Abstract
AbstractMalasseziayeast species are the dominant commensal fungal species of the human skin microbiota, but are also associated with inflammatory skin diseases, such as seborrheic dermatitis and atopic eczema (AE). Mala s 1, a β-propeller protein, is an allergen identified inMalassezia sympodialisinducing both IgE and T-cell reactivity in the majority of patients with AE. In this study, we aimed to elucidate the role of Mala s 1 allergen in skin disease. An anti-Mala s 1 antibody was used to investigate the cellular localisation of Mala s 1, the potential of Mala s 1 as a therapeutic target and examine cross-reactivity of the anti-Mala s 1 antibody with human skin. We demonstrate by high pressure freezing electron microscopy and immune-staining that Mala s 1 is located in the cell wall ofM. sympodialisyeast cells. Despite the ability of the anti-Mala s 1 antibody to bind to yeast cells, it did not inhibitM. sympodialisgrowth suggesting Mala s 1 may not be an attractive antifungal target. The Mala s 1 predicted protein sequence was analysedin silicoand was found to contain a motif indicative of a KELCH protein, a group of β-propeller proteins. Humans express a large number of KELCH proteins including some that are localised in the skin. To test the hypothesis that antibodies against Mala s 1 cross react with human skin proteins we examined the binding of anti-Mala s 1 antibody to human skin explant samples. Reactivity with the antibody was visualised in the epidermal layer of skin. To further characterise putative human targets recognised by the anti-Mala s 1 antibody, proteins were extracted from immunoblot gel bands and proteomic analysis performed. Several candidate human proteins were identified. To conclude, we propose that Mala s 1 is a KELCH-like β-propeller protein with similarity to human skin proteins and Mala s 1 recognition may trigger the production of cross-reactive responses that contribute to skin diseases associated withM. sympodialis.
Publisher
Cold Spring Harbor Laboratory