Atherosclerosis is the major underlying pathology of cardiovascular disease and is driven by dyslipidemia and inflammation. Inhibition of the immunoproteasome, a proteasome variant that is... Show moreAtherosclerosis is the major underlying pathology of cardiovascular disease and is driven by dyslipidemia and inflammation. Inhibition of the immunoproteasome, a proteasome variant that is predominantly expressed by immune cells and plays an important role in antigen presentation, has been shown to have immunosuppressive effects.We assessed the effect of ONX-0914, an inhibitor of the immunoproteasomal catalytic subunits LMP7 (proteasome subunit β5i/large multifunctional peptidase 7) and LMP2 (proteasome subunit β1i/large multifunctional peptidase 2), on atherosclerosis and metabolism in LDLr-/- and APOE*3-Leiden.CETP mice.ONX-0914 treatment significantly reduced atherosclerosis, reduced dendritic cell and macrophage levels and their activation, as well as the levels of antigen-experienced T cells during early plaque formation, and Th1 cells in advanced atherosclerosis in young and aged mice in various immune compartments. Additionally, ONX-0914 treatment led to a strong reduction in white adipose tissue mass and adipocyte progenitors, which coincided with neutrophil and macrophage accumulation in white adipose tissue. ONX-0914 reduced intestinal triglyceride uptake and gastric emptying, likely contributing to the reduction in white adipose tissue mass, as ONX-0914 did not increase energy expenditure or reduce total food intake. Concomitant with the reduction in white adipose tissue mass upon ONX-0914 treatment, we observed improvements in markers of metabolic syndrome, including lowered plasma triglyceride levels, insulin levels, and fasting blood glucose.We propose that immunoproteasomal inhibition reduces 3 major causes underlying cardiovascular disease, dyslipidemia, metabolic syndrome, and inflammation and is a new target in drug development for atherosclerosis treatment. Show less
Douna, H.; Mol, J. de; Amersfoort, J.; Schaftenaar, F.H.; Kiss, M.G.; Suur, B.E.; ... ; Foks, A.C. 2022
B and T cells are interconnected in the T follicular helper-germinal center B cell (TFH-GC B cell) axis, which is hyperactive during atherosclerosis development and loss of control along this axis... Show moreB and T cells are interconnected in the T follicular helper-germinal center B cell (TFH-GC B cell) axis, which is hyperactive during atherosclerosis development and loss of control along this axis results in exacerbated atherosclerosis. Inhibition of the TFH-GC B cell axis can be achieved by providing negative co-stimulation to TFH cells through the PD-1/PD-L1 pathway. Therefore, we investigated a novel therapeutic strategy using PD-L1-expressing B cells to inhibit atherosclerosis. We found that IFNγ-stimulated B cells significantly enhanced PD-L1 expression and limited TFH cell development. To determine whether IFNγ-B cells can reduce collar-induced atherosclerosis, apoE -/- mice fed a Western-type diet were treated with PBS, B cells or IFNγ-B cells for a total of 5 weeks following collar placement. IFNγ-B cells significantly increased PD-L1hi GC B cells and reduced plasmablasts. Interestingly, IFNγ-B cells-treated mice show increased atheroprotective Tregs and T cell-derived IL-10. In line with these findings, we observed a significant reduction in total lesion volume in carotid arteries of IFNγ-B cells-treated mice compared to PBS-treated mice and a similar trend was observed compared to B cell-treated mice. In conclusion, our data show that IFNγ-stimulated B cells strongly upregulate PD-L1, inhibit TFH cell responses and protect against atherosclerosis. Show less
A hallmark of advanced atherosclerosis is inadequate immunosuppression by regulatory T(Treg) cells inside atherosclerotic lesions. Dyslipidemia has been suggested to alter Treg cellmigration by... Show moreA hallmark of advanced atherosclerosis is inadequate immunosuppression by regulatory T(Treg) cells inside atherosclerotic lesions. Dyslipidemia has been suggested to alter Treg cellmigration by affecting the expression of specific membrane proteins, thereby decreasing Treg cellmigration towards atherosclerotic lesions. Besides membrane proteins, cellular metabolism has beenshown to be a crucial factor in Treg cell migration. We aimed to determine whether dyslipidemiacontributes to altered migration of Treg cells, in part, by affecting cellular metabolism.Dyslipidemia was induced by feeding Ldlr-/- mice a Western-type diet for 16-20weeks and intrinsic changes in Treg cells affecting their migration and metabolism were examined.Dyslipidemia was associated with altered mTORC2 signaling in Treg cells, decreased expression ofmembrane proteins involved in migration, including