title: Association of cell cycle expression of Ia-like antigenic determinations on normal human multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells with regulation in vitro by acidic isoferritins.
abstract: An association has been established between human Ia-like antigenic determinants, expression during DNA synthesis on multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells, and the regulatory action of acidic isoferritins in vitro. Treatment of human bone marrow cells with monoclonal anti-Ia (NE1-011) plus complement inhibited colony formation of CFU-GEMM) and BFU-E by 50%-70%. Reduction of colonies was similar whether bone marrow cells were exposed to anti-Ia plus complement, high specific tritiated thymidine (3HTdr), or acidic isoferritins. No further decrease was apparent with 3HTdr or acidic isoferritins after Ia-antigen+ CFU-GEMM or BFU-E were removed, or with anti-Ia plus complement or acidic isoferritins after S-phase CFU-GEMM or BFU-E were removed. Anti-Ia, in the absence of complement, had no effect on colony formation but blocked the inhibition of CFU-GEMM and BFU-E by acidic isoferritins. Demonstration of Ia-antigens on BFU-E and inhibition of BFU-E by acidic isoferritins appeared to require the presence of phytohemmagglutinin leukocyte conditioned medium (PHA-LCM) in the culture medium during the 14-day incubation period. these results implicate Ia-antigen+ cells, acidic isoferritins, and PHA-LCM in the regulation of multipotential and erythroid progenitor cells in vitro.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation; D003114:Colony-Forming Units Assay; D003601:Cytotoxicity Tests, Immunologic; D004247:DNA / Q000096:biosynthesis*; D000939:Epitopes; D005293:Ferritins / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D004247:DNA; D005293:Ferritins