CD23/Fc epsilon RII Antibody (691632) [Alexa Fluor™ Plus 405]

• Reactivity: Mu
• Clone: 691632
• Clonality: Monoclonal
• Host: Rat
• Conjugate: Alexa Fluor Plus 405

CD23/Fc epsilon RII Antibody (691632) [Alexa Fluor™ Plus 405] Summary

• Specificity: Detects mouse CD23/Fc epsilon RII in direct ELISAs. In direct ELISAs, no cross-reactivity with recombinant human (rh) Fc epsilon RIA or rhFc epsilon RIG is observed.
• Isotype: IgG2a
• Clonality: Monoclonal
• Host: Rat

Packaging, Storage & Formulations

• Storage: Protect from light. Do not freeze. 12 months from date of receipt, 2 to 8 °C as supplied
• Buffer: Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for CD23/Fc epsilon RII Antibody (691632) [Alexa Fluor™ Plus 405]

• BLAST-2
• CD23
• CD23A
• CD23CD23 antigen
• CLEC4J
• CLEC4JC-type lectin domain family 4 member J
• C-type lectin domain family 4, member J
• Fc epsilon RII
• Fc fragment of IgE, low affinity II, receptor for (CD23)
• FCE2Fc fragment of IgE, low affinity II, receptor for (CD23A)
• fc-epsilon-RII
• FCER2
• Fcer2a
• FceRII
• IGEBF
• Immunoglobulin E-binding factor
• low affinity immunoglobulin epsilon Fc receptor
• Ly-42
• Lymphocyte IgE receptor

Background

The low affinity receptor for IgE, Fc epsilon RII (designated CD23) is a member of subgroup II of the C-type (Ca²⁺-dependent) lectin superfamily (1-4). Mouse CD23 is a
45-49 kDa type II transmembrane glycoprotein that binds mouse, but not human, IgE (1-4). The longest isoform is 331 amino acids (aa) in length and contains a 23 aa cytoplasmic domain, a 26 aa transmembrane segment, and a 282 aa extracellular domain (ECD). The ECD C-type lectin domain binds both protein and carbohydrate, with separate sites for binding IgE, CD21, and beta 2 and alpha v integrins (2).  Coiled-coil topography within a connecting stalk contributes to oligomerization, which increases IgE affinity (1, 2). Mouse CD23 shares 88% aa identity with rat CD23 and up to 57% aa identity with isoforms of human, equine, porcine and bovine CD23. Isoforms which vary in the cytoplasmic sequence include the “a” isoform, which begins with the sequence MEENEYS and is constitutively expressed by B cells, and the “b” isoform, which begins with MDTHHT and is induced by IL-4 on a variety of inflammatory cells, B cells and epithelia (2, 5-7). The isoforms differentially participate in IgE-mediated endocytosis and phagocytosis (2, 8-10). CD23b and two 309 aa mouse CD23b isoforms, lacking either exon 5 or 6, also display distinct endocytic properties on intestinal epithelia (6, 11). Several soluble forms of CD23 are mainly generated by metalloprotease (especially ADAM10) and cysteine protease digestion, although potentially soluble mouse isoforms have also been sequenced (12-14). Both soluble and membrane-bound forms of CD23 include the lectin domain and show bioactivity. CD23 binding to monocyte integrins results in oxidative product generation and proinflammatory cytokine release (15). On human, but not mouse, B cells, sCD23 induces IgE secretion by binding CD21 (2, 9). In both, secreted IgE will bind B cell membrane CD23, rendering it unavailable for cleavage, and thus shutting down IgE production (2).

1. Kijimoto-Ochiai, S. (2002) Cell. Mol. Life Sci. 59:648.
2. Gould, H. and B.J. Sutton (2008) Nat. Rev. Immunol. 8:205.
3. Bettler, B. et al. (1989) Proc. Natl. Acad. Sci. USA 86:7566.
4. Gollnick, S.O. et al. (1990) J. Immunol. 144:1974.
5. Kondo, H. et al. (1994) Int. Arch. Allergy Immunol. 105:38.
6. Yu, L.C.H. et al. (2003) Am. J. Physiol. Gastrointest. Liver Physiol. 285:G223.
7. Sukumar, S. et al. (2006) J. Immunol. 176:4811.
8. Karagiannis, S.N. et al. (2001) Immunology 103:319.
9. Aubry, J-P. et al. (1992) Nature 358:505.
10. Sarfati, M. and G. Delespeese (1988) J. Immunol. 141:2195.
11. Montagnac, G. et al. (2005) Traffic 6:230.
12. Weskamp, G. et al. (2006) Nat. Immunol. 7:1293.
13. Schulz, O. et al. (1997) Eur. J. Immunol. 27:584.
14. Entrez Accession # EDL21949, EDL21951.
15. Lecoanet-Henchoz, S. et al. (1995) Immunity 3:119.

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.