title: Distinct bone marrow-derived and tissue-resident macrophage lineages proliferate at key stages during inflammation.
abstract: The general paradigm is that monocytes are recruited to sites of inflammation and terminally differentiate into macrophages. There has been no demonstration of proliferation of peripherally-derived inflammatory macrophages under physiological conditions. Here we show that proliferation of both bone marrow-derived inflammatory and tissue-resident macrophage lineage branches is a key feature of the inflammatory process with major implications for the mechanisms underlying recovery from inflammation. Both macrophage lineage branches are dependent on M-CSF during inflammation, and thus the potential for therapeutic interventions is marked. Furthermore, these observations are independent of Th2 immunity. These studies indicate that the proliferation of distinct macrophage populations provides a general mechanism for macrophage expansion at key stages during inflammation, and separate control mechanisms are implicated.
authors.affiliation: Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Luke C
authors.initials: LC
authors.lastname: Davies
authors.forename: Marcela
authors.initials: M
authors.lastname: Rosas
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Jenkins
authors.forename: Chia-Te
authors.initials: CT
authors.lastname: Liao
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Scurr
authors.forename: Frank
authors.initials: F
authors.lastname: Brombacher
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Fraser
authors.forename: Judith E
authors.initials: JE
authors.lastname: Allen
authors.forename: Simon A
authors.initials: SA
authors.lastname: Jones
authors.forename: Philip R
authors.initials: PR
authors.lastname: Taylor
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism; D001854:Bone Marrow Cells / Q000473:pathology*; D019070:Cell Lineage; D049109:Cell Proliferation; D005260:Female; D007249:Inflammation / Q000276:immunology / Q000473:pathology*; D015847:Interleukin-4 / Q000378:metabolism; D007700:Kinetics; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010538:Peritonitis / Q000276:immunology / Q000473:pathology; D019948:Receptors, Interleukin-4 / Q000378:metabolism; D015054:Zymosan
chemical_list: D000950:Antigens, Ly; D019948:Receptors, Interleukin-4; D015847:Interleukin-4; D016173:Macrophage Colony-Stimulating Factor; D015054:Zymosan