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How do Langerhans cells help defend the body from infection?

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Langerhans cells serve as vital "sentinel" cells of the immune system located within the epidermis. Because of their position near the skin surface and their large surface area—facilitated by dendritic processes—they are among the first cells to encounter foreign substances entering the body.1

These cells function as antigen-presenting cells that bind to invading molecules using specialized receptors on their cell membranes. Once they recognize a foreign particle, they convey this information to the lymphoid system, enabling the body to mount a defensive immunologic response.21

Additionally, Langerhans cells secrete immunostimulatory peptides, such as the epidermal-cell-derived thymocyte-activating factor (ETAF). This secretion enhances the immune responsiveness of the lymphoid system and plays a role in the body’s systemic reaction to infection and injury. By identifying pathogens and signaling the broader immune network, Langerhans cells are essential for defending the body against viral and bacterial infections.1