title: Local macrophage proliferation, rather than recruitment from the blood, is a signature of TH2 inflammation.
abstract: A defining feature of inflammation is the accumulation of innate immune cells in the tissue that are thought to be recruited from the blood. We reveal that a distinct process exists in which tissue macrophages undergo rapid in situ proliferation in order to increase population density. This inflammatory mechanism occurred during T helper 2 (T(H)2)-related pathologies under the control of the archetypal T(H)2 cytokine interleukin-4 (IL-4) and was a fundamental component of T(H)2 inflammation because exogenous IL-4 was sufficient to drive accumulation of tissue macrophages through self-renewal. Thus, expansion of innate cells necessary for pathogen control or wound repair can occur without recruitment of potentially tissue-destructive inflammatory cells.
authors.affiliation: Centre for Immunity, Infection and Evolution, and the Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Jenkins
authors.forename: Dominik
authors.initials: D
authors.lastname: Ruckerl
authors.forename: Peter C
authors.initials: PC
authors.lastname: Cook
authors.forename: Lucy H
authors.initials: LH
authors.lastname: Jones
authors.forename: Fred D
authors.initials: FD
authors.lastname: Finkelman
authors.forename: Nico
authors.initials: N
authors.lastname: van Rooijen
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDonald
authors.forename: Judith E
authors.initials: JE
authors.lastname: Allen
mesh_terms: D000818:Animals; D001769:Blood; D017178:Brugia malayi / Q000276:immunology; D049109:Cell Proliferation; D005260:Female; D005368:Filariasis / Q000276:immunology; D005370:Filarioidea / Q000276:immunology; D007249:Inflammation / Q000276:immunology*; D015847:Interleukin-4 / Q000276:immunology; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000166:cytology / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D015847:Interleukin-4