928 Hyphae production by malassezia furfur yeasts on reconstructed human epidermis

Malassezia spp. are commensal lipo-dependent yeasts colonizing sebum-rich regions of the human skin. Usually harmless, sometimes become involved in skin disorders such as pityriasis versicolor (PV), dandruff, folliculitis, psoriasis, but also seborrheic and atopic dermatitis. However, their precise role these pathologies remains poorly understood. In PV, overproliferate exhibit phenotypic changes. From a round or oval shape, filamentous structures named hyphae develop invade cornified layer epidermis. This fungal overload epidermal invasion lead to pigmentation defaults itching. Even if topical application antifungal agents is usually effective, relapse common resistant strains appear. Better characterization infection processes set up by needed for development new therapeutic strategies. this study, molecular mechanisms underlying hyphal production investigated. To aim, we developed an vitro model on reconstructed epidermis (RHE) furfur. After olive oil pre-treatment over RHE, inoculum topically applied, maintained four days. We highlight differences various M. furfur regard ability produce course infection. CBS 7019 6000 that tissue, leading alteration barrier, revealed with Lucifer Yellow assay, mRNA overexpression keratinocytes pro-inflammatory cytokines (e.g. IL-1α), well antimicrobial peptides hBD2). contrast, 14141 do not undergo phenotypical changes grow at tissue surface without altering tissue. Altogether, results provide adequate tool understand initiation infection, invasiveness between strains.