Buccal Epithelial Cells (buccal + epithelial_cell)

Distribution by Scientific Domains

Selected Abstracts

State of differentiation defines buccal epithelial cell affinity for cross-linking to Candida albicans Hwp1

Gomathinayagam Ponniah
Candida albicans utilizes mammalian cell-associated transglutaminase (TGase) activity to adhere covalently to human buccal epithelial cells (BECs) through Hyphal Wall Protein 1. Little is known about the factors leading to the identity and appearance of Hwp1 binding partners on cells lining the oral cavity. The observation that BECs vary in their ability to attach to C. albicans germ tubes and to bind recombinant Hwp1 (rHwp1) suggested that differentiation may play a role in affinity for germ tube attachment. Individual BECs were characterized for differentiation status and rHwp1 binding. rHwp1 bound to the more terminally differentiated cells displaying SPR3 and keratin 13 but not to less differentiated cells with abundant involucrin. Sequential expression of involucrin followed by SPR3 in oral keratinocytes was demonstrated using stratified organotypic cultures and a feeder layer system with the OKF6/TERT-2 cell line. Increased cross-linking of the lysine analogue 5-(biotinamido)pentylamine to cultured OKF6/TERT-2 cell proteins accompanied this increased expression of SPR3. Western blot analysis demonstrated the presence of rHwp1 cross-links to proteins from BECs or from OKF6/TERT-2 cells that had been mechanically dislodged from culture dishes. Therefore, the differentiation of SPR3 positive from involucrin positive cells is correlated with the acquisition of affinity for cross-linking to rHwp1 and covalent adhesion of germ tubes to BECs. [source]

Effects of date extract on adhesion of Candida species to human buccal epithelial cells in vitro

Khaled H. Abu-Elteen
Abstract: The adherence of three Candida species to human buccal epithelial cells (BEC) following treatment with different concentrations of date extract was investigated in vitro, as well as the effect of a mouth rinse with date extract on the adhesion of yeast to BEC. Adhesion of C.albicans, C.tropicalis and C.kefyr to BEC was significantly reduced after both short- and long-term periods of yeast exposure to various concentrations of date extract (reduction between 25% and 52% of the control value). A similar inhibition of adherence was observed upon pre-incubation of BEC with date extract. There was a significant reduction (P<0.001) in the adherence of yeast to BEC collected immediately or 5,20 min after an oral rinse with 10% date extract. No statistically significant difference was observed in the adhesion of BEC collected 30 min after an oral rinse with date extract and control BEC. In addition, pre-treatment of either Candida or BEC, or both, with date extract resulted in reduced adherence, the magnitude of which was largest when both types of cells were pre-treated. Date extract also inhibited germ-tube formation of C. albicans (56,85% inhibition), which might contribute to the effects on adherence. [source]

Identification of Candida albicans genes induced during thrush offers insight into pathogenesis

Shaoji Cheng
Summary Candida albicans causes a wide spectrum of diseases, ranging from mucocutaneous infections like oral thrush to disseminated candidiasis. Screening for C. albicans genes expressed within infected hosts might advance understanding of candidal pathogenesis, but is impractical using existing techniques. In this study, we used an antibody-based strategy to identify C. albicans genes expressed during thrush. We adsorbed sera from HIV-infected patients with thrush against candidal cells grown in vitro and screened a C. albicans genomic expression library. We identified 10 genes encoding immunogenic antigens and used reverse transcription-polymerase chain reaction to verify that they were induced within thrush pseudomembranes recovered from a patient. The in vivo induced genes are involved in diverse functions, including regulation of yeast-hyphal morphogenesis, adhesion to host cells, nutrient uptake, phospholipid biosynthesis and amino acid catabolism. Four genes encode known virulence determinants (HWP1, CST20, CPP1 and RBF1). Another gene, LPD1, for which a role in candidal pathogenesis is unknown, encodes a protein homologous to a bacterial virulence determinant. Most importantly, disruption of CaNOT5, a newly identified gene, conferred defects in morphogenesis, decreased adherence to human buccal epithelial cells and attenuated mortality during murine disseminated candidiasis, proving that our strategy can identify genes encoding novel virulence determinants. [source]

Effects of zinc and copper on adhesion and hemagglutination of Prevotella intermedia and Prevotella nigrescens

