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Liu Z, Smith H, Criglar JM, Valentin AJ, Karandikar U, Zeng XL, Estes MK, Crawford SE. Rotavirus-mediated DGAT1 degradation: A pathophysiological mechanism of viral-induced malabsorptive diarrhea. Proc Natl Acad Sci U S A 2023; 120:e2302161120. [PMID: 38079544 PMCID: PMC10743370 DOI: 10.1073/pnas.2302161120] [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: 02/15/2023] [Accepted: 10/11/2023] [Indexed: 12/18/2023] Open
Abstract
Gastroenteritis is among the leading causes of mortality globally in infants and young children, with rotavirus (RV) causing ~258 million episodes of diarrhea and ~128,000 deaths annually in infants and children. RV-induced mechanisms that result in diarrhea are not completely understood, but malabsorption is a contributing factor. RV alters cellular lipid metabolism by inducing lipid droplet (LD) formation as a platform for replication factories named viroplasms. A link between LD formation and gastroenteritis has not been identified. We found that diacylglycerol O-acyltransferase 1 (DGAT1), the terminal step in triacylglycerol synthesis required for LD biogenesis, is degraded in RV-infected cells by a proteasome-mediated mechanism. RV-infected DGAT1-silenced cells show earlier and increased numbers of LD-associated viroplasms per cell that translate into a fourfold-to-fivefold increase in viral yield (P < 0.05). Interestingly, DGAT1 deficiency in children is associated with diarrhea due to altered trafficking of key ion transporters to the apical brush border of enterocytes. Confocal microscopy and immunoblot analyses of RV-infected cells and DGAT1-/- human intestinal enteroids (HIEs) show a decrease in expression of nutrient transporters, ion transporters, tight junctional proteins, and cytoskeletal proteins. Increased phospho-eIF2α (eukaryotic initiation factor 2 alpha) in DGAT1-/- HIEs, and RV-infected cells, indicates a mechanism for malabsorptive diarrhea, namely inhibition of translation of cellular proteins critical for nutrient digestion and intestinal absorption. Our study elucidates a pathophysiological mechanism of RV-induced DGAT1 deficiency by protein degradation that mediates malabsorptive diarrhea, as well as a role for lipid metabolism, in the pathogenesis of gastroenteritis.
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Affiliation(s)
- Zheng Liu
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
- Department of Biosciences, Rice University, Houston, TX77005
| | - Hunter Smith
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
| | - Jeanette M. Criglar
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
| | - Antonio J. Valentin
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
| | - Umesh Karandikar
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
| | - Xi-Lei Zeng
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
- Department of Medicine, Baylor College of Medicine, Houston, TX77030
| | - Sue E. Crawford
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX77030
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Azadpour B, Aharipour N, Paryab A, Omid H, Abdollahi S, Madaah Hosseini H, Malek Khachatourian A, Toprak MS, Seifalian AM. Magnetically-assisted viral transduction (magnetofection) medical applications: An update. BIOMATERIALS ADVANCES 2023; 154:213657. [PMID: 37844415 DOI: 10.1016/j.bioadv.2023.213657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/23/2023] [Accepted: 10/06/2023] [Indexed: 10/18/2023]
Abstract
Gene therapy involves replacing a faulty gene or adding a new gene inside the body's cells to cure disease or improve the body's ability to fight disease. Its popularity is evident from emerging concepts such as CRISPR-based genome editing and epigenetic studies and has been moved to a clinical setting. The strategy for therapeutic gene design includes; suppressing the expression of pathogenic genes, enhancing necessary protein production, and stimulating the immune system, which can be incorporated into both viral and non-viral gene vectors. Although non-viral gene delivery provides a safer platform, it suffers from an inefficient rate of gene transfection, which means a few genes could be successfully transfected and expressed within the cells. Incorporating nucleic acids into the viruses and using these viral vectors to infect cells increases gene transfection efficiency. Consequently, more cells will respond, more genes will be expressed, and sustained and successful gene therapy can be achieved. Combining nanoparticles (NPs) and nucleic acids protects genetic materials from enzymatic degradation. Furthermore, the vectors can be transferred faster, facilitating cell attachment and cellular uptake. Magnetically assisted viral transduction (magnetofection) enhances gene therapy efficiency by mixing magnetic nanoparticles (MNPs) with gene vectors and exerting a magnetic field to guide a significant number of vectors directly onto the cells. This research critically reviews the MNPs and the physiochemical properties needed to assemble an appropriate magnetic viral vector, discussing cellular hurdles and attitudes toward overcoming these barriers to reach clinical gene therapy perspectives. We focus on the studies conducted on the various applications of magnetic viral vectors in cancer therapies, regenerative medicine, tissue engineering, cell sorting, and virus isolation.
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Affiliation(s)
- Behnam Azadpour
- Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran
| | - Nazli Aharipour
- Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran
| | - Amirhosein Paryab
- Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran
| | - Hamed Omid
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
| | - Sorosh Abdollahi
- Department of Biomedical Engineering, University of Calgary, Alberta, Canada
| | | | | | - Muhammet S Toprak
- Department of Applied Physics, KTH-Royal Institute of Technology, SE10691 Stockholm, Sweden
| | - Alexander M Seifalian
- Nanotechnology & Regenerative Medicine Commercialisation Centre (NanoRegMed Ltd, Nanoloom Ltd, & Liberum Health Ltd), London BioScience Innovation Centre, London, UK.
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Wang Y, Yu B, Luo Y, Zheng P, Mao X, Huang Z, Yu J, Luo J, Yan H, Wu A, He J. Interferon-λ3 alleviates intestinal epithelium injury induced by porcine rotavirus in mice. Int J Biol Macromol 2023; 240:124431. [PMID: 37060970 DOI: 10.1016/j.ijbiomac.2023.124431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 03/15/2023] [Accepted: 04/09/2023] [Indexed: 04/17/2023]
Abstract
Interferons are a group of glycoproteins that are expressed in various cell types in their inflammatory responses to infections. In this study, we explored the protective effects of porcine interferon-λ3 (PIFN-λ3) on intestinal inflammation and injury in mice induced by porcine rotavirus (PRV). BALB/c mice were administrated by PIFN-λ3 or phosphate buffer solution (PBS) for three days prior to PRV infection. We show that PRV infection caused acute inflammatory responses in mice, as indicated by increases in serum concentrations of inflammatory cytokines such as the interlukin-1β (IL-1β), interlukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) (P < 0.05). However, PIFN-λ3 administration not only decreased their concentrations but also elevated the concentrations of immunoglobulin (Ig) M and IgG in the PRV challenged mice (P < 0.05). PRV infection significantly decreased the jejunal villus height and the ratio of villus height to crypt depth (V/C); however, PIFN-λ3 treatment significantly elevated the villus height and the abundance of tight junction protein ZO-1 in the jejunum (P < 0.05). Moreover, PIFN-λ3 decreased the replication of PRV in the jejunal epithelium, but significantly increased the abundance of sIgA and the activities of maltase and sucrase in the PRV-challenged mice (P < 0.05). Interestingly, PIFN-λ3 elevated the expression levels of sodium/glucose cotransporter 1 (SGLT1) and mucin 2 (MUC2) in the PRV-challenged mice (P < 0.05). Moreover, PIFN-λ3 significantly increased the expression levels of IL-10, signal transducer and activator of transcription 1 (STAT1), and critical interferon-stimulated genes such as the 2'-5' oligoadenylate synthetase-like 1 (OASL1), interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and radical S-adenosyl methionine domain containing 2 (RSAD2) in the jejunum upon PRV infection (P < 0.05). The anti-virus and anti-inflammatory effect of PIFN-λ3 should make it an attractive candidate to prevent various pathogen-induced bowel diseases.
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Affiliation(s)
- Yuhan Wang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Yuheng Luo
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Xiangbing Mao
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Zhiqing Huang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Junqiu Luo
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Hui Yan
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Aimin Wu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China
| | - Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Chengdu, Sichuan Province 611130, PR China.
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Bruno C, Paparo L, Pisapia L, Romano A, Cortese M, Punzo E, Berni Canani R. Protective effects of the postbiotic deriving from cow's milk fermentation with L. paracasei CBA L74 against Rotavirus infection in human enterocytes. Sci Rep 2022; 12:6268. [PMID: 35428750 PMCID: PMC9012738 DOI: 10.1038/s41598-022-10083-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 03/11/2022] [Indexed: 01/17/2023] Open
Abstract
Rotavirus (RV) is the leading cause of acute gastroenteritis-associated mortality in early childhood. Emerging clinical evidence suggest the efficacy of the postbiotic approach based on cow's milk fermentation with the probiotic Lacticaseibacillus paracasei CBAL74 (FM-CBAL74) in preventing pediatric acute gastroenteritis, but the mechanisms of action are still poorly characterized. We evaluated the protective action of FM-CBAL74 in an in vitro model of RV infection in human enterocytes. The number of infected cells together with the relevant aspects of RV infection were assessed: epithelial barrier damage (tight-junction proteins and transepithelial electrical resistance evaluation), and inflammation (reactive oxygen species, pro-inflammatory cytokines IL-6, IL-8 and TNF-α, and mitogen-activated protein kinase pathway activation). Pre-incubation with FM-CBA L74 resulted in an inhibition of epithelial barrier damage and inflammation mediated by mitogen-activated protein kinase pathway activation induced by RV infection. Modulating several protective mechanisms, the postbiotic FM-CBAL74 exerted a preventive action against RV infection. This approach could be a disrupting nutritional strategy against one of the most common killers for the pediatric age.
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Affiliation(s)
- Cristina Bruno
- Department of Translational Medical Science, University of Naples Federico II, Naples, Italy.,ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Lorella Paparo
- Department of Translational Medical Science, University of Naples Federico II, Naples, Italy.,ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Laura Pisapia
- Institute of Genetics and Biophysics, CNR, Naples, Italy
| | - Alessia Romano
- ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Maddalena Cortese
- Department of Translational Medical Science, University of Naples Federico II, Naples, Italy.,ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Erika Punzo
- Department of Translational Medical Science, University of Naples Federico II, Naples, Italy.,ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Roberto Berni Canani
- Department of Translational Medical Science, University of Naples Federico II, Naples, Italy. .,ImmunoNutritionLab at CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Italy. .,European Laboratory for the Investigation of Food-Induced Diseases, University of Naples Federico II, Naples, Italy. .,Task Force for Microbiome Studies, University of Naples Federico II, Naples, Italy. .,Task Force for Nutraceuticals and Functional Foods, University of Naples Federico II, Naples, Italy.
