CD20 Antibody (L26)

Immunohistochemistry: CD20 Antibody (L26) [NBP2-44743] - CD20 cell staining in involved and uninvolved skin from a patient with systemic sclerosis (SSc). a Cellular infiltrate in involved skin (distal forearm biopsy) from a patient with early anti-Scl-70+ diffuse SSc showing an appreciable number of CD20+ cells in perivascular areas. b Uninvolved skin (buttock biopsy) from the same patient showing the presence of a smaller number of CD20+ cells around blood vessels. Original magnification 400x (a and b). Nuclei were counterstained by hematoxylin. Bottom insets show the infiltrating cells at a lower magnification (200x). Insets at the top of the figures show hematoxylin and eosin (H&E) staining of involved and uninvolved skin (50x). Image collected and cropped by CiteAb from the following publication (//arthritis-research.biomedcentral.com/articles/10.1186/s13075-018-1569-0) licensed under a CC-BY license.

Immunocytochemistry/Immunofluorescence: CD20 Antibody (L26) [NBP2-44743] - Immunofluorescence staining of Raji cells using CD20 Mouse Monoclonal Antibody (L26) followed by goat anti-Mouse IgG conjugated to CF488 (green). Nuclei are stained with Reddot.

Western Blot: CD20 Antibody (L26) [NBP2-44743] - Western Blot Analysis of Raji cell lysate using CD20 Mouse Monoclonal Antibody (L26).

Flow Cytometry: CD20 Antibody (L26) [NBP2-44743] - Cytometric Analysis of Raji cells using CD20 Mouse Monoclonal Antibody (L26) followed by Goat anti-Mouse IgG-CF488 (Blue); Isotype Control (Red).

Immunohistochemistry-Paraffin: CD20 Antibody (L26) [NBP2-44743] - Human Tonsil stained with CD20 Monoclonal Antibody (L26)

Immunohistochemistry-Paraffin: CD20 Antibody (L26) [NBP2-44743] - Human Lymphoma stained with CD20 Monoclonal Antibody (L26)

Product Discontinued

CD20 Antibody (L26) Summary

• Immunogen: Human tonsil B cells
• Localization: Predominantly cell surface with some cytoplasmic
• Marker: B-Cell Marker
• Specificity: Recognizes a protein of 30-33kDa, which is identified as CD20. Its epitope is located in the cytoplasmic domain of CD20 and was, therefore, ascribed as CD20cy in the 5th Workshop. CD20 is a non-Ig differentiation antigen of B-cells and its expression is restricted to normal and neoplastic B-cells, being absent from all other leukocytes and tissues. CD20 is expressed by pre B-cells and persists during all stages of B-cell maturation but is lost upon terminal differentiation into plasma cells. This MAb can be used for immunophenotyping of leukemia and malignant cells, B lymphocyte detection in peripheral blood and B cell localization in tissues. It reacts with the majority of B-cells present in peripheral blood and lymphoid tissues and their derived lymphomas. In lymphoid tissue, germinal center blasts and B-immunoblasts are particularly reactive. It is a reliable antibody for ascribing a B-cell phenotype in known lymphoid tissues. Rarely, CD20-positive T-cell lymphomas have been reported. Reactivity has also been noted with Reed-Sternberg cells in cases of Hodgkins disease, particularly of lymphocyte predominant type.
• Isotype: IgG2a Kappa
• Clonality: Monoclonal
• Host: Mouse
• Gene: MS4A1
• Purity: Protein A or G purified

Applications/Dilutions

• Dilutions:
  • Flow Cytometry 0.5-1 ug/million cells
  • Immunocytochemistry/ Immunofluorescence 1-2 ug/ml
  • Immunofluorescence 1:100-1:200
  • Immunohistochemistry 0.5-1 ug/ml
  • Immunohistochemistry-Paraffin 1:100-1:200
  • Western Blot 1-2 ug/ml
• Application Notes: Immunohistology (Formalin-fixed): 0.5-1ug/ml for 30 minutes at RT. Staining of formalin-fixed tissues requires boiling tissue sections in 10mM citrate buffer, pH 6.0, for 10-20 min followed by cooling at RT for 20 minutes.
  Optimal dilution for a specific application should be determined.

Reactivity Notes

Others not known.

Packaging, Storage & Formulations

• Storage: Store at 4C.
• Buffer: 10 mM PBS with 0.05% BSA
• Preservative: 0.05% Sodium Azide
• Concentration: 0.2 mg/ml
• Purity: Protein A or G purified

Notes

200ug/ml of antibody purified from Bioreactor Concentrate by Protein A or G. Prepared in 10 mM PBS with 0.05% BSA & 0.05% azide. Also available WITHOUT BSA & azide at 1.0 mg/ml (NBP2-80486).

Antibody with azide - store at 2 to 8C. Antibody without azide - store at -20 to -80C. Antibody is stable for 24 months. Non-hazardous.

