scholarly journals Candida albicans-Cell Interactions Activate Innate Immune Defense in Human Palate Epithelial Primary Cells via Nitric Oxide (NO) and β-Defensin 2 (hBD-2)

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 707 ◽  
Author(s):  
Ana Regina Casaroto ◽  
Rafaela Alves da Silva ◽  
Samira Salmeron ◽  
Maria Lúcia Rubo de Rezende ◽  
Thiago José Dionísio ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Immune Response ◽  
Candida Albicans ◽  
Epithelial Cells ◽  
Immune Defense ◽  
Innate Immune ◽  
Oral Epithelium ◽  
No Production ◽  
Fungal Invasion ◽  
Vitro Effect

The presence of Candida albicans in the biofilm underlying the dental prosthesis is related to denture stomatitis (DS), an inflammatory reaction of the oral mucosa. The oral epithelium, a component of the innate immune response, has the ability to react to fungal invasion. In this study, we evaluated the in vitro effect of viable C. albicans on the apoptosis, nitric oxide (NO) production, and β-defensin 2 (hBD-2) expression and production of human palate epithelial cells (HPECs). We further determined whether or not these effects were correlated with fungal invasion of epithelial cells. Interaction between HPEC primary culture and C. albicans was obtained through either direct or indirect cell–cell contact with a supernatant from a hyphal fungus. We found that the hyphae supernatants were sufficient to induce slight HPEC apoptosis, which occurred prior to the activation of the specific mechanisms of epithelial defense. The epithelial defense responses were found to occur via NO and antimicrobial peptide hBD-2 production only during direct contact between C. albicans and HPECs and coincided with the fungus’s intraepithelial invasion. However, although the hBD-2 levels remained constant in the HPEC supernatants over time, the NO release and hBD-2 gene expression were reduced at a later time (10 h), indicating that the epithelial defense capacity against the fungal invasion was not maintained in later phases. This aspect of the immune response was associated with increased epithelial invasion and apoptosis maintenance.

scholarly journals Vitamin D-Mediated Induction of Innate Immunity in Gingival Epithelial Cells

2011 ◽  
Vol 79 (6) ◽  
pp. 2250-2256 ◽  
Author(s):  
Laura McMahon ◽  
Kyell Schwartz ◽  
Ozlem Yilmaz ◽  
Eleith Brown ◽  
Lisa K. Ryan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Immune Response ◽  
Antibacterial Activity ◽  
Epithelial Cells ◽  
Innate Immune Response ◽  
Three Dimensional ◽  
Immune Defense ◽  
Innate Immune ◽  
Innate Immune Defense ◽  
Gingival Epithelial Cells

ABSTRACTHuman gingival epithelial cells (GEC) produce peptides, such as β-defensins and the cathelicidin LL-37, that are both antimicrobial and that modulate the innate immune response. In myeloid and airway epithelial cells, the active form of vitamin D3[1,25(OH)2D3] increases the expression and antibacterial activity of LL-37. To examine the activity of vitamin D on the innate immune defense of the gingival epithelium, cultured epithelial cells were treated with either 10−8M 1,25(OH)2D3or ethanol for up to 24 h. A time-dependent induction of LL-37 mRNA up to 13-fold at 24 h in both standard monolayer and three-dimensional cultures was observed. Induction of the vitamin D receptor and the 1-α-hydroxylase genes was also observed. The hydroxylase was functional, as LL-37 induction was observed in response to stimulation by 25(OH)D3. Through microarray analysis of other innate immune genes, CD14 expression increased 4-fold, and triggering receptor expressed on myeloid cells-1 (TREM-1) was upregulated 16-fold after 24 h of treatment with 1,25(OH)2D3. TREM-1 is a pivotal amplifier of the innate immune response in macrophages, leading to increased production by inflammatory response genes. Activation of TREM-1 on the GEC led to an increase in interleukin-8 (IL-8) mRNA levels. Incubation of three-dimensional cultures with 1,25(OH)2D3led to an increase in antibacterial activity against the periodontal pathogenAggregatibacter actinomycetemcomitanswhen the bacteria were added to the apical surface. This study is the first to demonstrate the effect of vitamin D on antibacterial defense of oral epithelial cells, suggesting that vitamin D3could be utilized to enhance the innate immune defense in the oral cavity.

scholarly journals HSP90 function is required for T2R bitter taste receptor nitric oxide production and innate immune responses in human airway epithelial cells and macrophages

