Analysis of the effect of ALA-PDT on macrophages in footpad model of mice infected with Fonsecaea monophora based on single-cell sequencing

Chromoblastomycosis (CBM) is a chronic neglected fungal disease that causes serious damage to the physical and mental health of patients. 5-Aminolevulinic acid photodynamic therapy (ALA-PDT) has garnered significant attention in the recent era for the treatment of CBM and has exhibited promising effects in several clinical case reports. We established a mice footpad infection model with Fonsecaea monophora and analyzed the impact of PDT treatment on the immune response of macrophages using single-cell sequencing. The results showed that infection of the mouse footpad skin with F. monophora results in an increase in inflammatory cells, primarily mononuclear-macrophages, with the activation of complement and enhancement of cell chemotaxis, leading to upregulation of anti-infection-related pathways. After ALA-PDT treatment, the number of inflammatory cells decreased, while macrophages upregulated the expression of antigen-recognition-related genes, enhancing phagocytosis and autophagy-related biological functions.