Enhancement of phagocytosis and cytotoxicity in macrophages by tumor-derived IL-18 stimulation?

• Published in: BMB reports Vol. 47; no. 5; pp. 286 - 291
• Main Authors: Xu, Henan, Toyota, Naoka, Xing, Yanjiang, Fujita, Yuuki, Huang, Zhijun, Touma, Maki, Wu, Qiong, Sugimoto, Kenkichi
• Format: Journal Article
• Language: Korean
• Published: 생화학분자생물학회 30.05.2014
• Subjects: angiogenesis; IL-18; macrophages; Nos2; phagocytosis; phagocytosis; macrophages; Nos2; IL-18; angiogenesis
• ISSN: 1976-6696; 1976-670X

Inoculation of mice with the murine NFSA cell line caused theformation of large tumors with necrotic tumor cores. FACSanalysis revealed accumulations of CD11b+ cells in the tumors. Microarray analysis indicated that the NFSA cells expressed ahigh level of the pro-inflammatory factor interleukin-18 (il-18),which is known to play a critical role in macrophages. However, little is known about the physiological function ofIL-18-stimulated macrophages. Here, we provide directevidence that IL-18 enhances the phagocytosis of RAW264 cellsand peritoneal macrophages, accompanied by the increasedexpression of tumor necrosis factor (tnf-α), interleukin-6 (il-6)and inducible nitric oxide synthase (Nos2). IL-18-stimulatedRAW264 cells showed an enhanced cytotoxicity to endothelialF-2 cells via direct cell-to-cell interaction and the secretion ofsoluble mediators. Taken together, our results demonstrate thattumor-derived IL-18 plays an important role in the phagocytosisof macrophages and that IL-18-stimulated macrophages maydamage tumor endothelial cells.[BMB Reports 2014; 47(5): 286-291]