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5
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Micronutrient Improvement of Epithelial Barrier Function in Various Disease States: A Case for Adjuvant Therapy. Int J Mol Sci 2022; 23:ijms23062995. [PMID: 35328419 PMCID: PMC8951934 DOI: 10.3390/ijms23062995] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/01/2022] [Indexed: 02/04/2023] Open
Abstract
The published literature makes a very strong case that a wide range of disease morbidity associates with and may in part be due to epithelial barrier leak. An equally large body of published literature substantiates that a diverse group of micronutrients can reduce barrier leak across a wide array of epithelial tissue types, stemming from both cell culture as well as animal and human tissue models. Conversely, micronutrient deficiencies can exacerbate both barrier leak and morbidity. Focusing on zinc, Vitamin A and Vitamin D, this review shows that at concentrations above RDA levels but well below toxicity limits, these micronutrients can induce cell- and tissue-specific molecular-level changes in tight junctional complexes (and by other mechanisms) that reduce barrier leak. An opportunity now exists in critical care—but also medical prophylactic and therapeutic care in general—to consider implementation of select micronutrients at elevated dosages as adjuvant therapeutics in a variety of disease management. This consideration is particularly pointed amidst the COVID-19 pandemic.
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6
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Chapuy-Regaud S, Allioux C, Capelli N, Migueres M, Lhomme S, Izopet J. Vectorial Release of Human RNA Viruses from Epithelial Cells. Viruses 2022; 14:231. [PMID: 35215825 PMCID: PMC8875463 DOI: 10.3390/v14020231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/07/2022] [Accepted: 01/21/2022] [Indexed: 02/04/2023] Open
Abstract
Epithelial cells are apico-basolateral polarized cells that line all tubular organs and are often targets for infectious agents. This review focuses on the release of human RNA virus particles from both sides of polarized human cells grown on transwells. Most viruses that infect the mucosa leave their host cells mainly via the apical side while basolateral release is linked to virus propagation within the host. Viruses do this by hijacking the cellular factors involved in polarization and trafficking. Thus, understanding epithelial polarization is essential for a clear understanding of virus pathophysiology.
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Affiliation(s)
- Sabine Chapuy-Regaud
- Department of Virology, CHU Purpan, F-31059 Toulouse, France; (N.C.); (M.M.); (S.L.); (J.I.)
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
| | - Claire Allioux
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
| | - Nicolas Capelli
- Department of Virology, CHU Purpan, F-31059 Toulouse, France; (N.C.); (M.M.); (S.L.); (J.I.)
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
| | - Marion Migueres
- Department of Virology, CHU Purpan, F-31059 Toulouse, France; (N.C.); (M.M.); (S.L.); (J.I.)
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
| | - Sébastien Lhomme
- Department of Virology, CHU Purpan, F-31059 Toulouse, France; (N.C.); (M.M.); (S.L.); (J.I.)
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
| | - Jacques Izopet
- Department of Virology, CHU Purpan, F-31059 Toulouse, France; (N.C.); (M.M.); (S.L.); (J.I.)
- INFINITy (Toulouse Institute for Infectious and Inflammatory Diseases), INSERM UMR1291, CNRS UMR5051, Université Toulouse III, CHU Purpan, F-31024 Toulouse, France;
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Tugizov S. Virus-associated disruption of mucosal epithelial tight junctions and its role in viral transmission and spread. Tissue Barriers 2021; 9:1943274. [PMID: 34241579 DOI: 10.1080/21688370.2021.19432749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
Oropharyngeal, airway, intestinal, and genital mucosal epithelia are the main portals of entry for the majority of human pathogenic viruses. To initiate systemic infection, viruses must first be transmitted across the mucosal epithelium and then spread across the body. However, mucosal epithelia have well-developed tight junctions, which have a strong barrier function that plays a critical role in preventing the spread and dissemination of viral pathogens. Viruses can overcome these barriers by disrupting the tight junctions of mucosal epithelia, which facilitate paracellular viral penetration and initiate systemic disease. Disruption of tight and adherens junctions may also release the sequestered viral receptors within the junctional areas, and liberation of hidden receptors may facilitate viral infection of mucosal epithelia. This review focuses on possible molecular mechanisms of virus-associated disruption of mucosal epithelial junctions and its role in transmucosal viral transmission and spread.
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Affiliation(s)
- Sharof Tugizov
- Department of Medicine, School of Medicine, University of California-San Francisco, San Francisco, CA, USA
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8
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Tugizov S. Virus-associated disruption of mucosal epithelial tight junctions and its role in viral transmission and spread. Tissue Barriers 2021; 9:1943274. [PMID: 34241579 DOI: 10.1080/21688370.2021.1943274] [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] [Indexed: 12/27/2022] Open
Abstract
Oropharyngeal, airway, intestinal, and genital mucosal epithelia are the main portals of entry for the majority of human pathogenic viruses. To initiate systemic infection, viruses must first be transmitted across the mucosal epithelium and then spread across the body. However, mucosal epithelia have well-developed tight junctions, which have a strong barrier function that plays a critical role in preventing the spread and dissemination of viral pathogens. Viruses can overcome these barriers by disrupting the tight junctions of mucosal epithelia, which facilitate paracellular viral penetration and initiate systemic disease. Disruption of tight and adherens junctions may also release the sequestered viral receptors within the junctional areas, and liberation of hidden receptors may facilitate viral infection of mucosal epithelia. This review focuses on possible molecular mechanisms of virus-associated disruption of mucosal epithelial junctions and its role in transmucosal viral transmission and spread.
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Affiliation(s)
- Sharof Tugizov
- Department of Medicine, School of Medicine, University of California-San Francisco, San Francisco, CA, USA
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Tight junction protein claudin-2 promotes cell entry of Bombyx mori cypovirus. Appl Microbiol Biotechnol 2021; 105:6019-6031. [PMID: 34324010 DOI: 10.1007/s00253-021-11456-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/24/2021] [Accepted: 07/03/2021] [Indexed: 10/20/2022]
Abstract
Claudin-2 is a major component of tight junctions (TJs), which play an important role in reovirus entry into host cells. The Bombyx mori cytoplasmic polyhedosis virus (BmCPV) relates to the cypovirus strain of the reovirus family. So far, the role of claudin-2 in the process of BmCPV infection is not known. In the present study, it was observed that increasing expression of the claudin-2 gene (CLDN2) may concomitantly elevate BmCPV infection. Contrarily, knockdown of CLDN2 expression by siRNAs can reduce BmCPV infection. Similarly, antibody-based blockage of claudin-2 could also decrease BmCPV cell entry. These results suggest that claudin-2 can promote BmCPV infection in vitro. Moreover, immunofluorescence (IF) assays showed that claudin-2 can interact with BmCPV during viral infection. Specifically, co-immunoprecipitation experiments indicated that claudin-2 binds the BmCPV VP7 (instead of VP3 proteins). The interaction between VP7 and claudin-2 was further confirmed by bimolecular fluorescence complementation (BIFC). Altogether, our results suggest that BmCPV cell entry can be promoted upon interaction of VP7 with claudin-2. These findings provide new mechanistic insights related to BmCPV infection. KEY POINTS: •Claudin-2 could promote BmCPV infection of cells. •Claudin-2 interacted with BmCPV during BmCPV infection. •Claudin-2 could interact with BmCPV VP7 protein, but not with VP3 proteins.
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The effects of denatured major bovine whey proteins on the digestive tract, assessed by Caco-2 cell differentiation and on viability of suckling mice. J DAIRY RES 2021; 88:221-225. [PMID: 33985600 DOI: 10.1017/s0022029921000376] [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: 11/05/2022]
Abstract
Alpha-lactalbumin (α-LA) and β-lactoglobulin (β-LG) are contained in bovine milk whey. Chemical and physical treatments are known to alter the conformation of these proteins and we have previously reported that α-LA denatured with trifluoroethanol (TFE) and isolated from sterilized market milk inhibited the growth of rat crypt IEC-6 cells. In the present study, we aimed to evaluate the effects of TFE-treated α-LA and β-LG on cell growth using cultured intestinal cells and on their safety using a suckling mouse model. First, we investigated the effect of the TFE-treated whey proteins on human colonic Caco-2 cells at various differentiation stages. In the undifferentiated stage, we assessed cell growth by a water-soluble tetrazolium-1 method. The native whey proteins enhanced cell proliferation, whereas the TFE-treated whey proteins strongly inhibited cell growth. We investigated cell barrier function in the post-differentiated stage by measuring transepithelial electrical resistance (TER). Not only native but also the TFE-treated whey proteins increased TER. Next, we evaluated whether the TFE-treated α-LA and β-LG have adverse effects on healthy suckling mice. No mice given by the TFE-treated samples showed any adverse symptoms. We also performed a safety test using a human rotavirus infected gastrointestinal disease suckling mice model. Even the TFE-treated whey proteins appeared to prevent the development of diarrheal symptoms without any adverse effects. Although we cannot know the effect of long-term ingestion of denatured whey proteins, these results suggest that they have no adverse effects on differentiated intestinal cells and digestive tract, at least in short-term ingestion.
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Tight Junctions as a Key for Pathogens Invasion in Intestinal Epithelial Cells. Int J Mol Sci 2021; 22:ijms22052506. [PMID: 33801524 PMCID: PMC7958858 DOI: 10.3390/ijms22052506] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/21/2021] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
Tight junctions play a major role in maintaining the integrity and impermeability of the intestinal barrier. As such, they act as an ideal target for pathogens to promote their translocation through the intestinal mucosa and invade their host. Different strategies are used by pathogens, aimed at directly destabilizing the junctional network or modulating the different signaling pathways involved in the modulation of these junctions. After a brief presentation of the organization and modulation of tight junctions, we provide the state of the art of the molecular mechanisms leading to permeability breakdown of the gut barrier as a consequence of tight junctions’ attack by pathogens, including bacteria, viruses, fungi, and parasites.
