Project description:Interleukin-10 (IL-10) is a pleiotropic anti-inflammatory cytokine produced and sensed by most hematopoietic cells. Genome wide association studies and experimental animal models point at a central role of the IL-10 axis in Inflammatory Bowel Diseases. Here we investigated the importance of intestinal macrophage production of IL-10 and their IL-10 exposure, as well as the existence of an IL-10-based autocrine regulatory loop in the gut. Specifically, we generated mice harboring IL-10 or IL-10 receptor (IL-10R?) mutations in intestinal lamina propria-resident chemokine receptor CX3CR1hi-expressingmacrophages. We found macrophage-derived IL-10 dispensable for gut homeostasis and maintenance of colonic T regulatory cells. In contrast, loss of IL-10 receptor expression impaired the critical conditioning of these monocyte-derived macrophages, but resulted in spontaneous development of severe colitis. Collectively, our results highlight IL-10 as a critical homeostatic macrophage-conditioning factor in the colon and define intestinal CX3CR1hi macrophages as a decisive factor that determines gut health or inflammation. Microarray of resident macrophages sorted from colons of Interleukin-10 deficeint mice and macrophage-restricted interleukin-10 receptor deficient mice versus colonic resident macrophages of wild type mice
Project description:Interleukin-10 (IL-10) is a pleiotropic anti-inflammatory cytokine produced and sensed by most hematopoietic cells. Genome wide association studies and experimental animal models point at a central role of the IL-10 axis in Inflammatory Bowel Diseases. Here we investigated the importance of intestinal macrophage production of IL-10 and their IL-10 exposure, as well as the existence of an IL-10-based autocrine regulatory loop in the gut. Specifically, we generated mice harboring IL-10 or IL-10 receptor (IL-10Rα) mutations in intestinal lamina propria-resident chemokine receptor CX3CR1hi-expressingmacrophages. We found macrophage-derived IL-10 dispensable for gut homeostasis and maintenance of colonic T regulatory cells. In contrast, loss of IL-10 receptor expression impaired the critical conditioning of these monocyte-derived macrophages, but resulted in spontaneous development of severe colitis. Collectively, our results highlight IL-10 as a critical homeostatic macrophage-conditioning factor in the colon and define intestinal CX3CR1hi macrophages as a decisive factor that determines gut health or inflammation.
Project description:That commensal bacteria can influence intestinal inflammation has been observed using other models of chronic colitis. Loss of IL-10, a major immunosuppressive cytokine, induces spontaneous colitis in mice. The incidence of spontaneous polyp formation in IL-10-deficient mice was also completely eliminated in the absence of STING We used microarrays to evaluate the inflammatory cytokine expression in the colon from IL10 KO mice and IL10/STING KO mice.
Project description:Tumor-associated macrophages (TAM) represent an abundant cell population of the immune infiltrate in solid tumors and have been shown to orchestrate escape from immune surveillance. Macrophages display a very plastic phenotype which is recapitulated in vitro by classifying certain subsets according to exposure with defined, individual cytokines. The tumor-promoting M2 macrophages are polarized in vitro by differentiating human monocyte-derived macrophages with the T helper cell type 2 (Th2) response cytokines interleukin-4 and interleukin-13 or the immunosuppressive cytokine interleukin-10. Notably, only the latter macrophage subset undergoes apoptosis when treated with the colony stimulating factor 1 receptor (CSF1R) blocking antibody emactuzumab. However, under physiologic conditions the phenotype of TAM is shaped by a combination of cytokines. Hence, we evaluated if the addition of IL-10 to IL-4 or IL-13 differentiated macrophages is able to override IL-4/-13 mediated signaling and to restore susceptibility to emactuzumab. Though addition of IL-10 did not restore emactuzumab susceptibility, we surprisingly detected that only IL-4 differentiated macrophages sustained their specific marker expression while IL-10 skewed the IL-13 differentiated macrophage profile towards the IL-10 regulated phenotype. In-depth characterization by gene expression profiling revealed unique signatures of IL-4+IL-10 and IL-13+IL-10 differentiated macrophage subsets characterized by upregulation of the canonical NFκB signaling or Wnt/β-catenin signaling pathways, respectively. In silico-based analysis of a large cohort of cancer patients revealed distinct interleukin-4 or interleukin-13 overexpression patterns in a subset of patients with partial co-expression of IL-10 but almost absent IL-4/IL-13 co-expression. These patients may have less TAM depletion under therapy with CSF1R inhibitors. Five different macrophage subtypes were differentiated for six days with respect to different cytokines and transcriptomically profiled with three biological replicates derived from three different human, healthy volunteer donors
Project description:Tumor-associated macrophages (TAM) represent an abundant cell population of the immune infiltrate in solid tumors and have been shown to orchestrate escape from immune surveillance. Macrophages display a very plastic phenotype which is recapitulated in vitro by classifying certain subsets according to exposure with defined, individual cytokines. The tumor-promoting M2 macrophages are polarized in vitro by differentiating human monocyte-derived macrophages with the T helper cell type 2 (Th2) response cytokines interleukin-4 and interleukin-13 or the immunosuppressive cytokine interleukin-10. Notably, only the latter macrophage subset undergoes apoptosis when treated with the colony stimulating factor 1 receptor (CSF1R) blocking antibody emactuzumab. However, under physiologic conditions the phenotype of TAM is shaped by a combination of cytokines. Hence, we evaluated if the addition of IL-10 to IL-4 or IL-13 differentiated macrophages is able to override IL-4/-13 mediated signaling and to restore susceptibility to emactuzumab. Though addition of IL-10 did not restore emactuzumab susceptibility, we surprisingly detected that only IL-4 differentiated macrophages sustained their specific marker expression while IL-10 skewed the IL-13 differentiated macrophage profile towards the IL-10 regulated phenotype. In-depth characterization by gene expression profiling revealed unique signatures of IL-4+IL-10 and IL-13+IL-10 differentiated macrophage subsets characterized by upregulation of the canonical NFκB signaling or Wnt/β-catenin signaling pathways, respectively. In silico-based analysis of a large cohort of cancer patients revealed distinct interleukin-4 or interleukin-13 overexpression patterns in a subset of patients with partial co-expression of IL-10 but almost absent IL-4/IL-13 co-expression. These patients may have less TAM depletion under therapy with CSF1R inhibitors.
