CD21

O CD21 (cluster de diferenciación 21) ou receptor do compoñente do complemento (3d/virus de Epstein Barr) 2 ou CR2 é unha proteína da superficie celular de certas células inmunes (fundamentalmente) que se une a certos compoñentes do sistema do complemento. Este receptor únese ao iC3b (derivado inactivo do C3b), C3dg, ou C3d do complemento.^[1] As células B teñen receptores CR2 nas súas superficies, o que permite que o sistema de complemento xogue un papel na activación e maduración das células B.^[2]

Pode encontrarse en linfocitos B maduros, linfocitos T, células do epitelio farínxeo, astrocitos e células dendríticas foliculares do bazo.^[3]

Interaccións editar

O CR2 nas células B maduras forma un complexo con outras dúas proteínas de membrana, o CD19 e o CD81(=TAPA-1). O complexo CR2-CD19-CD81 chámase a miúdo complexo correceptor de células B,^[4] porque o CR2 se une a antíxenos por medio do C3d (ou iC3b ou C3dg) unidos cando a IgM de membrana se une ao antíxeno. Isto dá lugar a que a célula B desenvolvan unha resposta moi ampliada ao antíxeno.^[1]

O receptor do complemento 2 interacciona con CD19.^[5]^[6]

O virus de Epstein-Barr (EBV) únese ás células B no CR2 durante a infección destas células. Yefenof et al. (1976) encontraron un completo solapamento dos receptores do EBV e os receptores do compoñente do complemento 3 (C3) en células B humanas.^[2]^[7]^[8]

Inmunohistoquímica editar

Aínda que o CR2 está presente en todas as células B maduras e células dendríticas foliculares (FDCs), este só se fai aparente cando se realiza a inmunohistoquímica en preparacións obtidas por criosección. En mostras de tecidos convencionais embebidas en parafina, soamente as células dendríticas foliculares reteñen o patrón de tinguidura. Como resultado, o CR2, chamado máis comunmente CD21 no contexto de inmunohistoquímica, pode usarse para demostrar a presenza da rede de células dendríticas foliculares en tecidos linfoides.

Esta característica pode ser útil no exame de tecidos nos que o centro xerminal normal foi borrado por procesos de doenzas, como a infección do VIH. O patrón da rede de células dendríticas foliculares pode tamén ser alterado nalgunhas condicións neoplásticas, como os linfomas MALT de células B, linfomas de células do manto, e algúns linfomas de células T. A enfermidade de Castleman está tipificada pola presenza de células dendríticas foliculares, e esta e os tumores de células dendríticas foliculares malignos poden, por tanto, ser demostrados usando anticorpos CR2/CD21.^[9]

Notas editar

↑ ^1,0 ^1,1 Frank K, Atkinson JP (2001). "Complement system." In Austen KF, Frank K, Atkinson JP, Cantor H. eds. Samter's Immunologic Diseases, 6th ed. Vol. 1, p. 281-298, Philadelphia: Lippincott Williams & Wilkins, ISBN 0-7817-2120-2.
↑ ^2,0 ^2,1 "Entrez Gene: CR2 complement component (3d/Epstein Barr virus) receptor 2".
↑ UniProt CR2 HUMAN
↑ Abbas AK, Lichtman AH (2003). Cellular and Molecular Immunology, 5th ed. Philadelphia: Saunders, ISBN 0-7216-0008-5
↑ Bradbury, L E; Kansas G S, Levy S, Evans R L, Tedder T F (1992). "The CD19/CD21 signal transducing complex of human B lymphocytes includes the target of antiproliferative antibody-1 and Leu-13 molecules". J. Immunol. (UNITED STATES) 149 (9): 2841–50. ISSN 0022-1767. PMID 1383329.
↑ Horváth, G; Serru V, Clay D, Billard M, Boucheix C, Rubinstein E (1998). "CD19 is linked to the integrin-associated tetraspans CD9, CD81, and CD82". J. Biol. Chem. (UNITED STATES) 273 (46): 30537–43. ISSN 0021-9258. PMID 9804823. doi:10.1074/jbc.273.46.30537.
↑ Yefenof E, Klein G, Jondal M, Oldstone MB (1976). "Surface markers on human B and T-lymphocytes. IX. Two-color immunofluorescence studies on the association between ebv receptors and complement receptors on the surface of lymphoid cell lines". Int. J. Cancer 17 (6): 693–700. PMID 181330. doi:10.1002/ijc.2910170602.
↑ OMIM COMPLEMENT COMPONENT RECEPTOR 2; CR2
↑ Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. pp. 93–94. ISBN 1-84110-100-1.

