Project description:Hyperlipidemia is accompanied by increased systemic inflammation. However, how hyperlipidemia affects T cell biology is still unclear. We aimed to detail the effects of hyperlipidemia on the T cell’s transcriptome, metabolome and lipidome. Low-density lipoprotein receptor-deficient (LDLR-/-) mice were subjected to a 0.15% high cholesterol diet (HCD), a normal chow diet (NCD) and T cells were analyzed. Hyperlipidemia induced an increase in CXCR3 on and IFN in CD4+ T cells, which was accompanied by transcriptomic changes in interleukin-mediated JAK/STAT signaling, interferon-γ signaling and a general pro-inflammatory immune response, suggesting that hyperlipidemia induces a Th1-like response. In these T cells, hyperlipidemia did not affect levels of metabolites involved in glycolysis or fatty acid oxidation, but enhanced amino acids levels. CD4+ T-cells of mice fed a HCD exhibited increased cellular cholesterol accumulation and an increased arachidonic acid (AA) to Docosahexaenoic acid (DHA) ratio, which was associated with T cell activation and IFN signaling. In vitro, T cell exposure to VLDL, but not LDL phenocopied these results. The effect of hyperlipidemia on T cell activation is reversible as transcriptional- and lipid profiles in LDLr-/ mice normalized 6 weeks after switching the HCD to NCD. In conclusion, hyperlipidemia induces a Th1-like response in CD4+ T cells, which is associated with an AA/DHA ratio in these cells. VLDL, but not LDL is the main lipid component driving hyperlipidemia induced T cell activation.
Project description:Hyperlipidemia is accompanied by increased systemic inflammation. However, how hyperlipidemia affects T cell biology is still unclear. We aimed to detail the effects of hyperlipidemia on the T cell’s transcriptome, metabolome and lipidome. Low-density lipoprotein receptor-deficient (LDLR-/-) mice were subjected to a 0.15% high cholesterol diet (HCD), a normal chow diet (NCD) and T cells were analyzed. Hyperlipidemia induced an increase in CXCR3 on and IFN in CD4+ T cells, which was accompanied by transcriptomic changes in interleukin-mediated JAK/STAT signaling, interferon-γ signaling and a general pro-inflammatory immune response, suggesting that hyperlipidemia induces a Th1-like response. In these T cells, hyperlipidemia did not affect levels of metabolites involved in glycolysis or fatty acid oxidation, but enhanced amino acids levels. CD4+ T-cells of mice fed a HCD exhibited increased cellular cholesterol accumulation and an increased arachidonic acid (AA) to Docosahexaenoic acid (DHA) ratio, which was associated with T cell activation and IFN signaling. In vitro, T cell exposure to VLDL, but not LDL phenocopied these results. The effect of hyperlipidemia on T cell activation is reversible as transcriptional- and lipid profiles in LDLr-/ mice normalized 6 weeks after switching the HCD to NCD. In conclusion, hyperlipidemia induces a Th1-like response in CD4+ T cells, which is associated with an AA/DHA ratio in these cells. VLDL, but not LDL is the main lipid component driving hyperlipidemia induced T cell activation.
Project description:Hyperlipidemia and T cell driven inflammation are important drivers of atherosclerosis, the principal underlying cause of cardiovascular disease. Here, we applied an in-depth multi-omics approach to detail the effects of hyperlipidemia on T cells. In vitro, exposure of CD4+ T cells to very low-density lipoprotein (VLDL), but not to low-density lipoprotein (LDL) resulted in upregulation of Th1 associated pathways, suggesting that VLDL serves as the main lipid component driving hyperlipidemia induced T cell activation. To further detail this response in vivo, T-cells of ldlr-/- fed a normal cholesterol or high cholesterol diet, which develop a strong increase in VLDL cholesterol and triglyceride levels, were investigated. CD4+ T cells of hyperlipidemic ldlr-/- mice exhibited an increased expression of CXC-chemokine receptor 3 (CXCR3) and produced more TNFα and interferon-γ (IFN-γ). Gene set enrichment analysis identified IFN-γ-mediated signaling as the most upregulated pathway in hyperlipidemic T cells. However, the classical Th1 associated transcription factor profile with strong upregulation of Tbet and downregulation of Gata3 was not observed. Hyperlipidemia did not affect levels of the CD4+ T-cell’s metabolites involved in glycolysis or other canonical metabolic pathways but enhanced amino acids levels. However, CD4+ T-cells of hyperlipidemic mice showed increased cellular cholesterol accumulation and an increased arachidonic acid (AA) to docosahexaenoic acid (DHA) ratio, which was associated with T cell activation and IFN-γ-mediated signaling. In conclusion, hyperlipidemia, and especially its VLDL component induces an atypicial Th1 response in CD4+ T-cells.
