Effects of specific antibodies on the interaction between the fungus Candida albicans and human oral mucosa.

Host-parasite interactions were studied in four groups: non-infected controls; infected carriers of Candida albicans without evidence of candidiasis; subjects with acute candidiasis; and subjects with chronic candidiasis. Specific anti-candida antibodies were demonstrated in saliva from subjects of all four groups; the titres reflected the degree of antigenic stimulation, being significantly higher in candidiasis than in controls or infected carriers. The adherence of C. albicans to buccal epithelial cells was not significantly different in a given saliva, regardless of whether the assay was carried out with autologous C. albicans and epithelial cells or with a stock strain in a standardized assay. Therefore, the standard assay was used to study the effects of specific salivary antibodies on adherence. A significant inverse correlation was found between salivary IgA anti-candida antibodies and the adherence of C. albicans to buccal epithelial cells, suggesting that IgA antibodies can inhibit adherence of candida to the oral mucosa. In some instances, removal of antibodies led to a significant increase in adherence; however, often this was not the case, indicating that some but not all of the antibodies present were capable of inhibiting the adherence of C. albicans to epithelial cells.

Oral candidiasis: effects of antifungal therapy upon clinical signs and symptoms, salivary antibody, and mucosal adherence of Candida albicans.

A human study of the effects of topical nystatin (Mycostatin) therapy of oral candidiasis showed that effects of treatment were limited to the time in which the drug was used. Two weeks of therapy resulted in significant reduction in number of organisms and marked improvement in signs and symptoms of candidiasis. The condition recurred rapidly following cessation of treatment. No change in specific anticandida antibody in saliva or in adherence of Candida albicans to mucosal epithelium (in vitro) was seen with treatment.

Quantitative relationships between Candida albicans in saliva and the clinical status of human subjects.

Patients with candidiasis had greater than 400 colony-forming units per ml of saliva, whereas carriers of Candida albicans had less than 400 colony-forming units per ml. Thus, quantitative cultures of saliva may aid in the diagnosis of oral candidiasis.

Relationship between germination of Candida albicans and increased adherence to human buccal epithelial cells.

A strong correlation was shown between germination and increased adherence of Candida albicans to human buccal epithelial cells, indicating that germination or other changes in the fungi accompanying germination were responsible for enhanced adherence. Partial inhibition of germination by cysteine resulted in a comparably lower adherence. Preferential adherence of germinated fungi occurred in competition assays with nongerminated and germinated fungi. The enhanced adherence to human mucosal cells of germinated C albicans could represent one mechanism contributing to the pathogenicity of the organism.

Adherence of Candida albicans to human buccal epithelial cells.

The adherence of Candida albicans to human buccal epithelial cells after 2 h at 37 degrees C was significantly greater in human saliva than in phosphate-buffered saline. in saliva, viable fungi adhered much better than did nonviable fungi, and this adherence was greater at 37 than at 25 degrees C. Viable yeasts, preincubated in saliva for 90 min at 37 degrees C before being washed and mixed with epithelial cells in phosphate-buffered saline, adhered better than nonviable yeasts or yeasts preincubated in phosphate-buffered saline. Enhanced adherence in saliva appeared to be associated with germination of the yeast cells. Conditions permitting germination (growth in tissue culture medium 199 at 37 degrees C but not at 25 degrees C) also supported enhanced adherence. After germination had occurred, the fungi could be killed with Formalin without interfering with their rapid and efficient adherence to epithelial cells. These data indicate that the enhanced adherence of C. albicans observed after incubation in saliva is related to changes in the fungi, rather than to a requirement for prolonged interaction between fungi and epithelial cells.

Immunologic responses to Candida albicans. III. Effects of passive transfer of lymphoid cells or serum on murine candidiasis.

Passive transfer of immune serum gave a significant degree of protection against deep seated candidiasis in mice. Repeated attempts to transfer resistance by the transfer of sensitized lymphoid cells gave negative results, even though cutaneous delayed hypersensitivity was transferred by the cells. The results suggest that cell-mediated immunity is not of primary importance in this model of murine candidiasis, and that humoral immunity contributes to protection.

Anesthesia and the modification of response to infection in mice.

Anesthetic-induced immunosuppression, if clinically significant, could modify the natural course of infectious disease in vivo. To test this bypothesis, the localized response to IM Candida albicans and the mortality following fecal peritonitis were examined in anesthetized mice. Using these 2 models, halothane anesthesia was found not to modify the natural history of local sepsis but to significantly accentuate the mortality associated with the more severe infection. Possible explanations for these results include significant inhibition of reticuloendothelial function or plasma opsonization with relatively minor derangements of peripheral leukocyte capability.

Immunity to syphilis: passive transfer in rabbits using serial doses of immune serum.

The influence of prolonged treatment with serial doses of immune serum initiated either 2 or 48 h before intracutaneous challenge with Treponema pallidum on the subsequent appearance and development of lesions was studied. Whereas treatment with large doses of immune serum initiated 48 h before treponemal challenge caused a delay of 9 to 20 days in the onset of lesions and marked suppression of lesion development. Treatment initiated 2 h before treponemal challenge failed to delay the onset of lesions and only moderately suppressed their development. Lesion development was suppressed as long as treatment was continued. The significance of the results is discussed.

Immunological responses to Candida albicans II. Amyloidosis in mice induced by candidiasis.

Candida albicans infection in the mouse thigh rapidly induces amyloidosis in mice of the C57BL/Ks strain; amyloid is induced more slowly and to a lesser extent by viable candida in C3H and AKR mice, and by both viable Saccharomyces cerevisiae and heat-killed C. albicans in C57BL/Ks mice.

Immunological responses to Candida albicans. I. Mouse-thigh lesion as a model for experimental candidiasis.

A mouse-thigh lesion model for experimental candidiasis is described. A standard inoculum of 5 x 10(8) yeast cells of Candida albicans, injected into the thigh muscle of C57BL/Ks mice, produced an easily measured thigh lesion that was self-limiting by 4 to 6 weeks, permitting a study of immunological responses to the infection. Examination of the histopathology of the lesion reveals that the cellular infiltrate is predominately granulocytic, and gives little evidence for an active, specific, cell-mediated immune response.