• Species Reactivity

  Human

• Specificity

  Detects human FCRL3/FcRH3 in direct ELISAs. In direct ELISAs, less than 5% cross-reactivity with recombinant human (rh) FCRL2 and rhFCRL5 is observed, and no cross-reactivity with rhFCRL1 or recombinant mouse FCRL3 is observed.

• Source

  Monoclonal Mouse IgG1 Clone # 546828

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human FCRL3/FcRH3    
  Arg14-Arg569    
  Accession # Q96P31

• 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

  Human peripheral blood lymphocytes

• 
  

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: FCRL3/FcRH3

FCRL3 (Fc Receptor-Like 3), also known as FcRH3, IRTA3, and SPAP2, is a 110 kDa molecule with sequence homology to classical Fc receptors. The type 1 transmembrane FCRL proteins contain from three to nine immunoglobulin-like domains. They are differentially expressed within the B cell lineage and can either promote or inhibit B cell proliferation and activation (1). Mature human FCRL3 consists of a 556 amino acid (aa) extracellular domain (ECD) with six Ig-like domains, a 21 aa transmembrane segment, and a 140 aa cytoplasmic domain with four immunotyrosine inhibitory motifs (ITIMs) (2-4). Within the ECD, human and mouse FCRL3 share 35% aa sequence identity. Alternate splicing generates several additional isoforms with deletions or substitutions in both the extracellular and intracellular regions. These include potentially secreted forms that are truncated following the second Ig-like domain (4). FCRL3 is expressed in secondary lymphoid organs on the surface of mature naïve and memory B cells, NK cells, and B cell lines derived from chronic lymphocytic leukemias (2, 3, 5). It is upregulated on B cells following LPS or anti-CD40 stimulation (6). A polymorphism in the FCRL3 promoter induces enhanced transcription and is associated with the development of autoimmune disorders in a Japanese population (6, 7). Tyrosine phosphorylation within the ITIMs of FCRL3 enables its association with SHP-1 (4).

• References:

1. Davis, R.S. (2007) Annu. Rev. Immunol. 25:525.

2. Miller, I. et al. (2002) Blood, 99:2662.

3. Davis, R.S. et al. (2001) Proc. Natl. Acad. Sci. 98:9772.

4. Xu, M.-J. et al. (2002) Biochem. Biophys. Res. Commun. 293:1037.

5. Polson, A.G. et al. (2006) Int. Immunol. 18:1363.

6. Kochi, Y. et al. (2005) Nat. Genet. 37:478.

7. Chistiakov, D.A. and A.P. Chistiakov (2007) Hum. Immunol. 68:375.

• Long Name:

  Fc Receptor-like 3

• Entrez Gene IDs:

  115352 (Human); 329693 (Mouse); 680697 (Rat)

• Alternate Names:

  CD307c; Fc receptor homolog 3; Fc receptor-like 3; Fc receptor-like protein 3; FcRH3; FCRL3; fcR-like protein 3; hIFGP3; IFGP3; immunoglobulin superfamily receptor translocation associated protein 3; IRTA3; SPAP2