Published online before print January 30, 2009
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* Department of Medicine and CRC for Chronic Inflammatory Diseases, The University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia;
Department of Biochemistry and Molecular Biology and CRC for Chronic Inflammatory Diseases, Institute for Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia; and
Clinical Hematology and Medical Oncology, Bone Marrow Transplant Unit, Royal Melbourne Hospital, Parkville, Victoria, Australia
1 Correspondence: University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Clinical Sciences Building, Royal Parade, Parkville, Victoria, 3050, Australia. E-mail: jahami{at}unimelb.edu.au
ABSTRACT
Information about the development and function of human macrophage lineage populations, such as osteoclasts, is limited because of the lack of defined in vitro systems for their large-scale generation. Two M-CSF-containing cytokine cocktails were found under serum-free conditions to expand dramatically and to differentiate over time human CD34+ hemopoietic stem cells into nonadherent and adherent macrophage populations. These populations exhibited increasing degrees of maturity over a 3-week period characterized by morphology, surface marker expression (CD11b, CD86, CD64, CD14, and c-Fms), phagocytic function, and gene-expression profiling using quantitative PCR and microarray analysis (principal component analysis, k-means clustering, and gene ontology classification). As assessed by the last criterion, the adherent population obtained at 3 weeks from the one protocol tested had high similarity to the well-studied peripheral blood monocyte-derived macrophages. The one population tested could be induced to differentiate into osteoclasts in the presence of M-CSF and receptor activator of NF-
B ligand, as judged by morphology, gene expression, and bone-resorbing ability. In addition to the large numbers of macrophage lineage cells able to be produced, this replicating system may be suitable for the molecular analysis of macrophage lineage commitment and progression and for gene targeting and delivery.
Key Words: M-CSF differentiation gene expression profile