ABSTRACT
The migration of lymphocytes to nonlymphatic tissue is an essential step in the homeostatic adaptation to injury and is involved in many reactive and neoplastic disorders. Besides granulocytes and monocyte/macrophages, which are leukocytes of the innate (non-adaptive) immune system, lymphocytes are cellular elements of the adaptive immune system and play a very important role in defense and disease. The skin is one of the principal organs that delimits the body from the outside world. As many injuries which originate from outside can hit the skin, lymphocyte migration to this organ has to be particularly well assured. Although B and natural killer lymphocytes can infiltrate the skin in various pathologic conditions, little is known about the mechanisms that direct them to the skin. The vast majority of lymphocytes which infiltrate the skin are T cells. Therefore, this chapter deals with the migration of T cells to the skin.
