MATERIAL AND METHODS Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression was evaluated by real-time polymerase chain reaction (PCR). RESULTS When exposed to gliadin, zonulin receptor-positive IEC6 and Caco2 cells released zonulin in the cell medium with subsequent zonulin binding to the cell surface, rearrangement of the cell cytoskeleton, loss of occludin-ZO1 protein-protein interaction, and increased monolayer permeability. Pretreatment with the zonulin antagonist FZI/0 blocked these changes without affecting zonulin release. When exposed to luminal gliadin, intestinal biopsies from celiac patients in remission expressed a sustained luminal zonulin release and increase in intestinal permeability that was blocked by FZI/0 pretreatment. Conversely, biopsies from non-celiac patients demonstrated a limited, transient zonulin release which was paralleled by an increase in intestinal permeability that never reached the level of permeability seen in celiac disease (CD) tissues. Chronic gliadin exposure caused down-regulation of both ZO-1 and occludin gene expression. CONCLUSIONS Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.
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Affiliation(s)
- Sandro Drago
- Mucosal Biology Research Center, Center for Celiac Research and Division of Pediatric Gastroenterology and Nutrition, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
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21
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Watts T, Berti I, Sapone A, Gerarduzzi T, Not T, Zielke R, Fasano A. Role of the intestinal tight junction modulator zonulin in the pathogenesis of type I diabetes in BB diabetic-prone rats. Proc Natl Acad Sci U S A 2005; 102:2916-21. [PMID: 15710870 PMCID: PMC549484 DOI: 10.1073/pnas.0500178102] [Citation(s) in RCA: 218] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Indexed: 12/13/2022] Open
Abstract
Increased intestinal permeability has been observed in numerous human autoimmune diseases, including type-1 diabetes (T1D) and its' animal model, the BB-wor diabetic prone rat. We have recently described zonulin, a protein that regulates intercellular tight junctions. The objective of this study was to establish whether zonulin-dependent increased intestinal permeability plays a role in the pathogenesis of T1D. In the BB diabetic-prone rat model of T1D, intestinal intraluminal zonulin levels were elevated 35-fold compared to control BB diabetic-resistant rats. Zonulin up-regulation was coincident with decreased small intestinal transepithelial electrical resistance, and was followed by the production of autoantibodies against pancreatic beta cells, which preceded the onset of clinically evident T1D by approximately 25 days. In those diabetic prone rats that did not progress to diabetes, both intraluminal zonulin and transepithelial electrical resistance were similar to those detected in diabetic-resistant animal controls. Blockade of the zonulin receptor reduced the cumulative incidence of T1D by 70%, despite the persistence of intraluminal zonulin up-regulation. Moreover, treatment responders did not seroconvert to islet cell antibodies. Combined together, these findings suggest that the zonulin-induced loss in small intestinal barrier function is involved in the pathogenesis of T1D in the BB diabetic-prone animal model.
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Affiliation(s)
- Tammara Watts
- Mucosal Biology Research Center and Division of Pediatric Gastroenterology and Nutrition, and Division of Pediatric Research, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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22
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Lee A, White N, van der Walle CF. The intestinal zonula occludens toxin (ZOT) receptor recognises non-native ZOT conformers and localises to the intercellular contacts. FEBS Lett 2003; 555:638-42. [PMID: 14675787 DOI: 10.1016/s0014-5793(03)01348-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A preliminary structural analysis of Vibrio cholerae zonula occludens toxin (ZOT) was made by equilibrium denaturation and circular dichroism. ZOT is a structurally unstable protein in aqueous solution (DeltaG((H2O)) 3.82 kcal/mol), the putative intra- and extracellular domains unfold co-operatively, with complete denaturation via observed conformational intermediates. Refolding of denatured ZOT is not dependent on disulphide bridge formation. Partial refolding of a maltose binding protein-ZOT fusion did not prevent its specific binding to the ZOT receptor on Caco-2 cells. Immuno-gold labelling showed that the ZOT receptor localises to the intercellular contacts between cells in a confluent monolayer.
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Affiliation(s)
- Alvin Lee
- Pharmaceutical Sciences, Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR, UK
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23
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Marinaro M, Fasano A, De Magistris MT. Zonula occludens toxin acts as an adjuvant through different mucosal routes and induces protective immune responses. Infect Immun 2003; 71:1897-902. [PMID: 12654806 PMCID: PMC152047 DOI: 10.1128/iai.71.4.1897-1902.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Zonula occludens toxin (Zot) is produced by Vibrio cholerae and has the ability to increase mucosal permeability by reversibly affecting the structure of tight junctions. Because of this property, Zot is a promising tool for mucosal drug and antigen (Ag) delivery. Here we show that Zot acts as a mucosal adjuvant to induce long-lasting and protective immune responses upon mucosal immunization of mice. Indeed, the intranasal delivery of ovalbumin with two different recombinant forms of Zot in BALB/c mice resulted in high Ag-specific serum immunoglobulin G titers that were maintained over the course of a year. Moreover, His-Zot induced humoral and cell-mediated responses to tetanus toxoid in C57BL/6 mice and protected the mice against a systemic challenge with tetanus toxin. In addition, we found that Zot also acts as an adjuvant through the intrarectal route and that it has very low immunogenicity compared to the adjuvant Escherichia coli heat-labile enterotoxin. Finally, by using an octapeptide representing the putative binding site of Zot and of its endogenous analogue zonulin, we provide evidence that Zot may bind a mucosal receptor on nasal mucosa and may mimic an endogenous regulator of tight junctions to deliver Ags in the submucosa. In conclusion, Zot is a novel and effective mucosal adjuvant that may be useful for the development of mucosal vaccines.