CD62L, CCR7 and S1Pr1, and decreased Tregcell migration towards lymph nodes. Furthermore, we discovered that diet-induced dyslipidemiainhibited mTORC1 signaling, induced PPARδ activation and increased fatty acid (FA) oxidation inTreg cells. Moreover, mass-spectrometry analysis of serum from Ldlr-/- mice with normolipidemia ordyslipidemia showed increases in multiple PPARδ ligands during dyslipidemia. Treatment with asynthetic PPARδ agonist increased the migratory capacity of Treg cells in vitro and in vivo in an FAoxidation dependent manner. Furthermore, diet-induced dyslipidemia actually enhanced Treg cellmigration into the inflamed peritoneum and into atherosclerotic lesions in vitro.Altogether, our findings implicate that dyslipidemia does not contribute toatherosclerosis by impairing Treg cell migration as dyslipidemia associated with an effector-likemigratory phenotype in Treg cells. Show less
The immune system is strongly involved in atherosclerosis and immune regulation generally leads to attenuated atherosclerosis. B and T lymphocyte attenuator (BTLA) is a novel co-receptor that... Show moreThe immune system is strongly involved in atherosclerosis and immune regulation generally leads to attenuated atherosclerosis. B and T lymphocyte attenuator (BTLA) is a novel co-receptor that negatively regulates the activation of B and T cells, however, there have been no reports of BTLA and its function in atherosclerosis or cardiovascular disease (CVD). We aimed to assess the dominant BTLA expressing leukocyte in CVD patients and to investigate whether BTLA has a functional role in experimental atherosclerosis. Stimulation of the BTLA pathway in Ldlr-/-mice reduces initial lesion development and increases collagen content of established lesions, presumably by shifting the balance between atherogenic follicular B cells and atheroprotective B cells and directing CD4+ T cells towards regulatory T cells. We provide the first evidence that BTLA is a very promising target for the treatment of atherosclerosis.We show that BTLA is primarily expressed on B cells in CVD patients and follicular B2 cells in low-density lipoprotein receptor-deficient (Ldlr-/-) mice. We treated Ldlr-/- mice that were fed a Western-type diet (WTD) with PBS, an isotype antibody or an agonistic BTLA antibody (3C10) for 6 weeks. We report here that the agonistic BTLA antibody significantly attenuated atherosclerosis. This was associated with a strong reduction in follicular B2 cells, while regulatory B and T cells were increased. The BTLA antibody showed similar immunomodulating effects in a progression study in which Ldlr-/- mice were fed a WTD for 10 weeks before receiving antibody treatment. Most importantly, BTLA stimulation enhanced collagen content, a feature of stable lesions, in preexisting lesions. Show less
Cardiovascular diseases form the most common cause of death worldwide, with atherosclerosis as main etiology. Atherosclerosis is marked by cholesterol rich lipoprotein deposition in the artery wall... Show moreCardiovascular diseases form the most common cause of death worldwide, with atherosclerosis as main etiology. Atherosclerosis is marked by cholesterol rich lipoprotein deposition in the artery wall, evoking a pathogenic immune response. Characteristic for the disease is the pathogenic accumulation of macrophages in the atherosclerotic lesion, which become foam cells after ingestion of large quantities of lipoproteins. We hypothesized that, by inducing a CD8 T cell response towards lipoprotein derived apolipoprotein-B100 (ApoB100), lesional macrophages, that are likely to cross-present lipoprotein constituents, can specifically be eliminated. Based on in silico models for protein processing and MHC-I binding, 6 putative CD8 T cell epitopes derived from ApoB100 were synthesized. HLA-A2 binding was confirmed for all peptides by T2 cell binding assays and recall responses after vaccination with the peptides proved that 5 of 6 peptides could induce CD8 T cell responses. Induction of ApoB100 specific CD8 T cells did not impact plaque size and cellular composition in HLA-A2 and human ApoB100 transgenic LDLr−/− mice. No recall response could be detected in cultures of cells isolated from the aortic arch, which were observed in cell cultures of splenocytes and mesenteric lymph nodes, suggesting that the atherosclerotic environment impairs CD8 T cell activation. Show less
