Langerhans' cells are dendritic cells abundant in epidermis, containing large granules called Birbeck granules. Dendritic cells (DCs are Immune cells and form part of the Mammalian Immune system. Birbeck granules are "tennis-racket" or rod shaped cytoplasmic organelles with a central linear density and a striated appearance They are normally present in lymph nodes, and can be found in other organs in the condition Histiocytosis. In Medicine, histiocytosis is an excessive number of Histiocytes that is an excessive number of tissue Macrophages, and is typically used

Section of skin showing large numbers of dendritic (Langerhans cells) in the epidermis. M. ulcerans infection, S100 immunoperoxidase stain)

Named after German anatomist and physician Paul Langerhans (1847-1888) who described it in skin when he was a medical student. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration A physician, medical practitioner or medical doctor who practices Medicine, and is concerned with maintaining or restoring human Health Paul Langerhans ( July 25 1847 - July 20 1888) was a German pathologist, physiologist biologist.

Function

On infection of an area of skin, the local Langerhans' cells will take up and process microbial antigens to become fully-functional antigen-presenting cells. An infection is the detrimental Colonization of a host Organism by a foreign Species. The skin is the outer covering of living tissue of an animal (or plant A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually An antigen (from antibody-generating) or immunogen is a substance that prompts the generation of Antibodies and can cause an immune response See also Antigen presentation An antigen-presenting cell ( APC) or accessory cell is a cell that displays foreign Antigen complexed

Generally, dendritic cells in tissue are active in the capture, uptake and processing of antigens. Tissue is a cellular organizational level intermediate between cells and a complete organism Once dendritic cells arrive in secondary lymphoid tissue however, they lose these properties while gaining the capacity to interact with naive T-cells. A naive T cell or Th0 cell is a T cell that has differentiated in Bone marrow, and successfully undergone the positive and negative processes of central

Langerhans' cells are derived from the cellular differentiation of monocytes with the marker "Gr-1" (also known as "Ly-6c/G"). In Developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized Cell type. The differentiation requires stimulation by colony stimulating factor-1. Colony-stimulating factors (CSFs are secreted Glycoproteins which bind to receptor proteins on the surfaces of Hemopoietic stem cells and thereby activate Intracellular ^[1] They are similar in morphology and function to macrophages. Macrophages ( Greek: "big eaters" from makros "large" + phagein "eat" ( Mø) are cells within the tissues that ^[2]

Clinical significance

LCH

In the rare disease Langerhans' cell histiocytosis (LCH), an excess of these cells is produced, which can cause damage to skin, bone and other organs. A rare disease (sometimes known as an orphan disease has such a low Prevalence in a population that a doctor in a busy General practice would not Langerhans Cell Histiocytosis (LCH is a rare Disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from Bone marrow The skin is the outer covering of living tissue of an animal (or plant Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce

HIV

Langerhans' cells capture HIV-1 virions by way of Fc receptor binding to antibody-coated virus. Langerhans' cells act as reservoirs for the HIV-1 virus, serving as a site of replication when T-cells become depleted (Robbins Pathology).

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. In Male Human Anatomy, the foreskin or prepuce (a technically broader term that also includes the Clitoral hood, the homologous The oral mucosa is the Mucous membrane epithelium of the Mouth. Human immunodeficiency virus ( HIV) is a Lentivirus (a member of the Retrovirus family that can lead to acquired immunodeficiency syndrome ^[3]

On March 4, 2007 the online Nature Medicine magazine published the letter "Langerin is a natural barrier to HIV-1 transmission by Langerhans cells",^[4] written by Dutch scientists which claims "that Langerin is able to scavenge viruses from the surrounding environment, thereby preventing infection. Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Nature Medicine is an Academic journal publishing research articles reviews news and commentaries in the biomedical area including both basic research and Langerin is a type II transmembrane cell surface receptor produced by Langerhans cells Langerin on mucosal Langerhans cells of the human genital "

See also

• histiocytosis
• Foreskin
• Paul Langerhans
• Langhans giant cell

References

External links

• Langerhans Cell Histiocytosis at eMedicine
• Illustration at trinity.edu
• Birbeck granules at djo.harvard.edu
• MeSH Langerhans+Cells