Project description:To investigate the immune suppression of PSGL-1 on hematological tumour cells, we established PSGL-1 KO EL4 cell line with CRISPR-Cas9 technique, which is used to construct subcutaneous model of hematoma on mice. After inoculation, CD45 positive immune cells were sorted from resected tomour tissue and prepared for RNA-seq in two groups: vector EL4 tissue and PSGL-1 KO EL4 tissue. We then analyzed gene expression profiling using sequencing data to look for differences occurred inside TME.
Project description:Inhalation of the amibient air polution ozone causes lung inflammation and can suppress host defense mechanisms, including impairing macrophage phagocytosis. Ozone reacts with cholesterol in the lung to form oxysterols, like secosterol A and secosterol B, which can form covalent adducts on cellular proteins. How oxysterol-protein adduction modifies the function of lung macrophages is unknown. Herein, we used a preoteomic screen to identify lung macrophage proteins that fomr adducts with ozone-derived oxysterols. Analysis show that the phagocytic receptor CD206 and CD64 formed adducts with secosterol A. Adduction of these receptors with ozone-derived oxysterols impaired ligand binding and corresponded with reduced macrophage phagocytosis. This work suggests a novle mechanism for the suppression of macrophage phagocytosis following ozone exposure through the generation of oxysterols and the formation of oxysterol-protein adducts on phagocytic receptors.
Project description:Cytotherapy is a revolutionary therapeutic agent representing the forefront of current cancer therapy, but its poor efficacy in the treatment of solid tumours remains challenging. Integration of tumour infiltration, targeted elimination and tumour microenvironment (TME) regulation functions in designing effective cytopharmaceuticals for solid tumours is necessary. Here, we designed on-demand editing macrophages (RILO-M1-G) constructed by surface glypican-3 (GPC3) peptide anchoring and inner R848/INCB024360-lipid particle (RILO) packing to combat hepatocellular carcinoma (HCC). Based on the tumour tendency and deep penetration of macrophages, the anchored GPC3 peptide on the membrane surface promoted macrophage-tumour cell recognition, thus enhancing specific tumour targeting and phagocytosis of tumour cells with high GPC3 expression. The packed RILOs were wrapped by C16-ceramide fused Escherichia coli-originated outer membrane vesicles (OMVs). OMVs facilitated RILO internalization through caveolin-mediated endocytosis to maintain a suitable nanostructure, C16-ceramide induced membrane invagination and exosome generation, leading to the release of packed RILOs through exosomes. These exosomes containing the TLR7/8 agonist R848 and IDO1 inhibitor INCB024360 enabled remodelling of the immunosuppressive TME by regulating the tumour-associated macrophage phenotype and enhancing T-cell viability. Furthermore, treatments with RILO-M1-G exerted remarkable therapeutic efficacy in a H22 tumour-bearing mouse model, rechallenged tumour model and orthotopic HCC mouse model compared with that of first-line HCC therapy. Overall, RILO-M1-G offered a new cytotherapeutic strategy for meeting the clinical demands of solid tumour treatment.
Project description:Ras homolog enriched in brain (Rheb1) is a small GTPase and is known to be a direct activator of mTORC1. Dysregulation of Rheb1 has been shown to impair the cellular-energetic state and cell homeostasis. However, the role of Rheb1 in monocytes/macrophages differentiation and maturation is not clear. Here, we investigate the role of Rheb1 in mouse myelopoiesis using a Rheb1 conditional deletion murine model. We found that the absolute number of macrophages decreased in the bone marrow (BM) of Rheb1-deficient mice. Loss of Rheb1 inhibited the monocyte-to-macrophage differentiation process. Additionally, Rheb1 deletion reduced phagocytosis ability of macrophages by inhibiting the mTORC1 signaling pathway. Furthermore, 3BDO (an activator of mTORC1) rescued the phagocytosis ability of Rheb1-deficient macrophages. Thus, Rheb1 is critical for macrophage production and phagocytosis and executes these activities possibly via mTORC1-dependent pathway.
Project description:Pathogenic Candida fungi are a leading cause of opportunistic, hospital-associated bloodstream infections with high mortality rates, typically in immunocompromised patients. Several species, including C. albicans, the most prevalent cause of infection, belong to the monophyletic CUG clade of yeasts. Much is known about the interaction of C. albicans with innate immune cells, which are crucial for controlling infection. Phagocytosis of C. albicans elicits transcriptional induction of several pathways involved in catabolism of non-glucose carbon sources that are important for virulence, termed alternative carbon metabolism. However, the response of other CUG clade species has not been characterized. In a separate dataset, we profiled transcriptional responses to primary murine bone marrow derived macrophages in six Candida species. Here we additionally profiled the response of M. guilliermondii, a yeast that is known as a cause of disseminated candidiasis as well as cutaneous infections. We find that similar to other CUG-clade Candida species, it mounts a robust alternative carbon metabolism response to phagocytosis.
Project description:We studied macrophage gene expression from mice fed chow diet (C) or 60% high fat diet (HF), that phagocytized C-RBC, HFD-RBC, or no RBC. Macrophages from mice on HF diet were activated toward a pro-inflammatory phenotype. In macrophages isolated from CD mice, RBC phagocytosis yielded a gene expression pattern similar to HF macrophages. Incubation of HF-RBC with macrophages resulted in a significantly more pronounced upregulation of pro-inflammatory chemokines as compared to C-RBC. Peritoneal macrophages were obtained from C57BL/6 mice fed either C or HF diet. Phagocytosis was performed in vitro with C-RBC or HF-RBC; macrophages not exposed to RBC served as a control. Affymetrix Mouse Gene 1.0 ST microarray chips were used to assess the gene expression profile.