Contribution of In Vivo and Organotypic 3D Models to Understanding the Role of Macrophages and Neutrophils in the Pathogenesis of Psoriasis

Figure 1

Location and function of macrophages and neutrophils in healthy (a) and psoriatic (b) skin. Langerhans cells and CD8 T cells are present in healthy epidermis, while CD4 T cells, as well as macrophages, NK T cells, dermal dendritic cells (DCs), and plasmacytoid dendritic cells (pDCs), are found in the dermis mainly composed by fibroblasts and extracellular matrix. Immune cell infiltrates are present in the psoriatic epidermis, consisting of activated CD4 and CD8 T cells and clusters of Munro’s abscess in the stratum corneum. In the dermis, the activation of cells of both innate and adaptive promotes an inflammatory response. Neutrophils and macrophages (differentiated from monocytes) infiltrate the dermis and secrete proinflammatory cytokines. The crosstalk between skin cells and immune cells leads to a complex inflammatory response and contributes to the development of a pathological epithelial phenotype. NET: neutrophil extracellular trap; Treg: regulatory T cell; M: macrophage.

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