Anti-Hu CD20 Purified

CD20 is a cell surface 33-37 (depending on the degree of phosphorylation) kDa non-glycosylated surface phosphoprotein expressed on mature and most malignant B cells, but not stem cells or plasma cells (low number of the CD20 has been also detected on a subpopulation of T lymphocytes and it can be expressed on follicular dendritic cells) . Its expression on B cells is synchronous with the expression of surface IgM. CD20 regulates transmembrane calcium conductance (probably functioning as a component of store-operated calcium channel), cell cycle progression and B-cell proliferation. It is associated with lipid rafts, but the intensity of this association depends on extracellular triggering, employing CD20 conformational change and/or BCR (B cell antigen receptor) aggregation. After the receptor ligation, BCR and CD20 colocalize and then rapidly dissociate before BCR endocytosis, whereas CD20 remains at the cell surface. CD20 serves as a useful target for antibody-mediated therapeutic depletion of B cells, as it is expressed at high levels on most B-cell malignancies, but does not become internalized or shed from the plasma membrane following mAb treatment.

Product Specifications

Certification

RUO

Reactivity

Cow, Human

Immunogen

Raji human Burkitt's lymphoma cell line

Target Antigen

CD20

Clone

MEM-97

Applications

FC (QC tested), IP

Concentration

1 mg/mL

Format

Purified

Buffer

Phosphate buffered saline (PBS), pH 7.4, 15 mM sodium azide

References & Citations

*Ohradanova-Repic A, Machacek C, Charvet C, Lager F, Le Roux D, Platzer R, Leksa V, Mitulovic G, Burkard TR, Zlabinger GJ, Fischer MB, Feuillet V, Renault G, Blüml S, Benko M, Suchanek M, Huppa JB, Matsuyama T, Cavaco-Paulo A, Bismuth G, Stockinger H: Extracellular Purine Metabolism Is the Switchboard of Immunosuppressive Macrophages and a Novel Target to Treat Diseases With Macrophage Imbalances. Front Immunol. 2018 Apr 27;9:852., URL: https://www.ncbi.nlm.nih.gov/pubmed/29780382 , *Strobl H, Takimoto M, Majdic O, Fritsch G, Scheinecker C, Höcker P, Knapp W: Myeloperoxidase expression in CD34+ normal human hematopoietic cells. Blood. 1993 Oct 1;82 (7) :2069-78., URL: http://www.ncbi.nlm.nih.gov/pubmed/7691248 , *Faldyna M, Samankova P, Leva L, Cerny J, Oujezdska J, Rehakova Z, Sinkora J: Cross-reactive anti-human monoclonal antibodies as a tool for B-cell identification in dogs and pigs. Vet Immunol Immunopathol. 2007 Sep 15;119 (1-2) :56-62. , URL: http://www.ncbi.nlm.nih.gov/pubmed/17673300 , *Brdicková N, Brdicka T, Angelisová P, Horváth O, Spicka J, Hilgert I, Paces J, Simeoni L, Kliche S, Merten C, Schraven B, Horejsí V: LIME: a new membrane Raft-associated adaptor protein involved in CD4 and CD8 coreceptor signaling. J Exp Med. 2003 Nov 17;198 (10) :1453-62., URL: http://www.ncbi.nlm.nih.gov/pubmed/14610046?itool=, *Polyak MJ, Deans JP: Alanine-170 and proline-172 are critical determinants for extracellular CD20 epitopes; heterogeneity in the fine specificity of CD20 monoclonal antibodies is defined by additional requirements imposed by both amino acid sequence and quaternary structure. Blood. 2002 May 1;99 (9) :3256-62., URL: https://www.ncbi.nlm.nih.gov/pubmed/11964291?dopt=, *Szollosi J, Horejsi V, Bene L, Angelisova P, Damjanovich S: Supramolecular complexes of MHC class I, MHC class II, CD20, and tetraspan molecules (CD53, CD81, and CD82) at the surface of a B cell line JY. J Immunol. 1996 Oct 1;157 (7) :2939-46., URL: https://www.ncbi.nlm.nih.gov/pubmed/8816400?dopt=A, *Leukocyte Typing V., Schlossman S. et al. (Eds.), Oxford University Press (1995) ., URL:

Other References

*Li H, Ayer LM, Polyak MJ, Mutch CM, Petrie RJ, Gauthier L, Shariat N, Hendzel MJ, Shaw AR, Patel KD, Deans JP. The CD20 calcium channel is localized to microvilli and constitutively associated with membrane rafts: antibody binding increases the affinity of the association through an epitope-dependent cross-linking-independent mechanism. J Biol Chem. 2004 May 7;279 (19) :19893-901., URL: https://pubmed.ncbi.nlm.nih.gov/17497959/, *Glennie MJ, French RR, Cragg MS, Taylor RP: Mechanisms of killing by anti-CD20 monoclonal antibodies. Mol Immunol. 2007 Sep;44 (16) :3823-37., URL: https://pubmed.ncbi.nlm.nih.gov/17768100/, *Cragg MS, Walshe CA, Ivanov AO, Glennie MJ: The biology of CD20 and its potential as a target for mAb therapy. Curr Dir Autoimmun. 2005;8:140-74., URL: https://pubmed.ncbi.nlm.nih.gov/15564720/, *Petrie RJ, Deans JP: Colocalization of the B cell receptor and CD20 followed by activation-dependent dissociation in distinct lipid rafts. J Immunol. 2002 Sep 15;169 (6) :2886-91., URL: https://pubmed.ncbi.nlm.nih.gov/12218101/, *Hultin LE, Hausner MA, Hultin PM, Giorgi JV: CD20 (pan-B cell) antigen is expressed at a low level on a subpopulation of human T lymphocytes. Cytometry. 1993;14 (2) :196-204., URL: https://www.ncbi.nlm.nih.gov/pubmed/7679964?dopt=A

Storage Conditions

Store at 2-8°C. Do not freeze.

Specificity

The antibody MEM-97 reacts with an extracellular epitope on CD20 (Bp35), a 33-37 kDa non-glycosylated membrane receptor with four transmembrane domains, expressed on B lymphocytes (it is lost on plasma cells), follicular dendritic cells, and at low levels on peripheral blood T lymphocytes.