KERATINOCYTES

Keratinocytes are maintained at various stages of differentiation in the epidermis and are responsible for forming tight junctions with the nerves of the skin. They also keep Langerhans cells of the epidermis and lymphocytes of the dermis in place... In addition to their structural role, keratinocytes play a role in immune system function. The skin is the first line of defense and keratinocytes serve as a barrier between an organism and its environment. In addition to preventing toxins and pathogens from entering an organisms body, they prevent the loss of moisture, heat and other important constituents of the body. In addition to their physical role, keratinocytes serve a chemical immune role as immunomodulators, responsible for secreting inhibitory cytokines in the absence of injury and stimulating inflammation and activating Langerhans cells in response to injury. Langerhans cells serve as antigen-presenting cells when there is a skin infection and are the first cells to process..