scholarly journals Transcriptional Responses of Candida albicans to Epithelial and Endothelial Cells

2009 ◽  
Vol 8 (10) ◽  
pp. 1498-1510 ◽  
Author(s):  
Hyunsook Park ◽  
Yaoping Liu ◽  
Norma Solis ◽  
Joshua Spotkov ◽  
Jessica Hamaker ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Candida Albicans ◽  
Epithelial Cells ◽  
Multiple Stressors ◽  
Cell Damage ◽  
Host Cells ◽  
Epithelial Cell Line ◽  
Transcriptional Responses ◽  
Oral Epithelial

ABSTRACT Candida albicans interacts with oral epithelial cells during oropharyngeal candidiasis and with vascular endothelial cells when it disseminates hematogenously. We set out to identify C. albicans genes that govern interactions with these host cells in vitro. The transcriptional response of C. albicans to the FaDu oral epithelial cell line and primary endothelial cells was determined by microarray analysis. Contact with epithelial cells caused a decrease in transcript levels of genes related to protein synthesis and adhesion, whereas contact with endothelial cells did not significantly influence any specific functional category of genes. Many genes whose transcripts were increased in response to either host cell had not been previously characterized. We constructed mutants with homozygous insertions in 22 of these uncharacterized genes to investigate their function during host-pathogen interaction. By this approach, we found that YCK2, VPS51, and UEC1 are required for C. albicans to cause normal damage to epithelial cells and resist antimicrobial peptides. YCK2 is also necessary for maintenance of cell polarity. VPS51 is necessary for normal vacuole formation, resistance to multiple stressors, and induction of maximal endothelial cell damage. UEC1 encodes a unique protein that is required for resistance to cell membrane stress. Therefore, some C. albicans genes whose transcripts are increased upon contact with epithelial or endothelial cells are required for the organism to damage these cells and withstand the stresses that it likely encounters during growth in the oropharynx and bloodstream.

scholarly journals Candida albicans Ecm33p Is Important for Normal Cell Wall Architecture and Interactions with Host Cells

2006 ◽  
Vol 5 (1) ◽  
pp. 140-147 ◽  
Author(s):  
Raquel Martinez-Lopez ◽  
Hyunsook Park ◽  
Carter L. Myers ◽  
Concha Gil ◽  
Scott G. Filler
Keyword(s):  
Endothelial Cells ◽  
Cell Wall ◽  
Candida Albicans ◽  
Epithelial Cells ◽  
Normal Cell ◽  
Cell Wall Integrity ◽  
Host Cells ◽  
Epithelial Cell Line ◽  
Oral Epithelial ◽  
Cell Wall Architecture

ABSTRACT Candida albicans ECM33 encodes a glycosylphosphatidylinositol-linked cell wall protein that is important for cell wall integrity. It is also critical for normal virulence in the mouse model of hematogenously disseminated candidiasis. To identify potential mechanisms through which Ecm33p contributes to virulence, we investigated the interactions of C. albicans ecm33Δ mutants with endothelial cells and the FaDu oral epithelial cell line in vitro. The growth rate of blastospores of strains containing either one or no intact copies of ECM33 was 50% slower than that of strains containing two intact copies of ECM33. However, all strains germinated at the same rate, forming similar-length hyphae on endothelial cells and oral epithelial cells. Strains containing either one or no intact copies of ECM33 had modestly reduced adherence to both types of host cells, and a markedly reduced capacity to invade and damage these cells. Saccharomyces cerevisiae expressing C. albicans ECM33 did not adhere to or invade epithelial cells, suggesting that Ecm33p by itself does not act as an adhesin or invasin. Examination of ecm33Δ mutants by transmission electron microscopy revealed that the cell wall of these strains had an abnormally electron-dense outer mannoprotein layer, which may represent a compensatory response to reduced cell wall integrity. The hyphae of these mutants also had aberrant surface localization of the adhesin Als1p. Collectively, these results suggest that Ecm33p is required for normal cell wall architecture as well as normal function and expression of cell surface proteins in C. albicans.

scholarly journals Calprotectin Expression In Vitro by Oral Epithelial Cells Confers Resistance to Infection by Porphyromonas gingivalis

2001 ◽  
Vol 69 (7) ◽  
pp. 4242-4247 ◽  
Author(s):  
K. Nisapakultorn ◽  
K. F. Ross ◽  
M. C. Herzberg
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Calcium Binding ◽  
Periodontal Diseases ◽  
Epithelial Cell Line ◽  
Transfected Cells ◽  
Cell Rounding ◽  
Oral Epithelial