Véxase tamén editar

Bibliografía editar

Cooper NR, Bradt BM, Rhim JS, Nemerow GR (1990). "CR2 complement receptor.". J. Invest. Dermatol. 94 (6 Suppl): 112S?117S. PMID 2161885. doi:10.1111/1523-1747.ep12876069.
Gauffre A, Viron A, Barel M; et al. (1992). "Nuclear localization of the Epstein-Barr virus/C3d receptor (CR2) in the human Burkitt B lymphoma cell, Raji.". Mol. Immunol. 29 (9): 1113–20. PMID 1323059. doi:10.1016/0161-5890(92)90044-X.
Levy E, Ambrus J, Kahl L; et al. (1992). "T lymphocyte expression of complement receptor 2 (CR2/CD21): a role in adhesive cell-cell interactions and dysregulation in a patient with systemic lupus erythematosus (SLE).". Clin. Exp. Immunol. 90 (2): 235–44. PMC 1554594. PMID 1424280. doi:10.1111/j.1365-2249.1992.tb07935.x.
Matsumoto AK, Kopicky-Burd J, Carter RH; et al. (1991). "Intersection of the complement and immune systems: a signal transduction complex of the B lymphocyte-containing complement receptor type 2 and CD19.". J. Exp. Med. 173 (1): 55–64. PMC 2118751. PMID 1702139. doi:10.1084/jem.173.1.55.
Tuveson DA, Ahearn JM, Matsumoto AK, Fearon DT (1991). "Molecular interactions of complement receptors on B lymphocytes: a CR1/CR2 complex distinct from the CR2/CD19 complex.". J. Exp. Med. 173 (5): 1083–9. PMC 2118840. PMID 1708808. doi:10.1084/jem.173.5.1083.
Kalli KR, Ahearn JM, Fearon DT (1991). "Interaction of iC3b with recombinant isotypic and chimeric forms of CR2.". J. Immunol. 147 (2): 590–4. PMID 1830068.
Barel M, Gauffre A, Lyamani F; et al. (1991). "Intracellular interaction of EBV/C3d receptor (CR2) with p68, a calcium-binding protein present in normal but not in transformed B lymphocytes.". J. Immunol. 147 (4): 1286–91. PMID 1831222.
Delcayre AX, Salas F, Mathur S; et al. (1991). "Epstein Barr virus/complement C3d receptor is an interferon alpha receptor.". EMBO J. 10 (4): 919–26. PMC 452735. PMID 1849076.
Kurtz CB, Paul MS, Aegerter M; et al. (1989). "Murine complement receptor gene family. II. Identification and characterization of the murine homolog (Cr2) to human CR2 and its molecular linkage to Crry.". J. Immunol. 143 (6): 2058–67. PMID 2528587.
Fujisaku A, Harley JB, Frank MB; et al. (1989). "Genomic organization and polymorphisms of the human C3d/Epstein-Barr virus receptor.". J. Biol. Chem. 264 (4): 2118–25. PMID 2563370.
Moore MD, Cooper NR, Tack BF, Nemerow GR (1988). "Molecular cloning of the cDNA encoding the Epstein-Barr virus/C3d receptor (complement receptor type 2) of human B lymphocytes.". Proc. Natl. Acad. Sci. U.S.A. 84 (24): 9194–8. PMC 299719. PMID 2827171. doi:10.1073/pnas.84.24.9194.
Weis JJ, Toothaker LE, Smith JA; et al. (1988). "Structure of the human B lymphocyte receptor for C3d and the Epstein-Barr virus and relatedness to other members of the family of C3/C4 binding proteins.". J. Exp. Med. 167 (3): 1047–66. PMC 2188894. PMID 2832506. doi:10.1084/jem.167.3.1047.
Weis JJ, Fearon DT, Klickstein LB; et al. (1986). "Identification of a partial cDNA clone for the C3d/Epstein-Barr virus receptor of human B lymphocytes: homology with the receptor for fragments C3b and C4b of the third and fourth components of complement.". Proc. Natl. Acad. Sci. U.S.A. 83 (15): 5639–43. PMC 386344. PMID 3016712. doi:10.1073/pnas.83.15.5639.
Weis JH, Morton CC, Bruns GA; et al. (1987). "A complement receptor locus: genes encoding C3b/C4b receptor and C3d/Epstein-Barr virus receptor map to 1q32.". J. Immunol. 138 (1): 312–5. PMID 3782802.
Aubry JP, Pochon S, Gauchat JF; et al. (1994). "CD23 interacts with a new functional extracytoplasmic domain involving N-linked oligosaccharides on CD21.". J. Immunol. 152 (12): 5806–13. PMID 7515913.
Matsumoto AK, Martin DR, Carter RH; et al. (1993). "Functional dissection of the CD21/CD19/TAPA-1/Leu-13 complex of B lymphocytes.". J. Exp. Med. 178 (4): 1407–17. PMC 2191213. PMID 7690834. doi:10.1084/jem.178.4.1407.
Barel M, Balbo M, Gauffre A, Frade R (1995). "Binding sites of the Epstein-Barr virus and C3d receptor (CR2, CD21) for its three intracellular ligands, the p53 anti-oncoprotein, the p68 calcium binding protein and the nuclear p120 ribonucleoprotein.". Mol. Immunol. 32 (6): 389–97. PMID 7753047. doi:10.1016/0161-5890(95)00005-Y.

