Editing Plasma cell (section)

== Development ==
After leaving the bone marrow, the B cell acts as an [[antigen-presenting cell]] (APC) and internalizes offending antigens, which are taken up by the B cell through [[receptor-mediated endocytosis]] and processed. Pieces of the antigen (which are now known as ''antigenic peptides'') are loaded onto [[MHC II]] molecules, and presented on its extracellular surface to [[CD4+ T cells]] (sometimes called ''T helper cells''). These T cells bind to the MHC II-antigen molecule and cause activation of the B cell. This is a type of safeguard to the system, similar to a [[two-factor authentication]] method. First, the B cells must encounter a foreign antigen and are then required to be activated by T helper cells before they differentiate into specific cells.<ref>{{Cite book |last=Hoffbrand |first=A. V. |url=https://www.worldcat.org/oclc/768731797 |title=Essential haematology |date=2011 |publisher=Wiley-Blackwell |others=P. A. H. Moss, J. E. Pettit |isbn=978-1-118-29397-3 |edition=6th |location=Malden, Mass. |chapter=Chapter 9 White Cells: Lymphocytes |oclc=768731797}}</ref>

Upon stimulation by a T cell, which usually occurs in [[germinal center]]s of [[secondary lymphoid organ]]s such as the [[spleen]] and [[lymph nodes]], the activated B cell begins to differentiate into more specialized cells. [[Germinal center]] B cells may differentiate into [[memory B cells]] or plasma cells.  Most of these B cells will become plasmablasts (or "immature plasma cells"), and eventually plasma cells, and begin producing large volumes of antibodies. Some B cells will undergo a process known as [[affinity maturation]].<ref name="Neuberger-2004">{{cite book | vauthors = Neuberger MS, Honjo T, Alt FW |title=Molecular biology of B cells |publisher=Elsevier |location=Amsterdam |year=2004 |pages=189–191 |isbn=0-12-053641-2 }}</ref> This process favors, by selection for the ability to bind antigen with higher affinity, the activation and growth of B cell clones able to secrete antibodies of higher affinity for the antigen.<ref name="Merino Tejero-2020">{{Cite journal |last1=Merino Tejero |first1=Elena |last2=Lashgari |first2=Danial |last3=García-Valiente |first3=Rodrigo |last4=Gao |first4=Xuefeng |last5=Crauste |first5=Fabien |last6=Robert |first6=Philippe A. |last7=Meyer-Hermann |first7=Michael |last8=Martínez |first8=María Rodríguez |last9=van Ham |first9=S. Marieke |last10=Guikema |first10=Jeroen E. J. |last11=Hoefsloot |first11=Huub |last12=van Kampen |first12=Antoine H. C. |date=2020 |title=Multiscale Modeling of Germinal Center Recapitulates the Temporal Transition From Memory B Cells to Plasma Cells Differentiation as Regulated by Antigen Affinity-Based Tfh Cell Help |journal=Frontiers in Immunology |volume=11 |pages=620716 |doi=10.3389/fimmu.2020.620716 |issn=1664-3224 |pmc=7892951 |pmid=33613551|doi-access=free }}</ref>

===Immature plasma cells===
[[File:Plasmablast, Wright stain.png|thumb|Plasmablast, [[Wright stain]].]]
The most immature blood cell that is considered of plasma cell lineage is the plasmablast.<ref name="isbn0-7817-6507-2">{{cite book | vauthors = Glader B, Greer JG, Foerster J, Rodgers GC, Paraskevas F |title=Wintrobe's Clinical Hematology, 2-Vol. Set |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2008 |pages=347 |isbn=978-0-7817-6507-7 }}</ref> Plasmablasts secrete more antibodies than B cells, but less than plasma cells.<ref name="Walport-2008">{{cite book |vauthors = Walport M, Murphy K, Janeway C, Travers PJ |title=Janeway's immunobiology |publisher=Garland Science |location=New York |year=2008 |pages=[https://archive.org/details/janewaysimmunobi00murp/page/387 387–388] |isbn=978-0-8153-4123-9 |url-access=registration |url=https://archive.org/details/janewaysimmunobi00murp/page/387 }}</ref> They divide rapidly and are still capable of internalizing antigens and presenting them to T cells.<ref name="Walport-2008" /> A cell may stay in this state for several days, and then either die or irrevocably differentiate into a mature, fully differentiated plasma cell.<ref name="Walport-2008" /> Differentiation of mature B cells into plasma cells is dependent upon the transcription factors [[Blimp-1]]/[[PRDM1]], [[BCL6]], and [[IRF4]].<ref name="Merino Tejero-2020" />