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Tomasz Jędrzejewski,1 Justyna Sobocińska,1 Małgorzata Pawlikowska,1 Artur Dzialuk,2 Sylwia Wrotek1 1Department of Immunology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Torun, 87-100, Poland; 2Department of Genetics, Faculty of Biological Sciences, Kazimierz Wielki University, Bydgoszcz, 85-090, PolandCorrespondence: Tomasz Jędrzejewski, Department of Immunology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, 1 Lwowska Str., Torun, 87-100, Poland, Tel +48 56 611 25 18, Email tomaszj@umk.pl Artur Dzialuk, Department of Genetics, Faculty of Biological Sciences, Kazimierz Wielki University, 10 Powstańców Wielkopolskich Ave., Bydgoszcz, 85-090, Poland, Tel +48 52 34 19 281, Email dzialuk@ukw.edu.plPurpose: Extract from the fungus Coriolus versicolor (CV) is classified as an immunological response modifier. Previously, we have shown that this extract induces interleukin 6 (IL-6)-related extension of lipopolysaccharide (LPS)-induced fever. This study investigated the effect of CV extract on the production of pro-inflammatory cytokines and the expression of components of signal transduction pathways leading to the secretion of cytokines from RAW 264.7 macrophages stimulated with different doses of LPS.Methods: RAW 264.7 cells were stimulated with CV extract alone or co-treated with CV extract and LPS. The level of IL-6 and tumour necrosis factor α (TNF-α) in the culture media was measured using ELISA. Protein expression of Toll-like receptor (TLR) 4, phosphorylated IκB (p-IκB), CD14 glycoprotein and phospho-phosphatidylinositol 3-kinase (p-PI3K) was evaluated using Western blot. The effects of TLR4, nuclear factor κB (NF-κB) and p-PI3K on cytokine secretion were estimated using inhibitors: TAK-242, JSH-23 and LY294002.Results: CV extract itself stimulates the secretion of IL-6 and TNF-α and increases the expression of TLR4, p-IκB and p-PI3K. The presence of CV extract during the treatment of cells with lower concentrations of LPS (10 and 100 ng/mL) increases the cytokine production. Co-stimulation of cells with CV extract and LPS at a higher dose (500 ng/mL) decreases the secretion of cytokines. This effect is related to the changes in the expression of TLR4, CD14 glycoprotein, p-IκB and p-PI3K.Conclusion: This is the first report showing that the CV extract-induced production of cytokines is mediated by the PI3K signalling pathway. This extract acts antagonistically or additively with LPS on the production of IL-6 and TNF-α, depending on the LPS concentration. Our results are helpful for illustrating the mechanisms for the immunostimulatory effect of CV extract in inflammatory processes.Keywords: Coriolus versicolor, pro-inflammatory cytokines, Toll-like receptor 4, phosphorylated IκB, phosphatidylinositol 3-kinase, CD14 glycoprotein |