M. Tamura
This study investigated the mechanism of protein attachment to the surface of the putative periodontal pathogens Prevotella intermedia and Prevotella nigrescens in artificial gingival crevicular fluid, and ways to increase protein attachment to the bacterial cells. The effects of cations on protein attachment, bacterial adhesion, and hemagglutination were examined, and cation-binding components on both bacterial species were identified. The presence of cations, especially zinc, copper and cerium, increased attachment of human serum proteins to both bacterial species. In contrast, the presence of hydrophobic inhibitors or sugars had little effect. Protein attachment was reduced by heat treatment of the bacterial cells. Pretreatment of bacteria with human serum proteins inhibited adhesion of both species to buccal epithelial cells and hemagglutination. These effects were enhanced by the presence of zinc and copper during pretreatment. Using a chelating column, specific zinc- and copper-binding proteins were identified on the surfaces of both bacterial species. [source]

Changes of virulence factors accompanying the phenomenon of induced fluconazole resistance in Candida albicans

MYCOSES, Issue 7-8 2000
K. Fekete-Forgács
Summary We investigated a fluconazole-sensitive (MICflu,=,5 ,g ml,1) clinical isolate and a fluconazole-resistant (MICflu >80 ,g ml,1) laboratory mutant Candida albicans strain developed from the sensitive one. We studied putative virulence factors including germination, adherence ability to either buccal epithelial cells or acrylate surface, the secreted aspartic proteinase, and the extracellular phospholipase activity of the two strains as well as their growth. The fluconazole-resistant strain proved to be superior to the original strain in all the virulence traits tested. The higher virulence of the fluconazole-resistant strain was also supported by a mouse model. These results suggest that the development of fluconazole resistance can be accompanied by serious morphological and physiological changes: several putative virulence traits, moreover the in vivo virulence can increase simultaneously. [source]

Effects of fluorides on Candida albicans

ORAL DISEASES, Issue 4 2008
S Flisfisch
Aims:, To assess whether a short exposure of Candida albicans to commonly used fluorides would affect growth, cell surface hydrophobicity, and adherence to buccal epithelial cells. Methods:,Candida albicans ATCC 90028 and 11 clinical isolates were used. Minimal inhibitory concentrations (MICs) of sodium fluoride (NaF) and of an amine fluoride,/,stannous fluoride combination (AmF,/,SnF2) were determined. Yeasts were exposed to MICs of tested agents for 1 h. Subsequently, their growth was recorded spectrophotometrically. Their cell surface hydrophobicity was assessed with n -hexadecane. Adherence to buccal epithelial cells was determined microscopically. Phosphate buffered saline (PBS) and chlorhexidine digluconate (CHX) served as controls. All results were analyzed by one-way ANOVA. Results:, MICs of AmF,/,SnF2 and CHX varied between 1 and 4 ,g ml,1, whereas those of NaF were 15 000 ,g ml,1. Statistically significant growth inhibition was detected after AmF,/,SnF2 (OD24 h ± SD 0.457 ± 0.059) and CHX (0.175 ± 0.065) in comparison with PBS (0.925 ± 0.087) and NaF (0.813 ± 0.081). All strains demonstrated uniform behavior. Only minor changes in cell surface hydrophobicity and adherence to buccal epithelial cells (BEC) were detected. Conclusion:, Growth inhibition of AmF,/,SnF2 was comparable with that of CHX whereas NaF had a weaker effect. Exposure to the fluorides did not seem to alter the cell surface hydrophobicity nor adherence to BEC. [source]

Optimizing DNA yield from buccal swabs in the elderly: Attempts to promote buccal cell growth in culture

David J. Vandenbergh
Participation in genetic studies is often limited by a volunteer's reluctance to donate blood samples. We wished to determine if alternate, less painful, methods to venipuncture could be used to collect cells to provide DNA for genotyping, and whether the cells could be grown in culture for extraction of DNA. Volunteers in the study were comprised of two groups. Nine individuals from a university campus were recruited to provide samples for initial experiments. A second group of 710 twins and singletons from North Carolina and of African-American descent were a part of an ongoing study of age-related traits and participated in collection of buccal swabs via the mail. A protocol was generated that maximizes the recovery of DNA from buccal swabs, which are easier to handle than saline rinses. The DNA recovered is stable over several years, allowing genotype tests at a future date. Attempts to encourage growth of buccal epithelial cells recovered from swabs in tissue culture proved unsuccessful. Buccal swabs work well for the collection of DNA, especially from nonclinic-based volunteers, and can be sent via the mail to the laboratory for DNA extraction. Thus, an inexpensive and efficient method exists for genetic studies of population-based samples. Am. J. Hum. Biol. 15:637,642, 2003. © 2003 Wiley-Liss, Inc. [source]