Heat-shock protein 90 inCandida albicans

Researches on Candidal heat-shock protein 90 (HSP90) in recent years are summarized.Candida albicans is a commensal pathogen in human and animals. In immunocompromised individuals it behaves as an opportunist pathogen, giving rise to superficial or systemic infections. Systemic candidosis is a common cause of death among immunocompromised and debilitated patients, in which the mortality is as high as 70%. HSP90 is now recognized as an immunodominant antigen inC. albicans and plays a key role in systemic candidosis as a molecular chaperone. The 47-ku peptide is the breakdown product of HSP90. Patients who has recovered from systemic candidosis produce high titre of antibodies to 47-ku antigen, whereas the fatal cases have little antibody or falling titres. The three commonest epitopes of candidal HSP90 have been mapped, epitopes C, B and H. Epitopes C and H are immunogenic. The antibody probes of both epitopes may be developed into a new serological test agents for systemic candidosis due to rather high specificity and sensitivity. The recent results establish HSP90 as an ATP-dependent chaperone that is involved in the folding of cell regulatory proteins and in the refolding of stress-denatured polypeptides. Some researches on fungal HSP90 and the treatment of patients with candidosis are reviewed as well.