Figure 5.

Epithelial imprinting of immunological memory: does LOR instruct the Langerhans cell (LC)? Epidermal Langerhans cells (LC) express tight junction proteins, project dendrites, and sample self-antigens and foreign antigens in the steady state. Loricrin knockout (LKO) epidermis exhibits a robust anti-oxidative response upon exposure to the ambient air, and keratinocyte antioxidants such as small proline-rich proteins (SPRR) or late cornified cell envelope (LCE) are upregulated. However, both SPRR and LCE cannot fully compensate for the biochemical property of loricrin (higher-order structure that enable a prompt intra- or inter-molecular disulfide formation); therefore, redox homeostasis (or metabolic environment) would be profoundly affected in the absence of loricrin. The altered epidermal microenvironment could condition LC (or other dendritic cell subsets) to limit an excessive inflammatory response.