title: CXCR7 protein is not expressed on human or mouse leukocytes.
abstract: Since the discovery that CXCR7 binds to CXCL12/SDF-1α, the role of CXCR7 in CXCL12-mediated biological processes has been under intensive scrutiny. However, there is no consensus in the literature on the expression of CXCR7 protein by peripheral blood cells. In this study we analyzed human and mouse leukocytes and erythrocytes for CXCR7 protein expression, using a competitive CXCL12 binding assay as well as by flow cytometry and immunohistochemistry using multiple CXCR7 Abs. CXCR7(-/-) mice were used as negative controls. Together, these methods indicate that CXCR7 protein is not expressed by human peripheral blood T cells, B cells, NK cells, or monocytes, or by mouse peripheral blood leukocytes. CXCR7 protein is, however, expressed on mouse primitive erythroid cells, which supply oxygen to the embryo during early stages of development. These studies therefore suggest that, whereas CXCR7 protein is expressed by primitive RBCs during murine embryonic development, in adult mammals CXCR7 protein is not expressed by normal peripheral blood cells.
authors.affiliation: ChemoCentryx, Inc., Mountain View, CA 94043, USA. rberahovich@chemocentryx.com
authors.forename: Robert D
authors.initials: RD
authors.lastname: Berahovich
authors.forename: Brian A
authors.initials: BA
authors.lastname: Zabel
authors.forename: Mark E T
authors.initials: ME
authors.lastname: Penfold
authors.forename: Susanna
authors.initials: S
authors.lastname: Lewén
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Miao
authors.forename: Lin
authors.initials: L
authors.lastname: Gan
authors.forename: Jaime
authors.initials: J
authors.lastname: Pereda
authors.forename: Jessica
authors.initials: J
authors.lastname: Dias
authors.forename: Igor I
authors.initials: II
authors.lastname: Slukvin
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: McGrath
authors.forename: Juan C
authors.initials: JC
authors.lastname: Jaen
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Schall
mesh_terms: D000328:Adult; D000818:Animals; D002469:Cell Separation; D004622:Embryo, Mammalian; D004912:Erythrocytes / Q000378:metabolism*; D005434:Flow Cytometry; D006410:Hematopoiesis / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007962:Leukocytes / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D054387:Receptors, CXCR / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C501896:ACKR3 protein, human; C501897:Cmkor1 protein, mouse; D054387:Receptors, CXCR