2021 ◽  
Author(s):  
Ryan M Carey ◽  
Benjamin M Hariri ◽  
Nithin D Adappa ◽  
James N Palmer ◽  
Robert J Lee
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Bitter Taste ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
No Production ◽  
Airway Epithelial ◽  
Primary Monocyte ◽  
Hsp 90

Bitter taste receptors (T2Rs) are G protein-coupled receptors (GPCRs) expressed in various cell types including ciliated airway epithelial cells and macrophages. T2Rs in these two airway innate immune cell types are activated by bitter products, including those secreted by common airway pathogens like Pseudomonas aeruginosa, leading to Ca2+-dependent activation of endothelial nitric oxide (NO) synthase (eNOS). NO production leads to enhanced mucociliary clearance and direct antibacterial effects by ciliated epithelial cells as well as increased phagocytosis by macrophages. Using biochemistry and live cell imaging, we explored the role of heat shock protein 90 (HSP90) in regulating T2R-dependent NO pathways in primary sinonasal epithelial cells, primary monocyte-derived macrophages, and a human bronchiolar cell line (H441). We used immunofluorescence to show that H441 cells express eNOS and certain T2Rs and that the bitterant denatonium benzoate activates NO production in an HSP90-dependent manner in cells grown either as submerged cultures and at air liquid interface. In primary sinonasal epithelial cells, we determined that HSP-90 inhibition reduces T2R-stimulated NO production and ciliary beating which are crucial for pathogen clearance. In primary monocyte-derived macrophages, we found that HSP-90 is integral to T2R-stimulated NO production and phagocytosis of FITC-labeled Escherichia coli and pHrodo-Staphylococcus aureus. Our study demonstrates that HSP90 serves an innate immune role by regulating NO production downstream of T2R signaling by augmenting eNOS activation without impairing upstream calcium signaling. These findings suggest that HSP90 plays an important role in airway antibacterial innate immunity and may be an important target in airway diseases like chronic rhinosinusitis, asthma, or cystic fibrosis.

scholarly journals A Biphasic Innate Immune MAPK Response Discriminates between the Yeast and Hyphal Forms of Candida albicans in Epithelial Cells

2010 ◽  
Vol 8 (3) ◽  
pp. 225-235 ◽  
Author(s):  
David L. Moyes ◽  
Manohursingh Runglall ◽  
Celia Murciano ◽  
Chengguo Shen ◽  
Deepa Nayar ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Innate Immune

Innate immune response in CF airway epithelia: hyperinflammatory?

2006 ◽  
Vol 291 (2) ◽  
pp. C218-C230 ◽  
Author(s):  
Terry E. Machen
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Innate Immune Response ◽  
Cellular Signaling ◽  
Basolateral Membrane ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Intracellular Ca

The lack of functional cystic fibrosis (CF) transmembrane conductance regulator (CFTR) in the apical membranes of CF airway epithelial cells abolishes cAMP-stimulated anion transport, and bacteria, eventually including Pseudomonas aeruginosa, bind to and accumulate in the mucus. Flagellin released from P. aeruginosa triggers airway epithelial Toll-like receptor 5 and subsequent NF-κB signaling and production and release of proinflammatory cytokines that recruit neutrophils to the infected region. This response has been termed hyperinflammatory because so many neutrophils accumulate; a response that damages CF lung tissue. We first review the contradictory data both for and against the idea that epithelial cells exhibit larger-than-normal proinflammatory signaling in CF compared with non-CF cells and then review proposals that might explain how reduced CFTR function could activate such proinflammatory signaling. It is concluded that apparent exaggerated innate immune response of CF airway epithelial cells may have resulted not from direct effects of CFTR on cellular signaling or inflammatory mediator production but from indirect effects resulting from the absence of CFTRs apical membrane channel function. Thus, loss of Cl−, HCO3−, and glutathione secretion may lead to reduced volume and increased acidification and oxidation of the airway surface liquid. These changes concentrate proinflammatory mediators, reduce mucociliary clearance of bacteria and subsequently activate cellular signaling. Loss of apical CFTR will also hyperpolarize basolateral membrane potentials, potentially leading to increases in cytosolic [Ca2+], intracellular Ca2+, and NF-κB signaling. This hyperinflammatory effect of CF on intracellular Ca2+and NF-κB signaling would be most prominently expressed during exposure to both P. aeruginosa and also endocrine, paracrine, or nervous agonists that activate Ca2+signaling in the airway epithelia.

