Role of surface mannan in the adherence of Candida albicans to fibrin-platelet clots formed in vitro

Abstract

An alkali-soluble extract from a cell wall preparation of Candida albicans was conjugated to sheep erythrocytes (SRBC) by using periodate oxidation or concanavalin A. Conjugated SRBC readily attached to a fibrin-platelet matrix, whereas nonconjugated SRBC did not. To determine the active component which promoted attachment of SRBC, the alkali-soluble fraction was treated with alpha-mannosidase, pronase, or glusulase or chemically degraded by acetolysis. The treated extract was then reconjugated with SRBC, and attachment was measured. When treated with alpha-mannosidase or degraded by acetolysis, the alkali-soluble extract failed to promote the adherence of SRBC to the fibrin-platelet matrix. Pronase- or glusulase-digested extract promoted attachment equally as well as untreated controls. In addition, when preabsorbed with antiserum to whole cells of C. albicans, the alkali extract abrogated the inhibition of adherence by antiserum, thus indicating its antigenicity. The extract consisted primarily of polysaccharide (72%) and contained a small amount of protein (less than 1%). Mannose and glucose (ratio, 3:1) were detected by gas-liquid chromatography. These data indicate that cell surface mannan may play an important role in the adherence of C. albicans to the fibrin-platelet matrices which form in vivo on the endocardium of heart valves.

Adherence of Candida albicans to human buccal epithelial cells after growth on different carbon sources

“…Preliminary evidence suggests that this surface material consists largely of mannoprotein [7]. Recently, Maisch and Calderone [8] have proposed a role for cell-surface mannan in the adherence of C. albicans to fibrin-platelet matrices, while Sobel et al [5] have shown that pretreatment of C. albicans with trypsin or chymotrypsin significantly inhibits adherence of the yeast to vaginal epithelial cells. In the present study, two C. albicans isolates from symptomless carriers showed only a 2-fold increase in adherence to buccal epithelial cells even after growth in 500 mM galactose medium.…”

Candida albicans β-Glucan-Containing Particles Increase HO-1 Expression in Oral Keratinocytes via a Reactive Oxygen Species/p38 Mitogen-Activated Protein Kinase/Nrf2 Pathway

“…We used the mass of ␤-GPs noted in those experiments as the amount to be added to cell cultures. The supernatant for the alkali-soluble fraction was neutralized with glacial acetic acid and then concentrated by flash evaporation at 30°C, dialyzed against deionized water for 24 h, and lyophilized before use as the alkali-soluble fraction (64). Mannan from C. albicans was isolated as previously described by Kogan et al (65).…”

Pathogenicity determinants of Candida

“…Work on the adherence of yeast led to the identification of cell wall components of C. albicans which may contribute to mucosal surface infection and penetration. Maisch & Calderone [ 100] suggested a role for surface mannan in the adherence of C. albicans to fibrin-platelet clots. Sandin et a/.…”