title: Murine spleen stromal cell line SPY3-2 maintains long-term hematopoiesis in vitro.
abstract: The hematopoietic microenvironment (HIM) of mouse spleen predominantly induces the differentiation of hematopoietic progenitors into erythroid lineage in vivo. However, the mechanisms of this phenomenon have not been fully explored because of the lack of an adequate in vitro system mimicking the spleen hematopoiesis. To reconstruct the HIM of mouse spleen in vitro, we established spleen stromal cell lines from a three-dimensional (3D) spleen primary culture in collagen gel matrix. Of these, SPY3-2 cells were negative for preadipocytic and endothelial markers, had a fibroblastoid morphology, and were not converted to adipocytes in the presence of 1 mumol/L hydrocortisone. They supported the maintenance and multilineal differentiation of hematopoietic progenitor cells for more than 8 weeks in vitro. The differentiated hematopoietic cells in the coculture medium were predominantly monocytes rather than granulocytes. Furthermore, erythropoiesis was predominantly induced in the presence of 2 U/mL erythropoietin and continued for more than 12 weeks. The number of burst-forming units-erythroid (BFU-E) was increased 10 times after 3 weeks of coculture, which was followed by pronounced production of erythroid cells in the coculture after week 4. SPY3-2 expressed high levels of c-kit ligand and low levels of granulocyte macrophage colony-stimulating factor and interleukin-3, and these molecules were all involved in this long-term erythropoiesis. Thus, the clonal SPY3-2 cell line will provide a novel HIM in vitro analogous to that of mouse spleen in vivo. These results suggest that 3D collagen gel culture may facilitate the establishment of functioning stromal cell lines of hematopoietic organ.
authors.affiliation: Department of Pathology, Okayama University Medical School, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Tsuchiyama
authors.forename: M
authors.initials: M
authors.lastname: Mori
authors.forename: S
authors.initials: S
authors.lastname: Okada
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001483:Base Sequence; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003094:Collagen; D003238:Connective Tissue / Q000502:physiology*; D003239:Connective Tissue Cells; D015672:Erythroid Precursor Cells / Q000166:cytology; D004920:Erythropoiesis / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology; D005782:Gels; D006411:Hematopoiesis, Extramedullary; D016298:Hematopoietic Cell Growth Factors / Q000032:analysis / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006854:Hydrocortisone / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology*; D019089:Stem Cell Factor
chemical_list: D000911:Antibodies, Monoclonal; D005782:Gels; D016298:Hematopoietic Cell Growth Factors; D007375:Interleukin-1; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D004921:Erythropoietin; D003094:Collagen; D006854:Hydrocortisone