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Affiliation(s)
- Mariarosaria Marinaro
- Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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Karyekar CS, Fasano A, Raje S, Lu R, Dowling TC, Eddington ND. Zonula occludens toxin increases the permeability of molecular weight markers and chemotherapeutic agents across the bovine brain microvessel endothelial cells. J Pharm Sci 2003; 92:414-23. [PMID: 12532391 DOI: 10.1002/jps.10310] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The purpose of this study was to examine the ability of Zonula occludens toxin (Zot) to reversibly open tight junctions in bovine brain microvessel endothelial cells (BBMECs) to enhance drug delivery via the paracellular pathway. Transport across BBMEC monolayers was examined for molecular weight markers and chemotherapeutic agents ([(14)C]sucrose, [(14)C]inulin, [(3)H]propranolol, [(3)H]doxorubicin, and [(14)C]paclitaxel) with Zot (0.0-4.0 microg/mL). TEER of monolayers was measured to assess effect and reversibility of Zot. Cell viability of BBMEC in the presence of Zot was assessed by trypan blue exclusion staining. Apparent permeability (P(app)), enhancement ratio (R), and percent increase in transport determined were statistically compared by ANOVA. A significant increase (p < 0.05) in P(app) was observed for the transport of [(14)C]sucrose, [(14)C]inulin, [(3)H]doxorubicin, and [(14)C]paclitaxel at a 4.0 microg/mL concentration of Zot. A significant concentration-dependent decrease in TEER was observed on treatment with Zot with rapid reversal to baseline after removal. Zot (4 micro/ml) was found to be nontoxic to the BBMECs after 2 hours incubation. In conclusion, Zot increased paracellular transport across the BBMEC in a reversible, concentration-dependent manner. Modulation of paracellular transport with Zot may be used to increase the brain permeability of potent central nervous system-active drugs, including anticancer agents.
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Affiliation(s)
- Chetan S Karyekar
- Pharmacokinetics Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 100 Penn Street, Baltimore, Maryland 21201, USA
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Cox DS, Raje S, Gao H, Salama NN, Eddington ND. Enhanced permeability of molecular weight markers and poorly bioavailable compounds across Caco-2 cell monolayers using the absorption enhancer, zonula occludens toxin. Pharm Res 2002; 19:1680-8. [PMID: 12458674 DOI: 10.1023/a:1020709513562] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
PURPOSE Zonula occludens toxin (Zot), a protein elaborated from Vibrio cholerae, has been shown to be capable of reversibly opening tight junctions. The objective of this work was to determine the stability of Zot and to examine the permeability of a series of molecular weight hydrophilic markers and therapeutic agents in the presence of Zot. METHOD The transport of molecular weight markers (i.e., PEG 4000, FITC-dextran 10.000 and inulin) and therapeutic agents (i.e., acyclcovir, cyclopsorin, paclitaxel. doxorubicin) was evaluated with Zot (0, 2, and 4 microg/mL) using Caco-2 cell monolayers. RESULTS Zot was found to be stable over a 10-day period. Significantly higher (p < 0.05) permeability of the molecular weight markers, in lin, and PEG4000 were observed with Zot (4 microg/mL). The transport of each therapeutic marker was significantly increased with paclitaxel displaying a >3-fold enhancement in Papp values with Zot (4 microg/mL). A 30% decrease in transepithelial electrical resistance values wa observed, which returned to baseline 30 min after Zot was removed. CONCLUSIONS Considering the problems of poor oral bioavailability, it is concluded that Zot is a promising drug delivery technology to be used to enhance drug transport across the intestinal mucosa. Future applications are targeted at assessing its usefulness in oral drug delivery using in vivo systems.
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Affiliation(s)
- Donna S Cox
- Pharmacokinetics Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 100 Penn Street, AHB, Baltimore, Maryland 21201-6808, USA
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26
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Affiliation(s)
- A Fasano
- Division of Pediatric Gastroenterology and Nutrition, University of Maryland School of Medicine, Baltimore, 21201, USA.
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27
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Di Pierro M, Lu R, Uzzau S, Wang W, Margaretten K, Pazzani C, Maimone F, Fasano A. Zonula occludens toxin structure-function analysis. Identification of the fragment biologically active on tight junctions and of the zonulin receptor binding domain. J Biol Chem 2001; 276:19160-5. [PMID: 11278543 DOI: 10.1074/jbc.m009674200] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Zonula occludens toxin (Zot) is an enterotoxin elaborated by Vibrio cholerae that increases intestinal permeability by interacting with a mammalian cell receptor with subsequent activation of intracellular signaling leading to the disassembly of the intercellular tight junctions. Zot localizes in the bacterial outer membrane of V. cholerae with subsequent cleavage and secretion of a carboxyl-terminal fragment in the host intestinal milieu. To identify the Zot domain(s) directly involved in the protein permeating effect, several zot gene deletion mutants were constructed and tested for their biological activity in the Ussing chamber assay and their ability to bind to the target receptor on intestinal epithelial cell cultures. The Zot biologically active domain was localized toward the carboxyl terminus of the protein and coincided with the predicted cleavage product generated by V. cholerae. This domain shared a putative receptor-binding motif with zonulin, the Zot mammalian analogue involved in tight junction modulation. Amino acid comparison between the Zot active fragment and zonulin, combined with site-directed mutagenesis experiments, confirmed the presence of an octapeptide receptor-binding domain toward the amino terminus of the processed Zot.
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Affiliation(s)
- M Di Pierro
- Division of Pediatric Gastroenterology and Nutrition and Gastrointestinal Pathophysiology Section, Center for Vaccine Development, Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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