• Species Reactivity

  Mouse

• Specificity

  Detects mouse FCRL5/FcRH3 in direct ELISAs. In direct ELISAs, less than 1% cross-reactivity with recombinant human FCRL5 is observed.

• Source

  Polyclonal Sheep IgG

• Purification

  Antigen Affinity-purified

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant mouse FCRL5/FcRH3    
  Gln27-Ala496 (predicted)    
  Accession # NP_899045

• Formulation

  Supplied in a saline solution containing BSA and Sodium Azide.

• Label

  Allophycocyanin

Applications

• 
  

  Recommended    
  Concentration

  Sample

• Flow Cytometry

  10 µL/10    ⁶ cells

  See below

• 
  

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

Data Examples

Preparation and Storage

• Shipping

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

• Stability & Storage

  Protect from light.    Do not freeze.    

• 12 months from date of receipt, 2 to 8 °C as supplied.

Background: FCRL5/FcRH5

Fc Receptor-Like 5 (FCRL5), also known as FcRH3 (FcRH5 in human), IRTA2, and CD307e, is a 90‑95 kDa member of the FCRL family of proteins whose amino acid (aa) sequence is reminiscent of that for classical Fc receptors. FCLR molecules are type 1 transmembrane proteins that 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, 2, 3). Mature mouse FCRL5 consists of a 470 aa extracellular domain (ECD), a 21 aa transmembrane segment, and a 79 aa cytoplasmic region. The ECD contains five Ig-like domains, while the cytoplasmic region possesses one ITAM-like motif and one immunotyrosine inhibitory motif (ITIM) (1, 3, 4). There are two major alleles for FCLR5 in mouse. The first was just described, and is found in BALB/c plus NZB mouse strains. The second is found in C57BL/6 mice, and differs by eleven scattered aa in the ECD. This creates one additional N-linked glycosylation site, and increases the SDS‑PAGE MW by 5 kDa (3). Alternate splicing of mouse FCRL5 generates at least one additional isoform that lacks the first Ig-like domain (aa 3‑90 of the mature molecule) (4). Human FCRL5, by contrast, contains up to nine Ig-like domains in a highly variable ECD, and over common regions, mouse and human FCRL5 share 49% aa sequence identity. CRL5 expression is restricted to mature B lineage cells in lymphoid tissues and blood, and is particularly noted to be expressed on T‑independent marginal zone and B1 B cells (3-8). Its ligation inhibits signaling through the B cell antigen receptor (9). Epstein-Barr virus transformation of B cells induces the up‑regulation of surface FCRL5 by a direct effect of its EBNA2 protein on FCRL5 gene transcription (10). FCRL5 on B cells functions as a receptor for the orthopoxvirus MHC class I-like protein OMCP (11). And based on the literature and R&D Systems testing, both mouse and human FCRL5 will bind to purified IgG with high affinity (5). In human, the FCRL5 gene maps to the 1q21 chromosomal locus, a common site of rearrangements in B cell malignancies. Notably, the FCRL5 protein is preferentially expressed in cell lines with 1q21 abnormalities, and is up‑regulated on tumor cells in some types of B cell malignancies (5, 7, 12‑14). In addition, soluble FCRL5 is elevated in the serum of many B cell leukemia patients (13, 15).

• References:

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

2. Maltais, L.J. et al. (2006) Nat. Immunol. 7:431.

3. Won, W-J. et al. (2006) J. Immunol. 177:6815.

4. Davis, R.S. et al. (2004) Int. Immunol. 16:1343.

5. Hatzivassiliou, G. et al. (2001) Immunity 14:277.

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

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

8. Vidal-Laliena, M. et al. (2005) Cell. Immunol. 236:6.

9. Haga, C.L. et al. (2007) Proc. Natl. Acad. Sci. 104:9770.

10. Mohan, J. et al. (2006) Blood 107:4433.

11. Campbell, J.A. et al. (2010) J. Immunol. 185:28.

12. Ise, T. et al. (2005) Clin. Cancer Res. 11:87.

13. Ise, T. et al. (2007) Leukemia 21:169.

14. Kazemi, T. et al. (2009) Cancer Immunol. Immunother. 58:989.

15. Ise, T. et al. (2006) Clin. Chem. Lab. Med. 44:594.

• Long Name:

  Fc Receptor-like 5

• Entrez Gene IDs:

  83416 (Human); 329693 (Mouse)

• Alternate Names:

  BXMAS1; BXMAS1MGC119592; CD307; CD307e antigen; CD307e; DKFZp667E2019; DKFZp667F216; Fc receptor homolog 5; Fc receptor-like 5; Fc receptor-like protein 5; FcRH5; FCRH5MGC119593; FCRL5; FcR-like protein 5; FLJ00333; FLJ00397; IFGP5; Immune receptor translocation-associated protein 2; immunoglobulin superfamily receptor translocation associated 2 (IRTA2); IRTA2; IRTA2MGC119590; PRO820