scholarly journals Bordetella pertussisAdenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Shakir Hasan ◽  
Nikhil Nitin Kulkarni ◽  
Arni Asbjarnarson ◽  
Irena Linhartova ◽  
Radim Osicka ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelium ◽  
Immune Defense ◽  
Innate Immune ◽  
Camp Signaling ◽  
Apical Surface ◽  
Bronchial Epithelial ◽  
Content Type ◽  
Functional Integrity ◽  
Cell Layers

ABSTRACTThe 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,Bordetella pertussis, 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 ofB. pertussisinfection and of adenylate cyclase toxin-hemolysin (CyaA) action on the functional integrity of human bronchial epithelial cells cultured at the air-liquid interface (ALI).B. pertussisadhesion 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 ofBordetella-infected airway epithelia.

Bovine mammary epithelial cells, initiators of innate immune responses to mastitis

2005 ◽  
Vol 45 (8) ◽  
pp. 757 ◽  
Author(s):  
C. Gray ◽  
Y. Strandberg ◽  
L. Donaldson ◽  
R. L. Tellam
Keyword(s):  
Immune Response ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Vital Role ◽  
Mammary Epithelial ◽  
Innate Immune ◽  
Mammary Tissue ◽  
Effector Cells ◽  
Bovine Mammary Epithelial Cells

Innate immunity plays a vital role in the protection of the bovine mammary gland against mastitis. Until recently, the migration of effector cells such as neutrophils and monocytes into the mammary gland was thought to provide the only defence against invading pathogens. However, mammary epithelial cells may also play an important role in the immune response, contributing to the innate defence of the mammary tissue through secretion of antimicrobial peptides and attraction of circulating immune effector cells. This paper reviews the innate immune pathways in mammary epithelial cells and examines their role in the initiation of an innate immune response to Gram-positive and Gram-negative bacteria.

scholarly journals TIFA Signaling in Gastric Epithelial Cells Initiates the cag Type 4 Secretion System-Dependent Innate Immune Response to Helicobacter pylori Infection

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Alevtina Gall ◽  
Ryan G. Gaudet ◽  
Scott D. Gray-Owen ◽  
Nina R. Salama
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Inflammatory Response ◽  
Secretion System ◽  
Innate Immune ◽  
Gastric Ulcers ◽  
Bacterial Clearance ◽  
Gastric Epithelial Cells ◽  
H Pylori

ABSTRACT Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, causing inflammation which, in some cases, leads to gastric ulcers and cancer. The clinical outcome of infection depends on a complex interplay of bacterial, host genetic, and environmental factors. Although H. pylori is recognized by both the innate and adaptive immune systems, this rarely results in bacterial clearance. Gastric epithelial cells are the first line of defense against H. pylori and alert the immune system to bacterial presence. Cytosolic delivery of proinflammatory bacterial factors through the cag type 4 secretion system ( cag -T4SS) has long been appreciated as the major mechanism by which gastric epithelial cells detect H. pylori . Classically attributed to the peptidoglycan sensor NOD1, recent work has highlighted the role of NOD1-independent pathways in detecting H. pylori ; however, the bacterial and host factors involved have remained unknown. Here, we show that bacterially derived heptose-1,7-bisphosphate (HBP), a metabolic precursor in lipopolysaccharide (LPS) biosynthesis, is delivered to the host cytosol through the cag -T4SS, where it activates the host tumor necrosis factor receptor-associated factor (TRAF)-interacting protein with forkhead-associated domain (TIFA)-dependent cytosolic surveillance pathway. This response, which is independent of NOD1, drives robust NF-κB-dependent inflammation within hours of infection and precedes NOD1 activation. We also found that the CagA toxin contributes to the NF-κB-driven response subsequent to TIFA and NOD1 activation. Taken together, our results indicate that the sequential activation of TIFA, NOD1, and CagA delivery drives the initial inflammatory response in gastric epithelial cells, orchestrating the subsequent recruitment of immune cells and leading to chronic gastritis. IMPORTANCE H. pylori is a globally prevalent cause of gastric and duodenal ulcers and cancer. H. pylori antibiotic resistance is rapidly increasing, and a vaccine remains elusive. The earliest immune response to H. pylori is initiated by gastric epithelial cells and sets the stage for the subsequent immunopathogenesis. This study revealed that host TIFA and H. pylori -derived HBP are critical effectors of innate immune signaling that account for much of the inflammatory response to H. pylori in gastric epithelial cells. HBP is delivered to the host cell via the cag -T4SS at a time point that precedes activation of the previously described NOD1 and CagA inflammatory pathways. Manipulation of the TIFA-driven immune response in the host and/or targeting of ADP-heptose biosynthesis enzymes in H. pylori may therefore provide novel strategies that may be therapeutically harnessed to achieve bacterial clearance.

