title: MiR-16 regulates mouse peritoneal macrophage polarization and affects T-cell activation.
abstract: MiR-16 is a tumour suppressor that is down-regulated in certain human cancers. However, little is known on its activity in other cell types. In this study, we examined the biological significance and underlying mechanisms of miR-16 on macrophage polarization and subsequent T-cell activation. Mouse peritoneal macrophages were isolated and induced to undergo either M1 polarization with 100 ng/ml of interferon-γ and 20 ng/ml of lipopolysaccharide, or M2 polarization with 20 ng/ml of interleukin (IL)-4. The identity of polarized macrophages was determined by profiling cell-surface markers by flow cytometry and cytokine production by ELISA. Macrophages were infected with lentivirus-expressing miR-16 to assess the effects of miR-16. Effects on macrophage-T cell interactions were analysed by co-culturing purified CD4(+) T cells with miR-16-expressing peritoneal macrophages, and measuring activation marker CD69 by flow cytometry and cytokine secretion by ELISA. Bioinformatics analysis was applied to search for potential miR-16 targets and understand its underlying mechanisms. MiR-16-induced M1 differentiation of mouse peritoneal macrophages from either the basal M0- or M2-polarized state is indicated by the significant up-regulation of M1 marker CD16/32, repression of M2 marker CD206 and Dectin-1, and increased secretion of M1 cytokine IL-12 and nitric oxide. Consistently, miR-16-expressing macrophages stimulate the activation of purified CD4(+) T cells. Mechanistically, miR-16 significantly down-regulates the expression of PD-L1, a critical immune suppressor that controls macrophage-T cell interaction and T-cell activation. MiR-16 plays an important role in shifting macrophage polarization from M2 to M1 status, and functionally activating CD4(+) T cells. This effect is potentially mediated through the down-regulation of immune suppressor PD-L1.
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Jia
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Junjun
authors.initials: J
authors.lastname: Miao
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Pathology, Medical College of Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Guoli
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Surgery, Clinical Medical College of Yangzhou University, Yangzhou, Jiangsu, China. wzhb403@163.com.
authors.forename: Zhengbing
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D060890:B7-H1 Antigen / Q000378:metabolism; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D016764:Cell Polarity / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D060890:B7-H1 Antigen; C498919:Cd274 protein, mouse; D016207:Cytokines; D035683:MicroRNAs; C522604:Mirn16 microRNA, mouse
keywords: CD4+ T cells; PD-L1; macrophage polarization; miR-16