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Cui T, Theuns S, Xie J, Nauwynck HJ. Porcine rotavirus mainly infects primary porcine enterocytes at the basolateral surface. Vet Res 2019; 50:110. [PMID: 31856906 PMCID: PMC6924034 DOI: 10.1186/s13567-019-0728-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/29/2019] [Indexed: 12/15/2022] Open
Abstract
Intestinal epithelium functions as a barrier to protect multicellular organisms from the outside world. It consists of epithelial cells closely connected by intercellular junctions, selective gates which control paracellular diffusion of solutes, ions and macromolecules across the epithelium and keep out pathogens. Rotavirus is one of the major enteric viruses causing severe diarrhea in humans and animals. It specifically infects the enterocytes on villi of small intestines. The polarity of rotavirus replication in their target enterocytes and the role of intestinal epithelial integrity were examined in the present study. Treatment with EGTA, a drug that chelates calcium and disrupts the intercellular junctions, (i) significantly enhanced the infection of rotavirus in primary enterocytes, (ii) increased the binding of rotavirus to enterocytes, but (iii) considerably blocked internalization of rotavirus. After internalization, rotavirus was resistant to EGTA treatment. To investigate the polarity of rotavirus infection, the primary enterocytes were cultured in a transwell system and infected with rotavirus at either the apical or the basolateral surface. Rotavirus preferentially infected enterocytes at the basolateral surface. Restriction of infection through apical inoculation was overcome by EGTA treatment. Overall, our findings demonstrate that integrity of the intestinal epithelium is crucial in the host's innate defense against rotavirus infection. In addition, the intercellular receptor is located basolaterally and disruption of intercellular junctions facilitates the binding of rotavirus to their receptor at the basolateral surface.
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Affiliation(s)
- Tingting Cui
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Sebastiaan Theuns
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Jiexiong Xie
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Hans J Nauwynck
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
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Rotavirus-Induced Early Activation of the RhoA/ROCK/MLC Signaling Pathway Mediates the Disruption of Tight Junctions in Polarized MDCK Cells. Sci Rep 2018; 8:13931. [PMID: 30224682 PMCID: PMC6141481 DOI: 10.1038/s41598-018-32352-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 09/06/2018] [Indexed: 02/02/2023] Open
Abstract
Intestinal epithelial tight junctions (TJ) are a major barrier restricting the entry of various harmful factors including pathogens; however, they also represent an important entry portal for pathogens. Although the rotavirus-induced early disruption of TJ integrity and targeting of TJ proteins as coreceptors are well-defined, the precise molecular mechanisms involved remain unknown. In the present study, infection of polarized MDCK cells with the species A rotavirus (RVA) strains human DS-1 and bovine NCDV induced a redistribution of TJ proteins into the cytoplasm, a reversible decrease in transepithelial resistance, and an increase in paracellular permeability. RhoA/ROCK/MLC signaling was identified as activated at an early stage of infection, while inhibition of this pathway prevented the rotavirus-induced early disruption of TJ integrity and alteration of TJ protein distribution. Activation of pMYPT, PKC, or MLCK, which are known to participate in TJ dissociation, was not observed in MDCK cells infected with either rotavirus strain. Our data demonstrated that binding of RVA virions or cogent VP8* proteins to cellular receptors activates RhoA/ROCK/MLC signaling, which alters TJ protein distribution and disrupts TJ integrity via contraction of the perijunctional actomyosin ring, facilitating virion access to coreceptors and entry into cells.
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Tamhankar M, Gerhardt DM, Bennett RS, Murphy N, Jahrling PB, Patterson JL. Heparan sulfate is an important mediator of Ebola virus infection in polarized epithelial cells. Virol J 2018; 15:135. [PMID: 30165875 PMCID: PMC6117897 DOI: 10.1186/s12985-018-1045-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 08/20/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Currently, no FDA-approved vaccines or treatments are available for Ebola virus disease (EVD), and therapy remains largely supportive. Ebola virus (EBOV) has broad tissue tropism and can infect a variety of cells including epithelial cells. Epithelial cells differ from most other cell types by their polarized phenotype and barrier function. In polarized cells, the apical and basolateral membrane domains are demarcated by tight junctions, and specialized sorting machinery, which results in a difference in composition between the two membrane domains. These specialized sorting functions can have important consequences for viral infections. Differential localization of a viral receptor can restrict virus entry to a particular membrane while polarized sorting can lead to a vectorial virus release. The present study investigated the impact of cell polarity on EBOV infection. METHODS Characteristics of EBOV infection in polarized cells were evaluated in the polarized Caco-2 model grown on semipermeable transwells. Transepithelial resistance (TEER), which is a function of tight junctions, was used to assess epithelial cell polarization. EBOV infection was assessed with immunofluorescence microscopy and qPCR. Statistical significance was calculated using one-way ANOVA and significance was set at p < 0.05. RESULTS Our data indicate that EBOV preferentially infects cells from the basolateral route, and this preference may be influenced by the resistance across the Caco-2 monolayer. Infection occurs without changes in cellular permeability. Further, our data show that basolateral infection bias may be dependent on polarized distribution of heparan sulfate, a known viral attachment factor. Treatment with iota-carrageenan, or heparin lyase, which interrupts viral interaction with cellular heparan sulfate, significantly reduced cell susceptibility to basolateral infection, likely by inhibiting virus attachment. CONCLUSIONS Our results show cell polarity has an impact on EBOV infection. EBOV preferentially infects polarized cells through the basolateral route. Access to heparan sulfate is an important factor during basolateral infection and blocking interaction of cellular heparan sulfate with virus leads to significant inhibition of basolateral infection in the polarized Caco-2 cell model.
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Affiliation(s)
- Manasi Tamhankar
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX USA
- University of Texas Health Science Center at San Antonio, San Antonio, TX USA
| | - Dawn M. Gerhardt
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD USA
| | - Richard S. Bennett
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD USA
| | - Nicole Murphy
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD USA
| | - Peter B. Jahrling
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD USA
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD USA
| | - Jean L. Patterson
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX USA
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Vlasova AN, Amimo JO, Saif LJ. Porcine Rotaviruses: Epidemiology, Immune Responses and Control Strategies. Viruses 2017; 9:v9030048. [PMID: 28335454 PMCID: PMC5371803 DOI: 10.3390/v9030048] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 12/13/2022] Open
Abstract
Rotaviruses (RVs) are a major cause of acute viral gastroenteritis in young animals and children worldwide. Immunocompetent adults of different species become resistant to clinical disease due to post-infection immunity, immune system maturation and gut physiological changes. Of the 9 RV genogroups (A–I), RV A, B, and C (RVA, RVB, and RVC, respectively) are associated with diarrhea in piglets. Although discovered decades ago, porcine genogroup E RVs (RVE) are uncommon and their pathogenesis is not studied well. The presence of porcine RV H (RVH), a newly defined distinct genogroup, was recently confirmed in diarrheic pigs in Japan, Brazil, and the US. The complex epidemiology, pathogenicity and high genetic diversity of porcine RVAs are widely recognized and well-studied. More recent data show a significant genetic diversity based on the VP7 gene analysis of RVB and C strains in pigs. In this review, we will summarize previous and recent research to provide insights on historic and current prevalence and genetic diversity of porcine RVs in different geographic regions and production systems. We will also provide a brief overview of immune responses to porcine RVs, available control strategies and zoonotic potential of different RV genotypes. An improved understanding of the above parameters may lead to the development of more optimal strategies to manage RV diarrheal disease in swine and humans.
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Affiliation(s)
- Anastasia N Vlasova
- Food Animal Health Research Program, CFAES, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH 44691, USA.
| | - Joshua O Amimo
- Department of Animal Production, Faculty of Veterinary Medicine, University of Nairobi, Nairobi 30197, Kenya.
- Bioscience of Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, Nairobi 30709, Kenya.
| | - Linda J Saif
- Food Animal Health Research Program, CFAES, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH 44691, USA.
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16
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17
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Zihni C, Balda MS, Matter K. Signalling at tight junctions during epithelial differentiation and microbial pathogenesis. J Cell Sci 2015; 127:3401-13. [PMID: 25125573 DOI: 10.1242/jcs.145029] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Tight junctions are a component of the epithelial junctional complex, and they form the paracellular diffusion barrier that enables epithelial cells to create cellular sheets that separate compartments with different compositions. The assembly and function of tight junctions are intimately linked to the actomyosin cytoskeleton and, hence, are under the control of signalling mechanisms that regulate cytoskeletal dynamics. Tight junctions not only receive signals that guide their assembly and function, but transmit information to the cell interior to regulate cell proliferation, migration and survival. As a crucial component of the epithelial barrier, they are often targeted by pathogenic viruses and bacteria, aiding infection and the development of disease. In this Commentary, we review recent progress in the understanding of the molecular signalling mechanisms that drive junction assembly and function, and the signalling processes by which tight junctions regulate cell behaviour and survival. We also discuss the way in which junctional components are exploited by pathogenic viruses and bacteria, and how this might affect junctional signalling mechanisms.
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Affiliation(s)
- Ceniz Zihni
- Department of Cell Biology, UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
| | - Maria S Balda
- Department of Cell Biology, UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
| | - Karl Matter
- Department of Cell Biology, UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
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18
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Tossetta G, Paolinelli F, Avellini C, Salvolini E, Ciarmela P, Lorenzi T, Emanuelli M, Toti P, Giuliante R, Gesuita R, Crescimanno C, Voltolini C, Di Primio R, Petraglia F, Castellucci M, Marzioni D. IL-1β and TGF-β weaken the placental barrier through destruction of tight junctions: an in vivo and in vitro study. Placenta 2014; 35:509-16. [PMID: 24768095 DOI: 10.1016/j.placenta.2014.03.016] [Citation(s) in RCA: 33] [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: 09/04/2013] [Revised: 03/19/2014] [Accepted: 03/24/2014] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Chorioamnionitis is a gestational pathological condition characterized by acute inflammation of the amniochorionic membranes and placentas leading to high concentrations of IL-1β, Il-6, Il-8 and TGF-β in the amniotic fluid. In normal conditions, the permeability of foeto-maternal barrier is due to the assembly and maintenance of different cellular junctional domains. METHODS In the present study, first we aimed to evaluate the protein expression (by immunohistochemistry and western blotting) and mRNA (by real time PCR) levels of the molecular components of tight junctions (Zonula occludens-1 and occludin), and of adherent junctions (VE-cadherin and β-catenin) in placentas from chorioamnionitis compared to that in normal pregnancies. RESULTS Western blotting results showed a significant down-regulation of occludin in placentas affected with chorioamnionitis. No differences were detected for the other proteins analysed. We evaluated whether occludin expression was regulated by IL-1β, IL-6, IL-8 and TGF-β by means of in vitro studies using HUVEC cultures and demonstrated a key role of IL-1β and TGF-β in the disappearance of occludin at cellular border. CONCLUSIONS We conclude by suggesting a pivotal role of these two cytokines in facilitating intra-placental infection via para-cellular way due to the disassembly of tight junctions at trophoblastic and endothelial cells in placental tissues.
