👤 Udeshika Kariyawasam

Macrophages differentiated with macrophage colony-stimulating factor (M-CSF) (M-Mac) are widely used as an experimental model. Interleukin 27 (IL-27)-polarized M-Mac (27M-Mac) suppresses HIV replication; however, the effects of IL-27 polarization on granulocyte-macrophage colony-stimulating factor (GM-CSF)-induced macrophages (GM-Mac) remain less investigation. Here, we compare multiple functional properties and gene expression profiles of 27M-Mac and IL-27-polarized GM-Mac (27GM-Mac). M-Mac and GM-Mac were generated from monocytes of healthy donors and subsequently treated with IL-27 for three days. HIV replication in 27M-Mac, GM-Mac, and 27GM-Mac was suppressed to nearly 10% of that in M-Mac; however, single-cell RNA sequencing showed that M-Mac clustered with GM-Mac, and 27M-Mac clustered with 27GM-Mac. Expression of CD38 and secretion of CXCL9 and C1q were significantly increased in 27M-Mac and 27GM-Mac compared with M-Mac and GM-Mac. Although CD16 and CD64 expression increased in 27M-Mac and 27GM-Mac relative to their respective controls, phagocytic activity in 27M-Mac and 27GM-Mac was 30% of that in M-Mac. Autophagy was promoted 3.7-fold more strongly in 27M-Mac than in M-Mac, reaching levels comparable to those in GM-Mac and 27GM-Mac. Collectively, these findings indicate that IL-27 polarizes M-Mac and GM-Mac toward transcriptionally and functionally similar subtypes, providing insight into the role of IL-27 in macrophage polarization and plasticity. Show less

Interleukin (IL)-27 is an anti-viral cytokine. IL-27-treated monocyte-derived macrophages (27-Mac) suppressed HIV replication. Macrophages are generally divided into two subtypes, M1 and M2 macrophages. M2 macrophages can be polarized into M2a, M2b, M2c, and M2d by various stimuli. IL-6 and adenosine induce M2d macrophages. Since IL-27 is a member of the IL-6 family of cytokines, 27-Mac was considered M2d macrophages. In the current study, we compared biological function and gene expression profiles between 27-Mac and M2d subtypes. Monocytes derived from health donors were differentiated to M2 using macrophage colony-stimulating factor. Then, the resulting M2 was polarized into different subtypes using IL-27, IL-6, or BAY60-658 (an adenosine analog). HIV replication was monitored using a p24 antigen capture assay, and the production of reactive oxygen species (ROS) was determined using a Hydrogen Peroxide Assay. Phagocytosis assay was run using GFP-labeled opsonized E. coli. Cytokine production was detected by the IsoPlexis system, and the gene expression profiles were analyzed using single-cell RNA sequencing (scRNA-seq). 27-Mac and BAY60-658-polarized M2d (BAY-M2d) resisted HIV infection, but IL-6-polarized M2d (6-M2d) lacked the anti-viral effect. Although phagocytosis activity was comparable among the three macrophages, only 27-Mac, but neither 6-M2d nor BAY-M2d, enhanced the generation of ROS. The cytokine-producing profile of 27-Mac did not resemble that of the two subtypes. The scRNA-seq revealed that 27-Mac exhibited a different clustering pattern compared to other M2ds, and each 27-Mac expressed a distinct combination of anti-viral genes. Furthermore, 27-Mac did not express the biomarkers of M2a, M2b, and M2c. However, it significantly expressed CD38 (p<0.01) and secreted CXCL9 (p<0.001), which are biomarkers of M1. These data suggest that 27-Mac may be classified as either an M1-like subtype or a novel subset of M2, which resists HIV infection mediated by a different mechanism in individual cells using different anti-viral gene products. Our results provide a new insight into the function of IL-27 and macrophages. Show less

Inflammatory bowel disease (IBD) is characterized by gastrointestinal inflammation comprised of Crohn's disease and ulcerative colitis. Centers for Disease Control and Prevention report that 1.3% of the population of the United States (approximately 3 million people) were affected by the disease in 2015, and the number keeps increasing over time. IBD has a multifactorial etiology, from genetic to environmental factors. Most of the IBD treatments revolve around disease management, by reducing the inflammatory signals. We previously identified the surface layer protein A (SlpA) of Show less