Project description:We aimed to decipher the effect of the neuropeptide TAFA4 on human M2c macrophage polarization. We used monocytes isolated from peripheral blood of three independant donors and generated different polarisations in the presence or absence of TAFA4. Monocytes were cultured with M-CSF for six days to induce their differentiation in macrophages (Mφ). On day six, the cells were left untreated or were treated for two days with dexamethasone to induce their M2c polarization. After differentiation and polarization, 100,000 cells from each condition and donor were sorted to remove debris and dead cells, then used for the sequencing.
Project description:In response to microenvironmental signals macrophages undergo different activation, indicated as classic/M1 and alternative/M2 polarization. C-Myc transcription factor could be an essential player in M2 polarization. Functional relevance of c-Myc in M2 macrophage biology is investigated by evaluating the effect of 100-58F4, on the transcriptional profile induced on human macrophages by IL-4. Human monocytes were obtained from normal donor buffy coats by two-step gradient centrifugation using Ficoll (Biochrom) and Percoll (Amersham). Non-adherent cells were discarded, and the purified monocytes were incubated for 7 days in RPMI 1640 (Biochom) supplemented with 10% FCS (HyClone) and 100 ng/mL M-CSF to obtain resting macrophages. Macrophage polarization was obtained by removing the culture medium and culturing cells in RPMI 1640 supplemented with 10% FCS and 100 ng/mL LPS plus 20 ng/mL IFN-gamma (M1 polarization) or 20 ng/mL IL-4 (M2 polarization) for 24 h. When needed, chemical inhibitors were added with IL-4.
Project description:Research on the mechanism of Cytotoxic Necrotizing Factor 1 in regulating macrophage polarization.To study the molecular mechanisms through which CNF1 induces M1 macrophage polarization, we analyzed gene expression profiles of BMDMs treated with CNF1 or dialysis buffer.
Project description:<p>Macrophages are prominent immune cells in the tumor microenvironment that can be educated into pro-tumoral phenotype by tumor cells to favor tumor growth and metastasis. The mechanisms that mediate a mutualistic relationship between tumor cells and macrophages remain poorly characterized. Here, we have shown <em>in vitro</em> that different human and murine cancer cell lines release branched‐chain α‐ketoacids (BCKAs) into the extracellular milieu, which influence macrophage polarization in an monocarboxylate transporter 1 (MCT1)‐dependent manner. We found that α‐ketoisocaproate (KIC) and α‐keto‐β‐methylvalerate (KMV) induced a pro‐tumoral macrophage state, whereas α‐ketoisovalerate (KIV) exerted a pro‐inflammatory effect on macrophages. This process was further investigated by a combined metabolomics/proteomics platform. KMV and KIC altered macrophage tricarboxylic acid (TCA) cycle intermediates and increased polyamine metabolism. Proteomic and pathway analyses revealed that the three BCKAs, especially KMV, exhibited divergent effects on the inflammatory signal pathways, phagocytosis, apoptosis and redox balance. These findings uncover cancer‐derived BCKAs as novel determinants for macrophage polarization with potential to be selectively exploited for optimizing antitumor immune responses.</p>
Project description:In response to microenvironmental signals macrophages undergo different activation, indicated as classic/M1 and alternative/M2 polarization. C-Myc transcription factor could be an essential player in M2 polarization. Functional relevance of c-Myc in M2 macrophage biology is investigated by evaluating the effect of 100-58F4, on the transcriptional profile induced on human macrophages by IL-4.
Project description:Macrophages are innate immune cells characterized by their plasticity and their ability to react to various environmental stimuli. These cells are involved in a multiple number of tissular functions in homeostasis and pathological contexts. According to their environment these cells could be polarized toward different states of activation which determine their functional orientation. A large part of the macrophage biology field is devoted to better define what polarizations are, from a molecular point of view. It is now accepted that a multidimensional model of polarization is needed to grasp the broad phenotype repertoire depending on various environmental signals. Oxygen tension is one of these tissular environmental parameters. We designed this study to obtain a proteomic signature of various polarizations in human monocytes derived macrophages. We also seek to explore how environmental oxygen tension varying from an atmospheric composition (18.6% O2) to a “tissular normoxia” (3% O2) could modify our classification of macrophages’ polarization. We have obtained various polarization specific proteins and oxygen sensors for human macrophages. One example is arachidonate 15-lipoxygenase (ALOX15) which is a IL4/IL13 polarization specific proteins up regulated under low oxygen exposure associated to an increase of the phagocytosis rate of apoptotic cells. These results illustrate the necessity to take into account physicochemical parameters like oxygen when macrophage polarization is studied to correctly assess their functions in tissues.