Investigations on the regulation of secreted aspartyl proteinases in a model of oral candidosis and in vivo

By means of RT-PCR and specific primers the expression of SAP1-6 and SAP8 w as investigated with respect to the time course in an in vitro candidosis m odel based on reconstituted human mucosal epithelium. Corresponding morphol ogical alterations of the epithelium were documented by light microscopy. T he detection of Sap was performed immunoelectron microscopically using a mo noconal antibody. In the oral candidosis model SAP1 and SAP3 transcripts we re detected 42 h after inoculation corresponding to first histopathological changes. Additional SAP6 expression was observed six hours later concomita ntly with germ-tube formation. Later on SAP2 ad SAP8 transcripts were found after 60 h. On protein level it was possible to demonstrate Sap antigens w ithin Candida and markedly deteriorated epithelial cells. Initial experimen ts with proteinase mutants and proteinase inhibitors showed reduction of hi stological damage. In a clinical specimen obtained from a twenty nine-year- old female patient suffering from acute oral candidosis SAP1, 3 and 6 could be demonstrated corresponding to the findings in vitro after 48 h. Investi gating a clinical specimen obtained from a lesion of chronic oral candidosi s in an HIV-infected patient also showed SAP2 expression. On the basis of o ur results a relationship between the expression of particular SAP genes an d the turn up of lesions looks as probable as a relevant contribution to th e in vivo infection.