FcγRI/CD64 Rabbit Monoclonal Antibody (Clone 027)

CD64, also known as high-affinity immunoglobulin γ receptor I (FcγRI), is a transmembrane glycoprotein that binds the Fc region of IgG.¹ It is composed of a ligand-binding α-chain, which contains three extracellular Ig-like domains, a transmembrane region, and a cytoplasmic domain, and two γ-chains, which contain immunoreceptor tyrosine-based activation motifs (ITAMs) that mediate signal transduction.^2,3,4 CD64 is constitutively expressed in myeloid cells, including monocytes and macrophages, but can be induced in neutrophils in response to IFN-γ or G-CSF.^5,3 It is involved in phagocytosis, cytokine release, antibody-dependent cell-mediated cytotoxicity (ADCC), and antigen presentation to primed T cells.^1,6 Mouse CD64 selectively forms immune complexes with IgG2a, whereas human CD64 forms immune complexes with IgG1, IgG3, and IgG4.^1,7 Knockout of Fcgr1, the gene encoding CD64, inhibits clearance of B. pertussis infection in mice.¹ Increased serum levels of CD64 are associated with sepsis.⁸ Cayman’s FcγRI/CD64 Rabbit Monoclonal Antibody (Clone 027) can be used for flow cytometry (FC), immunocytochemistry (ICC), and immunofluorescence (IF) applications.

WARNING This product is not for human or veterinary use.

1. loan-Facsinay, A., de Kimpe, S.J., Hellwig, S.M.M., et al. FcγRI (CD64) contributes substantially to severity of arthritis, hypersensitivity responses, and protection from bacterial infection. Immunity 16(3), 391-402 (2002).

2. van der Poel, C.E., Spaapen, R.M., van de Winkel, J.G.J., et al. Functional characteristics of the high affinity IgG receptor, FcγRI. J. Immunol. 186(5), 2699-2704 (2011).

3. Akinrinmade, O.A., Chetty, S., Daramola, A.K., et al. CD64: An attractive immunotherapeutic target for M1-type macrophage mediated chronic inflammatory diseases. Biomedicines 5(3), 56 (2017).

4. Hamdan, T.A., Lang, P.A., and Lang, K.S. The diverse functions of the ubiquitous Fcγ receptors and their unique constituent, FcRγ subunit. Pathogens 9(2), 140 (2020).

5. Sears, D.W., Osman, N., Tate, B., et al. Molecular cloning and expression of the mouse high affinity Fc receptor for IgG. J. Immunol. 144(1), 371-378 (1990).

6. Barnes, N., Gavin, A.L., Tan, P.S., et al. FcγRI-deficient mice show multiple alterations to inflammatory and immune responses. Immunity 16(3), 379-389 (2002).

7. Bruhns, P., Iannascoli, B., England, P., et al. Specificity and affinity of human Fcγ receptors and their polymorphic variants for human IgG subclasses. Blood 113(16), 3716-3725 (2009).

8. Tan, T.L., Ahmad, N.S., Nasuruddin, D.N., et al. CD64 and group II secretory phospholipase A₂ (sPLA₂-IIA) as biomarkers for distinguishing adult sepsis and bacterial infections in the emergency department. PLoS ONE 11(3), e0152065 (2016).