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Bhat, Meenakshi; Toledo-Velasquez, David; Wang, Liying; Malanga, C. J.; Joseph, K. H.; Rojanasakul, Yon

doi:10.1023/a:1018906504944

Cited by 58 publications

(12 citation statements)

References 27 publications

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“…Similar reductions in the levels of ZO-1 and occludin were also observed upon treatment of Caco-2 cell layers with Staphylococcus aureus alpha-toxin, which permeabilizes cellular membrane and enables the influx of extracellular calcium ions into cells (59). Indeed, elevation of the intracellular Ca 2ϩ concentration due to ionomycin was shown to cause a drop in TEER (60)(61)(62). Translocation of the AC domain polypeptide across the cell membrane is itself accompanied by calcium influx, and in certain cell types the CyaA-generated cAMP can open the L-type calcium channels (63,64).…”

Section: Discussionmentioning

confidence: 58%

Bordetella pertussis Adenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

et al. 2018

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The airway epithelium restricts the penetration of inhaled pathogens into the underlying tissue and plays a crucial role in the innate immune defense against respiratory infections. The whooping cough agent, , adheres to ciliated cells of the human airway epithelium and subverts its defense functions through the action of secreted toxins and other virulence factors. We examined the impact of infection and of adenylate cyclase toxin-hemolysin (CyaA) action on the functional integrity of human bronchial epithelial cells cultured at the air-liquid interface (ALI). adhesion to the apical surface of polarized pseudostratified VA10 cell layers provoked a disruption of tight junctions and caused a drop in transepithelial electrical resistance (TEER). The reduction of TEER depended on the capacity of the secreted CyaA toxin to elicit cAMP signaling in epithelial cells through its adenylyl cyclase enzyme activity. Both purified CyaA and cAMP-signaling drugs triggered a decrease in the TEER of VA10 cell layers. Toxin-produced cAMP signaling caused actin cytoskeleton rearrangement and induced mucin 5AC production and interleukin-6 (IL-6) secretion, while it inhibited the IL-17A-induced secretion of the IL-8 chemokine and of the antimicrobial peptide beta-defensin 2. These results indicate that CyaA toxin activity compromises the barrier and innate immune functions ofinfected airway epithelia.

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Section: Discussionmentioning

confidence: 58%

Bordetella pertussis Adenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

et al. 2018

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“…The TEER values of the controls, an acellular scaffold and MRC-5 single culture, did not increase, maintaining baseline TEER measurements of ∼100 Ω cm 2 . Although human lung ex vivo TEER results are not available in the literature, ex vivo rabbit airway epithelium has been reported to be 260–320 Ω cm 2 for the trachea 29 and 266 Ω cm 2 for the bronchus. 30 Thus, the maximal TEER recorded in our 3D model are comparable to the data available for animal ex vivo TEERs.…”

Section: Resultsmentioning

confidence: 99%

Immunocompetent 3D Model of Human Upper Airway for Disease Modeling and In Vitro Drug Evaluation

et al. 2014

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The development of more complex in vitro models for the assessment of novel drugs and chemicals is needed because of the limited biological relevance of animal models to humans as well as ethical considerations. Although some human-cell-based assays exist, they are usually 2D, consist of single cell type, and have limited cellular and functional representation of the native tissue. In this study, we have used biomimetic porous electrospun scaffolds to develop an immunocompetent 3D model of the human respiratory tract comprised of three key cell types present in upper airway epithelium. The three cell types, namely, epithelial cells (providing a physical barrier), fibroblasts (extracellular matrix production), and dendritic cells (immune sensing), were initially grown on individual scaffolds and then assembled into the 3D multicell tissue model. The epithelial layer was cultured at the air–liquid interface for up to four weeks, leading to formation of a functional barrier as evidenced by an increase in transepithelial electrical resistance (TEER) and tight junction formation. The response of epithelial cells to allergen exposure was monitored by quantifying changes in TEER readings and by assessment of cellular tight junctions using immunostaining. It was found that epithelial cells cocultured with fibroblasts formed a functional epithelial barrier at a quicker rate than single cultures of epithelial cells and that the recovery from allergen exposure was also more rapid. Also, our data show that dendritic cells within this model remain viable and responsive to external stimulation as evidenced by their migration within the 3D construct in response to allergen challenge. This model provides an easy to assemble and physiologically relevant 3D model of human airway epithelium that can be used for studies aiming at better understanding lung biology, the cross-talk between immune cells, and airborne allergens and pathogens as well as drug delivery.