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Affiliation(s)
- G Tossetta
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - F Paolinelli
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - C Avellini
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - E Salvolini
- Department of Molecular and Clinical Sciences-Histology, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - P Ciarmela
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - T Lorenzi
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - M Emanuelli
- Department of Clinical Sciences, Section of Biochemistry, Università Politecnica delle Marche, 60131 Ancona, Italy.
| | - P Toti
- Department of Medical Biotechnologies, Pathology Unit, University of Siena, Siena, Italy.
| | - R Giuliante
- Department of Clinical Sciences, Section of Biochemistry, Università Politecnica delle Marche, 60131 Ancona, Italy.
| | - R Gesuita
- Department of Biomedical Sciences and Public Health, Epidemiological and Bio-statistic Centre, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - C Crescimanno
- Faculty of Engineering, Architecture and Physical Education, Università Kore, 94100 Enna, Italy.
| | - C Voltolini
- Department of Molecular and Developmental Medicine-Obstetrics and Gynecology, University of Siena, 53100 Siena, Italy.
| | - R Di Primio
- Department of Molecular and Clinical Sciences-Histology, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - F Petraglia
- Department of Molecular and Developmental Medicine-Obstetrics and Gynecology, University of Siena, 53100 Siena, Italy.
| | - M Castellucci
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
| | - D Marzioni
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy.
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Tria SA, Ramuz M, Jimison LH, Hama A, Owens RM. Sensing of barrier tissue disruption with an organic electrochemical transistor. J Vis Exp 2014:e51102. [PMID: 24561449 DOI: 10.3791/51102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The gastrointestinal tract is an example of barrier tissue that provides a physical barrier against entry of pathogens and toxins, while allowing the passage of necessary ions and molecules. A breach in this barrier can be caused by a reduction in the extracellular calcium concentration. This reduction in calcium concentration causes a conformational change in proteins involved in the sealing of the barrier, leading to an increase of the paracellular flux. To mimic this effect the calcium chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetra acetic acid (EGTA) was used on a monolayer of cells known to be representative of the gastrointestinal tract. Different methods to detect the disruption of the barrier tissue already exist, such as immunofluorescence and permeability assays. However, these methods are time-consuming and costly and not suited to dynamic or high-throughput measurements. Electronic methods for measuring barrier tissue integrity also exist for measurement of the transepithelial resistance (TER), however these are often costly and complex. The development of rapid, cheap, and sensitive methods is urgently needed as the integrity of barrier tissue is a key parameter in drug discovery and pathogen/toxin diagnostics. The organic electrochemical transistor (OECT) integrated with barrier tissue forming cells has been shown as a new device capable of dynamically monitoring barrier tissue integrity. The device is able to measure minute variations in ionic flux with unprecedented temporal resolution and sensitivity, in real time, as an indicator of barrier tissue integrity. This new method is based on a simple device that can be compatible with high throughput screening applications and fabricated at low cost.
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Affiliation(s)
- Scherrine A Tria
- Department of Bioelectronics, Ecole Nationale Superieure des Mines
| | - Marc Ramuz
- Department of Bioelectronics, Ecole Nationale Superieure des Mines
| | - Leslie H Jimison
- Research and Exploratory Development Division, Applied Physics Laboratory, Johns Hopkins University
| | - Adel Hama
- Department of Bioelectronics, Ecole Nationale Superieure des Mines
| | - Roisin M Owens
- Department of Bioelectronics, Ecole Nationale Superieure des Mines;
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20
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Lee K, Gu S, Jin L, Le TTN, Cheng LW, Strotmeier J, Kruel AM, Yao G, Perry K, Rummel A, Jin R. Structure of a bimodular botulinum neurotoxin complex provides insights into its oral toxicity. PLoS Pathog 2013; 9:e1003690. [PMID: 24130488 PMCID: PMC3795040 DOI: 10.1371/journal.ppat.1003690] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 07/11/2013] [Indexed: 11/24/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and cause the fatal disease botulism, a flaccid paralysis of the muscle. BoNTs are released together with several auxiliary proteins as progenitor toxin complexes (PTCs) to become highly potent oral poisons. Here, we report the structure of a ∼760 kDa 14-subunit large PTC of serotype A (L-PTC/A) and reveal insight into its absorption mechanism. Using a combination of X-ray crystallography, electron microscopy, and functional studies, we found that L-PTC/A consists of two structurally and functionally independent sub-complexes. A hetero-dimeric 290 kDa complex protects BoNT, while a hetero-dodecameric 470 kDa complex facilitates its absorption in the harsh environment of the gastrointestinal tract. BoNT absorption is mediated by nine glycan-binding sites on the dodecameric sub-complex that forms multivalent interactions with carbohydrate receptors on intestinal epithelial cells. We identified monosaccharides that blocked oral BoNT intoxication in mice, which suggests a new strategy for the development of preventive countermeasures for BoNTs based on carbohydrate receptor mimicry. Food-borne botulinum neurotoxin (BoNT) poisoning results in fatal muscle paralysis. But how can BoNT–a large protein released by the bacteria clostridia–survive the hostile gastrointestinal (GI) tract to gain access to neurons that control muscle contraction? Here, we report the complete structure of a bimodular ∼760 kDa BoNT/A large progenitor toxin complex (L-PTC), which is composed of BoNT and four non-toxic bacterial proteins. The architecture of this bacterial machinery mimics an Apollo lunar module, whereby the “ascent stage” (a ∼290 kDa module) protects BoNT from destruction in the GI tract and the 3-arm “descent stage” (a ∼470 kDa module) mediates absorption of BoNT by binding to host carbohydrate receptors in the small intestine. This new finding has helped us identify the carbohydrate-binding sites and the monosaccharide IPTG as a prototypical oral inhibitor, which extends survival following lethal BoNT/A intoxication of mice. Hence, pre-treatment with small molecule inhibitors based on carbohydrate receptor mimicry can provide temporary protection against BoNT entry into the circulation.
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Affiliation(s)
- Kwangkook Lee
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Shenyan Gu
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Lei Jin
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Thi Tuc Nghi Le
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Luisa W. Cheng
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| | - Jasmin Strotmeier
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | | | - Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
- * E-mail: (AR); (RJ)
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
- Neuroscience, Aging and Stem Cell Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (AR); (RJ)
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Che P, Tang H, Li Q. The interaction between claudin-1 and dengue viral prM/M protein for its entry. Virology 2013; 446:303-13. [PMID: 24074594 DOI: 10.1016/j.virol.2013.08.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/18/2013] [Accepted: 08/09/2013] [Indexed: 02/04/2023]
Abstract
Dengue disease is becoming a huge public health concern around the world as more than one-third of the world's population living in areas at risk of infection. In an effort to assess host factors interacting with dengue virus, we identified claudin-1, a major tight junction component, as an essential cell surface protein for dengue virus entry. When claudin-1 was knocked down in Huh 7.5 cells via shRNA, the amount of dengue virus entering host cells was reduced. Consequently, the progeny virus productions were decreased and dengue virus-induced CPE was prevented. Furthermore, restoring the expression of claudin-1 in the knockdown cells facilitated dengue virus entry. The interaction between claudin-1 and dengue viral prM protein was further demonstrated using the pull-down assay. Deletion of the extracellular loop 1 (ECL1) of claudin-1 abolished such interaction, so did point mutations C54A, C64A and I32M on ECL1. These results suggest that the interaction between viral protein prM and host protein claudin-1 was essential for dengue entry. Since host and viral factors involved in virus entry are promising therapeutic targets, determining the essential role of claudin-1 could lead to the discovery of entry inhibitors with attractive therapeutic potential against dengue disease.
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Affiliation(s)
- Pulin Che
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States; University of Alabama at Birmingham, Department of Medicine, Division of Infectious Diseases, BBRB 562, 845 19th Street South, Birmingham, AL 35294, United States
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Jacobi SK, Moeser AJ, Blikslager AT, Rhoads JM, Corl BA, Harrell RJ, Odle J. Acute effects of rotavirus and malnutrition on intestinal barrier function in neonatal piglets. World J Gastroenterol 2013; 19:5094-5102. [PMID: 23964143 PMCID: PMC3746381 DOI: 10.3748/wjg.v19.i31.5094] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 04/24/2013] [Accepted: 06/06/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of protein-energy malnutrition on intestinal barrier function during rotavirus enteritis in a piglet model.
METHODS: Newborn piglets were allotted at day 4 of age to the following treatments: (1) full-strength formula (FSF)/noninfected; (2) FSF/rotavirus infected; (3) half-strength formula (HSF)/noninfected; or (4) HSF/rotavirus infected. After one day of adjustment to the feeding rates, pigs were infected with rotavirus and acute effects on growth and diarrhea were monitored for 3 d and jejunal samples were collected for Ussing-chamber analyses.
RESULTS: Piglets that were malnourished or infected had lower body weights on days 2 and 3 post-infection (P < 0.05). Three days post-infection, marked diarrhea and weight loss were accompanied by sharp reductions in villus height (59%) and lactase activity (91%) and increased crypt depth (21%) in infected compared with non-infected pigs (P < 0.05). Malnutrition also increased crypt depth (21%) compared to full-fed piglets. Villus:crypt ratio was reduced (67%) with viral infection. There was a trend for reduction in transepithelial electrical resistance with rotavirus infection and malnutrition (P = 0.1). 3H-mannitol flux was significantly increased (50%; P < 0.001) in rotavirus-infected piglets compared to non-infected piglets, but there was no effect of nutritional status. Furthermore, rotavirus infection reduced localization of the tight junction protein, occludin, in the cell membrane and increased localization in the cytosol.
CONCLUSION: Overall, malnutrition had no additive effects to rotavirus infection on intestinal barrier function at day 3 post-infection in a neonatal piglet model.
