title: The monoclonal antibody ER-BMDM1 recognizes a macrophage and dendritic cell differentiation antigen with aminopeptidase activity.
abstract: Here we describe the reactivity of monoclonal antibody (mAb) ER-BMDM1, directed against a 160-kDa cell membrane-associated antigen (Ag) with amino-peptidase activity. The aminopeptidase recognized by ER-BMDM1 is present on various mouse macrophage (M phi) and dendritic cell (DC) subpopulations as well as on microvillous epithelia. Analysis of ER-BMDM1 Ag expression in in vitro models of M phi maturation revealed that the Ag is expressed at increasing levels upon maturation of M phi. In vivo, high level expression of the ER-BMDM1 Ag occurs after the monocytic stage of maturation, since bone marrow cells and peripheral blood monocytes are essentially ER-BMDM1 negative. Analysis of isolated-resident and elicited M phi populations showed that ER-BMDM1 recognizes a specific subpopulation of mature M phi: only some resident peritoneal and alveolar M phi are ER-BMDM1 positive, whereas virtually all thioglycollate-elicited peritoneal exudate M phi bind the mAb. In lymphoid organs, a subpopulation of M phi is recognized as well as interdigitating cells (IDC) located in T cell areas. Phenotypic analysis of isolated DC--the in vitro equivalents of IDC--from spleen and lymph nodes confirmed that the majority of this important antigen-presenting cell population expresses the ER-BMDM1 aminopeptidase. The molecular characteristics of the ER-BMDM1 Ag suggest that it may represent the mouse homolog of human CD13.
authors.affiliation: Department of Immunology, Erasmus University, Rotterdam, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Leenen
authors.forename: M
authors.initials: M
authors.lastname: Melis
authors.forename: G
authors.initials: G
authors.lastname: Kraal
authors.forename: A T
authors.initials: AT
authors.lastname: Hoogeveen
authors.forename: W
authors.initials: W
authors.lastname: Van Ewijk
mesh_terms: D000626:Aminopeptidases / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000943:Antigens, Differentiation / Q000276:immunology*; D003713:Dendritic Cells / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006825:Hybridomas; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000276:immunology; D008099:Liver / Q000276:immunology; D008168:Lung / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D008264:Macrophages / Q000201:enzymology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000626:Aminopeptidases