Immunopathological consequences of immune reactivity against fungal commensals (e.g. skin allergic disorders)

Fig5

The yeast Malassezia is by far the most abundant fungal commensal on the mammalian skin. However, besides its commensal lifestyle, Malassezia, is also associated with diseases. Malassezia has been associated with several common skin disorders such as atopic dermatitis (AD) in humans and dogs. AD is a chronic allergic skin disease with a complex etiology that affects up to 30% of the human population and 10% of dogs. The role of Malassezia in the pathogenesis of disease is not well understood. Based on clinical association studies and our own results from experimental studies, we postulate that the immune response to Malassezia, which is normally host protective, actively contributes to the manifestation of chronic inflammatory and allergic skin diseases in predisposed individuals.We have shown that the IL-17 pathway is actively involved in promoting inflammation in the atopic skin. This project dissects the mechanisms of IL-17 mediated skin inflammation and explores the crosstalk between type 17 and type 2 immunity in the allergic skin. Together, this will shed light onto how perturbations of the equilibrium between microbiota and immune system can result in common inflammatory skin disorders such as AD.

Funding: Swiss National Science Foundation  http://p3.snf.ch/project-189255

LEGEND: Malassezia exacerbates inflammation in the barrier-disrupted skin. Experimental application of the fungus onto tape-stripped murine ear skin results in a strong increase in ear thickness characterized by edema, hyperplasia and hyperkeratosis.