Participation of epidermal langerhans cells in human pathology and their potential as targets for drug development: a review of literature.

Langerhans cells (LC) are antigen presenting cells of the epidermis originated from bone marrow progenitors that arrive into the epidermis through the blood vessels LC are also referred to as dendritic cells. In the presence of antigens LC become activated and migrate from the skin to the lymph nodes where they induce T cells responses, therefore, LC function as sentinels of the epidermis and constitute, in part the Skin Immune System (SIS). LC have been implicated in the pathogenesis and pathophysiology of diverse diseases such as atopic dermatitis, alopecia areata, human immunodeficiency virus infection (HIV) and melanoma, among others. The aim of this review is to draw the attention of pharmacologists towards LC as targets for drug action and drug development due to their immunesurveillance function. LC modulate the SIS as an endogenous mechanism of defense against many infectious agents, xenobiotics, and for the treatment of cancer, infections, and autoimmune diseases. A review of the literature on LC is presented here giving emphasis to LC cell cycle and cellular and molecular characteristics, LC possible role in human pathologies, and LC therapeutic potential.

Effects of single administration of diethylstilbestrol on murine langerhans cells.

Diethylstilbestrol (DES) is a synthetic compound with potent estrogenic actions useful in the treatment of prostate carcinoma despite the fact that it can also induce some forms of neoplasia. Both effects are thought to be related to its estrogenic actions and very little attention has been focused on the possible effect of DES on the immune response. Skin is the largest organ of the body and constitutes the first line of defense against xenobiotics. The Skin Immune System (SIS) has become the center of attention of research for the development of new therapeutic approaches for neoplasic diseases. Langerhans cells (LC), as an element of SIS, are "professional" antigen presenting cells resident in the skin that participate in the immune response associated with tolerance and acquired immunity to antigens. Hence in this work we studied the effect of DES on LC of murine skin as a model to analyze the possible effect of DES on the immune response. Male CD-1 mice (20 to 35 g body weight) were treated topically (TO) or subcutaneously (SC) with DES (10 and 100 mg/kg, dissolved in ethanol) and sacrificed at 12, 84 and 228 hr. LC were quantified in the ear skin of mice using both an enzymatic histochemical technique to demonstrate ATP-ase activity; and an indirect immunohistochemical assay for detecting class II molecules of the major histocompatibility complex (MHC-II). DES induced a significant time- and dose- dependent reduction in the number of LC (P < 0.05). Data presented here suggest that estrogens may exert a modulatory action on LC.