Editing Langerhans cell (section)

==Function==
In [[skin]] [[infection]]s, the local Langerhans cells take up and process [[microbe|microbial]] [[antigen]]s to become fully functional [[antigen-presenting cell]]s.<ref name="Monnot">{{cite journal | vauthors = Monnot GC, Wegrecki M, Cheng TY, Chen YL, Sallee BN, Chakravarthy R, Karantza IM, Tin SY, Khaleel AE, Monga I, Uwakwe LN, Tillman A, Cheng B, Youssef S, Ng SW, Shahine A, Garcia-Vilas JA, Uhlemann AC, Bordone LA, Han A, Rohde CH, Ogg G, Moody DB, Rossjohn J, de Jong A| title = Staphylococcal phosphatidylglycerol antigens activate human T cells via CD1a | journal = Nature Immunology | volume = 24 | issue = 1 | pages = 110–122 | date = January 2023 | pmid = 35265979 | doi = 10.1038/s41590-022-01375-z| s2cid = 255039948 | pmc = 10389259 }}</ref>

Generally, tissue-resident macrophages are involved in immune homeostasis and the uptake of [[Apoptosis|apoptotic bodies]]. However, Langerhans cells can also take on a [[dendritic cell]]-like phenotype and migrate to [[lymph node]]s to interact with [[naive T-cell]]s.{{Medical citation needed|date=June 2021}}

[[Matrix metalloproteinase]] is important and necessary for langerhans cell when it passes [[stratum basale]].<ref>{{Cite journal |last=Ratzinger |first=Gudrun |last2=Stoitzner |first2=Patrizia |last3=Ebner |first3=Susanne |last4=Lutz |first4=Manfred B. |last5=Layton |first5=Guy T. |last6=Rainer |first6=Christian |last7=Senior |first7=Robert M. |last8=Shipley |first8=J. Michael |last9=Fritsch |first9=Peter |last10=Schuler |first10=Gerold |last11=Romani |first11=Nikolaus |date=2002-05-01 |title=Matrix metalloproteinases 9 and 2 are necessary for the migration of Langerhans cells and dermal dendritic cells from human and murine skin |url=https://pubmed.ncbi.nlm.nih.gov/11970978/ |journal=Journal of Immunology |volume=168 |issue=9 |pages=4361–4371 |doi=10.4049/jimmunol.168.9.4361 |issn=0022-1767 |pmid=11970978}}</ref>

Langerhans cells derive from primitive erythro-myeloid progenitors that arise in the yolk sac outside the [[embryo]] in the first trimester of pregnancy, and under normal circumstances persist throughout life, being replenished by local [[Cell proliferation|proliferation]] as necessary. If the skin becomes severely inflamed, perhaps because of infection, blood monocytes are recruited to the affected region and [[Cellular differentiation|differentiate]] into replacement LCs.<ref>{{cite journal |doi=10.1097/MOH.0000000000000202 |title=Langerhans cell origin and regulation |year=2016 |last1=Collin|first1=Matthew|last2=Milne|first2=Paul |journal=Current Opinion in Hematology |volume=23 |issue=1 |pages=28–35 |pmc=4685746 |pmid=26554892}}</ref>

[[Langerin]] is a protein found in Langerhans cells,<ref name="pmid14610287">{{cite journal |doi=10.1385/IR:28:2:93 |title=Langerin/CD207 Sheds Light on Formation of Birbeck Granules and Their Possible Function in Langerhans Cells |year=2003 |last1=Valladeau |first1=Jenny |last2=Dezutter-Dambuyant |first2=Colette |last3=Saeland |first3=Sem |journal=Immunologic Research |volume=28 |issue=2 |pages=93–107 |pmid=14610287|s2cid=37296843 }}</ref> and [[dendritic cells]].<ref name="pmid18086861">{{cite journal |doi=10.1084/jem.20071724 |title=The dermis contains langerin+ dendritic cells that develop and function independently of epidermal Langerhans cells |year=2007 |last1=Poulin |first1=Lionel Franz |last2=Henri |first2=Sandrine |last3=de Bovis |first3=Béatrice |last4=Devilard |first4=Elisabeth |last5=Kissenpfennig |first5=Adrien |last6=Malissen |first6=Bernard |journal=Journal of Experimental Medicine |volume=204 |issue=13 |pages=3119–31 |pmid=18086861 |pmc=2150992 |url=http://pure.qub.ac.uk/portal/files/18113605/JEM1_2008.pdf |access-date=2018-11-04 |archive-url=https://web.archive.org/web/20180719214424/https://pure.qub.ac.uk/portal/files/18113605/JEM1_2008.pdf |archive-date=2018-07-19 |url-status=dead }}</ref>

'''LCs''' contain a large amount of [[cannabinoid receptor type 2]] (CB2), that by activation by [[SR-144,528|agonists]], attenuate both the recruitment of [[eosinophil]]s and ear [[Allergy|swelling]] in chronic [[contact dermatitis]] induced by repeated challenge.<ref>{{Cite journal |last=Oka |first=Saori |date=2006 |title=Involvement of the Cannabinoid CB2 Receptor and Its Endogenous Ligand 2-Arachidonoylglycerol in Oxazolone-Induced Contact Dermatitis in Mice |url=https://journals.aai.org/jimmunol/article/177/12/8796/74027/Involvement-of-the-Cannabinoid-CB2-Receptor-and |access-date=2023-03-26 |journal=Journal of Immunology |volume=177 |issue=12 |pages=8796–9505 |doi=10.4049/jimmunol.177.12.8796 |pmid=17142782 |s2cid=11946479 |doi-access=free }}</ref>