THE SIGNIFICANCE OF M1 AND M2 MONOCYTES IN SYSTEMIC SCLEROSIS

Background: Recently, the relation between M2 macrophage and fibrosis have been reported in several diseases including systemic sclerosis (SSc). Similar with macrophages, monocytes can be classified into M1 and M2 subset, and the relation of imbalance of these monocytes with disease such as rheumatoid arthritis have been reported1,2. Objectives: In this study, we attempted to investigate relationship among M1 or M2 monocytes in SSc. Methods: This study included 23 SSc patients and 20 healthy donors. Using fluorescence-activated cell sorting, we defined CD14, CD68 and CCR2 positive cells as M1 monocytes and CD14, CX3CR1 and CD163 positive cells as M2 monocytes. We examined the ability of cytokines/chemokines secretion of CD14 positive cells from SSc by multiplex bead array assay using MAP human cytokine/chemokine Magnetic Bead Panel which can measure 38 cytokines/chemokines. We next extracted M2 monocytes from CD14-positive cells using FACS, and we used the rest of the CD14 positive cells as M1-dominant monocytes. Then, we evaluated their ability of TGF-β production by multiplex bead array assay. Results: SSc patients had higher M2/M1 ratio as compared with healthy control (7.00 vs 1.63, P M1 (M2/M1 ratio\u003e1) were higher than that from CD14 positive cells which consists M2 Conclusion: Our present study suggested that the imbalance of M1/M2 monocytes might contribute to pathogenesis of SSc. References: [1]Fadini GP, Simoni F, Cappellari R, et al. Pro-inflammatory monocyte-macrophage polarization imbalance in human hypercholesterolemia and atherosclerosis. Atherosclerosis 2014; 237(2): 805-8. [2]Fukui S, Iwamoto N, Takatani A, et al. M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis. Front Immunol 2017; 8: 1958. Disclosure of Interests: None declared