Alternate Names for CD20 Antibody (L26)

• B1
• B-lymphocyte antigen CD20
• B-lymphocyte cell-surface antigen B1
• B-lymphocyte surface antigen B1
• Bp35
• Bp35MGC3969
• CD20 antigen
• CD20 receptor
• CD20
• CD20S7
• CVID5
• LEU-16
• Leukocyte surface antigen Leu-16
• Ly-44
• Membrane-spanning 4-domains subfamily A member 1
• membrane-spanning 4-domains, subfamily A, member 1
• MS4A1
• MS4A2
• S7

Background

CD20 is a non-glycosylated phosphoprotein that is expressed on the surface of normal and malignant B cells and functions in mediating calcium transport and B cell differentiation (1,2). CD20 is encoded by the membrane-spanning 4-domain family A member 1 (MS4A1) gene and, in humans, is located on chromosome 11q12 (1). The CD20 protein is 297 amino acids (aa) in length with a theoretical molecular weight (MW) of 33 kDa (1,2). Structurally, the CD20 protein has four membrane-spanning domains, two extracellular loop domains, and intracellular N- and C-terminal domains (1,2). CD20 is expressed at specific stages of B cell maturation including pre-B cells, mature naive and activated B cells, and memory B cells, but is absent from plasmablasts and plasma cells (1,3,4). Expression of CD20 is often increased on malignant B cells associated with various B cell disorders such as chronic lymphocytic leukemia (CLL), multiple sclerosis (MS), and rheumatoid arthritis (2-4). Anti-CD20 monoclonal antibody (mAb)-based therapies have become an appealing target for treating these immune-related disorders and cancers (1-5). Rituximab, a chimeric mAb, was the first FDA approved CD20 monoclonal antibody for the treatment of non-Hodgkin's lymphoma that is now commonly used to treat MS (2,3). Since its initial approval in 1997, several other chimeric and humanized anti-CD20 mAbs have been developed including Ofatumumab, Ublituximab, and Obinutuzumab (1-5). B cell depletion via CD20 mAbs can occur under different mechanisms such as antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), complement-dependent cytotoxicity (CDC), and direct induction of apoptosis (1-4). Many ongoing studies are focused on combination therapies with CD20 mAbs as an addition to chemotherapy, B cell receptor (BCR) signaling inhibitors, or BH3 mimetics (1,2,4). Additionally, the effects of bispecific antibodies and CD20 chimeric antigen receptor (CAR) T cell therapies are under investigation for the treatment of B cell malignancies (4,5).

References

1. Pavlasova G, Mraz M. The regulation and function of CD20: an "enigma" of B-cell biology and targeted therapy. Haematologica. 2020; 105(6):1494-1506. https://doi.org/10.3324/haematol.2019.243543

2. Payandeh Z, Bahrami AA, Hoseinpoor R, et al. The applications of anti-CD20 antibodies to treat various B cells disorders. Biomed Pharmacother. 2019; 109:2415-2426. https://doi.org/10.1016/j.biopha.2018.11.121

3. Margoni M, Preziosa P, Filippi M, Rocca MA. Anti-CD20 therapies for multiple sclerosis: current status and future perspectives. J Neurol. 2022; 269(3):1316-1334. https://doi.org/10.1007/s00415-021-10744-x

4. Klein C, Jamois C, Nielsen T. Anti-CD20 treatment for B-cell malignancies: current status and future directions. Expert Opin Biol Ther. 2021; 21(2):161-181. https://doi.org/10.1080/14712598.2020.1822318

5. Sharman JP. Targeting CD20: teaching an old dog new tricks. Hematology Am Soc Hematol Educ Program. 2019; 2019(1):273-278. https://doi.org/10.1182/hematology.2019000031

Limitations

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

Publications for CD20 Antibody (NBP2-44743)(3)

Publications using NBP2-44743

• Ukita M, Hamanishi J, Yoshitomi H et al. CXCL13-producing CD4+ T cells accumulate in early phase of tertiary lymphoid structures in ovarian cancer JCI insight 2022-05-12 [PMID: 35552285] (IF/IHC, Human)
• Lande R, Pietraforte I, Mennella A et al Complementary Effects of Carbamylated and Citrullinated LL37 in Autoimmunity and Inflammation in Systemic Lupus Erythematosus Int J Mol Sci 2021-02-10 [PMID: 33562078]
  
  Details:
  Citation using the Alexa Fluor 594 version of this antibody.
• Bosello S, Angelucci C, Lama G et al. Characterization of inflammatory cell infiltrate of scleroderma skin: B cells and skin score progression. Arthritis Res. Ther. 2018-04-18 [PMID: 29669578] (IF/IHC, Human)

Bioinformatics

• Gene Symbol: MS4A1
• Uniprot:
  • P11836()
  • P11836()