In vitro cytokine release from rat type II pneumocytes and alveolar macrophages following exposure to JP-8 jet fuel in co-culture

• Published in: Toxicology (Amsterdam) 2002-05, Vol.173 (3), p.211-219
• Main Authors: Wang, Shengjun, Young, R.Scotte, Sun, Nina N., Witten, Mark L.
• Format: Article
• Language: English
• Subjects: Alveolar macrophages; Animals; Biological and medical sciences; Cell Line, Transformed; Chemical and industrial products toxicology. Toxic occupational diseases; Co-cultures; Coculture Techniques; Cytokines; Cytokines - metabolism; Hydrocarbons - pharmacology; Interleukin-1 - metabolism; Interleukin-10 - metabolism; Interleukin-6 - metabolism; JP-8 jet fuel; Macrophages, Alveolar - cytology; Macrophages, Alveolar - drug effects; Macrophages, Alveolar - metabolism; Male; Medical sciences; Metabolism; Petroleum - adverse effects; Rats; Rats, Inbred F344; Time Factors; Toxicology; Tumor Necrosis Factor-alpha - metabolism; Type II pneumocytes; Various organic compounds
• ISSN: 0300-483X; 1879-3185
• DOI: 10.1016/S0300-483X(02)00037-9

Alveolar type II epithelial cells (AIIE) and pulmonary alveolar macrophages (PAM) are involved in pulmonary toxicity of JP-8 jet fuel exposure. To further elucidate their inflammatory mechanisms, the effect(s) of JP-8 jet fuel on cytokine secretion were examined in a transformed rat AIIE cell line (RLE-6TN) culture alone, primary PAM (from Fischer 344 rats) culture alone, and the co-culture of AIIE and primary PAM. A series of JP-8 jet fuel concentrations (0–0.8 μg/ml), which may actually be encountered in alveolar space of lungs exposed in vivo, were placed in cell culture for 24 h. Cultured AIIE alone secreted spontaneously interleukin (IL)-1β and -6 [below detectable limits for IL-10 and tumor necrosis factor-α (TNF-α)], whereas cultured PAM alone secreted IL-1β, -10, and TNF-α, in a concentration-dependent manner. These data suggest that the release of cytokines, not only from PAM but also from AIIE cells, may contribute to JP-8 jet fuel-induced inflammatory response in the alveolar space. However, the co-cultures of AIIE and PAM showed no significant changes in IL-1β, -6, and TNF-α at any JP-8 jet fuel concentration compared to control values. These cytokine levels in co-cultures of AIIE and PAM were inversely related to these of cultured AIIE or PAM alone. Interestingly, IL-10 levels in the co-culture system were concentration-dependently increased up to 1058% at JP-8 concentrations of 0.8 μg/ml, although under detectable limits in cultured AIIE alone and no significant concentration change in cultured PAM alone. It appears that PAM may possibly act via paracrine and/or autocrine pathways to signal AIIE cells to regulate cytokine release.