ABSTRACT Calprotectin, an S100 calcium-binding protein with broad-spectrum antimicrobial activity in vitro, is expressed in neutrophils, monocytes, and gingival keratinocytes. In periodontitis, calprotectin appears upregulated and is detected at higher levels in gingival crevicular fluid and tissue specimens. How calprotectin contributes to the pathogenesis of periodontal diseases is unknown. To isolate the effects of calprotectin, a calprotectin-negative oral epithelial cell line was transfected with calprotectin genes to enable expression.Porphyromonas gingivalis was permitted to bind and invade transfected cells expressing calprotectin and sham transfectants. Rates of invasion into both cell lines were compared using the antibiotic protection assay. Transfected cells expressing calprotectin showed 40 to 50% fewer internalized P. gingivalis than sham transfectants. Similarly, binding to calprotectin expressing cells was reduced approximately twofold at all time points (15, 30, 45, and 60 min) as estimated by immunofluorescence analysis. Independent of invasion, however, prolonged exposure to P. gingivalisinduced epithelial cell rounding and detachment from the substratum. These morphological changes were delayed, however, in cells expressing calprotectin. Using P. gingivalis protease-deficient mutants, we found that Arg-gingipain and Lys-gingipain contributed to epithelial cell rounding and detachment. In conclusion, expression of calprotectin appears to protect epithelial cells in culture against binding and invasion by P. gingivalis. In addition, cells expressing calprotectin are more resistant to detachment mediated by Arg-gingipain and Lys-gingipain. In periodontal disease, calprotectin may augment both the barrier protection and innate immune functions of the gingival epithelium to promote resistance to P. gingivalis infection.

scholarly journals Relationship between Candida albicans Virulence during Experimental Hematogenously Disseminated Infection and Endothelial Cell Damage In Vitro

2004 ◽  
Vol 72 (1) ◽  
pp. 598-601 ◽  
Author(s):  
Angela A. Sanchez ◽  
Douglas A. Johnston ◽  
Carter Myers ◽  
John E. Edwards ◽  
Aaron P. Mitchell ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Candida Albicans ◽  
Endothelial Cell ◽  
Cell Damage ◽  
Endothelial Cell Damage ◽  
Disseminated Infection ◽  
Lethal Infection ◽  
Cell Lining ◽  
Wild Type Parent

ABSTRACT Candida albicans must penetrate the endothelial cell lining of the vasculature to invade the deep tissues during a hematogenously disseminated infection. We compared 27 C. albicans mutants with their wild-type parent for their capacity to damage endothelial cells in vitro and cause a lethal infection in mice following tail vein inoculation. Of 10 mutants with significantly impaired capacity to damage endothelial cells, all had attenuated virulence. Therefore, the endothelial cell damage assay can be used as a screen to identify some virulence factors relevant to hematogenously disseminated candidiasis.

scholarly journals Role of Shiga Toxins in Cytotoxicity and Immunomodulatory Effects of Escherichia coli O157:H7 during Host-Bacterial Interactions in vitro

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 48 ◽  
Author(s):  
Bruballa ◽  
Shiromizu ◽  
Bernal ◽  
Pineda ◽  
Sabbione ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Time Course ◽  
Cell Damage ◽  
Enterohemorrhagic Escherichia Coli ◽  
Host Cells ◽  
Epithelial Cell Line ◽  
Bacterial Survival ◽  
E Coli ◽  
Clinical Conditions

Enterohemorrhagic Escherichia coli (EHEC) strains are food-borne pathogens that can cause different clinical conditions. Shiga toxin 2a and/or 2c (Stx2)-producing E. coli O157:H7 is the serotype most frequently associated with severe human disease. In this work we analyzed the hypothesis that host cells participate in Stx2 production, cell damage, and inflammation during EHEC infection. With this aim, macrophage-differentiated THP-1 cells and the intestinal epithelial cell line HCT-8 were incubated with E. coli O157:H7. A time course analysis of cellular and bacterial survival, Stx2 production, stx2 transcription, and cytokine secretion were analyzed in both human cell lines. We demonstrated that macrophages are able to internalize and kill EHEC. Simultaneously, Stx2 produced by internalized bacteria played a major role in macrophage death. In contrast, HCT-8 cells were completely resistant to EHEC infection. Besides, macrophages and HCT-8 infected cells produce IL-1β and IL-8 inflammatory cytokines, respectively. At the same time, bacterial stx2-specific transcripts were detected only in macrophages after EHEC infection. The interplay between bacteria and host cells led to Stx production, triggering of inflammatory response and cell damage, all of which could contribute to a severe outcome after EHEC infections.

