title: Effects of pulmonary exposure to diesel exhaust particles on extrathoracic CD4 polarization in asthmatic mice.
abstract: Although diesel exhaust particles (DEP) exacerbate murine allergic asthma, the mechanisms remain unclarified. This study elucidated the effects of pulmonary exposure to DEP on extrathoracic allergen-induced CD4 polarization using an ex vivo system in asthmatic mice. Mice were divided into 4 groups, and vehicle, DEP, ovalbumin (OVA), or DEP + OVA was intratracheally instilled biweekly 5 times. Twenty-four h after the last intratracheal instillation, the spleen was removed. Mononuclear cells were isolated from the spleen and stimulated in vitro with OVA; thereafter, the number of separated CD4(+) cells was counted. The number of separated CD4(+) cells was significantly greater in the OVA or the DEP + OVA group than in the vehicle group. Furthermore, the number was significantly greater in the DEP + OVA than in the DEP or the OVA group. Taken together, in vivo DEP exposure amplified extrathoracic CD4 polarization in asthmatic subjects.
authors.affiliation: National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan. inoue.kenichirou@nies.go.jp
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Inoue
authors.forename: Eiko
authors.initials: E
authors.lastname: Koike
authors.forename: Rie
authors.initials: R
authors.lastname: Yanagisawa
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Takano