Ligazóns externas editar

MeshName - Complement+Receptors+2 [1]

[Frank-1] 1,0 ^1,1 Frank K, Atkinson JP (2001). "Complement system." In Austen KF, Frank K, Atkinson JP, Cantor H. eds. Samter's Immunologic Diseases, 6th ed. Vol. 1, p. 281-298, Philadelphia: Lippincott Williams & Wilkins, ISBN 0-7817-2120-2.

[entrez_1380-2] 2,0 ^2,1 "Entrez Gene: CR2 complement component (3d/Epstein Barr virus) receptor 2".

[3] UniProt CR2 HUMAN

[Abbas-4] Abbas AK, Lichtman AH (2003). Cellular and Molecular Immunology, 5th ed. Philadelphia: Saunders, ISBN 0-7216-0008-5

[pmid1383329-5] Bradbury, L E; Kansas G S, Levy S, Evans R L, Tedder T F (1992). "The CD19/CD21 signal transducing complex of human B lymphocytes includes the target of antiproliferative antibody-1 and Leu-13 molecules". J. Immunol. (UNITED STATES) 149 (9): 2841–50. ISSN 0022-1767. PMID 1383329.

[pmid9804823-6] Horváth, G; Serru V, Clay D, Billard M, Boucheix C, Rubinstein E (1998). "CD19 is linked to the integrin-associated tetraspans CD9, CD81, and CD82". J. Biol. Chem. (UNITED STATES) 273 (46): 30537–43. ISSN 0021-9258. PMID 9804823. doi:10.1074/jbc.273.46.30537.

[pmid181330-7] Yefenof E, Klein G, Jondal M, Oldstone MB (1976). "Surface markers on human B and T-lymphocytes. IX. Two-color immunofluorescence studies on the association between ebv receptors and complement receptors on the surface of lymphoid cell lines". Int. J. Cancer 17 (6): 693–700. PMID 181330. doi:10.1002/ijc.2910170602.

[8] OMIM COMPLEMENT COMPONENT RECEPTOR 2; CR2

[Leong-9] Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. pp. 93–94. ISBN 1-84110-100-1.

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