scholarly journals Activation of oral epithelial EphA2-EFGR signaling by Candida albicans virulence factors

2018 ◽  
Author(s):  
Marc Swidergall ◽  
Norma V. Solis ◽  
Nicolas Millet ◽  
Manning Y. Huang ◽  
Jianfeng Lin ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Inflammatory Response ◽  
Virulence Factors ◽  
Growth Factor Receptor ◽  
Host Cells ◽  
Cell Receptors ◽  
Proinflammatory Mediators ◽  
Epidermal Growth

AbstractDuring oropharyngeal candidiasis (OPC), Candida albicans invades and damages oral epithelial cells, which respond by producing proinflammatory mediators that recruit phagocytes to foci of infection. The ephrin type-A receptor 2 (EphA2) detects β-glucan and plays a central role in stimulating epithelial cells to release proinflammatory mediators during OPC. The epidermal growth factor receptor (EGFR) also interacts with C. albicans and is known to be activated by the Als3 adhesin/invasin and the Ece1/Candidalysin pore-forming toxin. Here, we investigated the interactions among EphA2, EGFR, Als3 and Ece1/Candidalysin during OPC. We found that Als3 and Ece1/Candidalysin function in the same pathway to damage epithelial cells in vitro. They also work together to cause OPC in mice. EGFR and EphA2 constitutively associate with each other as part of a physical complex and are mutually dependent for C. albicans-induced activation. In vitro, either Als3 or Ece1/Candidalysin is required for C. albicans to activate EGFR, sustain EphA2 activation, and stimulate epithelial cells to secrete CXCL8/IL-8 and CCL20. In the mouse model of OPC, Ece1/Candidalysin alone activates EGFR and induces CXCL1/KC and CCL20 production. Ece1/Candidalysin is also necessary for the production of IL-1α and IL-17A independently of Als3 and EGFR. These results delineate the complex interplay between host cell receptors and C. albicans virulence factors during the induction of OPC and the resulting oral inflammatory response.Author summaryOropharyngeal candidiasis occurs when the fungus Candida albicans proliferates in the mouth. The disease is characterized by fungal invasion of the superficial epithelium and a localized inflammatory response. Two C. albicans virulence factors contribute to the pathogenesis of OPC, Als3 which enables the organisms to adhere to and invade host cells and Ece1/Candidalysin which is pore-forming toxin that damages host cells. Two epithelial cell receptors, ephrin type-A receptor 2 (EphA2) and the epidermal growth factor receptor (EGFR) are activated by C. albicans. Here, we show that EphA2 and EGFR form part of complex and that each receptor is required to activate the other. Als3 and Ece1/Candidalysin function in the same pathway to damage epithelial cells. In isolated epithelial cells, both of these virulence factors activate EphA2 and EGFR, and stimulate the production of inflammatory mediators. In the mouse model of OPC, Ece1/Candidalysin elicits of a subset of the oral inflammatory response. Of the cytokines and chemokines induced by this toxin, some require the activation of EGFR while others are induced independently of EGFR. This work provides a deeper understanding of the interactions among C. albicans virulence factors and host cell receptors during OPC.

scholarly journals Potential Suppressive Effect of Nicotine on the Inflammatory Response in Oral Epithelial Cells: An In Vitro Study

2021 ◽  
Vol 18 (2) ◽  
pp. 483
Author(s):  
Na An ◽  
Jasmin Holl ◽  
Xuekui Wang ◽  
Marco Aoqi Rausch ◽  
Oleh Andrukhov ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Periodontal Diseases ◽  
Suppressive Effect ◽  
Cell Surface Expression ◽  
Epithelial Cell Line ◽  
Oral Epithelial Cells ◽  
Tnf Α ◽  
Oral Epithelial ◽  
The Impact

