title: Characterization and regulation of RB6-8C5 antigen expression on murine bone marrow cells.
abstract: Murine bone marrow cells expressing the cell surface Ag RB6-8C5 were identified by fluorescence-activated cell-sorting analysis using a rat IgG mAb. The fluorescent intensity of RB6-8C5 was variable on bone marrow cells. This made it possible to separate bone marrow cells into distinct subpopulations, RB6-8C5neg, RB6-8C5lo, and RB6-8C5hi cells. Morphologic analysis of the sorted populations demonstrated that the Ag was expressed on myeloid cells. The expression of RB6-8C5 increases with granulocyte maturation, whereas expression is transient on cells in the monocytic lineage. The RB6-8C5hi sorted cells were enriched for end-stage neutrophils (75%), whereas the RB6-8C5lo sorted cells contained more immature myeloid cells and myelocytes (75%). Lymphocytes and macrophages were less than 5% in any RB6-8C5+ population, whereas the erythroid precursors were RB6-8C5neg. The colony forming unit culture (CFU-C) (greater than 90%) were found in the RB6-8C5neg and RB6-8C5lo populations, and all the CFU-granulocyte, erythroid, megakaryocyte, and macrophage (CFU-GEMM) and burst-forming units-erythroid (BFU-E) were in the RB6-8C5neg population. Granulocyte-macrophage-CSFR (GM-CSFR) and IL-1 alpha R were expressed on RB6-8C5hi bone marrow cells, whereas no receptors could be detected on RB6-8C5neg and RB6-8C5lo cells. The expression of the RB6-8C5 Ag can be induced on RB6-8C5neg cells in liquid culture by IL-3 and granulocyte-macrophage CSF. Thus, RB6-8C5 is a myeloid differentiation Ag whose expression can be regulated by cytokines.
authors.affiliation: Program Resources, Inc./DynCorp, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201.
authors.forename: K
authors.initials: K
authors.lastname: Hestdal
authors.forename: F W
authors.initials: FW
authors.lastname: Ruscetti
authors.forename: J N
authors.initials: JN
authors.lastname: Ihle
authors.forename: S E
authors.initials: SE
authors.lastname: Jacobsen
authors.forename: C M
authors.initials: CM
authors.lastname: Dubois
authors.forename: W C
authors.initials: WC
authors.lastname: Kopp
authors.forename: D L
authors.initials: DL
authors.lastname: Longo
authors.forename: J R
authors.initials: JR
authors.lastname: Keller
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology*; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D005434:Flow Cytometry; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006410:Hematopoiesis; D007377:Interleukin-3 / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D051379:Mice; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D017472:Receptors, Interleukin-1; D013154:Spleen / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D015214:Antigens, Differentiation, Myelomonocytic; D000954:Antigens, Surface; D007377:Interleukin-3; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D016179:Granulocyte Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor