EMR1, the human homolog of F4/80, is an eosinophil‐specific receptor

Abstract

The EGF-TM7 F4/80 is a defining marker of murine macrophage populations. Applying flow cytometric analysis using the newly generated mAb A10, and quantitative real-time PCR, we here report the surprising observation that the human ortholog of F4/80, EGFlike module containing mucin-like hormone receptor (EMR)1, is absent on mononuclear phagocytic cells including monocytes, macrophages, and myeloid dendritic cells. Unexpectedly, we found that EMR1 expression is restricted to eosinophilic granulocytes, where expression is overlapping with the eotaxin receptor CCR3 and the immunoglobulin-like lectin Siglec-8. Absence on other leukocytes, including basophils, implies that EMR1 is a highly specific marker for eosinophils in humans.

Proteomic cell surface phenotyping of differentiating acute myeloid leukemia cells

“…Proteins in cluster number 3 included well known markers of granulocytic differentiation, such as CD66a, CD300a, CD11c, CD11b, CD35 and CD55. 36,37 EMR3 and EMR1, which were described as granulocyte markers, 38,39 were also identified with highly increased protein abundances after ATRA stimulation. Furthermore, cell surface proteins were identified, which are known to show increased protein abundances after ATRA stimulation, such as CD36, CD38, CD54, and CY24B.…”

“…Only small changes in protein abundances were detected in the 2 AML cell lines after ATRA stimulation for CD97 and EMR2, which are both known to be important for granulocyte migration. 45,46 In contrast, the 2 functionally less well characterized EGF-TM7 receptors, EMR1 and EMR3, 38,39 were detected with highly increased protein abundances in both AML cell lines after ATRA stimulation by the CSC technology ( Figure 5C). Furthermore, protein abundances of 2 members of the plexin family were detected to be differently regulated by ATRA.…”

Elusive Identities and Overlapping Phenotypes of Proangiogenic Myeloid Cells in Tumors

“…Indeed, the human homolog of F4/80, the EGF-like module containing mucin-like hormone receptor-1, is expressed by eosinophils rather than monocytes or macrophages. 98 Elevated numbers of CD68 ϩ TAMs have been correlated with increased vascularization in human tumors. 99 VEGFR-1 expression has also been reported on TAMs in tumors.…”

Immunocytokines: a novel class of products for the treatment of chronic inflammation and autoimmune conditions

“…Radiolabeled antibody preparations accumulated in tumors, but to large extent also in the kidney, spleen and liver [49]. The human homolog, EMR1, however, is not expressed on macrophages but on mature blood and tissue eosinophil granulocytes, which makes this approach hardly translatable to man [50]. For eosinophilic disorders, however, EMR1 has been shown to be a promising target because antibodies directed against EMR1 enhance killing of eosinophils by natural killer cells in non-human primates [51].…”