Identification of novel subsets amongst dendritic cells and macrophages generated from the culture of bone marrow

Abstract

Abstract Dendritic cells (DCs) play pivotal roles in various immune responses by sampling and presenting antigens to naïve T cells and inducing the subsequent T-cell activation or tolerance. In vitro culture systems have been widely used to study DC biology. The culture of bone marrow (BM) with the aids of a hematopoietic cytokine, Fms-like tyrosine kinase 3 ligand (FLT3L), yields plasmacytoid DCs (pDCs) and classical DCs (cDCs), whereas the culture of BM in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) produces BM-derived DCs and macrophages considered to possess inflammatory phenotypes. In the present study, various antibodies including DC-specific monoclonal antibodies were utilized to carefully describe the subsets of cells present in the cultures of BM with GM-CSF or FLT3L. We identified new subsets of DCs and macrophages: 3 different subsets of DCs and macrophages were characterized from the CD11c+ MHCIIhi cells in the BM culture with Flt3L by flow cytometric analyses. The newly discovered subsets of DCs and macrophages present in the BM culture require further investigation to distinguish and elucidate their phenotypes and functions in details.