Progress in the regulatory effects of tumor-derived exosomes on macrophage polarization / 中华微生物学和免疫学杂志

Mononuclear macrophages are versatile cells that can have different responses to various microenvironmental signals. Under different stimuli of circumstances, macrophages can be fully polarized into classically activated macrophages (M1) and alternatively activated macrophages (M2), which are the extremes of a continuum of functional states. Nuclear factor-κB, cyclooxygenase 2, anoxia status, proto-oncogene MYC, Toll-like receptor signaling pathway, Notch signaling pathway and cytokines are all closely involved in the transition of tumor-associated macrophages from M1 to M2 phenotype. Macrophages that infiltrate tumor tissues are driven by tumor-derived cytokines to acquire a polarized M2 phenotype. These functionally polarized cells play a key role in the subversion of adaptive immunity and in inflammatory circuits that promote tumor development and progression. Exosomes derived from tumors have the characteristics of tumor cells and could participate in multiple processes of tumorigenesis and development. This review focused on exosomes derived from various cancer cells and discussed the role of the payloads of tumor-derived exosomes in modulating macrophage polarization in the tumor immune microenvironment and the intracellular signal mechanisms involved.

IL-17 A promotes differentiation and maturation of bone marrow-derived dendritic cells by cooperating with GM-CSF and LPS / 中国免疫学杂志

Objective:To investigate the effect of IL-17A on the differentiation and maturation of murine bone marrow-derived dendritic cells( BMDCs ) . Methods: Murine bone marrow cells were isolated and cultured in RPMI1640 complete medium in the presence of GM-CSF(20 ng/ml) for 8 days to induce differentiation of murine bone marrow cells to DC progenitors. Then these cells were treated with LPS(1 μg/ml) for 36 h which polarized immature DCs into mature DCs. Different concentrations of rmIL-17A(10 or 100 ng/ml) was added to the culture medium at different stages of BMDC differentiation and maturation. Co-stimulatory molecules expression on BMDC were analyzed by flow cytometry,and the culture supernatants were analyzed for IL-12p40 and IL-10 level by ELISA. Results:rmIL-17 could promote co-stimulatory molecules( CD40,CD80,CD86 and MHCⅡ) expression on BMDCs in a does-dependent manner,especially,the expression of CD40 and MHCⅡhad a significant increase in high concentration of rmIL-17A group;rmIL-17A was added while LPS induced maturation of BMDCs. CD40,CD80,CD86 and MHCⅡexpression on BMDC increased sharply in LPS plus rmIL-17A stimulation group,besides,CD86,MHCⅡ showed a higher level expression on BMDC with the increase of con-centration of rmIL-17A. Furthermore,secretion of IL-12p40 and IL-10 increased significantly in the group of DCs treated with LPS plus low concentration of rmIL-17 compared with the group without rmIL-17(P<0. 001). However,high concentration of rmIL-17A group showed significantly higher levels of IL-12p40(P<0. 001),but there was no difference in IL-10. Conclusion:IL-17A promotes the phe-notypic development of BMDC progenitors propagated in GM-CSF and cooperate with LPS to induce BMDC differentiation and matura-tion.