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“…2ϩ with 8 mM EGTA can reversibly increase the permeability of tracheal epithelia (36,37). Also, a brief apical application of H 2 O has been reported to transiently increase permeability of airway epithelia to macromolecules and DNA (38).…”

Section: The Basolateral Surface Is Accessible To Virus In Airway Epimentioning

confidence: 97%

Basolateral Localization of Fiber Receptors Limits Adenovirus Infection from the Apical Surface of Airway Epithelia

Walters

Grunst

Bergelson

et al. 1999

Journal of Biological Chemistry

334

304

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Recent identification of two receptors for the adenovirus fiber protein, coxsackie B and adenovirus type 2 and 5 receptor (CAR), and the major histocompatibility complex (MHC) Class I ␣-2 domain allows the molecular basis of adenoviral infection to be investigated. Earlier work has shown that human airway epithelia are resistant to infection by adenovirus. Therefore, we examined the expression and localization of CAR and MHC Class I in an in vitro model of well differentiated, ciliated human airway epithelia. We found that airway epithelia express CAR and MHC Class I. However, neither receptor was present in the apical membrane; instead, both were polarized to the basolateral membrane. These findings explain the relative resistance to adenovirus infection from the apical surface. In contrast, when the virus was applied to the basolateral surface, gene transfer was much more efficient because of an interaction of adenovirus fiber with its receptors. In addition, when the integrity of the tight junctions was transiently disrupted, apically applied adenovirus gained access to the basolateral surface and enhanced gene transfer. These data suggest that the receptors required for efficient infection are not available on the apical surface, and interventions that allow access to the basolateral space where fiber receptors are located increase gene transfer efficiency.The mechanism of infection by type 2 and type 5 adenovirus has been extensively studied. However, most of the knowledge on adenoviral infection has been obtained from studies done on immortalized cell lines. The first steps in adenovirus infection are thought to involve primarily two proteins in the capsid, fiber and penton base (1-3). The fiber protein is important for binding to a high affinity fiber receptor. In a human oral epidermoid carcinoma cell line (KB cells), A549 cells, and HeLa cells, this receptor is thought to be present in the range of 3,000 -10,000 receptors/cell (4 -6). NIH 3T3 cells, which are resistant to adenovirus infection, have less than 100 receptors/ cell (7). After binding to the fiber receptor, penton base interaction with ␣ V ␤ 3 and ␣ V ␤ 5 integrins facilitates internalization via receptor-mediated endocytosis (2,8,9). The acidic pH the virus encounters in the endosome may trigger a conformational change that releases the virus into the cytoplasm (10 -12) and allows the adenovirus capsid to travel to the nucleus (2, 13). Then viral proteins and DNA bind to the nuclear pore complex, capsid disassembly continues, and DNA enters the nucleus accompanied by DNA-associated protein 7 (1, 2, 14). These studies have concluded that a high affinity fiber receptor is required for binding and infection and that an ␣ V ␤ integrin acts as a co-receptor.We and others (15-22) have found infection of ciliated airway epithelia by adenovirus to be inefficient. In an in vitro model of human airway epithelia, we found that unlike infections of HeLa cells adenovirus infection of ciliated airway epithelia was quite limited and that which did occur w...

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Untitled

Cited by 58 publications

References 27 publications

Bordetella pertussis Adenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

Bordetella pertussis Adenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

Immunocompetent 3D Model of Human Upper Airway for Disease Modeling and In Vitro Drug Evaluation

Basolateral Localization of Fiber Receptors Limits Adenovirus Infection from the Apical Surface of Airway Epithelia

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