title: Differential expression of class II MHC antigens in subpopulations of human hematopoietic progenitor cells.
abstract: Expression of major histocompatibility complex class II Ags HLA-DR, HLA-DP, and HLA-DQ on human BM granulocyte-erythroid-macrophage-megakaryocyte CFU (CFU-GEMM), BFU-E, and CFU-GM was examined by indirect immunofluorescence, cell sorting, and complement-mediated cytotoxicity. BM, highly enriched for progenitor cells by depletion of mature hematopoietic elements, was further separated by sterile sorting into HLA-DR (-), low, intermediate, and high intensity HLA-DR (+), as well as HLA-DP (+) and HLA-DP (-) cell fractions and assayed for progenitor cell content. In addition, in the case of HLA-DR, CFU-GM response to inhibition by prostaglandin E was determined. Cell sorting and cytotoxicity data confirm that approximately 95% of assayable erythroid, myeloid, and multipotential progenitor cells expressed HLA-DR, whereas HLA-DQ Ags were undetectable. HLA-DR and HLA-DP Ags were co-expressed on 61% of these progenitor cells, predominantly those expressing HLA-DR at high intensity. Day 7 and 14 CFU-GM showed a trend toward segregation to the high HLA-DR (+) cell fractions, especially when recombinant human G-CSF was used to stimulate clone formation. Both day 7 and day 14 CFU-GMs were found predominantly in the HLA-DP (+) cell fraction. In contrast, BFU-E and CFU-GEMM were found in the low intensity HLA-DR cell fraction and predominantly in the HLA-DP (-) fraction. Both eosinophil CFU and cells giving rise to basophil/mast cells in suspension culture were found in the low and intermediate intensity HLA-DR fractions, but could be segregated into HLA-DP (+) and HLA-DP (-) cell fractions, respectively. Functional analysis of day 7 CFU-GM segregated, based upon HLA-DR intensity, indicated a positive correlation between increasing HLA-DR intensity and responsiveness to inhibition by prostaglandin E. Furthermore, only those CFU-GM expressing HLA-DR at high intensity could be removed by cytolytic treatment using a mAb anti-HLA-DR previously shown to be selective for CFU-GM responsive to PGE and in S phase of the cell cycle.
authors.affiliation: Department of Hematopoietic Regulation, Sloan-Kettering Institute, New York, NY 10021.
authors.forename: O G
authors.initials: OG
authors.lastname: Ottmann
authors.forename: K H
authors.initials: KH
authors.lastname: Nocka
authors.forename: M A
authors.initials: MA
authors.lastname: Moore
authors.forename: L M
authors.initials: LM
authors.lastname: Pelus
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D000938:Antigen-Presenting Cells / Q000166:cytology; D001853:Bone Marrow / Q000276:immunology*; D001854:Bone Marrow Cells; D002469:Cell Separation; D003114:Colony-Forming Units Assay; D003602:Cytotoxicity, Immunologic; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000502:physiology*; D006801:Humans
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II