Evidence that mannans of Candida albicans are responsible for adherence of yeast forms to spleen and lymph node tissue

Abstract

We have described a unique binding system between Candida albicans yeast-form cells and the marginal zone of mouse spleen (16). The chemical nature of the fungal adhesin(s) involved in this binding phenomenon was examined. A fraction obtained by 2-mercaptoethanol extraction (2-ME extract) of fungal cells caused a dose-response inhibition of yeast cell adherence to splenic marginal zone sites and also to subcapsular and medullary sinuses of mouse popliteal lymph nodes. Latex beads coated with the 2-ME extract showed a pattern of spleen and lymph node tissue binding identical to that observed with yeast cells. The extracted adhesins retained their binding activity in vivo. When 0.5 mg of the 2-ME extract was given intravenously to mice, spleen tissue removed up to 3 h later showed over 80% inhibition of yeast cell binding to the spleen marginal zone, and over 50% inhibition was retained for at least 24 h. The adhesins bound to a concanavalin A affinity column and were eluted by 0.5 M ac-methyl-D-mannopyranoside, and the eluted adhesins were designated Fr.II. Fr.II was further fractionated by DEAE-Sephacel ion-exchange column chromatography, and one especially active and abundant fraction was designated Fr.IIa. The adhesin moiety appeared to be carbohydrate, because the activity of Fr.IIa was destroyed by 20 mM sodium periodate or by 5 U of ac-mannosidase, but boiling (30 min) or proteinase K (100 ,ug/ml) treatments had no effect. Chemically, whereas the 2-ME extract contained significant amounts of protein and mannose, Fr.IIa consisted of over 98% mannose and less than 0.5% protein. These data strongly suggest that the mannan portion within a mannoprotein is responsible for the binding of yeast cells to splenic marginal zone and to subcapsular and medullary sinuses of mouse lymph node tissue.

The relationship between the acid and alkaline phosphatase activity and the adherence of clinical isolates of Candida parapsilosis to human buccal epithelial cells

“…However, the significance of this finding, portrayed here for the first time, remains to be determined. Since cell wall components such as adhesins have been implicated in the adhesion of Candida to host cells (28,46,47), differential interspecies or intraspecies adhesion implies variations in the molecular structure of the cell wall and/or the subcellular components such as enzymes which contribute to this process.…”

“…Candidal adhesion, which has been recognized as a critical initial step in colonization and infection of a host (1 l), entails both physical forces and biological processes (25,26). Mannoprotein adhesins involved in the candidal adhesion to mammalian tissues have been demonstrated and purified from the yeast cell surfaces (27,28). The presence of phosphorylated mannoproteins in the candidal cell wall (29) and the knowledge that during germination and concomitant adherence of germ tubes to surfaces, a process of surface mannoprotein degradation and simultaneous presentation of new molecules which can interact with host proteins may occur (30) hint at an involvement of candidal phosphatases in adhesion.…”

Isolation and Characterization of a Major Antigenic Component of Malassezia globosa to IgE Antibodies in Sera of Patients with Atopic Dermatitis

“…For detection of mannans in the antigenic components, lectin blotting with concanavalin A (Con A) (from Canavalia ensifonnis, specific for oc-D-Man and cs-D-Glc) was performed. The procedure of lectin blotting with Con A was similar to that described previously (9). After SOS-PAGE, the get was etectcoblotted onto a pots(NiAkidine difluoride (PVDF) sheet (Millipore, Bedford, Mass., U.S.A.) and the sheet was soaked into 3% BSA in Tris-HC1 containing 0.5 N NaC1 (TBS) for 30 min at 20 to 25 C. The sheet was then incubated for 40 min at 20 to 25 C with 4 lig/m1 of horseradish peroxidase (HRP)conjugated Con A (Honen Co., Tokyo) in TBS containing 1% BSA.…”

Selection and pathogenicity of Candida albicans in HIV infection

“…Thus, alterations to salivary composition or to mucosal tissues as a result of HIV infection may provide a selective pressure sufficient to induce alterations in adherence properties of colonising Candida. Kanbe et al, 1993;Li and Cutler. 1993).…”