Role of Candida albicans in Granulomatous Tissue Reactions. I. In Vitro Degradation of C. albicans and Immunospecificity of Split Products

Abstract

Several mannan-containing fractions were obtained from whole cells, cell walls, and cytoplasm of Candida albicans by means of treatment with hot formamide or precipitation with (NH4)2SO4. The immunological and chemical characteristics of the fractions were compared with those of C. albicans mannan prepared by standard procedures. Antisera to C. albicans from rabbits immunized with whole cells of the organism were found to be primarily directed against the mannan content. With use of such antisera, mannan was localized in both the inner and outer layers of the cell wall, whereas the middle layer was found in all likelihood to represent the glucan polymer. Stepwise removal of mannan from whole cells or cell walls resulted in increasing loss of periodic acid-Schiff staining, immunofluorescence, and peroxidase reactivity. Thus, it appears that mannan is responsible for the ability of cell walls of C. albicans to be stained by periodic acid-Schiff or labeled with fluorescent antibody. The component of the pathogen most resistant to physical or chemical treatment was the glucan, which lacked all immunological reactivity.

Specific inhibition of in vitro Candida-induced lymphocyte proliferation by polysaccharidic antigens present in the serum of patients with chronic mucocutaneous candidiasis.

“…High antibody titers against Candida antigens (including antimannan antibodies) (21) are usually detected in CMCC patients (4). This, however, does not exclude that poorly immunogenic Candida antigens, including glucan (27), may escape the humoral response. In experiments with antiCandida antibody coupled columns, glucan could be absorbed as the peptido-gluco-mannan complex of the Candida cell wall (24).…”

Mechanisms of Attachment of Neutrophils to Candida albicans Pseudohyphae in the Absence of Serum, and of Subsequent Damage to Pseudohyphae by Microbicidal Processes of Neutrophils In Vitro

“…Neutrophil receptors may also have enzymatic activity which can be detected (4). Another possibility is that of a cell receptor for mannose (5), because the Candida cell wall has a high content of mannose, primarily in the form of mannans (6,7). The Candida cell wall also contains glucans, glucomannans, perhaps chitin, and mannoproteins (7)(8)(9)(10), which might be involved in reactions with surface receptors of neutrophils.…”

“…Another possibility is that of a cell receptor for mannose (5), because the Candida cell wall has a high content of mannose, primarily in the form of mannans (6,7). The Candida cell wall also contains glucans, glucomannans, perhaps chitin, and mannoproteins (7)(8)(9)(10), which might be involved in reactions with surface receptors of neutrophils. Our previous studies indicated that only live and not killed Candida interacted with neutrophils (1), suggesting that the material which is recognized by neutrophils is either labile or loosely attached to the Candida surface.…”

First Human Model of In Vitro Candida albicans Persistence within Granuloma for the Reliable Study of Host-Fungi Interactions

“…The granuloma-response resembled chronic human pathology, where pathogens persist in tissue at low levels. This contrasts with previous models using cell lines or human peripheral blood cells [31]–[34], [41], [42], which utilized high concentrations of living or dead C. albicans .…”