The immune system is strongly involved in atherosclerosis and immune regulation generally leads to attenuated atherosclerosis. B and T lymphocyte attenuator (BTLA) is a novel co-receptor that... Show moreThe immune system is strongly involved in atherosclerosis and immune regulation generally leads to attenuated atherosclerosis. B and T lymphocyte attenuator (BTLA) is a novel co-receptor that negatively regulates the activation of B and T cells, however, there have been no reports of BTLA and its function in atherosclerosis or cardiovascular disease (CVD). We aimed to assess the dominant BTLA expressing leukocyte in CVD patients and to investigate whether BTLA has a functional role in experimental atherosclerosis.\nStimulation of the BTLA pathway in Ldlr-/-mice reduces initial lesion development and increases collagen content of established lesions, presumably by shifting the balance between atherogenic follicular B cells and atheroprotective B cells and directing CD4+ T cells towards regulatory T cells. We provide the first evidence that BTLA is a very promising target for the treatment of atherosclerosis.\nWe show that BTLA is primarily expressed on B cells in CVD patients and follicular B2 cells in low-density lipoprotein receptor-deficient (Ldlr-/-) mice. We treated Ldlr-/- mice that were fed a Western-type diet (WTD) with PBS, an isotype antibody or an agonistic BTLA antibody (3C10) for 6 weeks. We report here that the agonistic BTLA antibody significantly attenuated atherosclerosis. This was associated with a strong reduction in follicular B2 cells, while regulatory B and T cells were increased. The BTLA antibody showed similar immunomodulating effects in a progression study in which Ldlr-/- mice were fed a WTD for 10 weeks before receiving antibody treatment. Most importantly, BTLA stimulation enhanced collagen content, a feature of stable lesions, in preexisting lesions. Show less
Atherosclerosis is the main underlying pathology of cardiovascular disease. Atherosclerosis is caused by an immune response which is directed against (modified) lipoproteins which accumulate in the... Show moreAtherosclerosis is the main underlying pathology of cardiovascular disease. Atherosclerosis is caused by an immune response which is directed against (modified) lipoproteins which accumulate in the vessel wall. Over time, this accumulation of lipids and immune cells induce morphological abnormalities in the vessel wall which cause the vessel lumen to narrow. This narrowing of the lumen (stenosis) causes ischemia in the downstream tissue. Prolonged ischemia causes myocardial ischemia and/or stroke. The research described in my thesis examines a well-recognized risk factor of atherosclerosis, being dyslipidemia, from an entirely new perspective. More specifically, it describes how dyslipidemia affects intrinsic metabolic processes in T cells, the conductors of the immune response characterizing atherosclerosis, and how this affects their function. My research has contributed to knowledge on the pathophysiology of atherosclerosis and might one day pave the way for the development of novel therapeutic approaches to treat cardiovascular disease. Show less
Macroautophagy (or autophagy) is a conserved cellular process in which cytoplasmic cargo is targeted for lysosomal degradation. Autophagy is crucial for the functional integrity of different... Show more Macroautophagy (or autophagy) is a conserved cellular process in which cytoplasmic cargo is targeted for lysosomal degradation. Autophagy is crucial for the functional integrity of different subsets of T cells in various developmental stages. Since atherosclerosis is an inflammatory disease of the vessel wall which is partly characterized by T cell mediated autoimmunity, we investigated how advanced atherosclerotic lesions develop in mice with T cells that lack autophagy-related protein 7 (Atg7), a protein required for functional autophagy. Mice with a T cell-specific knock-out of Atg7 (Lck-Cre Atg7f/f) had a diminished naïve CD4+ and CD8+ T cell compartment in the spleen and mediastinal lymph node as compared to littermate controls (Atg7f/f). Lck-Cre Atg7f/f and Atg7f/f mice were injected intravenously with rAAV2/8-D377Y-mPCSK9 and fed a Western-type diet to induce atherosclerosis. While Lck-Cre Atg7f/f mice had equal serum Proprotein Convertase Subtilisin/Kexin type 9 levels as compared to Atg7f/f mice, serum cholesterol levels were significantly diminished in Lck-Cre Atg7f/f mice. Histological analysis of the liver revealed less steatosis, and liver gene expression profiling showed decreased expression of genes associated with hepatic steatosis in Lck-Cre Atg7f/f mice as compared to Atg7f/f mice. The level of hepatic CD4+ and CD8+ T cells was greatly diminished but both CD4+ and CD8+ T cells showed a relative increase in their IFNγ and IL-17 production upon Atg7 deficiency. Atg7 deficiency furthermore reduced the hepatic NKT cell population which was decreased to < 0.1% of the lymphocyte population. Interestingly, T cell-specific knock-out of Atg7 decreased the mean atherosclerotic lesion size in the tri-valve area by over 50%. Taken together, T cell-specific deficiency of Atg7 resulted in a decrease in hepatic steatosis and limited inflammatory potency in the (naïve) T cell compartment in peripheral lymphoid tissues, which was associated with a strong reduction in experimental atherosclerosis. Show less
