CD20 is a non-glycosylated phosphoprotein expressed on the surface of all mature B-cells.
B-lymphocyte antigen CD20 is a protein that in humans is encoded by the MS4A1 gene.[1][2]
This gene encodes a member of the membrane-spanning 4A gene family. Members of this nascent protein family are characterized by common structural features and similar intron/exon splice boundaries and display unique expression patterns among hematopoietic cells and nonlymphoid tissues. This gene encodes a B-lymphocyte surface molecule which plays a role in the development and differentiation of B-cells into plasma cells. This family member is localized to 11q12, among a cluster of family members. Alternative splicing of this gene results in two transcript variants which encode the same protein.[2]
Function
The protein has no known natural ligand[3] and its function is unclear. It is suspected that it acts as a calcium channel in the cell membrane.
Expression
CD20 is expressed on all stages of B cell development except the first and last; it is present from pre-pre B cells through memory cells, but not on either pro-B cells or plasma cells.[4]
It is found on B-cell lymphomas, hairy cell leukemia, and B-cell chronic lymphocytic leukemia. It is also found on skin/melanoma cancer stem cells.[5]
Clinical significance
It is the target of the monoclonal antibodies rituximab, Ibritumomab tiuxetan, and tositumomab, which are all active agents in the treatment of all B cell lymphomas and leukemias. Additional antibody therapeutics under development (phase II or III clinical trials) include AME-133v (Applied Molecular Evolution), Ocrelizumab (Roche), Ofatumumab (Genmab), TRU-015 (Trubion) and IMMU-106 (Immunomedics).[6]
FMC7 appears to be a conformational variant.[7]
References
- ^ Tedder TF, Streuli M, Schlossman SF, Saito H (Mar 1988). "Isolation and structure of a cDNA encoding the B1 (CD20) cell-surface antigen of human B lymphocytes". Proc Natl Acad Sci U S A 85 (1): 208-12. PMID 2448768.
- ^ a b "Entrez Gene: MS4A1 membrane-spanning 4-domains, subfamily A, member 1". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=931.
- ^ The biology of CD20 and its potential as a target for mAb therapy.[1]
- ^ Bona, Constantin; Francisco A. Bonilla (1996). "5". Textbook of Immunology. Martin Soohoo (2 ed.). CRC Press. p. 102. ISBN 9783718605965.
- ^ Fang D, Nguyen TK, Leishear K, et al. (2005). "A tumorigenic subpopulation with stem cell properties in melanomas". Cancer Res. 65 (20): 9328–37. doi:10.1158/0008-5472.CAN-05-1343. PMID 16230395.
- ^ Note: information included in this article only found in table present in print version of article. K. John Morrow Jr (2008-06-15). "Methods for Maximizing Antibody Yields". Genetic Engineering & Biotechnology News (Mary Ann Liebert, Inc.): p. 36. http://www.genengnews.com/articles/chitem.aspx?aid=2514. Retrieved 2008-07-06.
- ^ Polyak MJ, Ayer LM, Szczepek AJ, Deans JP (2003). "A cholesterol-dependent CD20 epitope detected by the FMC7 antibody". Leukemia 17 (7): 1384–9. doi:10.1038/sj.leu.2402978. PMID 12835728.
Further reading
- Macardle PJ, Nicholson IC (2003). "CD20.". J. Biol. Regul. Homeost. Agents 16 (2): 136–8. PMID 12144126.
- Tamayose K, Sato N, Ando J, et al. (2002). "CD3-negative, CD20-positive T-cell prolymphocytic leukemia: case report and review of the literature.". Am. J. Hematol. 71 (4): 331–5. doi:10.1002/ajh.10224. PMID 12447967.
- Küster H, Zhang L, Brini AT, et al. (1992). "The gene and cDNA for the human high affinity immunoglobulin E receptor beta chain and expression of the complete human receptor.". J. Biol. Chem. 267 (18): 12782–7. PMID 1535625.
- Einfeld DA, Brown JP, Valentine MA, et al. (1988). "Molecular cloning of the human B cell CD20 receptor predicts a hydrophobic protein with multiple transmembrane domains.". EMBO J. 7 (3): 711–7. PMID 2456210.
- Tedder TF, Disteche CM, Louie E, et al. (1989). "The gene that encodes the human CD20 (B1) differentiation antigen is located on chromosome 11 near the t(11;14)(q13;q32) translocation site.". J. Immunol. 142 (7): 2555–9. PMID 2466898.
- Tedder TF, Klejman G, Schlossman SF, Saito H (1989). "Structure of the gene encoding the human B lymphocyte differentiation antigen CD20 (B1).". J. Immunol. 142 (7): 2560–8. PMID 2466899.
- Loken MR, Shah VO, Dattilio KL, Civin CI (1987). "Flow cytometric analysis of human bone marrow. II. Normal B lymphocyte development.". Blood 70 (5): 1316–24. PMID 3117132.
