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What role do Langerhans cells play in the immune defense of the skin?

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Learn how regenerative properties of the skin helps to protect the human body from the external environment — human skin Human skin, whose cells are generated continuously by the body, serves as a protective barrier between the inside of the human body and the environment.

Langerhans cells serve as vital "sentinel" cells within the epidermis, acting as a primary line of defense for the immune system. Positioned near the skin's surface, they are among the first cells to encounter foreign substances that penetrate the skin.1

These cells function as antigen-presenting cells by using specialized receptors on their cell membrane to distinguish between invading molecules and host tissue. Their dendritic processes provide a large surface area that facilitates this recognition. Once a foreign substance is identified, Langerhans cells convey this information to the lymphoid system, enabling the body to initiate a targeted immunologic response.21

Furthermore, Langerhans cells secrete immunostimulatory peptides, such as epidermal-cell-derived thymocyte-activating factor (ETAF), which enhance the immune responsiveness of the lymphoid system. By releasing these regulatory substances, they influence the body's systemic capacity to defend against viral infections, bacterial pathogens, and cancerous growths.1