In vitro study of the effect of nanoparticle-rich diesel exhaust particles on IL-18 production in splenocytes

Abstract

-It has been shown that pulmonary exposure to diesel exhaust particles (DEP) disrupts the immune system, presenting as exacerbating effects on allergic manifestations (e.g., allergic asthma). However, since a model inhalation system has not been developed, the impact of nano-level DEP on health has not been satisfactorily investigated. Our institute (the National Institute for Environmental Studies) established an "environmental nanoparticle exposure system applied in animals" in 2005 and since then, we have explored the health effects of exposure to these types of agent. The present study was conducted to investigate the in vitro effects of nanoparticle-rich DEP (NRDEP) on primary splenocytes from atopyprone hosts. NC/Nga mouse-derived splenic mononuclear cells were co-cultured with NRDEP (0-50 μg/ ml); thereafter, the production/release of interleukin (IL)-18 in the culture supernatants was evaluated by means of ELISA. NRDEP increased IL-18 production/release by splenocytes in a dose-dependent manner with an overall trend (with significance vs. 10 μg/ml of NRDEP). In contrast, 50 μg/ml of NRDEP inhibited production/release. These results suggest that NRDEP can activate naïve splenic mononuclear cells from atopy-prone animals in terms of IL-18 induction.

Diesel exhaust particles exacerbate allergic rhinitis in mice by disrupting the nasal epithelial barrier

“…DEP was collected at the National Institute for Environmental Studies (Tsukuba, Ibaraki, Japan), and was suspended in vehicle with 0.05% Tween-80 before use, as described previously [20]. DEP was collected at the National Institute for Environmental Studies (Tsukuba, Ibaraki, Japan), and was suspended in vehicle with 0.05% Tween-80 before use, as described previously [20].…”

“…To detect TJs, polyclonal rabbit IgG antibody for mouse zonula occludens-1 (ZO-1) and claudin-1, and Alexa 488 anti-rabbit IgG were purchased from Invitrogen (San Diego, CA, USA). DEP was collected at the National Institute for Environmental Studies (Tsukuba, Ibaraki, Japan), and was suspended in vehicle with 0.05% Tween-80 before use, as described previously [20]. Briefly, an 8-L diesel engine (Jo8C; Hino Motors, Tokyo, Japan) was used as a source of DEP.…”

Immunotoxic Effect of Low-Dose Methylmercury Is Negligible in Mouse Models of Ovalbumin or Mite-Induced Th2 Allergy

“…20) Furthermore, our previous studies in vitro suggest that DEP induce cytokine production by splenocytes isolated from atopy-prone NC/Nga mice. 21,22) By contrast, effects of MeHg on immune system have been still elusive. However, our results presented here suggest that MeHg is unlikely to increase immune responses in mice with a dysregulated immune system.…”