Expression of Fungal and Host Markers in Models of Dermatophytosis on Mice and Human Epidermis

Increasing resistance of dermatophytes against antifungals creates global public health problems, rendering essential a better understanding of virulence mechanisms and factors determining host specificity of dermatophytes. Because dermatophytes switch from a saprophytic to a parasitic lifestyle by reprogramming gene expression, reliable experimental models are needed to investigate the pathogenesis of dermatophytosis. In this study, a relevant mouse model of Trichophyton benhamiae dermatophytosis was assessed, together with a model based on reconstructed human epidermis, allowing their respective validation regarding fungal gene expressed during infection. The use of a standardized inoculum induced a natural-like superficial infection in mice. The severity and persistence of lesions enabled the assessment of infection markers, including mouse-specific proinflammatory molecules and fungal genes previously reported as potential virulence factors. Upregulated expression of fungal genes, including those encoding subtilisins, in infected reconstructed human epidermis revealed that dermatophytes deploy similar processes as those observed during in vivo infection. The reconstructed human epidermis model was then used to compare infections by anthropophilic Trubrum and zoophilic Tbenhamiae. Therefore, these 2 models represent complementary analytical tools to study the pathogenesis of acute dermatophytoses. In addition, we have identified certain fungal markers of infection and highlighted the existence of different mechanisms deployed by zoophilic versus anthropophilic dermatophytes.