Adhesin - receptor interactions in the attachment ofCandida albicansto host epithelial cells

1995 ◽  
Vol 73 (S1) ◽  
pp. 1147-1153 ◽  
Author(s):  
L. Julia Douglas
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Blood Group Antigen ◽  
Receptor Interaction ◽  
Environmental Signals ◽  
Yeast Form ◽  
Adhesion Receptor ◽  
Receptor Interactions ◽  
Fimbrial Adhesin ◽  
Protein Portion

The ability of Candida albicans to adhere to a variety of host surfaces is thought to be an important factor in the pathogenesis of candidosis. Adhesion of the yeast form of the fungus to epithelial cells can involve several kinds of adhesion – receptor interaction. Yeast adhesins are typically mannoproteins associated with fibrils or fimbriae on the fungal surface. Lectinlike interactions have been identified between the protein portion of two mannoprotein adhesins and glycosides containing L-fucose or N-acetylglucosamine. The fucoside-binding adhesin has been purified and shown to have an affinity for glycosphingolipid receptors carrying the H blood-group antigen. A fimbrial adhesin has also been described that binds to gangliosides containing a βGalNAc(1–4)βGal disaccharide sequence. Other mannoprotein adhesins proposed recently include the factor 6 epitope present on serotype A strains of C. albicans and an integrin analogue. Adhesin expression appears to be regulated by a number of environmental signals, including osmolarity and the availability of iron and sugars. Additional adhesion-dependent signals might trigger further responses such as the initiation of morphogenesis. Key words: Candida albicans, yeast adhesion, epithelial cell adhesion.

Equilibrium analysis of binding of Candida albicans to human buccal epithelial cells

1990 ◽  
Vol 36 (5) ◽  
pp. 336-340 ◽  
Author(s):  
William Staddon ◽  
Tom Todd ◽  
Randall T. Irvin
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Copy Number ◽  
Incubation Temperature ◽  
Temperature Shift ◽  
Equilibrium Analysis ◽  
High Copy Number ◽  
Buccal Epithelial Cells ◽  
Low Copy Number ◽  
Receptor Interactions

The effect of growth temperature on the binding of Candida albicans to human buccal epithelial cells (BECs) was examined using an equilibrium of binding analysis. Candida albicans was cultured in M9 medium either for 12 h at 25 °C or for 9 h at 25 °C and then shifted to 37 °C for 3 h. The temperature shift did not result in germ tube formation; however, the adherence of C. albicans to BECs was altered. Shifting temperature increased the yeast's ability to bind to BECs. A Langmuir adsorption isotherm was used to calculate the maximum number of available binding sites (N) and the apparent association constants of binding (Ka) for all resolvable adhesin–receptor interactions. Three classes of adhesin–receptor interactions were resolved when the yeast was cultured at 25 °C and included a low copy number site (N = 3.0 cfu/BEC; Ka = 2.11 × 10−6 mL/cfu), a medium copy number site (N = 23.6 cfu/BEC, Ka = 8.21 × 10−7 mL/cfu), and a high copy number site (N = 91.7 cfu/BEC, Ka = 3.35 × 10−8 mL/cfu). Two classes of adhesin–receptor interactions were resolved when the incubation temperature was shifted to 37 °C: a low copy number site (N = 4.5 cfu/BEC, Ka = 3.98 × 10−6 mL/cfu) and a high copy number site (N = 150.5 cfu/BEC, Ka = 8.47 × 10−8 mL/cfu). Augmented C. albicans adherence to BECs due to the elevated growth temperatures appears to result from a temperature-regulated alteration in the C. albicans adhesin that recognizes a high copy number receptor site with relatively low affinity.

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.

scholarly journals The Roles of Chromatin Accessibility in Regulating the Candida albicans White-Opaque Phenotypic Switch

2021 ◽  
Vol 7 (1) ◽  
pp. 37
Author(s):  
Mohammad N. Qasim ◽  
Ashley Valle Arevalo ◽  
Clarissa J. Nobile ◽  
Aaron D. Hernday
Keyword(s):  
Candida Albicans ◽  
Cell Fate ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Phenotypic Switching ◽  
Phenotypic Switch ◽  
Chromatin Remodelers ◽  
Environmental Signals ◽  
Cell Fate Decisions ◽  
Simple Model System

Candida albicans, a diploid polymorphic fungus, has evolved a unique heritable epigenetic program that enables reversible phenotypic switching between two cell types, referred to as “white” and “opaque”. These cell types are established and maintained by distinct transcriptional programs that lead to differences in metabolic preferences, mating competencies, cellular morphologies, responses to environmental signals, interactions with the host innate immune system, and expression of approximately 20% of genes in the genome. Transcription factors (defined as sequence specific DNA-binding proteins) that regulate the establishment and heritable maintenance of the white and opaque cell types have been a primary focus of investigation in the field; however, other factors that impact chromatin accessibility, such as histone modifying enzymes, chromatin remodelers, and histone chaperone complexes, also modulate the dynamics of the white-opaque switch and have been much less studied to date. Overall, the white-opaque switch represents an attractive and relatively “simple” model system for understanding the logic and regulatory mechanisms by which heritable cell fate decisions are determined in higher eukaryotes. Here we review recent discoveries on the roles of chromatin accessibility in regulating the C. albicans white-opaque phenotypic switch.

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

scholarly journals Inhibition of adherence of the yeast Candida albicans to buccal epithelial cells by synthetic aromatic glycoconjugates

2018 ◽  
Vol 160 ◽  
pp. 82-93 ◽  
Author(s):  
Harlei Martin ◽  
Mairead Mc Govern ◽  
Lorna Abbey ◽  
Aisling Gilroy ◽  
Stephanie Mullins ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Buccal Epithelial Cells

scholarly journals IILLS: predicting virus-receptor interactions based on similarity and semi-supervised learning

2019 ◽  
Vol 20 (S23) ◽  
Author(s):  
Cheng Yan ◽  
Guihua Duan ◽  
Fang-Xiang Wu ◽  
Jianxin Wang
Keyword(s):  
Infectious Diseases ◽  
Cross Validation ◽  
Sequence Similarity ◽  
Least Square ◽  
Computational Method ◽  
Receptor Interaction ◽  
Virus Receptor ◽  
Receptor Interactions ◽  
Leave One Out ◽  
Fold Cross Validation

Abstract Background Viral infectious diseases are the serious threat for human health. The receptor-binding is the first step for the viral infection of hosts. To more effectively treat human viral infectious diseases, the hidden virus-receptor interactions must be discovered. However, current computational methods for predicting virus-receptor interactions are limited. Result In this study, we propose a new computational method (IILLS) to predict virus-receptor interactions based on Initial Interaction scores method via the neighbors and the Laplacian regularized Least Square algorithm. IILLS integrates the known virus-receptor interactions and amino acid sequences of receptors. The similarity of viruses is calculated by the Gaussian Interaction Profile (GIP) kernel. On the other hand, we also compute the receptor GIP similarity and the receptor sequence similarity. Then the sequence similarity is used as the final similarity of receptors according to the prediction results. The 10-fold cross validation (10CV) and leave one out cross validation (LOOCV) are used to assess the prediction performance of our method. We also compare our method with other three competing methods (BRWH, LapRLS, CMF). Conlusion The experiment results show that IILLS achieves the AUC values of 0.8675 and 0.9061 with the 10-fold cross validation and leave-one-out cross validation (LOOCV), respectively, which illustrates that IILLS is superior to the competing methods. In addition, the case studies also further indicate that the IILLS method is effective for the virus-receptor interaction prediction.

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