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Inagaki M, Yamamoto M, Cairangzhuoma, Xijier, Yabe T, Uchida K, Kawasaki M, Nakagomi T, Nakagomi O, Minamoto N, Kanamaru Y. Multiple-dose therapy with bovine colostrum confers significant protection against diarrhea in a mouse model of human rotavirus-induced gastrointestinal disease. J Dairy Sci 2012. [PMID: 23200479 PMCID: PMC7094275 DOI: 10.3168/jds.2012-5847] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rotavirus is the most important etiologic agent of severe gastroenteritis. Previously, we reported that skimmed and concentrated bovine late colostrum (SCBLC) obtained from normal unimmunized cows at 6 to 7d after parturition effectively prevented against human rotavirus (HRV)-induced severe gastroenteritis in vivo, when administered as a single dose 60 min before viral inoculation. In the present study, we examined the efficacy of multiple administrations of SCBLC at smaller dosages after viral inoculation in vivo. We demonstrate that multiple administrations within 24h after virus inoculation resulted in earlier recovery from diarrheal symptoms, in an administration frequency-dependent manner. Furthermore, we investigated whether isolated IgG anti-HRV activity in SCBLC was equivalent to that of IgG isolated from bovine mature milk as measured by in vitro activity assays. We found that IgG-containing fractions from SCBLC and mature milk exhibited approximately the same level of anti-HRV activity. We concluded that the SCBLC contains a high level of IgG against HRV-induced severe gastroenteritis, which will be possible to use in protective effects in immunocompromised hosts, such as children and the elderly. Multiple doses of SCBLC during the early stages of infection or lower dosage of SCBLC given as a single dose both resulted in relief of diarrheal symptoms.
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Affiliation(s)
- M Inagaki
- Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan
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Wang H, Moon S, Wang Y, Jiang B. Multiple virus infection alters rotavirus replication and expression of cytokines and Toll-like receptors in intestinal epithelial cells. Virus Res 2012; 167:48-55. [DOI: 10.1016/j.virusres.2012.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/30/2012] [Accepted: 04/02/2012] [Indexed: 01/18/2023]
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25
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Bonazzi M, Cossart P. Impenetrable barriers or entry portals? The role of cell-cell adhesion during infection. ACTA ACUST UNITED AC 2012; 195:349-58. [PMID: 22042617 PMCID: PMC3206337 DOI: 10.1083/jcb.201106011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cell-cell adhesion plays a fundamental role in cell polarity and organogenesis. It also contributes to the formation and establishment of physical barriers against microbial infections. However, a large number of pathogens, from viruses to bacteria and parasites, have developed countless strategies to specifically target cell adhesion molecules in order to adhere to and invade epithelial cells, disrupt epithelial integrity, and access deeper tissues for dissemination. The study of all these processes has contributed to the characterization of molecular machineries at the junctions of eukaryotic cells that have been better understood by using pathogens as probes.
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Affiliation(s)
- Matteo Bonazzi
- Centre Nationale de la Recherche Scientifique, UMR 5236, CPBS, CNRS, 34293 Montpellier, France.
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The actin cytoskeleton as a barrier to virus infection of polarized epithelial cells. Viruses 2011; 3:2462-77. [PMID: 22355449 PMCID: PMC3280511 DOI: 10.3390/v3122462] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 12/07/2011] [Accepted: 12/15/2011] [Indexed: 12/12/2022] Open
Abstract
Many diverse viruses target a polarized epithelial monolayer during host invasion. The polarized epithelium is adept at restricting the movement of solutes, ions, macromolecules, and pathogens across the mucosa. This regulation can be attributed to the presence of a junctional complex between adjacent cells and to an intricate network of actin filaments that provides support to the subapical membrane and stabilizes intercellular junctions. It is therefore not surprising that many viruses have evolved highly varied strategies to dissolve or modulate the cortical actin meshwork to promote infection of polarized cells. In this review, we will discuss the cell biological properties of the actin cytoskeleton in polarized epithelial cells and review the known mechanisms utilized by viral pathogens to manipulate this system in order to facilitate their infection.
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Humen MA, Pérez PF, Liévin-Le Moal V. Lipid raft-dependent adhesion of Giardia intestinalis trophozoites to a cultured human enterocyte-like Caco-2/TC7 cell monolayer leads to cytoskeleton-dependent functional injuries. Cell Microbiol 2011; 13:1683-702. [PMID: 21790940 DOI: 10.1111/j.1462-5822.2011.01647.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Gardia intestinalis, the aetiological agent of giardiasis, one of the most common intestinal diseases in both developing and developed countries, induces a loss of epithelial barrier function and functional injuries of the enterocyte by mechanisms that remain unknown. Three possible mechanisms have been proposed: (i) Giardia may directly alter the epithelial barrier after a close interaction between the trophozoite and polarized intestinal cells, (ii) intestinal functions may be altered by factors secreted by Giardia including an 'enterotoxin', proteinases and lectins, and (iii) based on mouse studies, a mechanism involving the intervention of activated T lymphocytes. We used fully differentiated cultured human intestinal Caco-2/TC7 cells forming a monolayer and expressing several polarized functions of enterocytes of small intestine to investigate the mechanisms by which G. intestinalis induces structural and functional alterations in the host intestinal epithelium. We first report that adhesion of G. intestinalis at the brush border of enterocyte-like cells involves the lipid raft membrane microdomains of the trophozoite. We report an adhesion-dependent disorganization of the apical F-actin cytoskeleton that, in turn, results in a dramatic loss of distribution of functional brush border-associated proteins, including sucrase-isomaltase (SI), dipeptidylpeptidase IV (DPP IV) and fructose transporter, GLUT5, and a decrease in sucrose enzyme activity in G. intestinalis-infected enterocyte-like cells. We observed that the G. intestinalis trophozoite promotes an adhesion-dependent decrease in transepithelial electrical resistance (TER) accompanied by a rearrangement of functional tight junction (TJ)-associated occludin, and delocalization of claudin-1. Finally, we found that whereas the occludin rearrangement induced by G. intestinalis was related to apical F-actin disorganization, the delocalization of claudin-1 was not.
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Lipson SM, Gordon RE, Ozen FS, Karthikeyan L, Kirov N, Stotzky G. Cranberry and Grape Juices Affect Tight Junction Function and Structural Integrity of Rotavirus-Infected Monkey Kidney Epithelial Cell Monolayers. FOOD AND ENVIRONMENTAL VIROLOGY 2011; 3:46-54. [PMID: 35255646 DOI: 10.1007/s12560-011-9055-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Accepted: 02/22/2011] [Indexed: 06/14/2023]
Abstract
Cranberry juice (CJ) and grape juice (GJ) from Vaccinium macrocarpon and Vitis labrusca, respectively, and purified proanthocyanidins (PACs) from these species are recognized to possess antiviral activity. The effects of CJ and GJ on tight junction (TJ) structure and function among rotavirus-infected monkey kidney epithelial cells (MA-104) in monolayer cultures were evaluated. Antiviral activity by cranberry PACs of rotavirus in cell-free suspension was investigated by a rotavirus antigen [i.e., viral capsid protein 6 (VP6)] capture enzyme-linked immunosorbent assay (ELISA) and by transmission electron microscopy (TEM). MA-104 monolayers were treated with CJ, GJ, or cranberry juice cocktail (CJC) drink before inoculation with rotavirus. TJ function and structural integrity were measured by changes in transepithelial electrical resistance (TEER) and by reduction of signal intensity of the TJ α-claudin 1 by immunofluorescence. The inhibitory activity of CJ and GJ on viral RNA synthesis, as a function of viral concentration, was determined by reverse transcription polymerase chain reaction (rtPCR). After 4 days, virus-infected monolayers pretreated with GJ (Concord and Niagara GJs) had TEER readings similar to uninfected controls. CJ and CJC also had a significant protective effect (P < 0.05) on TJ function, but to a lesser extent than GJ. Disorganization of TJ integrity commenced at 24- to 36-h post-viral inoculation, but this effect was reduced by pretreatment with CJ or GP of monolayer cultures. TEM showed aggregation of rotavirus by cranberry PACs. The destruction of rotavirus capsid proteins VP6, in cell-free suspension was inversely related to the concentration of cranberry PACs (C-PAC). Loss of rotavirus RNA by CJ or GJ was inversely related to viral infectivity titers. CJ, GJ, or PAC-associated antiviral activity has been linked to modifications in cellular physiologic events and to physical factors (e.g., PAC-mediated viral aggregation) that probably compromise viral infectivity. Multiple cell physiological and physical events must be considered when determining the mechanisms associated with the antiviral (i.e., rotavirus) activity of CJ, GJ, and PACs.
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Affiliation(s)
- Steven M Lipson
- Department of Biology, St. Francis College, 180 Remsen Street, Brooklyn Heights, NY, 11201, USA.
| | | | - Fatma S Ozen
- Department of Biology, St. Francis College, 180 Remsen Street, Brooklyn Heights, NY, 11201, USA
- School of Veterinary Medicine, University of Selcuk, Konya, Turkey
| | - Laina Karthikeyan
- New York College of Technology, City University of New York, Brooklyn, NY, USA
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Tylosema esculentum (Marama) Tuber and Bean Extracts Are Strong Antiviral Agents against Rotavirus Infection. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2011:284795. [PMID: 21423688 PMCID: PMC3057194 DOI: 10.1155/2011/284795] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 12/01/2010] [Accepted: 01/09/2011] [Indexed: 12/24/2022]
Abstract
Tylosema esculentum (marama) beans and tubers are used as food, and traditional medicine against diarrhoea in Southern Africa. Rotaviruses (RVs) are a major cause of diarrhoea among infants, young children, immunocompromised people, and domesticated animals. Our work is first to determine anti-RV activity of marama bean and tuber ethanol and water extracts; in this case on intestinal enterocyte cells of human infant (H4), adult pig (CLAB) and adult bovine (CIEB) origin. Marama cotyledon ethanolic extract (MCE) and cotyledon water extract (MCW) without RV were not cytotoxic to all cells tested, while seed coat and tuber extracts showed variable levels of cytotoxicity. Marama cotyledon ethanolic and water extracts (MCE and MCW, resp.) (≥0.1 mg/mL), seed coat extract (MSCE) and seed coat water extract (MSCW) (0.01 to 0.001 mg/mL), especially ethanolic, significantly increased cell survival and enhanced survival to cytopathic effects of RV by at least 100% after in vitro co- and pre-incubation treatments. All marama extracts used significantly enhanced nitric oxide release from H4 cells and enhanced TER (Ω/cm2) of enterocyte barriers after coincubation with RV. Marama cotyledon and seed coat extracts inhibited virion infectivity possibly through interference with replication due to accumulation of nitric oxide. Marama extracts are therefore promising microbicides against RV.
