title: Interleukin-25 and interleukin-13 production by alveolar macrophages in response to particles.
abstract: Particle inhalation-induced lung inflammation acts as an adjuvant to allergens or respiratory viral infection in a process that is mediated by macrophages and epitheliums. The production of interleukin (IL)-4 and IL-13 by activated T cells is involved in the augmentation of Th2-type immune responses to particles, and IL-25 induces the synthesis of IL-4 and IL-13. However, whether IL-13 and IL-25 are directly regulated by particle instillation in the lung has not been studied. The aim of this study was to reveal particle induction of IL-13 and IL-25 in the lung. TiO(2) instillation potently induced the mRNA expression for IL-25 and IL-13 in lung tissue extracts 24 h after treatment, as compared with the sham group. Immunostaining for IL-25 and IL-13 showed strong positivity for macrophages in the inflammatory lung lesions of TiO(2)-treated rats. The alveolar macrophages expressed IL-25 and IL-13 24 h after in vitro stimulation with TiO(2) particles in dose- and time-dependent manners, with maximal induction at 24 and 48 h after stimulation, respectively. The sequence of the rat IL-25 gene is 95% homologous with the mouse IL-25 gene. These findings indicate that alveolar macrophages play an important role in particle-induced lung inflammation via direct induction of IL-13 and IL-25 production.
authors.affiliation: Division of Allergy and Respiratory Diseases, Department of Internal Medicine, Soonchunhyang University Hospital, 1174 Jung-dong, Wonmi-gu, Bucheon-si, Gyeonggido 420-767, Republic of Korea.
authors.forename: Chun-Mi
authors.initials: CM
authors.lastname: Kang
authors.forename: An-Soo
authors.initials: AS
authors.lastname: Jang
authors.forename: Mi-Hyun
authors.initials: MH
authors.lastname: Ahn
authors.forename: Jeong-Ah
authors.initials: JA
authors.lastname: Shin
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Kim
authors.forename: Yun-Sung
authors.initials: YS
authors.lastname: Choi
authors.forename: Tai-Youn
authors.initials: TY
authors.lastname: Rhim
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Park
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D015870:Gene Expression / Q000276:immunology; D018793:Interleukin-13 / Q000235:genetics* / Q000378:metabolism; D007378:Interleukins / Q000235:genetics* / Q000378:metabolism; D016676:Macrophages, Alveolar / Q000502:physiology*; D008297:Male; D011014:Pneumonia / Q000139:chemically induced / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014025:Titanium
chemical_list: D018793:Interleukin-13; D007378:Interleukins; D012333:RNA, Messenger; C504693:interleukin-25, rat; C009495:titanium dioxide; D014025:Titanium