A novel mannose-containing sialoprotein adhesin involved in the binding of Candida albicans cells to DMBT1.

Abstract

Candida albicans colonizes the oral cavity and causes oral candidiasis and early childhood caries synergistically with cariogenic Streptococcus mutans. Colonization of oral tissues with C. albicans is an essential step in the initiation of these infectious diseases. Deleted in malignant brain tumors 1 (DMBT1), also known as salivary agglutinin or gp-340, belongs to the scavenger receptor cysteine-rich (SRCR) superfamily and has important functions in innate immunity. In the oral cavity, DMBT1 causes microbial adherence to tooth enamel and oral mucosa surfaces, but the adherence of C. albicans to DMBT1 has not been examined. In this study, we investigated the binding of C. albicans to DMBT1 and isolated the fungal components responsible for the binding. Candida albicans specifically bound to DMBT1 and strongly bound to the peptide domain SRCRP2. Binding to SRCRP2 was inhibited by N-acetylneuraminic acid and mannose and by lectins recognizing these sugars. The isolated component had a molecular mass of 25 kDa, contained sialic acid and mannose residues, and inhibited C. albicans binding to SRCRP2. The localization of the 25-kDa protein on the surface of C. albicans cell walls was confirmed by immunostaining and a cell ELISA using an antiserum to the protein, and Western blotting revealed the presence of the 25-kDa protein in the cell wall fraction of C. albicans. These results suggest that the isolated adhesin is localized on the surface of C. albicans cell walls and that sialic acid and mannose residues in the adhesin play a significant role in the binding reaction.

• Authors: Daisuke Setoguchi, Emi Nagata, Takahiko Oho
• Journal: Molecular oral microbiology (Mol Oral Microbiol) Vol. 37 Issue 4 Pg. 154-163 (08 2022) ISSN: 2041-1014 [Electronic] Denmark
• PMID: 35675924 (Publication Type: Journal Article)
• Copyright: © 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemical References

• Adhesins, Bacterial
• Calcium-Binding Proteins
• DMBT1 protein, human
• DNA-Binding Proteins
• Receptors, Cell Surface
• Sialoglycoproteins
• Tumor Suppressor Proteins
• N-Acetylneuraminic Acid
• Mannose

Topics

• Adhesins, Bacterial (metabolism)
• Calcium-Binding Proteins
• Candida albicans (metabolism)
• DNA-Binding Proteins (metabolism)
• Humans
• Mannose
• N-Acetylneuraminic Acid
• Receptors, Cell Surface (chemistry, metabolism)
• Sialoglycoproteins (metabolism)
• Tumor Suppressor Proteins