pepstatin and Candidiasis--Vulvovaginal

Oral candidosis is a common problem in immunocompromised patients, and whilst Candida albicans is regarded as the principal cause of infection, other non-Candida albicans Candida (NCAC) species are increasingly being recognized as human pathogens. Relatively little is known about the virulence factors associated with NCAC species, and the aim of this study was to use a reconstituted human oral epithelium (RHOE) to examine epithelial infection withCandida parapsilosis. Strains originating from the oral and vaginal mucosa and from the urinary tract were all shown to colonize RHOE in a strain-dependent manner. Strain differences were found in the colonizing morphology and in the extent of invasion of the RHOE. Low invasion of RHOE was detected for strains after 12 h, whereas extensive tissue damage was evident after 24 h when assessed using histological examination and lactate dehydrogenase activity determination. Tissue damage was reduced in the presence of pepstatin A, although C. parapsilosis invasion of the tissue was not inhibited. Real-time polymerase chain reaction of secreted aspartyl proteinase (SAP) genes (SAPP1-3) showed that expression was strain dependent, with an increased expression generally occurring for Candida infecting RHOE compared with planktonic equivalents. In summary, C. parapsilosis was not highly invasive of RHOE but did induce significant tissue damage, which could relate to specific SAPgene expression.

Topics: Aspartic Acid Endopeptidases; Candida; Candidiasis; Candidiasis, Oral; Candidiasis, Vulvovaginal; Epithelium; Female; Fungal Proteins; Humans; L-Lactate Dehydrogenase; Microscopy, Confocal; Microscopy, Electron, Scanning; Mouth Mucosa; Pepstatins; Polymerase Chain Reaction; Protease Inhibitors; Time Factors; Urinary Tract Infections; Virulence

The aspartate proteinase inhibitor pepstatin A was used to study a possible correlation among proteinase activity and other virulence factors of Candida albicans strains isolated from the vaginal environment of patients in three different clinical conditions: asympthomatic, vulvovaginal candidiasis (VVC) and recurrent vulvovaginal candidiasis (RVVC). The addition of 1.0 muM pepstatin A did not have any significant effect on hyphae formation, biofilm production and in the cell surface hydrofobicity of isolates in the three different clinical conditions. However, pepstatin A reduced the adherence of C. albicans to vaginal mucosa epithelial cells (53.1, 48.7 and 59.9%, respectively to isolates from asymptomatic, VVC and RVVC patients). This result suggests that the secreted aspartate proteinases (Saps) of this fungal pathogen may have auxiliary roles in cellular adhesion.

Topics: Adolescent; Adult; Aged; Aspartic Acid Endopeptidases; Biofilms; Candida albicans; Candidiasis, Vulvovaginal; Cell Adhesion; Female; Fungal Proteins; Humans; Hydrophobic and Hydrophilic Interactions; Hyphae; Middle Aged; Mucous Membrane; Pepstatins; Protease Inhibitors; Recurrence; Vagina; Virulence; Virulence Factors

Highly active antiretroviral therapy that includes human immunodeficiency virus (HIV) aspartyl protease inhibitors (PIs) causes a decline in the incidence of some opportunistic infections in AIDS, and this decline is currently attributed to the restoration of specific immunity. The effect of two PIs (indinavir and ritonavir) on the enzymatic activity of a secretory aspartyl protease (Sap) of Candida albicans (a major agent of mucosal disease in HIV-infected subjects) and on growth and experimental pathogenicity of this fungus was evaluated. Both PIs strongly (>/=90%) and dose dependently (0.1-10 microM) inhibited Sap activity and production. They also significantly reduced Candida growth in a nitrogen-limited, Sap expression-dependent growth medium and exerted a therapeutic effect in an experimental model of vaginal candidiasis, with an efficacy comparable to that of fluconazole. Thus, besides the expected immunorestoration, patients receiving PI therapy may benefit from a direct anticandidal activity of these drugs.

Topics: AIDS-Related Opportunistic Infections; Animals; Antifungal Agents; Aspartic Acid Endopeptidases; Candida albicans; Candidiasis, Oral; Candidiasis, Vulvovaginal; Female; HIV Protease Inhibitors; Humans; Indinavir; Pepstatins; Protease Inhibitors; Rats; Ritonavir

The role of antibodies (Abs) in the resistance to vaginal infection by Candida albicans was investigated by using a rat vaginitis model. Animals receiving antimannoprotein (anti-MP) and anti-aspartyl proteinase (Sap) Ab-containing vaginal fluids from rats clearing a primary C. albicans infection showed a highly significant level of protection against vaginitis compared to animals given Ab-free vaginal fluid from noninfected rats. Preabsorption of the Ab-containing fluids with either one or both proteins MP and Sap sequentially reduced or abolished, respectively, the level of protection. A degree of protection against vaginitis was also conferred by postinfectious administration of anti-Sap and anti-MP monoclonal antibodies (provided the latter were directed against mannan rather than protein epitopes of MP) and by intravaginal immunization with a highly purified, polysaccharide-free Sap preparation. Postinfectious administration of pepstatin A, a potent Sap inhibitor, greatly accelerated the clearance of C. albicans from rat vagina. No anti-MP or anti-Sap Abs were elicited during a C. albicans vaginal infection of congenitally athymic nude rats. Although they were as able as their euthymic counterparts to clear the primary infection, these animals did not show increased resistance to a rechallenge, demonstrating that induction of anticandidal protection in normal rats was a thymus-dependent Ab response. Overall, our data strengthen the concept that Abs against some defined Candida antigens are relevant in the mechanism of acquired anticandidal protection in vaginitis. The T-cell dependence of this protection may also provide a link between cell-mediated and humoral immunity in vaginal infection.

Topics: Animals; Antibodies, Fungal; Antibodies, Monoclonal; Aspartic Acid Endopeptidases; Candida albicans; Candidiasis, Vulvovaginal; Female; Mannans; Pepstatins; Rats; Rats, Nude; Vaccination