Studies of Immune Responses in Candida vaginitis

The widespread occurrence of vaginal candidiasis and the development of resistance against anti-fungal agents has stimulated interest in understanding the pathogenesis of this disease. The aim of our work was to characterize, in an animal model of vaginal candidiasis, the mechanisms that play a role in the induction of mucosal immunity against C. albicans and the interaction between innate and adaptive immunity. Our studies evidenced the elicitation of cell-mediated immunity (CMIs) and antibody (Abs)-mediated immunity with a Th1 protective immunity. An immune response of this magnitude in the vagina was very encouraging to identify the proper targets for new strategies for vaccination or immunotherapy of vaginal candidiasis. Overall, our data provide clear evidence that it is possible to prevent C. albicans vaginal infection by active intravaginal immunization with aspartyl proteinase expressed as recombinant protein. This opens the way to a modality for anti-Candida protection at the mucosa. The recombinant protein Sap2 was assembled with virosomes, and a vaccine PEVION7 (PEV7) was obtained. The results have given evidence that the vaccine, constituted of virosomes and Secretory aspartyl proteinase 2 (Sap2) (PEV7), has an encouraging therapeutic potential for the treatment of recurrent vulvovaginal candidiasis

Production of a Mouse Antiserum to Bacteroides fragilis Enterotoxin Using a Recombinant Enterotoxin Precursor

The precursor of the Bacteroides fragilis metalloprotease enterotoxin was cloned and expressed in Escherichia coli, which was not able to process the precursor into the biologically active enterotoxin. Mouse antiserum elicited to the recombinant precursor reacted with the purified enterotoxin and with a crude enterotoxin preparation from an enterotoxigenic strain. The antiserum neutralized the cytotoxic activity of the enterotoxin in HT-29 cells

The <it>MP65 gene </it>is required for cell wall integrity, adherence to epithelial cells and biofilm formation in <it>Candida albicans</it>

<p>Abstract</p> <p>Background</p> <p>The <it>MP65 </it>gene of <it>Candida albicans </it>(orf19.1779) encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a <it>mp65Δ </it>mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation.</p> <p>Results</p> <p>The <it>mp65Δ </it>mutant showed a high sensitivity to a range of cell wall-perturbing and degrading agents, especially Congo red, which induced morphological changes such as swelling, clumping and formation of hyphae. The <it>mp65Δ </it>mutant showed an activation of two MAPKs (Mkc1p and Cek1p), a high level of expression of two stress-related genes (DDR48 and <it>SOD5</it>), and a modulated expression of β-glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the <it>mp65Δ </it>mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the mentioned properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion.</p> <p>Conclusions</p> <p>We demonstrate that the <it>MP65 </it>gene of <it>Candida albicans </it>plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus.</p

Use of SCW4 gene primers in PCR methods for the identification of six medically important Aspergillus species

Aspergillus species are the cause of invasive mold infections in immunocompromised patients: Aspergillus fumigatus, A. flavus and A. terreus account for most cases of invasive aspergillosis (IA). As certain species are associated with higher mortality and vary in their resistance to antifungal therapy, diagnosis requires increasingly rapid molecular methods that enable sensitive detection and species discrimination. We have developed PCR and Multiplex PCR assays for the detection of six medically important Aspergillus spp. species DNA in bronchoalveolar lavage (BAL) specimens from hematology and intensive care unit (ICU) patients at risk of IA, using different species and genus-specific PCR primers, selected within the SCW4 gene, encoding a cell wall glucanase of A. fumigatus, similar to mannoprotein Mp65 of Candida albicans. The genus-specific PCR primers were able to amplify only Aspergillus DNAs but not that belonging to other fungal genera tested. The species-specific PCR primers allowed differentiation of each Aspergillus species by the amplicon length produced. The methods described in this study are rapid (less than 4 h), reproducible, simple and specific and demonstrate potential application in the clinical laboratory