Smoking is a well-recognized risk factor for oral mucosal and periodontal diseases. Nicotine is an important component of cigarette smoke. This study aims to investigate the impact of nicotine on the viability and inflammatory mediator production of an oral epithelial cell line in the presence of various inflammatory stimuli. Oral epithelial HSC-2 cells were challenged with nicotine (10−8–10−2 M) for 24 h in the presence or absence of Porphyromonas gingivalis lipopolysaccharide (LPS, 1 µg/mL) or tumor necrosis factor (TNF)-α (10−7 M) for 24 h. The cell proliferation/viability was determined by MTT assay. Gene expression of interleukin (IL)-8, intercellular adhesion molecule (ICAM)-1, and β-defensin was assayed by qPCR. The production of IL-8 protein and cell surface expression of ICAM-1 was assessed by ELISA and flow cytometry, respectively. Proliferation/viability of HSC-2 cells was unaffected by nicotine at concentrations up to 10−3 M and inhibited at 10−2 M. Nicotine had no significant effect on the basal expression of IL-8, ICAM-1, and β-defensin. At the same time, it significantly diminished P. gingivalis LPS or the TNF-α-induced expression levels of these factors. Within the limitations of this study, the first evidence was provided in vitro that nicotine probably exerts a suppressive effect on the production of inflammatory mediators and antimicrobial peptides in human oral epithelial cells.

scholarly journals Candida albicans Secreted Aspartic Protease 7 is Essential for Damage of Human Oral Epithelial Cells

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Yang HP ◽  
◽  
Tsang PCS ◽  
Pow EHN ◽  
Lam OLT ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Mutant Strain ◽  
Tissue Damage ◽  
Wide Spectrum ◽  
Host Cells ◽  
Wild Type ◽  
Oral Epithelial Cells ◽  
Disruption Method ◽  
Oral Epithelial

Aims: Candida albicans is an important human fungal pathogen in clinical settings. It possesses a wide spectrum of virulence traits, including but not limited to the production of Secreted Aspartic Proteases (SAPs), to invade host cells under predisposing conditions. The aims of the present study were to investigate the functional role of C. albicans SAP7 in invasion ability. Methods: The present study was carried out to construct C. albicans sap7Δ/Δ mutant strain using a PCR-based gene disruption method. The behaviors of this SAP7 knockout strain was evaluated and compared with the wild type and SAP7 complemented strains between human oral epithelial cells with respect to endocytosis, invasion, and tissue damage. Results: Compared with the wild type C. albicans strain, a 52% reduction in the endocytosis of the sap7Δ/Δ mutant strain by oral epithelial cells was observed, as well as a 25% attenuation of internalization, and a 27% reduction of tissue damage (P<0.05). Conclusion: Our data clearly demonstrates that C. albicans SAP7 contributes to tissue invasion into human oral epithelial cells which warrant further investigations as potential targets for antifungal interventions.

scholarly journals Novel Aggregation Properties of Candida albicans Secreted Aspartyl Proteinase Sap6 Mediate Virulence in Oral Candidiasis

2015 ◽  
Vol 83 (7) ◽  
pp. 2614-2626 ◽  
Author(s):  
Rohitashw Kumar ◽  
Darpan Saraswat ◽  
Swetha Tati ◽  
Mira Edgerton
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Oral Candidiasis ◽  
Oral Microbiome ◽  
Proteinase Activity ◽  
Adhesion Properties ◽  
Content Type ◽  
Oral Epithelial Cells ◽  
Oral Epithelial ◽  
Cell Cell

Candida albicans, a commensal fungus of the oral microbiome, causes oral candidiasis in humans with localized or systemic immune deficiencies. Secreted aspartic proteinases (Saps) are a family of 10 related proteases and are virulence factors due to their proteolytic activity, as well as their roles in adherence and colonization of host tissues. We found that mice infected sublingually withC. albicanscells overexpressing Sap6 (SAP6OE and a Δsap8strain) had thicker fungal plaques and more severe oral infection, while infection with the Δsap6strain was attenuated. These hypervirulent strains had highly aggregative colony structurein vitroand higher secreted proteinase activity; however, the levels of proteinase activity ofC. albicansSaps did not uniformly match their abilities to damage cultured oral epithelial cells (SCC-15 cells). Hyphal induction in cells overexpressing Sap6 (SAP6OE and Δsap8cells) resulted in formation of large cell-cell aggregates. These aggregates could be produced in germinated wild-type cells by addition of native or heat-inactivated Sap6. Sap6 bound only to germinated cells and increasedC. albicansadhesion to oral epithelial cells. The adhesion properties of Sap6 were lost upon deletion of its integrin-binding motif (RGD) and could be inhibited by addition of RGD peptide or anti-integrin antibodies. Thus, Sap6 (but not Sap5) has an alternative novel function in cell-cell aggregation, independent of its proteinase activity, to promote infection and virulence in oral candidiasis.

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