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30
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Moyes SM, Morris JF, Carr KE. Macrophages increase microparticle uptake by enterocyte-like Caco-2 cell monolayers. J Anat 2010; 217:740-54. [PMID: 20880316 DOI: 10.1111/j.1469-7580.2010.01304.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Caco-2 cells form an enterocyte-like monolayer that has been used to explore small intestinal microparticle uptake. They are a useful functional model for the investigation of in vivo drug delivery systems and the uptake of particulate environmental pollutants. The aim of this paper was to determine if the previously reported decrease in Caco-2 transepithelial resistance following exposure to macrophages was matched by increased microparticle uptake, especially as macrophage phagocytosis simulates removal of particles from the subepithelial compartment. Caco-2 cells were grown as a monoculture for 21 days on insert membranes. A compartmentalised model involved Caco-2 cells in the upper compartment, with THP-1-derived macrophages adhering to the base of the underlying well, the two cell populations communicating only through the shared culture medium. Caco-2 cells were also cultured in macrophage-conditioned medium and all groups were exposed apically to 2 μm latex particles for 5 or 60 min. Parameters measured were: transepithelial resistance; cytokine levels; cell dimensions and the distribution of nuclei, actin and junctional proteins. Subepithelial particle numbers, defined as those located below the insert membrane, were also counted and were significantly increased in the Caco-2/macrophage model, with over 90% associated with the macrophages. Other changes induced by the presence of macrophages included decreased transepithelial resistance levels, diffuse localisation of some junctional proteins, higher proinflammatory cytokine levels, disorganisation of cell shape and decreased cell height associated with actin reorganisation. Macrophage-conditioned medium produced a smaller transepithelial resistance decrease than the Caco-2/macrophage model and there were few other changes. In conclusion, culture of Caco-2 cells with underlying macrophages produced a lower, less organised epithelium and greater microparticle uptake.
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Affiliation(s)
- Siobhan M Moyes
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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31
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Abstract
A wide variety of different viruses use tight junction (TJ) proteins in the course of infection and different mechanisms of pathogen–TJ interactions have been described; pathogens may induce the reorganization or degradation of distinct TJ proteins, reorganization of the cell cytoskeleton, activation of host-cell signaling pathways and/or use TJ proteins as receptors to enter host cells. Most recently, the TJ proteins claudin-1 and occludin have been identified as essential host factors for HCV entry. Furthermore, TJ protein occludin has been shown to play an important role in the species specificity of HCV infection. Recent data suggest that claudin-1 is a promising target for antiviral strategies. The aim of this article is to elucidate the impact of the interplay between pathogens and TJ proteins for pathogen–host interactions, summarize recent findings regarding the role of TJ proteins in HCV entry and highlight the relevance of TJ proteins for the development of novel antiviral strategies.
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Affiliation(s)
| | - Marine Turek
- Inserm, U748, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U748, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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Turner HL, Turner JR. Good fences make good neighbors: Gastrointestinal mucosal structure. Gut Microbes 2010; 1:22-29. [PMID: 21327113 PMCID: PMC3035135 DOI: 10.4161/gmic.1.1.11427] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 02/01/2010] [Accepted: 02/04/2010] [Indexed: 02/07/2023] Open
Abstract
The gastrointestinal lumen is home to over 400 species of microorganisms. The composition of this microbial community varies along the length of the gastrointestinal tract as a function of regional epithelial secretory activity as well as diet and other defined and undefined determinants. Improved understanding of the factors that impact luminal microbial populations and development of means to modulate gut microbes for therapeutic benefit hold great promise. The gastrointestinal epithelium, which regulates interactions between microbes and the mammalian host, is the topic of this review.
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Affiliation(s)
- Hannah L Turner
- Department of Pathology; The University of Chicago; Chicago, IL USA
| | - Jerrold R Turner
- Department of Pathology; The University of Chicago; Chicago, IL USA
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Rodríguez LS, Barreto A, Franco MA, Angel J. Immunomodulators released during rotavirus infection of polarized caco-2 cells. Viral Immunol 2009; 22:163-72. [PMID: 19435412 DOI: 10.1089/vim.2008.0110] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rotavirus preferentially replicates in enterocytes and "danger signals" released by these cells are likely to modulate viral immunity. As a model of these events, we studied selected immunomodulators released during rotavirus infection of polarized Caco-2 cells grown in transwell cultures (TW). At early time points post-infection the virus was detected mainly in the apical side of the TWs, but this tendency was progressively lost concomitantly with disruption of the cell monolayer and cell death. Rotavirus-infected cells released IL-8, PGE(2), small quantities of TGF-beta1, and the constitutive and inducible heat shock proteins HSC70 and HSP70, but not IL-1beta, IL-6, IL-10, IL-12p70, or TNF-alpha. This set of immunomodulators is known to induce a non-inflammatory (non-Th-1) immune response, and may be determining, in part, the relatively low T-cell immune response observed in blood samples after RV infection.
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Affiliation(s)
- Luz-Stella Rodríguez
- Instituto de Genética Humana, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
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Guttman JA, Finlay BB. Tight junctions as targets of infectious agents. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:832-41. [PMID: 19059200 DOI: 10.1016/j.bbamem.2008.10.028] [Citation(s) in RCA: 268] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 10/01/2008] [Accepted: 10/29/2008] [Indexed: 12/17/2022]
Abstract
The epithelial barrier is a critical border that segregates luminal material from entering tissues. Essential components of this epithelial fence are physical intercellular structures termed tight junctions. These junctions use a variety of transmembrane proteins coupled with cytoplasmic adaptors, and the actin cytoskeleton, to attach adjacent cells together thereby forming intercellular seals. Breaching of this barrier has profound effects on human health and disease, as barrier deficiencies have been linked with the onset of inflammation, diarrhea generation and pathogenic effects. Although tight junctions efficiently restrict most microbes from penetrating into deeper tissues and contain the microbiota, some pathogens have developed specific strategies to alter or disrupt these structures as part of their pathogenesis, resulting in either pathogen penetration, or other consequences such as diarrhea. Understanding the strategies that microorganisms use to commandeer the functions of tight junctions is an active area of research in microbial pathogenesis. In this review we highlight and overview the tactics bacteria and viruses use to alter tight junctions during disease. Additionally, these studies have identified novel tight junction protein functions by using pathogens and their virulence factors as tools to study the cell biology of junctional structures.
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Affiliation(s)
- Julian A Guttman
- Simon Fraser University, Department of Biological Sciences, Shrum Science Centre, Burnaby, BC, Canada V5A 1S6.
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35
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Hulst M, Kerstens H, de Wit A, Smits M, van der Meulen J, Niewold T. Early transcriptional response in the jejunum of germ-free piglets after oral infection with virulent rotavirus. Arch Virol 2008; 153:1311-22. [PMID: 18523839 PMCID: PMC2441536 DOI: 10.1007/s00705-008-0118-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 05/16/2008] [Indexed: 11/25/2022]
Abstract
Germ-free piglets were orally infected with virulent rotavirus to collect jejunal mucosal scrapings at 12 and 18 hours post infection (two piglets per time point). IFN-gamma mRNA expression was stimulated in the mucosa of all four infected piglets, indicating that they all responded to the rotavirus infection. RNA pools prepared from two infected piglets were used to compare whole mucosal gene expression at 12 and 18 hpi to expression in uninfected germ-free piglets (n = 3) using a porcine intestinal cDNA microarray. Microarray analysis identified 13 down-regulated and 17 up-regulated genes. Northern blot analysis of a selected group of genes confirmed the data of the microarray. Genes were functionally clustered in interferon-regulated genes, proliferation/differentiation genes, apoptosis genes, cytoskeleton genes, signal transduction genes, and enterocyte digestive, absorptive, and transport genes. Down-regulation of the transport gene cluster reflected in part the loss of rotavirus-infected enterocytes from the villous tips. Data mining suggested that several genes were regulated in lower- or mid-villus immature enterocytes and goblet cells, probably to support repair of the damaged epithelial cell layer at the villous tips. Furthermore, up-regulation was observed for IFN-γ induced guanylate binding protein 2, a protein that effectively inhibited VSV and EMCV replication in vitro (Arch Virol 150:1213–1220, 2005). This protein may play a role in the small intestine’s innate defense against enteric viruses like rotavirus.
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Affiliation(s)
- Marcel Hulst
- Animal Sciences Group of Wageningen University and Research Center, P. O. Box 65, 8200 AB, Lelystad, The Netherlands.
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Catto-Smith AG, Emselle S, Bishop RF. Changes in macromolecular transport appear early in Caco-2 cells infected with a human rotavirus. Scand J Gastroenterol 2008; 43:314-22. [PMID: 18266175 DOI: 10.1080/00365520701711786] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Rotavirus is a major cause of viral gastroenteritis, but its interaction with intestinal mucosa is poorly understood. The aim of this study was to examine the effect of Wa rotavirus (VP7 serotype 1) on barrier function in confluent Caco-2 cell monolayers. Wa is the most common serotype causing severe diarrhoea in humans. MATERIAL AND METHODS. We examined light and electron microscopic morphology, macromolecular transport, paracellular permeability, electrical parameters, disaccharidases and cytoskeletal structure in Wa- and in control sham-infected cells using a homologous human virus-cell system resembling human infection. RESULTS During the first 48 h following Wa infection, there was no evidence of loss of integrity or of cytopathic effect in the monolayer. A significant cytopathic effect was noticed after 48 h. Further studies examined the initial 24-h period during which there was no evidence of significant injury. Apical-to-basolateral transcytosis of the macromolecule horseradish peroxidase (HRP) was selectively inhibited at 4 and 24 h post-infection with Wa. There were no significant changes in basolateral-to-apical transcytosis, endocytosis or in apical-to-apical recycling of HRP after Wa infection. G- and F-actin levels were significantly reduced within an area corresponding to the viroplasm in Wa-infected cells but not elsewhere in the monolayer. CONCLUSIONS The early stages of rotavirus infection, before gross epithelial injury, are associated with a selective reduction in the apical uptake and transcytosis of macromolecules. We speculate that this is an epithelial defence mechanism.
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Affiliation(s)
- Anthony G Catto-Smith
- Department of Gastroenterology and Clinical Nutrition, Royal Children's Hospital, Melbourne, Australia.