Project description:Mitochondrial electron transport chain (ETC) function modulates macrophage biology, however, mechanisms underlying mitochondrial ETC control of macrophage immune responses are not fully understood. Here we report that mutant mice with mitochondrial ETC complex III (CIII)-deficient macrophages exhibit increased susceptibility to influenza A virus and LPS-induced endotoxic shock. Cultured bone marrow-derived macrophages (BMDMs) isolated from these mitochondrial CIII-deficient mice released less IL-10 than controls following TLR3 or TLR4 stimulation. Surprisingly, restoring mitochondrial respiration without generating superoxide using alternative oxidase (AOX) was not sufficient to reverse LPS-induced endotoxic shock susceptibility or restore IL-10 release. However, activation of protein kinase A (PKA) rescued IL-10 release in mitochondrial CIII-deficient BMDMs following LPS stimulation. Additionally, mitochondrial CIII deficiency did not affect BMDM responses to interleukin-4 (IL-4) stimulation. Thus, our results highlight the essential role of mitochondrial CIII generated superoxide in the release of anti-inflammatory IL-10 in response to TLR stimulation
Project description:IL17B protected mice from dextran sodium sulfate (DSS)-induced colitis since IL17B deficiency resulted in severe DSS-induced colitis with exaggerated weight loss, shorter colon length, and elevated proinflammatory cytokine production in colon. For mechanism study, we use single cell transcriptional analyses of CD45+ immune cells in colonic lamina propria to detect the effect of IL-17B on colon LP immune cells in colitis. We found increased inflammatory macrophages infiltration in colon lamina propria after colitis induction expressing inflammatory cytokines such as S100a9, S100a8, Tnf, which was confirmed by real-time PCR and flow cytometry. Reconstitute of Il17b-/- mice with recombinant IL17B alleviated the severity of DSS-induced colitis. IL17B treatment also inhibited LPS-induced inflammation in bone marrow derived macrophage and in mice. These data indicate that IL17B exerting its inhibitory role in inflammation by regulating inflammatory macrophage response. In view of the protective effect of IL17B on DSS-induced colitis and LPS-induced inflammation, IL17B might represent a novel potential therapeutic approach to treat the inflammation.
Project description:IL17B protected mice from dextran sodium sulfate (DSS)-induced colitis since IL17B deficiency resulted in severe DSS-induced colitis with exaggerated weight loss, shorter colon length, and elevated proinflammatory cytokine production in colon. For mechanism study, we use single cell transcriptional analyses of CD45+ immune cells in colonic lamina propria to detect the effect of IL-17B on colon LP immune cells in colitis. We found increased inflammatory macrophages infiltration in colon lamina propria after colitis induction expressing inflammatory cytokines such as S100a9, S100a8, Tnf, which was confirmed by real-time PCR and flow cytometry. Reconstitute of Il17b-/- mice with recombinant IL17B alleviated the severity of DSS-induced colitis. IL17B treatment also inhibited LPS-induced inflammation in bone marrow derived macrophage and in mice. These data indicate that IL17B exerting its inhibitory role in inflammation by regulating inflammatory macrophage response. In view of the protective effect of IL17B on DSS-induced colitis and LPS-induced inflammation, IL17B might represent a novel potential therapeutic approach to treat the inflammation.
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive M-NM-1-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-M-NM-3-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response. Total 6 samples were examined. Splenic dendritic cells were treated with IL-21 and/or GM-CSF studying STAT3 and STAT5B binding in the genome
Project description:Lcn2 is involved in host defense against pathogens, but the function in intestinal mucosal immunity and inflammation remains largely unknown. Genetic ablation of Lcn2 results in early-onset colitis and spontaneous emergence of right-sided colonic tumors in the setting of IL-10 deficiency (Lcn2-/-;IL10-/- mice). To address whether inflammation or other mechanisms drives the site-specific tumor locations gene expression analyses in proximal versus distal colons of Lcn2-/- IL10-/- mice were performed. Differential expression between distal colon versus cecum and proximal colon samples were analyses using Affymetrix MoGene 2.0 ST arrays on formalin-fixed, paraffin-embedded tissue sections of Lcn2-/-; IL10-/-mice.