EXPLORING EFFECTS OF INTERLEUKIN-33 ON JAK/STAT SIGNALLING PATHWAYS IN MACROPHAGES

Authors : Mehmet Zafer KALAYCİ, Zubeyir ELMAZOGLU, Vedat BULUT

Pages : 32-44

View : 24 | Download : 15

Publication Date : 2022-04-30

Article Type : Research Paper

Abstract :It is known that IL-33 cytokine plays role in pathogenesis of some diseases. The dual role of macrophages within the tumor microenvironment is well-known and dependent on their plasticity. Macrophages mainly serve as the component of innate immune system, but they also act as a bridge between innate and acquired immune system with their antigen presentation capacity. Macrophages can change their functions by being polarized to classical M1 and alternative M2 macrophages via cytokine cocktails, such as interferon-, transforming growth factor- and interleukin-4, -10, -13. Tumor promoting effects are mainly associated with tumor-associated macrophages (TAMs) resembling the M2 types of macrophages. On the other hand, macrophages shifted to M1 type are capable of antitumour activities. Investigation of down-stream intracellular signaling pathways is very important in order to understand completely its role in pathogenesis of diseases mentioned above, as well as, to determine appropriate hypothesis in studies of therapeutic agents related to down-stream intracellular signaling pathways. This study is aimed to enlighten the effect of IL-33 on tyrosine kinase and JAK/STAT intracellular signaling pathways in macrophage cell line, J774.1. Therefore, mrIL-33 in several concentrations will be added into cell cultures of J774 stimulated by IFN-γ plus LPS or unstimulated. Then, tyrosine kinase (Tk) activities, levels and activation of Jak/STAT activities will be measured. In this study, it was observed that IL-33 additions in prior to mrIFN-γ 40 U/mL plus LPS 10 ng/mL stimulation decreased Tyk-2 levels in the group in which IL-33 levels were used at 10 ng/mL (p<0.05). In order to monitor the effects of IL-33 on tyk2, it was observed that tyrosine kinase tyk2 levels did not change when IL-33 was added to cell cultures at 10ng/mL and 100 ng/mL concentrations after 0, 4 and 18 hours. When IL-33 was applied to the J774.1 macrophage cell line at a concentration of 10 ng/mL at different times, an increase in Tyk-2 phosphorylation was observed. When IL-33 was applied to J774.1 cells at concentrations of 10 ng/mL and 100 ng/mL 4 and 18 hours before IFN-γ stimulation, statistically increased phosphorylated STAT levels were found in all IL-33 applied groups compared to the control group. These results show that high-dose IL-33 administration creates a synergistic effect on STAT activation with IFN-γ stimulation. This study will lead to observation of the effect of IL-33 in intracellular signaling pathways of macrophages. Then, it will be going through the proper channels to understand effective mechanisms of IL-33, as a therapeutic target in neoplasms.
Keywords : IL 33, intracellular signaling pathways, tyrosine kinase, JAK, STAT, INF γ