THE HIGHLY IMMUNOGENIC ENOLASE AND HSP70P ARE ADVENTITIOUS CANDIDA-ALBICANS CELL-WALL PROTEINS

Screening cDNA libraries with polyclonal antibody preparations against Candida albicans yeast or mycelial cell walls resulted in isolation o f several positive clones. Some of them encoded enolase; others encode d a protein of the 70 kDa heat-shock protein family (Hsp7Op), etc. The presence of these cytosolic proteins in the cell wall of actively gro wing C. albicans was discovered by analytical (SDS-PACE and Western bl ot) and cytological (indirect immunofluorescence) experiments. Supplem entation of cell cultures with papulacandin B, an antibiotic that inhi bits formation of the beta-glucan skeleton, resulted in the release of enolase to the supernatant fluids; this release was prevented when 0. 6 M KCl was present as an osmotic stabilizer. The cell wall of C. albi cans incorporated exogenously added proteins (enolase and Escherichia coil and C. albicans cytosolic proteins). The presence in the C. albic ans cell wall of enolase, Hsp7Op, and probably other intracellular pro teins that are highly immunogenic might help the fungal cells to evade the host defences, and consequently could represent a survival mechan ism for C. albicans 'in vivo'.