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Hantavirus causing hemorrhagic fever with renal syndrome enters from the apical surface and requires decay-accelerating factor (DAF/CD55). J Virol 2008; 82:4257-64. [PMID: 18305044 DOI: 10.1128/jvi.02210-07] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The Old World hantaviruses, members of the family Bunyaviridae, cause hemorrhagic fever with renal syndrome (HFRS). Transmission to humans occurs via inhalation of aerosols contaminated with the excreta of infected rodents. The viral antigen is detectable in dendritic cells, macrophages, lymphocytes, and, most importantly, microvascular endothelial cells. However, the site and detailed mechanism of entry of HFRS-causing hantaviruses in polarized epithelial cells have not yet been defined. Therefore, this study focused on the entry of the pathogenic hantaviruses Hantaan and Puumala into African green monkey kidney epithelial cells and primary human endothelial cells. The polarized epithelial and endothelial cells were found to be susceptible to hantavirus infection exclusively from the apical surface. Treatment with phosphatidylinositol-specific phospholipase C, which removes glycosylphosphatidylinositol (GPI)-anchored proteins from the cell surface, protects cells from infection, indicating that hantaviruses require a GPI-anchored protein as a cofactor for entry. Decay-accelerating factor (DAF)/CD55 is a GPI-anchored protein of the complement regulatory system and serves as a receptor for attachment to the apical cell surface for a number of viruses. Infection was reduced by the pretreatment of hantaviral particles with human recombinant DAF. Moreover, the treatment of permissive cells with DAF-specific antibody blocked infection. These results demonstrate that the Old World hantaviruses Hantaan and Puumala enter polarized target cells from the apical site and that DAF is a critical cofactor for infection.
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Abstract
The rotavirus is the major cause of infantile gastroenteritis. The virus infects the mature enterocytes of the villus tip of the small intestine and induces a watery diarrhea. Diarrhea can occur in the absence of histological changes in the intestine, and, conversely, the histological changes can be asymptomatic. Rotavirus decreases the activities of digestive enzymes at the apical brush border membrane and inhibits Na+ -solute cotransport systems. Accumulation of carbohydrates in the intestinal lumen as well as malabsorption of nutrients and a concomitant inhibition of water absorption can lead to a malabsorptive component of diarrhea. Since the discovery of the NSP4 enterotoxin, several hypotheses have been proposed in favour of an additional secretion component in the pathogenesis of diarrhea. Rotavirus induces a moderate net chloride secretion at the onset of the diarrhea. The mechanisms appear to different from those used by bacterial enterotoxin that cause pure secretory diarrhea. Rotavirus stimulated C1- reabsorption in villi, and failed to stimulate C1- secretion in crypt. Intestinal villi could secrete chloride as a result of rotavirus infection. The chloride secretory response is regulated by a dependant calcium signalling pathway induced by NSP4. The overall response is weak, suggesting that NSP4 may exert both secretory and subsequent antisecretory actions, hence limiting C1- secretion.
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Affiliation(s)
- M Lorrot
- Service de Pédiatrie Générale, Hôpital Robert Debré 82, Boulevard Sérurier 75019 Paris, France.
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39
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Beau I, Cotte-Laffitte J, Géniteau-Legendre M, Estes MK, Servin AL. An NSP4-dependant mechanism by which rotavirus impairs lactase enzymatic activity in brush border of human enterocyte-like Caco-2 cells. Cell Microbiol 2007; 9:2254-66. [PMID: 17506819 DOI: 10.1111/j.1462-5822.2007.00956.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lactase-phlorizin hydrolase (LPH, EC 3.2.1.23-62) is a brush border membrane (BBM)-associated enzyme in intestinal cells that hydrolyse lactose, the most important sugar in milk. Impairing in lactase activity during rotavirus infection has been described in diseased infants but the mechanism by which the functional lesion occurs remains unknown. We undertook a study to elucidate whether rotavirus impairs the lactase enzymatic activity in BBM of human enterocyte cells. In this study we use cultured human intestinal fully differentiated enterocyte-like Caco-2 cells to demonstrate how the lactase enzymatic activity at BBM is significantly decreased in rhesus monkey rotavirus (RRV)-infected cells. We found that the decrease in enzyme activity is not dependent of the Ca(2+)- and cAMP-dependent signalling events triggered by the virus. The LPH biosynthesis, stability, and expression of the protein at the BBM of infected cells were not modified. We provide evidence that in RRV-infected cells the kinetic of lactase enzymatic activity present at the BBM was modified. Both BBM(control) and BBM(RRV) have identical K(m) values, but hydrolyse the substrate at different rates. Thus, the BBM(RRV) exhibits almost a 1.5-fold decreased V(max) than that of BBM(control) and is therefore enzymatically less active than the latter. Our study demonstrate conclusively that the impairment of lactase enzymatic activity at the BBM of the enterocyte-like Caco-2 cells observed during rotavirus infection results from an inhibitory action of the secreted non-structural rotavirus protein NSP4.
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Affiliation(s)
- Isabelle Beau
- INSERM, UMR 756, Signalisation et Physiopathologie des Cellules Epithéliales, Châtenay-Malabry, France
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Beau I, Cotte-Laffitte J, Amsellem R, Servin AL. A protein kinase A-dependent mechanism by which rotavirus affects the distribution and mRNA level of the functional tight junction-associated protein, occludin, in human differentiated intestinal Caco-2 cells. J Virol 2007; 81:8579-86. [PMID: 17553883 PMCID: PMC1951370 DOI: 10.1128/jvi.00263-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We found that at the tight junctions (TJs) of Caco-2 cell monolayers, rhesus monkey rotavirus (RRV) infection induced the disappearance of occludin. Confocal laser scanning microscopy showed the disappearance of occludin from the cell-cell boundaries without modifying the expression of the other TJ-associated proteins, ZO-1 and ZO-3. Western immunoblot analysis of RRV-infected cells showed a significant fall in the levels of the nonphosphorylated form of occludin in both Triton X-100-insoluble and Triton X-100-soluble fractions, without any change in the levels of the phosphorylated form of occludin. Quantitative reverse transcription-PCRs revealed that the level of transcription of the gene that encodes occludin was significantly reduced in RRV-infected cells. Treatment of RRV-infected cells with Rp-cyclic AMP and protein kinase A inhibitors H89 and KT5720 during the time course of the infection restored the distribution of occludin and a normal level of transcription of the gene that encodes occludin.
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Affiliation(s)
- Isabelle Beau
- Faculté de Pharmacie, INSERM Unit 510, Châtenay-Malabry, France 92296
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41
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Berkova Z, Crawford SE, Blutt SE, Morris AP, Estes MK. Expression of rotavirus NSP4 alters the actin network organization through the actin remodeling protein cofilin. J Virol 2007; 81:3545-53. [PMID: 17229686 PMCID: PMC1866088 DOI: 10.1128/jvi.01080-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 12/19/2006] [Indexed: 12/16/2022] Open
Abstract
Rotavirus is a major cause of infantile gastroenteritis with a multifactorial pathogenesis. As with many other pathogens, rotavirus infection and replication leads to rearrangement of the cytoskeleton with disorganization of cytoskeletal elements such as actin and cytokeratin through a calcium-dependent process that has not been fully characterized. The rotavirus enterotoxin NSP4, shown previously to elevate intracellular calcium levels when added exogenously as well as when expressed intracellularly, is a key player in intracellular calcium regulation during rotavirus infection. Here, we investigated the role NSP4 may play in actin rearrangement. Expression of NSP4 fused to enhanced green fluorescent protein (NSP4-EGFP), but not expression of EGFP alone, caused stabilization of long cellular projections in fully confluent HEK 293 cells. Cells expressing NSP4-EGFP for 24 h were also resistant to cell rounding induced by cytochalasin D. Quantification of filamentous actin (F-actin) content by using rhodamine-conjugated phalloidin and flow cytometry showed an elevated F-actin content in NSP4-EGFP-expressing and rotavirus-infected cells in comparison with that in nonexpressing and noninfected cells. Normalization of intracellular calcium levels prevented alterations of F-actin content. Observed changes in F-actin amounts correlated with the increased activation of the actin-remodeling protein cofilin. These calcium-dependent actin rearrangements induced by intracellular NSP4 expression may contribute to rotavirus pathogenesis by interfering with cellular processes dependent on subcortical actin remodeling, including ion transport and viral release.
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Affiliation(s)
- Zuzana Berkova
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, 1200 Moursund Street, Houston, TX 77030-3404, USA
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42
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Beau I, Berger A, Servin AL. Rotavirus impairs the biosynthesis of brush-border-associated dipeptidyl peptidase IV in human enterocyte-like Caco-2/TC7 cells. Cell Microbiol 2007; 9:779-89. [PMID: 17081193 DOI: 10.1111/j.1462-5822.2006.00827.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Rotavirus is the leading cause of severe dehydrating diarrhoea in infants and young children worldwide. This virus infects mature enterocytes in the small intestine, and induces structural and functional damage. In the present study, we have identified a new mechanism by which rotavirus impairs a brush border-associated intestinal protein. We show that infection of enterocyte-like Caco-2/TC7 cells by rhesus monkey rotavirus (RRV) impairs the biosynthesis of dipeptidyl peptidase IV (DPP IV), an important hydrolase in the digestion of dietary proline-rich proteins. We show that the enzyme activity of DPP IV was reduced, and that rearrangements of the protein occurred at the apical domain of the RRV-infected cells. Using pulse-chase experiments and cell surface immunoprecipitation, we have demonstrated that RRV infection did not affect the stability or apical targeting of DPP IV, but did induce a dramatic decrease in its biosynthesis. Using quantitative RT-PCR, we showed that RRV had no effect on the level of expression of DPP IV mRNA, suggesting that the observed decrease in the biosynthesis of the protein is related to an effect of the virus at the translational level.
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Affiliation(s)
- Isabelle Beau
- Institut National de la Santé et de la Recherche Médicale, Université Paris XI, UMR-S 756, Signalisation et Physiopathologie des Cellules Epithéliales, Faculté de Pharmacie, Châtenay-Malabry, F-92296 France
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Bugarcic A, Taylor JA. Rotavirus nonstructural glycoprotein NSP4 is secreted from the apical surfaces of polarized epithelial cells. J Virol 2006; 80:12343-9. [PMID: 17035333 PMCID: PMC1676281 DOI: 10.1128/jvi.01378-06] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
NSP4, a nonstructural glycoprotein encoded by rotavirus, is involved in the morphogenesis of virus particles in the endoplasmic reticulum of infected cells. NSP4 is also implicated in the pathophysiology of rotavirus-induced diarrhea by acting as an enterotoxin. To mediate enterotoxic effects in vivo, NSP4 must be secreted or released from rotavirus-infected cells in a soluble form; however, previous studies have indicated that NSP4 is a transmembrane glycoprotein localized within endomembrane compartments in infected cells. In this study, we examined the fate of NSP4 synthesized in Caco-2 cells infected with bovine rotavirus. Our studies reveal that NSP4 is actively secreted into the culture medium, preferentially from the infected-cell apical surface. The secretion of NSP4 is dramatically inhibited by brefeldin A and monensin, suggesting that a Golgi-dependent pathway is involved in release of the protein. In agreement with the proposed involvement of the Golgi apparatus during secretion, secreted NSP4 appears to undergo additional posttranslational modification compared to its cell-associated counterpart and is partially resistant to deglycosylation by endoglycosidase H. Our experiments identify a novel, soluble form of NSP4 secreted from virus-infected cells with the potential to carry out the enterotoxigenic role previously attributed to recombinant forms of the protein.