Project description:Th17 cells are enriched by sorting FR4-CD4+ T cells from SKG mice. A large number of Th17 cells also develop spontaneously when CD4+ T cells from IFN-g-deficient (IFN-g-/-) BALB/c mice are transferred to T cell-deficient RAG2-deficient (RAG2-/-) mice and subjected to homeostatic proliferation, whereas they fail to develop in similar transfer of IL-6-deficient (IL-6-/-) CD4+ T cells to IL-6-/- RAG2-/- mice. To explore the functional molecules specifically expressed by Th17 cells, we conducted Gene Microarray analysis between 10-month-old SKG FR4-CD4+ cells and age-matched BALB/c FR4-CD4+ cells, and between IFN-g-/- CD4+ cells transferred to RAG2-/- mice and IL-6-/- CD4+ T cells transferred to IL-6-/- RAG2-/- mice. The analysis revealed that 1,556 and 115 genes were up-regulated in 10-month-old SKG FR4-CD4+ and IFN-g-/- CD4+ T cells after homeostatic proliferation, respectively, with 29 genes shared by the two groups of genes. The 29 genes included those encoding cytokines, chemokines, and their receptors, such as IL-1 receptor type1 (IL-1R1), IL-17, IL-22, IL-21, CCR6, and CCL20. Experiment Overall Design: We conducted Gene Microarray analysis between 10-month-old SKG FR4-CD4+ cells and age-matched BALB/c FR4-CD4+ cells, and between IFN-g-/- CD4+ cells transferred to RAG2-/- mice and IL-6-/- CD4+ T cells transferred to IL-6-/- RAG2-/- mice using GeneChip Mouse Genome 430 2.0 Array (Affymetrix). Each gruop has three replicates.
Project description:To explore the effect of hyperlipidemia on macrophages' innate immune response to Porphyromonas gingivalis invasion 12 samples, 3 replicates in 4 groups, with cells from hyperlipidemic ApoE deficient mice and nonhyperlipidemic C57BL/6 mice stimulate with or without P.gingivalis(Pg)
Project description:Type I IFN-signaling suppresses an excessive IFN-{gamma} response and prevents lung damage and chronic inflammation following Pneumocystis (PC)-infection and clearance in CD4 T cell-competent mice. Type I IFN -signaling in pulmonary CD11c+ DCs and alveolar macrophages may prevent chronic inflammation following PC lung infection and clearance by suppressing an excessive IFN-g-response via the induction of SOCS1.
Project description:Type I IFN-signaling suppresses an excessive IFN-{gamma} response and prevents lung damage and chronic inflammation following Pneumocystis (PC)-infection and clearance in CD4 T cell-competent mice. Type I IFN -signaling in pulmonary CD11c+ DCs and alveolar macrophages may prevent chronic inflammation following PC lung infection and clearance by suppressing an excessive IFN-g-response via the induction of SOCS1. IFNAR-/- and wildtype mice were both Pneumocystis infected via itratracheal instillation. Pulmonary CD11c+ cells were isolated from collagen digested lungs at day 7 and day 14 post infection from both wildtype and IFNAR-/- mice using a magnetic cell sorting technique from Miltenyi with CD11c microbeads. Cells from three individual animals per group were isolated and assessed. Comparison of 2 treatment types at 2 timepoints to determine whether type I IFN signaling is initiated in resident and early recruited pulmonary CD11c+ cells following Pneumocystis lung infection and whether this is relevant to the outcome of the inflammatory response during the initiation of clearance.