A Clonogenic Bone Marrow Progenitor Specific for Macrophages and Dendritic Cells

TLDR

Macrophages and dendritic cells are key immune cells of the mononuclear phagocyte system, yet their origin and lineage remain poorly understood. The study isolates and clonally analyzes a mouse bone marrow progenitor that gives rise to monocytes, multiple macrophage subsets, and resident spleen dendritic cells. Differentiation from this progenitor was recapitulated in vitro using macrophage colony‑stimulating factor and granulocyte‑macrophage colony‑stimulating factor. The results show that macrophages and dendritic cells renew from a common progenitor, supporting the cellular basis of the mononuclear phagocyte system.

Abstract

Macrophages and dendritic cells (DCs) are crucial for immune and inflammatory responses and belong to a network of cells that has been termed the mononuclear phagocyte system (MPS). However, the origin and lineage of these cells remain poorly understood. Here, we describe the isolation and clonal analysis of a mouse bone marrow progenitor that is specific for monocytes, several macrophage subsets, and resident spleen DCs in vivo. It was also possible to recapitulate this differentiation in vitro by using treatment with the cytokines macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. Thus, macrophages and DCs appear to renew from a common progenitor, providing a cellular and molecular basis for the concept of the MPS.