Pokeweed mitogen
{{Short description|Type of protein}}
Pokeweed mitogen is a mitogen derived from the roots of Phytolacca americana. It functions as a lectin and a mitotic stimulus for the division of lymphocytes.
Biological functions
This lectin specifically induces the proliferation of B cells, plasma cells and T cells.{{Citation|title=Pokeweed Mitogen|date=2005|url=https://doi.org/10.1007/3-540-27806-0_1183|work=Encyclopedic Reference of Immunotoxicology|pages=509|editor-last=Assenmacher|editor-first=Mario|place=Berlin, Heidelberg|publisher=Springer|language=en|doi=10.1007/3-540-27806-0_1183|isbn=978-3-540-27806-1|access-date=2021-11-30|editor2-last=Avraham|editor2-first=Hava Karsenty|editor3-last=Avraham|editor3-first=Shalom|editor4-last=Bala|editor4-first=Shukal|url-access=subscription}} This lectin contains Toll-like receptor 4 (TLR4) proteins which signals for the B-cell for a proliferative response. B cells are shown to have no response to pure PWM without the Toll-like receptor suggesting that PWM inducing ability relies on TLR4 protein's presence for the signaling of B-cells and the response.
Research
PWM can contribute to B-cell assay or other lymphocytes for testing. The amplified number of proliferated cells makes it easier to test different lymphocyte functions, biological mechanisms, and response to different stimuli. Pokeweed mitogen is also used in research studies to stimulate different lymphocytes and observe change. When looking at deficiency of CD26 in knockout mice, after stimulation with PWM the role of CD26 in development of CD4+ T cells was observed.{{Cite journal |last1=Yan |first1=Shuling |last2=Marguet |first2=Didier |last3=Dobers |first3=Jörg |last4=Reutter |first4=Werner |last5=Fan |first5=Hua |date=2003 |title=Deficiency of CD26 results in a change of cytokine and immunoglobulin secretion after stimulation by pokeweed mitogen |url=http://dx.doi.org/10.1002/eji.200323469 |journal=European Journal of Immunology |volume=33 |issue=6 |pages=1519–1527 |doi=10.1002/eji.200323469 |pmid=12778469 |s2cid=13371173 |issn=0014-2980|doi-access=free }} Another study where PWM was used as a stimulus was in the proteome analysis of lymphocytes of different immune phenotypes in cows.{{Cite journal |last1=Kleinwort |first1=Kristina J. H. |last2=Degroote |first2=Roxane L. |last3=Hirmer |first3=Sieglinde |last4=Korbonits |first4=Lucia |last5=Lorenz |first5=Lea |last6=Scholz |first6=Armin M. |last7=Hauck |first7=Stefanie M. |last8=Deeg |first8=Cornelia A. |date=2022-02-08 |title=Bovine Peripheral Blood Derived Lymphocyte Proteome and Secretome Show Divergent Reaction of Bovine Immune Phenotypes after Stimulation with Pokeweed Mitogen |journal=Proteomes |volume=10 |issue=1 |pages=7 |doi=10.3390/proteomes10010007 |pmid=35225986 |pmc=8883952 |issn=2227-7382|doi-access=free }} Other research involves the PWM lectin playing a role in cancer detection. The PWM lectin was found to have affinity for human colorectal cancers indicating its usefulness in analysis of glycoconjugates found in colorectal cancer and detection of cancerous tissue.{{Cite journal |last1=Aoki |first1=T |last2=Kawano |first2=J |last3=Oinuma |first3=T |last4=Haraguchi |first4=Y |last5=Eto |first5=T |last6=Suganuma |first6=T |date=1993 |title=Human colorectal carcinoma-specific glycoconjugates detected by pokeweed mitogen lectin. |url=http://dx.doi.org/10.1177/41.9.8102627 |journal=Journal of Histochemistry & Cytochemistry |volume=41 |issue=9 |pages=1321–1330 |doi=10.1177/41.9.8102627 |pmid=8102627 |s2cid=26077790 |issn=0022-1554|doi-access=free |url-access=subscription }}
Clinical significance
Pokeweed mitogen has the ability to play a role in immunology. It can test for immunodeficiency by inducing cell proliferation and test for abnormal counts of lymphocytes.{{cite journal | vauthors = Bekeredjian-Ding I, Foermer S, Kirschning CJ, Parcina M, Heeg K | title = Poke weed mitogen requires Toll-like receptor ligands for proliferative activity in human and murine B lymphocytes | journal = PLOS ONE | volume = 7 | issue = 1 | pages = e29806 | date = 2012-01-04 | pmid = 22238657 | pmc = 3251602 | doi = 10.1371/journal.pone.0029806 | bibcode = 2012PLoSO...729806B | doi-access = free }} It can also induce proliferation of cells that target tumors, which is useful for the treatment of cancer.{{cite journal | vauthors = Numa K, Tani T, Kodama M | title = Trial of anticancer immunotherapy with immobilized pokeweed mitogen: immunotherapy by extracorporeal circulation | journal = Cancer Immunology, Immunotherapy | volume = 32 | issue = 2 | pages = 125–130 | date = 1990 | pmid = 2289204 | doi = 10.1007/BF01754209 | s2cid = 26066215 | pmc = 11038877 }} Other studies in mice showed that PWM contributes to weight-loss effects and increased glucose uptake which makes this lectin a subject for implementation in diabetes or obesity in humans.{{Cite journal|last1=Lazarus|first1=Dougals D.|last2=Trimble|first2=Linda A.|last3=Moldawer|first3=Lyle L.|date=1998-01-01|title=The metabolic effects of pokeweek mitogen in mice|url=https://www.metabolismjournal.com/article/S0026-0495(98)90196-2/abstract|journal=Metabolism: Clinical and Experimental|language=English|volume=47|issue=1|pages=75–82|doi=10.1016/S0026-0495(98)90196-2|issn=0026-0495|pmid=9440481|url-access=subscription}}