Nitric oxide attenuates epithelial-mesenchymal transition in alveolar epithelial cells

2007 ◽  
Vol 293 (1) ◽  
pp. L212-L221 ◽  
Author(s):  
Shilpa Vyas-Read ◽  
Philip W. Shaul ◽  
Ivan S. Yuhanna ◽  
Brigham C. Willis
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Epithelial Cells ◽  
Epithelial Mesenchymal Transition ◽  
Alveolar Epithelial Cells ◽  
No Production ◽  
Mesenchymal Transition ◽  
Alveolar Epithelial ◽  
Oxide Synthase ◽  
Tgf Β1

Patients with interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF) and bronchopulmonary dysplasia (BPD), suffer from lung fibrosis secondary to myofibroblast-mediated excessive ECM deposition and destruction of lung architecture. Transforming growth factor (TGF)-β1 induces epithelial-mesenchymal transition (EMT) of alveolar epithelial cells (AEC) to myofibroblasts both in vitro and in vivo. Inhaled nitric oxide (NO) attenuates ECM accumulation, enhances lung growth, and decreases alveolar myofibroblast number in experimental models. We therefore hypothesized that NO attenuates TGF-β1-induced EMT in cultured AEC. Studies of the capacity for endogenous NO production in AEC revealed that endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) are expressed and active in AEC. Total NOS activity was 1.3 pmol·mg protein−1·min−1 with 67% derived from eNOS. TGF-β1 (50 pM) suppressed eNOS expression by more than 60% and activity by 83% but did not affect iNOS expression or activity. Inhibition of endogenous NOS with l-NAME led to spontaneous EMT, manifested by increased α-smooth muscle actin (α-SMA) expression and a fibroblast-like morphology. Provision of exogenous NO to TGF-β1-treated AEC decreased stress fiber-associated α-SMA expression and decreased collagen I expression by 80%. NO-treated AEC also retained an epithelial morphology and expressed increased lamellar protein, E-cadherin, and pro-surfactant protein B compared with those treated with TGF-β alone. These findings indicate that NO serves a critical role in preserving an epithelial phenotype and in attenuating EMT in AEC. NO-mediated regulation of AEC fate may have important implications in the pathophysiology and treatment of diseases such as IPF and BPD.

scholarly journals Candida albicans Activation of Human Monocytes Toward M2 Profile is Reversed by Amphotericin B and Fluconazole

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Icely PA ◽  
◽  
Vigezzi C ◽  
Rodriguez E ◽  
Miró MS ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Immune Cells ◽  
Fungal Growth ◽  
Antifungal Drugs ◽  
Arginase Activity ◽  
Intrinsic Activity ◽  
No Production ◽  
Human Monocytes

Phagocytes, including monocytes/macrophages, play an important role in the host defense during Candida albicans infections. In the L-arginine metabolism, the balance between the activation of two enzymes, inducible Nitric Oxide Synthase (iNOS) and arginase, promotes in the macrophages two alternative metabolic states, while M1 profile is related with host protection, M2 favored the fungal growth and evasion. Our aim was to evaluate the effect of Amphotericin B (AMB) and Fluconazole (FLC) on polarization of human monocytes to M2 profile induced by C. albicans. The human monocytic (Mo) cell line U937 was co-cultured with viable yeast of C. albicans, or Lipopolysaccharides (LPS) or Phorbol-12-myristate-13-acetate (PMA). Nitric Oxide (NO), cytokines production and arginase activity were evaluated. The effect of AMB or FLC on these metabolic pathways in immune cells and on fungus intrinsic arginase activity was studied. C. albicans inhibits NO production in human-monocyte and induces strong host arginase activity (p<0.0001). AMB and FLC inhibited C. albicansinduced arginase activity in immune cells (p<0.001), reaching a percentage of inhibition of 90% for AMB and 78% for FLC. Arginase intrinsic activity of the fungus was blocked by nor-NOHA (arginase inhibitor) and AMB (p<0.05). These results show that C. albicans drives human Mo toward M2 profile and that both antifungal drugs evaluated have the ability to revert C. albicans-induced M2 profile. In a relevant manner, it also provides data about additional effect of AMB as inhibitor of C. albicans endogenous arginase activity. Here in we provide new evidence for the effect of these drugs over the immune cells and the yeast.

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