Variability in expression of antigens responsible for serotype specificity in Candida albicans

Abstract

The monoclonal antibody (mAb) B9E, which reacts with a cell wall surface determinant of Candida albicans serotype A, and a polyclonal monospecif ic antiserum against the antigen 6 (IF6) were used to investigate the expression of the antigens responsible for the serotype specificity in C. albicans under different growth conditions. By indirect immunofluorescence, both antibodies reacted with the cell wall surface of serotype A yeast cells and germ tubes grown in witm but no reactivity was observed with serotype B yeast cells. In some cases, only a weak reactivity restricted to a zone close to the parent yeast cell was observed in serotype B germ tubes stained with mAb B9E. Both antibodies reacted strongly with yeast cells and germ tubes present in kidney abscesses from rabbits infected with both serotypes, but only serotype A yeast cells and germ tubes present in smears from patients with vulvovaginal candidiasis reacted with B9E and IF6 antibodies. The expression of antigens reactive with both antibodies was modulated by the pH of the environment in which the fungus was grown. Both antibodies showed a similar pattern of reactivity when studied with a spectrofluorometer. Serotype A yeast cells showed maximum reactivity when cells were grown on Sabouraud dextrose broth supplemented with yeast extract a t pH 4.6. The lowest reactivity was observed in cells grown a t pH 2.0. Conversely, the reactivity of serotype B yeast cells increased a t alkaline pH values, the highest being in cells grown a t pH values of 7.2 and 9.5. A precise use of the methods employed in studies on C. albicans serotype prevalence will be important to avoid the influence of pH on the expression of antigens conferring serotype specificity.

β-1,2-Mannosylation of Candida albicans Mannoproteins and Glycolipids Differs with Growth Temperature and Serotype

“…Conversely, studies performed with polyclonal antibodies from immunized or infected rabbits have shown that serotype B strains may gain factor 6 (specific for serotype A) in vivo and produce germ tubes that express antigen 6 (32). This observation was confirmed by using an MAb (2). Other experiments have shown that acellular extracts of serotype B cells contain enzymes (mannosyl transferases) required for the construction of serotype A epitopes (35).…”

A Monoclonal Antibody Directed against aCandida albicansCell Wall Mannoprotein Exerts Three Anti-C. albicansActivities

“…IFA was carried out as described previously (1). Briefly, the fungal species studied were grown on Sabouraud agar plates for 48 h at 24 or 37°C, resuspended in PBS at a cell density of 10 6 cells/ml, and placed on Tefloncoated immunofluorescence slides.…”

β-1,2 Oligomannose Adhesin Epitopes Are Widely Distributed over the Different Families of Candida albicans Cell Wall Mannoproteins and Are Associated through both N- and O-Glycosylation Processes

“…3B) (57). ␤-Mans are epitopes of anti-C. albicans polyclonal antibodies (63,74) and monoclonal antibodies (MAbs) with finely tuned specificity based on the ␤-Man chain length or the association with ␣-1,2-Mans (2,7,20,22,36,70). Some of these antibodies have been shown to be protective in experimental models of systemic or vaginal candidiasis (9,20,21).…”