LANGERHAN CELLS / oral surgery courses
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LANGERHAN CELLS / oral surgery courses
- 1. LANGERHAN CELLS INDIAN DENTAL ACADEMY LEADER IN CONTINUING DENTAL EDUCATION www.indiandentalacademy.com
- 2. INTRODUCTION Langerhans cells are dendritic cells (antigen- presenting immune cells) of the skin and mucosa, and contain large granules called Birbeck granules. They are present in all layers of the epidermis, but are most prominent in the stratum spinosum. www.indiandentalacademy.com
- 3. They also occur in the papillary dermis, particularly around blood vessels, as well as in the mucosa of the mouth, foreskin, and vagina. They can be found in other tissues, such as lymph nodes, particularly in association with the condition Langerhans cell histiocytosis (LCH). Section of skin showing large numbers of dendritic cells (Langerhans cells) in the epidermis. (M. ulcerans infection, S100 immunoperoxidase stain.) www.indiandentalacademy.com
- 4. HISTORY The Langerhans cell is named after Paul Langerhans,a German physician and anatomistwho discovered the cells at the age of 21 while he was a medical student. Because of their dendritic nature, he mistakenly identified the cells as part of the nervous system.[5] www.indiandentalacademy.com
- 5. FUNCTION In skin infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells. Generally, dendritic cells in tissue are active in the capture, uptake and processing of antigens. Once dendritic cells arrive in secondary lymphoid tissue, however, they lose these properties while gaining the capacity to interact with naive T-cells. www.indiandentalacademy.com
- 7. Langerhans cells derive from the cellular differentiationof monocytes with the marker "Gr-1" (also known as "Ly-6G/Ly-6C"). This differentiation requires stimulation by colony stimulating factor (CSF)-1. They are similar in morphology and function to macrophages. Langerin is a protein found in Langerhans cells,and other types of dendritic cells www.indiandentalacademy.com
- 8. The Islets of Langerhans are pockets of endocrine cells in the pancreas. These cells produce glucagon and insulin. They are located near the small intestine. Langerhans cells are located in A Basal layer B Horny layer C Granular layer D Prickle cell layer www.indiandentalacademy.com
- 9. Langerhans DC are those that capture antigen, migrate to lymphoid tissues and present antigen to T cells. The lymphoid DCs -- the DC subset that originates from CD34+ cells committed to the lymphoid lineage, are CD11c- and are driven to become DCs by IL-3. S100 is normally present in cells derived from the neural crest (Schwann cells and melanocytes), chondrocytes, adipocytes, myoepithelial cells,macrophages, Langerhans www.indiandentalacademy.com
- 10. CLINICAL SIGNIFICANCE LCH In the rare disease Langerhans cell histiocytosis (LCH), an excess of these cells is produced. This can cause damage to skin, bone and other organs. HIV Langerhans cells may be initial cellular targets in the sexual transmission of HIV and may be a target, reservoir, and vector of dissemination. Langerhans cells have been observed in foreskin, vaginal, and oral mucosa of humans; the lower concentrations in oral mucosa suggest that it is not a likely source of HIV infection relative to foreskin and vaginal mucosa. www.indiandentalacademy.com