Limiting the pro-inflammatory immune response is critical for the treatment of atherosclerosis. Regulatory B cells (Bregs) can modulate the immune response through interleukin-10 (IL-10). Current... Show moreLimiting the pro-inflammatory immune response is critical for the treatment of atherosclerosis. Regulatory B cells (Bregs) can modulate the immune response through interleukin-10 (IL-10). Current data regarding Bregs and atherosclerosis is scarce and conflicting.\n B cells on atherosclerosis.\n B cells on atherosclerosis.\n B cells in atherosclerosis. Show less
Bizino, M.B.; Tao, Q.; Amersfoort, J.; Siebelink, H.M.J.; Bogaard, P.J. van den; Geest, R.J. van der; Lamb, H.J. 2018
Lipocalin-2 (Lcn2) is a glycoprotein which can be secreted by immune cells. Several studies in humans have suggested Lcn2 can be used as a biomarker for the detection of unstable atherosclerotic... Show moreLipocalin-2 (Lcn2) is a glycoprotein which can be secreted by immune cells. Several studies in humans have suggested Lcn2 can be used as a biomarker for the detection of unstable atherosclerotic lesions, partly as it is known to interact with MMP-9. mice to assess the functional role of Lcn2 in different stages of atherosclerosis. Atherosclerotic lesions were characterized through histological analysis and myeloid cell populations were examined using flow cytometry. mice. Altogether, these findings suggest that Lcn2 deficiency promotes lesion growth in earlier stages of the disease while it decreases MMP-9 activity and necrotic core size in advanced atherosclerosis. BACKGROUND AND AIMS METHODS RESULTS CONCLUSIONS Show less
B-and T-lymphocyte attenuator (BTLA) is a co-inhibitory molecule which was identified as a marker for Th1 cells. However, nowadays it is known that BTLA is most abundantly expressed on B cells.... Show moreB-and T-lymphocyte attenuator (BTLA) is a co-inhibitory molecule which was identified as a marker for Th1 cells. However, nowadays it is known that BTLA is most abundantly expressed on B cells. Also, we showed earlier that BTLA was specifically expressed on atherogenic follicular B2 cells with low expression on other B cell subtypes. Since it has been shown that stimulating co-inhibitory pathways can greatly influence atherosclerosis, we aimed to induce BTLA signaling in diet-induced atherosclerosis.For the initiaton study, LDLR-/- mice were fed a western type diet (WTD) for 6 weeks and received twice a week i.p. injections with an agonistic BTLA antibody. Mice in the control groups either received PBS or an isotype control antibody. For the progression study, mice were first fed a WTD for 10 weeks after which they received the same treatment as in the initiation experiment.Lesion development in mice receiving the agonistic BTLA antibody was significantly lower than in mice treated with PBS (PBS:2.6±0.8x105 μm2 vs. BTLA:1.5±0.8x105 μm2; p<0.05). A similar trend was observed in mice treated with the isotype control (Isotype: 2.4±0.9x105 μm2 vs. BTLA; p=0.07). This corresponded with a major decrease in circulating (PBS: 44.2±4.9%, Isotype: 50.6±5.8% vs. BTLA: 24.5±12.0%; p<0.0001) and splenic CD19+ B cells (PBS:29.1±4.2%, Isotype:30.8.±3.6% vs. BTLA:21.1±7.4%; p<0.01 and p<0.001). The antibody specifically targeted atherogenic follicular B2 cells (picture), while atheroprotective B cells (marginal zone, B1 and B10) were all increased compared to mice receiving PBS or the isotype antibody. Although the BTLA antibody did not reduce already established lesions, it signficantly increased the collagen content, indicating a more stable lesion phenotype.In conclusion, stimulation of the BTLA pathway in experimental atherosclerosis in LDLR-/- mice reduces lesion development and increases stability of established lesions, presumably by specifically inhibiting atherogenic B cells, while leaving atheroprotective B cell subsets unaffected. Show less