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Affiliation(s)
- Andrea Bugarcic
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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44
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Hayasaka D, Maeda K, Ennis FA, Terajima M. Increased permeability of human endothelial cell line EA.hy926 induced by hantavirus-specific cytotoxic T lymphocytes. Virus Res 2006; 123:120-7. [PMID: 16979772 DOI: 10.1016/j.virusres.2006.08.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 08/14/2006] [Accepted: 08/16/2006] [Indexed: 12/27/2022]
Abstract
Hantavirus infection causes two human diseases, hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. The typical feature of these diseases is increased permeability in microvascular beds in the kidneys and the lungs, respectively. The mechanism of capillary leakage, however, is not understood. Some evidence suggests that hantavirus disease pathogenesis is immunologically mediated by cytotoxic T lymphocytes and other immune cells in target organs producing inflammatory cytokines. In this study we examined the roles of virus-specific cytotoxic T lymphocytes in increased permeability of human endothelial cells infected with hantavirus. We used a human CD8(+) hantavirus-specific cytotoxic T lymphocyte line, 1A-E2, specific for the HLA-A24-restricted epitope in Sin Nombre and Puumala virus G2 protein, and the human endothelial cell line, EA.hy926 that expresses HLA-A24 molecule. The cytotoxic T lymphocyte line recognized and lysed target cells infected with Sin Nombre virus, and in transwell permeability assays increased permeability of EA.hy926 cell monolayer infected with Sin Nombre virus or recombinant adenovirus expressing the Sin Nombre virus G2 protein. These results suggest that cytotoxic T lymphocyte activity contribute to capillary leakage observed in patients with hantavirus pulmonary syndrome or hemorrhagic fever with renal syndrome.
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Affiliation(s)
- Daisuke Hayasaka
- Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
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45
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Molecular Virology of Enteric Viruses (with Emphasis on Caliciviruses). VIRUSES IN FOODS 2006:43-100. [PMCID: PMC7120911 DOI: 10.1007/0-387-29251-9_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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46
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Abstract
We review here recent advances in our knowledge on trafficking and assembly of rotavirus and rotaviral proteins in intestinal cells. Assembly of rotavirus has been extensively studied in nonpolarized kidney epithelial MA104 cells, where several data indicate that most if not all the steps of rotavirus assembly take place within the endoplasmic reticulum (ER) and that rotavirus is release upon cell lysis. We focus here on data obtained in intestinal cells that argue for another scheme of rotavirus assembly, where the final steps seem to take place outside the ER with an apically polarized release of rotavirus without significant cell lysis. One of the key observations made by different groups is that VP4 and other structural proteins interact substantially with specialized membrane microdomains enriched in cholesterol and sphingolipids termed rafts. In addition, recent data point to the fact that VP4 does not localize within the ER or the Golgi apparatus in infected intestinal cells. The mechanisms by which VP4, a cytosolic protein, may be targeted to the apical membrane in these cells and assembles with the other structural proteins are discussed. The identification of cellular proteins such as Hsp70, flotillin, rab5, PRA1 and cytoskeletal components that interact with VP4 may help to define an atypical polarized trafficking pathway to the apical membrane of intestinal cells that will be raft-dependent and by-pass the classical exocytic route.
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Affiliation(s)
- Polly Roy
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT UK
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47
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Benureau Y, Huet JC, Charpilienne A, Poncet D, Cohen J. Trypsin is associated with the rotavirus capsid and is activated by solubilization of outer capsid proteins. J Gen Virol 2005; 86:3143-3151. [PMID: 16227238 DOI: 10.1099/vir.0.81045-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The rotavirus capsid is made up of three concentric protein layers. The outer layer, consisting of VP7 and VP4, is lost during virus entry into the host cell. Rotavirus field isolates can be adapted to high-titre growth in tissue culture by treatment with trypsin and by supplementing the culture medium with trypsin, which cleaves VP4 into two fragments, VP8* and VP5*. It is known that protease inhibitors reduce the replication of rotavirus in vitro and in vivo and also diminish disease symptoms in a mouse model. To clarify the molecular basis of these observations, a series of assays were conducted on purified rotavirus particles grown in the presence of trypsin. Results of HPLC and mass spectrometry followed by N-terminal sequencing showed that viral particles contain molecules of trypsin. When associated with triple-layer particles (TLPs), trypsin is inactive and not accessible to protease inhibitors, such as aprotinin. When the outer layer is solubilized by calcium-chelating agents, VP5*, VP8* and VP7 are released and the associated trypsin is activated, allowing cleavage of the viral capsid proteins, as well as other exogenous proteins. It is shown that addition of trypsin inhibitors significantly reduces synthesis of viral mRNA and viral proteins in cells and has a major inhibitory effect if present when virus enters the cell. These data indicate that incorporation of trypsin into rotavirus particles may enhance its infectivity.
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Affiliation(s)
- Yann Benureau
- Virologie Moléculaire et Structurale, CNRS-INRA, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
| | - Jean Claude Huet
- Biochimie et Structure des Protéines, INRA, 78352 Jouy-en-Josas Cedex, France
| | - Annie Charpilienne
- Virologie Moléculaire et Structurale, CNRS-INRA, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
| | - Didier Poncet
- Virologie Moléculaire et Structurale, CNRS-INRA, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
| | - Jean Cohen
- Virologie Moléculaire et Structurale, CNRS-INRA, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
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48
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Ivanov AI, Nusrat A, Parkos CA. Endocytosis of the apical junctional complex: mechanisms and possible roles in regulation of epithelial barriers. Bioessays 2005; 27:356-65. [PMID: 15770686 DOI: 10.1002/bies.20203] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tight junctions (TJ) and adherens junctions (AJ) regulate cell-cell adhesion and barrier function of simple polarized epithelia. These junctions are positioned in the apical end of the lateral plasma membrane and form the so-called apical junctional complex (AJC). Although initially seen as purely structural features, the AJC is now known to play important roles in cell differentiation and proliferation. The AJC is a highly dynamic entity, undergoing rapid remodeling during normal epithelial morphogenesis and under pathologic conditions. There is growing evidence that remodeling of the AJC is mediated by internalization of junctional proteins. This review summarizes what is known about endocytic pathways, intracellular destinations and signaling cascades involved in internalization of AJC proteins. Potential biological roles for AJC endocytosis in maintaining functional apical junctions, reversible opening of epithelial barrier and disruption of intercellular adhesion are also discussed.
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Affiliation(s)
- Andrei I Ivanov
- Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Room 115, 615 Michael Street, Atlanta, GA 30322, USA.
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Chaïbi C, Cotte-Laffitte J, Sandré C, Esclatine A, Servin AL, Quéro AM, Géniteau-Legendre M. Rotavirus induces apoptosis in fully differentiated human intestinal Caco-2 cells. Virology 2005; 332:480-90. [PMID: 15680413 DOI: 10.1016/j.virol.2004.11.039] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 07/07/2004] [Accepted: 11/18/2004] [Indexed: 01/06/2023]
Abstract
Rotaviruses, which are the main cause of viral gastroenteritis in young children, induce structural and functional damages in infected mature enterocytes of the small intestine. To investigate a relationship between rotavirus infection and cell death by apoptosis, we used the human intestinal Caco-2 cell line. We demonstrated by several methods including TUNEL and ELISA detection of cytoplasmic histone-associated DNA fragments that the infection of fully differentiated Caco-2 cells by the RRV rotavirus strain induces apoptosis. Rotavirus infection leads to the loss of mitochondrial membrane potential and the release of cytochrome C from mitochondria. We showed that rotavirus-induced apoptosis was dependent of the multiplicity of infection and increased with time from 4 h to 24 h of infection. Flow cytometric analysis showed that DNA fragmentation occurs in productively infected cells, suggesting that rotavirus induces apoptosis by a direct mechanism. We also demonstrated that non-replicative RRV particles are not sufficient to induce apoptosis and viral gene expression seems required. Intracellular calcium plays a role in RRV-induced apoptosis because treatment with an intracellular calcium ion chelator (BAPTA-AM) partially inhibited apoptosis.
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Affiliation(s)
- Charlotte Chaïbi
- Institut National de la Santé et de la Recherche Médicale, U 510, Pathogènes et Fonctions des Cellules Epithéliales Polarisées, Faculté de Pharmacie, 5 rue J.B. Clément, 92290 Châtenay-Malabry, France
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50
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Nava P, López S, Arias CF, Islas S, González-Mariscal L. The rotavirus surface protein VP8 modulates the gate and fence function of tight junctions in epithelial cells. J Cell Sci 2004; 117:5509-19. [PMID: 15494377 DOI: 10.1242/jcs.01425] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Rotaviruses constitute a major cause of diarrhea in young mammals. Rotaviruses utilize different integrins as cell receptors, therefore upon their arrival to the intestinal lumen their integrin receptors will be hidden below the tight junction (TJ), on the basolateral membrane. Here we have studied whether the rotavirus outer capsid proteins are capable of opening the paracellular space sealed by the TJ. From the outermost layer of proteins of the rotavirus, 60 spikes formed of protein VP4 are projected. VP4 is essential for virus-cell interactions and is cleaved by trypsin into peptides VP5 and VP8. Here we found that when these peptides are added to confluent epithelial monolayers (Madin-Darby canine kidney cells), VP8 is capable of diminishing in a dose dependent and reversible manner the transepithelial electrical resistance. VP5 exerted no effect. VP8 can also inhibit the development of newly formed TJs in a Ca-switch assay. Treatment with VP8 augments the paracellular passage of non-ionic tracers, allows the diffusion of a fluorescent lipid probe and the apical surface protein GP135, from the luminal to the lateral membrane, and triggers the movement of the basolateral proteins Na+-K+-ATPase, alphanubeta3 integrin and beta1 integrin subunit, to the apical surface. VP8 generates a freeze-fracture pattern of TJs characterized by the appearance of loose end filaments, that correlates with an altered distribution of several TJ proteins. VP8 given orally to diabetic rats allows the enteral administration of insulin, thus indicating that it can be employed to modulate epithelial permeability.
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Affiliation(s)
- Porfirio Nava
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Mexico DF 07000, Mexico
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