title: Competent dendritic cells derived from CD34+ progenitors express CMRF-44 antigen early in the differentiation pathway.
abstract: Differentiation of CD34(+) haematopoietic stem cells into functional dendritic cells (DC) was investigated using the mAb CMRF-44 and other mAb against DC-associated markers. GM-CSF mobilized peripheral blood stem cells were obtained from healthy donors by leukapheresis. CD34(+) cells were purified using CD34(+)-positive selection,and subsequent immunomagnetic depletion of CD14 and CD2 cells. CD34(+) cells were cultured in medium supplemented with one or more of GM-CSF,TNF-alpha, IL-4 or IL-6. CMRF-44 Ag expression was monitored by flow cytometry, and DC function by allogeneic MLR and tetanus toxoid(TT) presentation assays. CD34(+) cells quickly acquired the CMRF-44 Ag when cultured in the presence of TNF-alpha. By day 3, more than 50% of the cells were double-positive for CD34 and CMRF-44. CD34 expression was gradually lost, so that by day 9, the majority of the cells were CD34(-)/CMRF-44(+).GM-CSF and TNF-alpha also induced CD40 expression, and up-regulation of CD54 and MHC class II on CD34(+) cells; their expression was correlated to the CMRF-44 Ag. Day 3 CD34(+)/CMRF-44(+) cells,but not CD34(+)/CMRF-44(-) cells, become potent APC when cultured further with GM-CSF plus TNF-alpha. These CMRF-44(+) cells were potent inducers of Th1-type immune response in the primary allogeneic MLR and present TT to autologous CD4(+) T cells. TNF-alpha alone is sufficient to induce CMRF-44 expression on CD34(+) cells, but in combination with GM-CSF expands the CMRF-44(+) population. CMRF-44 expression correlates with DC function and may be a useful early marker for commitment of CD34(+) cells to the DC differentiation pathway.
authors.affiliation: CellPro Inc., Bothell,Washington, USA.
authors.forename: Tatsue
authors.initials: T
authors.lastname: Monji
authors.forename: JerilynTynes
authors.initials: J
authors.lastname: Petersons
authors.forename: Narinder K
authors.initials: NK
authors.lastname: Saund
authors.forename: Slavica
authors.initials: S
authors.lastname: Vuckovic
authors.forename: Derek Nigel John
authors.initials: DN
authors.lastname: Hart
authors.forename: Karen
authors.initials: K
authors.lastname: Auditore-Hargreaves
authors.forename: Grant
authors.initials: G
authors.lastname: Risdon
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D018952:Antigens, CD34 / Q000032:analysis* / Q000235:genetics; D000943:Antigens, Differentiation / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D013234:Stem Cells / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor