Expression of fungal and host markers in a relevant mouse model of dermatophytosis
Description
Dermatophytoses are the most common skin mycoses affecting humans and animals worldwide. The increasing resistance of dermatophytes to antifungal agents is creating a serious public health problem, and a better understanding of the pathogenesis of dermatophytosis is essential. As dermatophytes can switch from a saprophytic to a parasitic lifestyle by reprogramming gene expression, as demonstrated for Trichophyton benhamiae in guinea pigs, reliable animal models are still needed. Our aim was to develop a relevant mouse model of T. benhamiae dermatophytosis, to study host-fungus relationship. The use of a specific standardized fungal mixture of spores, germ tubes and mycelium as inoculum induced a natural-like superficial infection in mice, with hyphae invading the epidermis and inflammatory epidermal and dermal infiltration of polymorphonuclear cells. The severity and persistence of lesions, together with optimization of the extraction method for murine and fungal RNA recovery, enabled the expression of infection markers to be assessed. While infection induces early overexpression of mouse-specific pro-inflammatory genes, several fungal genes are also overexpressed, including those encoding certain subtilisins (SUB) previously reported as potential virulence factors, such as SUB3 and SUB6. Our mouse model therefore appears to be a good analytical tool for studying the pathophysiology of acute dermatophytoses.