Langerhans cell 1552139 225344558 2008-07-13T05:16:29Z AlphaEta 2368277 Expanding quote by Geijtenbeek and adding citation. '''Langerhans' cells''' are [[dendritic cells]] abundant in [[Epidermis (skin)|epidermis]], containing large granules called [[Birbeck granules]]. They are normally present in lymph nodes, and can be found in other organs in the condition [[Histiocytosis]]. [[Image:Dendritic cells.jpg|thumb|Section of skin showing large numbers of dendritic (Langerhans cells) in the epidermis. (''M. ulcerans'' infection, S100 immunoperoxidase stain.)]] Specifically, the Langerhans cells are located primarily in the [[stratum spinosum]] portion of the epidermis. Named after [[Germany|German]] [[anatomist]] and [[physician]] [[Paul Langerhans]] (1847-1888) who described it in skin when he was a medical student. ==Function== On [[infection]] of an area of [[skin]], the local Langerhans' cells will take up and process [[microbe|microbial]] [[antigen]]s to become fully-functional [[antigen-presenting cell]]s. Generally, dendritic cells in [[biological tissue|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-cell]]s. Langerhans' cells are derived from the [[cellular differentiation]] of monocytes with the marker "Gr-1" (also known as "Ly-6c/G"). The differentiation requires stimulation by [[colony stimulating factor]]-1.<ref>{{cite journal | author = Ginhoux F, Tacke F, Angeli V, Bogunovic M, Loubeau M, Dai X, Stanley E, Randolph G, Merad M | title = Langerhans cells arise from monocytes in vivo | journal = Nat Immunol | volume = 7 | issue = 3 | pages = 265–73 | year = 2006 | pmid = 16444257 | doi = 10.1038/ni1307}}</ref> They are similar in morphology and function to [[macrophages]]. <ref name=T4> Semester 4 medical lectures at Uppsala University 2008 by Leif Jansson</ref> ==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. ===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.<ref>{{cite journal | author = Hussain, LA, Lehner T | title = Comparative Investigation of Langerhans' cells and Potential Receptors for HIV in Oral, Genitourinary and Rectal Epithelia | journal = Immunology | volume = 85 | pages = 475–484 | year = 1995 |pmid=7558138}}</ref> On [[March 4]] [[2007]] the online [[Nature Medicine]] magazine published the letter "Langerin is a natural barrier to HIV-1 transmission by Langerhans cells."<ref>{{cite journal |author=de Witte L, Nabatov A, Pion M, Fluitsma D, de Jong M, de Gruijl T, Piguet V, van Kooyk Y, Geijtenbeek T |title=Langerin is a natural barrier to HIV-1 transmission by Langerhans cells |journal=Nat Med |volume=13 |issue=3 |pages=367–71 |year=2007 |pmid=17334373 |doi=10.1038/nm1541}}</ref> Teunis Geijtenbeek, one of the authors of the study, said that "[[Langerin]] is able to scavenge viruses from the surrounding environment, thereby preventing infection" and "since generally all tissues on the outside of our bodies have Langerhans cells, we think that the human body is equipped with an antiviral defense mechanism, destroying incoming viruses."<ref>{{cite news |first=E.J. |last=Mundell |title=Scientists Discover 'Natural Barrier' to HIV |url=http://sexualhealth.e-healthsource.com/index.php?p=news1&id=602421 |work= |publisher=HealthDay News via sexualhealth.e-healthsource.com |date=March 5, 2007 |accessdate=2008-07-13 }}</ref> ==See also== * [[histiocytosis]] * [[Foreskin]] * [[Paul Langerhans]] * [[Langhans giant cell]] ==References== {{reflist}} ==External links== * {{eMedicine|derm|216|Langerhans Cell Histiocytosis}} * [http://www.trinity.edu/rblyston/MicroA/Lectures/L34-html/img018.jpg Illustration at trinity.edu] * [http://www.djo.harvard.edu/site.php?url=/physicians/gr/356&page=GR_AG Birbeck granules at djo.harvard.edu] * {{MeshName|Langerhans+Cells}} {{Blood}} [[Category:Mononuclear phagocytes]] [[Category:Integumentary system]] {{Cell-biology-stub}} [[fr:Cellule de Langerhans]] [[it:Cellula di Langerhans]] [[nl:Langerhanscel]] [[ja:ランゲルハンス細胞]] [[pl:Komórka Langerhansa]] [[pt:Célula de Langerhans]] [[ur:لینگرہانس خلیہ]] [[zh:郎格罕细胞]]