title: The adhesion molecule E-cadherin and a surface antigen recognized by the antibody 9C4 are selectively expressed on erythroid cells of defined maturational stages.
abstract: The antigen expression of immature erythroid bone marrow cells was studied using two recently generated monoclonal antibodies (mAb), mAb 67A4 and 9C4, with specificities for the epithelial cell adhesion molecule E-cadherin (E-cad; mAb 67A4), and a novel 110 kDa differentiation antigen (mAb 9C4) with unknown molecular structure. Pappenheim staining of FACS-purified cells labeled with mAb 9C4 and anti-glycophorin A (GA) revealed that the majority of the 9C4+GA- and 9C4+GA+ cells consisted of erythroblasts. In contrast, the E-cad-positive population comprised normoblasts and erythroblasts. While the E-cad+GA- fraction contained mainly erythroblasts and basophilic normoblasts, the E-Cad+GA+ population was enriched in orthochromatic and polychromatophilic normoblasts. By colony assays of affinity column-purified cells it could be shown that erythroid colony forming units (CFU-E) were enriched and erythroid burst forming units (BFU-E) were depleted in the 9C4- and E-cad-positive fractions. Flow cytometric analysis of bone marrow cells double-labeled with mAb 67A4 and anti-CD71, anti-CD117, anti-CD34, or anti-GA revealed that about 90% of the E-cad-positive cells coexpressed CD71, about 70% were positive for CD117, about 50% for GA, and only about 5% coexpressed CD34. The expression pattern of 9C4 antigen was similar to that of E-Cad with the exception that only a minority of the 9C4-positive cells coexpressed GA. Lymphoid and myeloid markers were negative on both the E-Cad- and 9C4-positive populations. In these studies we describe the identification of a new mAb-defined antigen which is specifically expressed on erythroblasts and CFU-E(9C4) and demonstrate that E-Cad is not only expressed on epithelial cells but also on erythropoietic cells of defined maturational stages.
authors.affiliation: Second Department of Internal Medicine, University of Tübingen, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Bühring
authors.forename: T
authors.initials: T
authors.lastname: Müller
authors.forename: R
authors.initials: R
authors.lastname: Herbst
authors.forename: S
authors.initials: S
authors.lastname: Cole
authors.forename: I
authors.initials: I
authors.lastname: Rappold
authors.forename: W
authors.initials: W
authors.lastname: Schuller
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: U
authors.initials: U
authors.lastname: Fritzsch
authors.forename: C
authors.initials: C
authors.lastname: Faul
authors.forename: S
authors.initials: S
authors.lastname: Armeanu
authors.forename: A
authors.initials: A
authors.lastname: Ullrich
authors.forename: G
authors.initials: G
authors.lastname: Klein
authors.forename: H
authors.initials: H
authors.lastname: Schmidt
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism*; D001854:Bone Marrow Cells; D015820:Cadherins / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry; D006021:Glycophorins / Q000276:immunology / Q000378:metabolism; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000378:metabolism / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D015820:Cadherins; D006021:Glycophorins