• Species Reactivity

  Mouse

• 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.    
   

• Source

  Monoclonal Rat IgG2a Clone # 691632

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant mouse CD23/Fc epsilon RII    
  Glu50-Pro331    
  Accession # P20693

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 700

Applications

• Recommended    
  Concentration

  Sample

• Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  Mouse splenocytes

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: CD23/Fc epsilon RII

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).

• References:

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.

• Long Name:

  Fc epsilon Receptor II

• Entrez Gene IDs:

  2208 (Human); 14128 (Mouse); 171075 (Rat)

• Alternate Names:

  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