Role of dendritic cells and B cells in the skin of imiquimod (IMQ)-induced psoriasis-like mouse model.

Abstract

BACKGROUND: Psoriasis is a chronic inflammatory skin disease traditionally characterized by T cell-mediated immune responses. However, dendritic cells (DCs) and B cells also contribute to immune regulation in psoriasis. Their role in disease progression remains underexplored. METHODS: This study utilized an imiquimod (IMQ)-induced psoriasis-like mouse model to investigate DC and B cell dynamics at different stages of disease progression (day 3, day 5 and day 7). Skin lesions were evaluated using the Psoriasis Area and Severity Index (PASI) and histological analysis. Flow cytometry was performed to assess the expression of CD11cMHCIIDCs and CD19CD38B cells, while gene expression analysis using reverse transcriptase polymerase chain reaction (RT-PCR) ofandwas conducted to elucidate immune modulation within the psoriasis skin microenvironment. RESULTS: IMQ application induced progressive skin thickening, erythema and scaling, with PASI scores significantly increased at day 7 compared to controls (&#xa0;=&#xa0;0.002), reflecting pronounced inflammation. Histological analysis revealed epidermal hyperplasia, hyperkeratosis and dermal immune cell infiltration. Skin CD11cMHCIIDCs were significantly elevated at day 3 (&#xa0;<&#xa0;0.01), corresponding with upregulation ofandgenes, while CD19CD38B cells expanded at later stages, peaking at day 7 (&#xa0;<&#xa0;0.0001), associated with increased,,andexpression. A reduction in circulating B cells was observed alongside increased skin infiltration, suggesting a possible redistribution associated with inflammation. CONCLUSION: Early DC activation corresponded with the initiation phase of inflammation, while the later expansion of B cells appeared to coincide with sustained inflammatory activity and disease progression. The coordinated presence of DCs and B cells in the skin microenvironment may influence disease severity and pathogenesis, which could provide fundamental insights for future investigations into potential therapeutic strategies.