- Stamenkovic I, Seed B (1988). "Analysis of two cDNA clones encoding the B lymphocyte antigen CD20 (B1, Bp35), a type III integral membrane protein.". J. Exp. Med. 167 (6): 1975–80. doi:10.1084/jem.167.6.1975. PMID 3260267.
- Bofill M, Janossy G, Janossa M, et al. (1985). "Human B cell development. II. Subpopulations in the human fetus.". J. Immunol. 134 (3): 1531–8. PMID 3871452.
- Deans JP, Kalt L, Ledbetter JA, et al. (1995). "Association of 75/80-kDa phosphoproteins and the tyrosine kinases Lyn, Fyn, and Lck with the B cell molecule CD20. Evidence against involvement of the cytoplasmic regions of CD20.". J. Biol. Chem. 270 (38): 22632–8. PMID 7545683.
- Valentine MA, Licciardi KA, Clark EA, et al. (1993). "Insulin regulates serine/threonine phosphorylation in activated human B lymphocytes.". J. Immunol. 150 (1): 96–105. PMID 7678037.
- Bubien JK, Zhou LJ, Bell PD, et al. (1993). "Transfection of the CD20 cell surface molecule into ectopic cell types generates a Ca2+ conductance found constitutively in B lymphocytes.". J. Cell Biol. 121 (5): 1121–32. doi:10.1083/jcb.121.5.1121. PMID 7684739.
- Shirakawa T, Li A, Dubowitz M, et al. (1994). "Association between atopy and variants of the beta subunit of the high-affinity immunoglobulin E receptor.". Nat. Genet. 7 (2): 125–9. doi:10.1038/ng0694-125. PMID 7920628.
- Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides.". Gene 138 (1-2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298.
- Szepetowski P, Perucca-Lostanlen D, Gaudray P (1993). "Mapping genes according to their amplification status in tumor cells: contribution to the map of 11q13.". Genomics 16 (3): 745–50. doi:10.1006/geno.1993.1257. PMID 8325649.
- Algino KM, Thomason RW, King DE, et al. (1996). "CD20 (pan-B cell antigen) expression on bone marrow-derived T cells.". Am. J. Clin. Pathol. 106 (1): 78–81. PMID 8701937.
- Szöllósi J, Horejsí V, Bene L, et al. (1996). "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. 157 (7): 2939–46. PMID 8816400.
- Kanzaki M, Lindorfer MA, Garrison JC, Kojima I (1997). "Activation of the calcium-permeable cation channel CD20 by alpha subunits of the Gi protein.". J. Biol. Chem. 272 (23): 14733–9. doi:10.1074/jbc.272.23.14733. PMID 9169438.
- Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library.". Gene 200 (1-2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149.
External links
|
Proteins: clusters of differentiation (see also list of human clusters of differentiation) |
|
| 1-50 |
CD1 ( a-c, 1A, 1D, 1E) · CD2 · CD3 ( γ, δ, ε) · CD4 · CD5 · CD6 · CD7 · CD8 ( a) · CD9 · CD10 · CD11 ( a, b, c) · CD13 · CD14 · CD15 · CD16 ( A, B) · CD18 · CD19 · CD20 · CD21 · CD22 · CD23 · CD24 · CD25 · CD26 · CD27 · CD28 · CD29 · CD30 · CD31 · CD32 ( A, B) · CD33 · CD34 · CD35 · CD36 · CD37 · CD38 · CD39 · CD40 · CD41 · CD42 ( a, b, c, d) · CD43 · CD44 · CD45 · CD46 · CD47 · CD48 · CD49 ( a, b, c, d, e, f) · CD50
|
|
| 51-100 |
CD51 · CD52 · CD53 · CD54 · CD55 · CD56 · CD57 · CD58 · CD59 · CD61 · CD62 ( E, L, P) · CD63 · CD64 ( A, B, C) · CD66 ( a, b, c, d, e, f) · CD68 · CD69 · CD70 · CD71 · CD72 · CD73 · CD74 · CD78 · CD79 ( a, b) · CD80 · CD81 · CD82 · CD83 · CD84 · CD85 ( a, d, e, h, j, k) · CD86 · CD87 · CD88 · CD89 · CD90 · CD91- CD92 · CD93 · CD94 · CD95 · CD97 · CD98 · CD99 · CD100
|
|
| 101-150 |
|
|
| 151-200 |
CD151 · CD152 · CD153 · CD154 · CD155 · CD156 ( a, b, c) · CD157 · CD158 ( a, d, e, i, k) · CD159 ( a, c) · CD160 · CD161 · CD162 · CD163 · CD164 · CD166 · CD167 ( a, b) · CD168 · CD169 · CD170 · CD171 · CD172 ( a, b, g) · CD174 · CD177 · CD178 · CD179 ( a, b) · CD181 · CD182 · CD183 · CD184 · CD185 · CD186 · CD191 · CD192 · CD193 · CD194 · CD195 · CD196 · CD197 · CDw198 · CDw199 · CD200
|
|
| 201-250 |
|
|
| 251-300 |
|
|
| 301-350 |
|
|
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)