Editing B cell (section)

{{Short description|Type of white blood cell}}
{{About|the immune system cell|the electrical cell|Battery (vacuum tube)|β-cell of pancreas|beta cell}}
{{Infobox cell
| Name        = B  lymphocyte
cell
| Latin       = lymphocytus B
| Image       = Blausen 0624 Lymphocyte B cell (crop).png
| Caption     = Animation of B cell
| Precursor   = [[Hematopoietic stem cell]]
| System      = [[Immune system]]
}}

'''B cells''', also known as '''B lymphocytes''', are a type of [[white blood cell]] of the [[lymphocyte]] subtype.<ref name=":0">{{Cite book|title = Janeway's Immunobiology |edition=8th | vauthors = Murphy K |publisher = Garland Science |year = 2012|isbn = 9780815342434|location = New York}}</ref> They function in the [[humoral immunity]] component of the [[adaptive immune system]].<ref name=":0" /> B cells produce [[antibody]] molecules which may be either secreted or inserted into the plasma membrane where they serve as a part of [[B-cell receptor]]s.<ref name="Alberts 2002">{{Cite book | vauthors = Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P |date=2002| chapter = B Cells and Antibodies | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK26884/| title = Molecular Biology of the Cell |publisher=Garland Science | edition = 4th }}</ref> When a naïve or [[memory B cell]] is activated by an antigen, it proliferates and differentiates into an antibody-secreting effector cell, known as a plasmablast or plasma cell.<ref name="Alberts 2002"/> In addition, B cells [[Antigen presentation|present antigens]] (they are also classified as professional [[Antigen-presenting cell|antigen-presenting cells, APCs]]) and secrete [[cytokine]]s.<ref name=":0" /> In [[mammal]]s B cells [[Cellular differentiation|mature]] in the [[bone marrow]], which is at the core of most [[bone]]s.<ref name=":1">{{cite journal | vauthors = Cooper MD | title = The early history of B cells | journal = Nature Reviews. Immunology | volume = 15 | issue = 3 | pages = 191–197 | date = March 2015 | pmid = 25656707 | doi = 10.1038/nri3801 | author-link = Max Dale Cooper | doi-access = free }}</ref> In [[bird]]s, B cells mature in the [[bursa of Fabricius]], a lymphoid organ where they were first discovered by Chang and Glick,<ref>{{Cite journal |last1=Glick |first1=Bruce |last2=Chang |first2=Timothy S. |last3=Jaap |first3=R. George |date=1956-01-01 |title=The Bursa of Fabricius and Antibody Production |journal=Poultry Science |language=en |volume=35 |issue=1 |pages=224–225 |doi=10.3382/ps.0350224 |issn=0032-5791|doi-access=free }}</ref> which is why the ''B'' stands for ''bursa'' and not ''bone marrow'', as commonly believed.

B cells, unlike the other two classes of lymphocytes, [[T cell]]s and [[natural killer cell]]s, express [[B-cell receptor|B cell receptors (BCRs)]] on their [[cell membrane]].<ref name=":0" /> BCRs allow the B cell to [[Molecular binding|bind]] to a foreign [[antigen]], against which it will initiate an antibody response.<ref name=":0" /> B cell receptors are extremely specific, with all BCRs on a B cell recognizing the same [[epitope]].<ref>{{cite journal |last1=Jespersen |first1=Martin Closter |last2=Mahajan |first2=Swapnil |last3=Peters |first3=Bjoern |last4=Nielsen |first4=Morten |last5=Marcatili |first5=Paolo |title=Antibody Specific B-Cell Epitope Predictions: Leveraging Information From Antibody-Antigen Protein Complexes |journal=Frontiers in Immunology |doi=10.3389/fimmu.2019.00298 |date=2019|volume=10 |page=298 |pmid=30863406 |pmc=6399414 |doi-access=free }}</ref>