Cytokine Regulation of the Macrophage M[stod]o System Studied Using the Colony Stimulating Factor-1-Deficient [i]op/op[r] Mouse. Wieslaw Wiktor-Jedrzejczak, and Siamon Gordon. Dept. of Immunology, Central Clinical Hospital, Military School of Medicine, Warsaw, Poland; and Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
APStracts 2:0017P, 1996.
ABSTRACT
The macrophage (M[stod]o) lineage is more complex than other myeloid lineages of hematopoietic cells and includes strikingly different end cells such as Kupffer cells, alveolar M[stod]o, histiocytes, serosal M[stod]o, synovial type A cells, microglia, osteoclasts, and possibly dendritic cells. These cells are formed under the influence of primary M[stod]o growth factors such as colony stimulating factor (CSF)-1, granulocyte-M[stod]o (GM)-CSF, and interleukin-3. The dissection of the system has been greatly facilitated by discovery of the osteopetrotic [i]op/op[r] mouse, which has a spontaneous knockout of the gene for CSF-1 and possesses generalized but differential deficiency of various local subpopulations of M[stod]o. Studies using this model indicate that the M[stod]o lineage is split into CSF-1-dependent and CSF-1-independent cells that are largely independently regulated. These contribute variably to different local populations and have largely, but not totally, overlapping functions. Both CSF-1 and GM-CSF are responsible for transition of cells of the M[stod]o lineage from bone marrow to blood, and from blood to tissues, and have a critical extramedullary role. Regulation of the M[stod]o system by CSF- 1 is complex, with some local populations dependent on circulating CSF-1 and some supported exclusively by locally produced CSF-1. Colony stimulating factor-1-dependent M[stod]o are not required for the generation of a specific immune response. Instead, most likely they play a regulatory role in various tissue reactions including responses to bacterial infection, neoplasia, and atherosclerosis. A hypothetical major role of CSF-1-independent M[stod]o is to collaborate with lymphocytes in mounting an immune response. These issues need further exploration using animals with knockouts of genes for other M[stod]o growth and activation factors and their receptors.

APS Manuscript Number P.
Article publication pending October 1996, Physiological Reviews.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996