Human peripheral blood lymphocytes were stained with Mouse Anti-Human CD19 APC-conjugated Monoclonal Antibody (FAB4867A) and either (A) Mouse Anti-Human CD23/Fce RII Monoclonal Antibody (Catalog # MAB123) or (B) Mouse IgG₁Isotype Control (MAB002) followed by Phycoerythrin-conjugated Anti-Mouse IgG Secondary Antibody (F0102B). View our protocol for Staining Membrane-associated Proteins.

Detection of CD23/Fc epsilon RII in Human Lymph Nodes.

CD23/Fc epsilon RII was detected in immersion fixed paraffin-embedded sections of Human Lymph Nodes using Mouse Anti-Human CD23/Fc epsilon RII Monoclonal Antibody (Catalog # MAB123) at 5 µg/mL for 1 hour at room temperature followed by incubation with the Anti-Goat IgG VisUCyte™ HRP Polymer Antibody (Catalog # VC004). Before incubation with the primary antibody, tissue was subjected to heat-induced epitope retrieval using VisUCyte Antigen Retrieval Reagent-Basic (Catalog # VCTS021). Tissue was stained using DAB (brown) and counterstained with hematoxylin (blue). Specific staining was localized to cell membrane in lymphocytes. View our protocol for IHC Staining with VisUCyte HRP Polymer Detection Reagents.

Applications for Human CD23/Fc epsilon RII Antibody

Application

Recommended Usage

Blockade of Receptor-ligand Interaction

In a functional ELISA, 0.5-2.5 µg/mL of this antibody will block 50% of the binding of 500 ng/mL of human IgE to immobilized Recombinant Human CD23/Fc epsilon RII (Catalog # 123-FE) coated at 2 µg/mL (100 µL/well). At 20 μg/mL, this antibody will block >90% of the binding.

CyTOF-ready

Ready to be labeled using established conjugation methods. No BSA or other carrier proteins that could interfere with conjugation.

Flow Cytometry

0.25 µg/10⁶ cells
Sample: Human peripheral blood lymphocytes

Immunohistochemistry

5-25 µg/mL
Sample: Immersion fixed paraffin-embedded sections of Human Lymph Nodes

Western Blot

1 µg/mL
Sample: Recombinant Human CD23/Fc epsilon RII (Catalog # 123-FE)

Please Note: Optimal dilutions of this antibody should be experimentally determined.

Formulation, Preparation, and Storage

Purification

Protein A or G purified from hybridoma culture supernatant

Reconstitution

Reconstitute at 0.5 mg/mL in sterile PBS. For liquid material, refer to CoA for concentration.

Formulation

Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. See Certificate of Analysis for details.
*Small pack size (-SP) is supplied either lyophilized or as a 0.2 µm filtered solution in PBS.

Shipping

Lyophilized product is shipped at ambient temperature. Liquid small pack size (-SP) is shipped with polar packs. Upon receipt, store immediately at the temperature recommended below.

Stability & Storage

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.

12 months from date of receipt, -20 to -70 °C as supplied.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: CD23/Fc epsilon RII

CD23 (also named B cell differentiation antigen) is a member of subgroup II of the C-type (Ca⁺⁺-dependent) lectin superfamily (1‑5). Human CD23 is a 47 kDa type II transmembrane glycoprotein that is expressed by a wide variety of cell types (6‑10). The full-length receptor is 321 amino acids (aa) in length and contains a 274 aa extracellular region, a 26 aa transmembrane segment, and a 21 aa cytoplasmic domain. The extracellular region contains a C-type lectin domain and a connecting stalk with coiled-coil topography (3, 11). The lectin domain binds both protein and carbohydrate in an apparently Ca⁺⁺ independent manner (11). The coiled-coil region contributes to oligomerization (11, 12). The lectin domain in human CD23 (aa 162‑284) is 64%, 62% and 68% aa identical to the lectin domains in mouse, rat and bovine CD23, respectively. In the cytoplasmic region, two FC isoforms exist which arise from alternate start sites (6, 12). The “a” (or long) isoform begins with the sequence MEEGQYS and is constitutively expressed by B cells. It is believed to participate in IgE-mediated endocytosis (13). The “b” (or short) isoform begins with MNPPSQ and is induced on a wide variety of cell types by IL-4 (6). Fcb reportedly contributes to IgE-mediated phagocytosis (13). Fcb expressing cells include eosinophils, monocytes, visceral smooth muscle and intestinal epithelium (6, 14, 15). At least four soluble forms of CD23 are known to exist. They range in molecular weight from 25 kDa to 37 kDa, with the 25 kDa form predominating in sera (16). Soluble CD23 (sFc) is generated by metalloprotease (ADAM8; ADAM15; ADAM28) and cysteine-protease activity (16‑18). Cleavage usually occurs between aa 150‑160 (7, 8). It is unclear if sequential metalloprotease-cysteine protease activity is necessary for the generation of all soluble forms. Both soluble and membrane-bound CD23 show bioactivity. Ligands for CD23 include CD21, IgE, CD11b, and CD11c (19‑21). CD23 binding to CD11b and Cd11c on monocytes results in oxidative product generation and proinflammatory cytokine release (21). On B cells, sCD23 induces IgE secretion by binding CD21. Conversely, secreted IgE will, in turn, bind B cell membrane CD23, rendering it unavailable for cleavage, and thus shutting down IgE production (11).

References

Kijimoto-Ochiai, S. (2002) Cell. Mol. Life Sci. 59:648.
Heyman, B. (2000) Annu. Rev. Immunol. 18:709.
Bajorath, J. and A. Aruffo (1996) Protein Sci. 5:240.
Drickamer, K. (1993) Curr. Opin. Struct. Biol. 3:393.
Drickamer, K. (1999) Curr. Opin. Struct. Biol. 9:585.
Yokota, A. et al. (1988) Cell 55:611.
Ludin, C. et al. (1987) EMBO J. 6:109.
Ikuta, K. et al. (1987) Proc. Natl. Acad. Sci. USA 84:819.
Kikutani, H. et al. (1986) Cell 47:657.
Letellier, M. et al. (1988) J. Immunol. 141:2374.
Hibbert, R.G. et al. (2005) J. Exp. Med. 202:751.
Beavuil, A.J. et al. (1992) Proc. Natl. Acad. Sci. USA 89:753.
Yokota, A. et al. (1992) Proc. Natl. Acad. Sci. USA 89:5030.
Belleau, J.T. et al. (2005) Clin. Mol. Allergy 3:6.
Tu, Y. et al. (2005) Gastroenterology 129:928.
Marolewski, A.E. et al. (1998) Biochem. J. 333:573.
Fourie, A.M. et al. (2003) J. Biol. Chem. 278:30469.
Karagiannis, S.N. et al. (2001) Immunology 103:319.
Aubry, J-P. et al. (1992) Nature 358:505.
Sarfati, M. and G. Delespeese (1988) J. Immunol. 141:2195.
Lecoanet-Henchoz, S. et al. (1995) Immunity 3:119.

Long Name

Fc epsilon Receptor II

Alternate Names

CD23, CLEC4J, Fc epsilon RII, FCER2, Fcer2a, FceRII, IGEBF, Ly-42

Entrez Gene IDs

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

Gene Symbol

FCER2

UniProt

P06734

Additional CD23/Fc epsilon RII Products

Product Documents for Human CD23/Fc epsilon RII Antibody

Product Datasheets

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COA

SDS

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Product Specific Notices for Human CD23/Fc epsilon RII Antibody

For research use only

Citations
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Calculators
Flow Cytometry