CD8 T cells make up a large amount of lymphocytes in atherosclerotic plaques, however their role in atherosclerosis has not been thoroughly studied. Since ApoB100 is a key antigen in... Show moreCD8 T cells make up a large amount of lymphocytes in atherosclerotic plaques, however their role in atherosclerosis has not been thoroughly studied. Since ApoB100 is a key antigen in atherosclerosis and a plausible vaccination target, we were interested in the role of ApoB100 specific CD8 T cells in atherosclerosis. To be directly relevant for human vaccination HLA-A2 transgenic (HLA-A2) and human ApoB100 transgenic (hApoB100tg) mice were used.HLA-A2 restricted CD8 T cell epitopes derived from human ApoB100 were in silico predicted using The “Proteasomal cleavage/TAP transport/MHC class I combined predictor”of the immune epitope database. Best 6 epitopes were synthesized and binding to HLA-A2 assesed with T2 cell binding assays. To assess induction of peptide specific CD8 T cells, HLA-A2 transgenic mice were vaccinated with peptide pulsed DCs. Peptide recall responses were measured with flow cytometry. To study whether vaccination with ApoB100 derived CD8 T cell epitopes could influence atherosclerosis, male hApoB100tg HLA-A2tg LDLrKO mice (n=10-11) were vaccinated with peptide pulsed bone marrow derived DCs and boosted a week later with with αCD40 and Poly(I:C) and peptides. Animals were fed western type diet for 11 weeks following DC vaccination, after which they were sacrificed to assess aortic root lesion development.All predicted HLA-A2 restricted CD8 T cell epitopes stabilized HLA-A2 in T2 cell binding assays, indicating binding of all peptides to HLA-A2. For 5 of 6 peptides peptide specific recall response were measured a week after vaccination with peptide pulsed DCs. Vaccination with these CD8 T cell epitopes did not lead to reduced atherosclerosis. 10 weeks after the booster vaccination still peptide specific CD8 T cell responses could be detected, indicating that the vaccination was succesful.We have identified 5 HLA-A2 restricted ApoB100 derived CD8 T cell epitopes. Vaccination with these peptides did induce long lasting ApoB100 specific CD8 T cells, however did not affect atherosclerosis in male hApoB100tg HLA-A2tg LDLrKO mice Show less
This review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoim...Show moreThis review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoimmunity. Multiple therapeutic approaches using existing pharmaceuticals are possible from a rationale in which T cell metabolism forms the hub in dampening the T cell component of autoimmunity in metabolic diseases. Future research into the effects of a metabolically aberrant micro-environment on T cell metabolism and its potential as a therapeutic target for immunomodulation could lead to novel treatment strategies for metabolic disease-associated autoimmunity. Show less
This review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and... Show moreThis review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoimmunity. Multiple therapeutic approaches using existing pharmaceuticals are possible from a rationale in which T cell metabolism forms the hub in dampening the T cell component of autoimmunity in metabolic diseases. Future research into the effects of a metabolically aberrant micro-environment on T cell metabolism and its potential as a therapeutic target for immunomodulation could lead to novel treatment strategies for metabolic disease-associated autoimmunity. Show less
This review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and... Show moreThis review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoimmunity. Multiple therapeutic approaches using existing pharmaceuticals are possible from a rationale in which T cell metabolism forms the hub in dampening the T cell component of autoimmunity in metabolic diseases. Future research into the effects of a metabolically aberrant micro-environment on T cell metabolism and its potential as a therapeutic target for immunomodulation could lead to novel treatment strategies for metabolic disease-associated autoimmunity. Show less
This review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and... Show moreThis review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoimmunity. Multiple therapeutic approaches using existing pharmaceuticals are possible from a rationale in which T cell metabolism forms the hub in dampening the T cell component of autoimmunity in metabolic diseases. Future research into the effects of a metabolically aberrant micro-environment on T cell metabolism and its potential as a therapeutic target for immunomodulation could lead to novel treatment strategies for metabolic disease-associated autoimmunity. Show less
This review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and... Show moreThis review discusses the relevant metabolic pathways and their regulators which show potential for T cell metabolism-based immunotherapy in diseases hallmarked by both metabolic disease and autoimmunity. Multiple therapeutic approaches using existing pharmaceuticals are possible from a rationale in which T cell metabolism forms the hub in dampening the T cell component of autoimmunity in metabolic diseases. Future research into the effects of a metabolically aberrant micro-environment on T cell metabolism and its potential as a therapeutic target for immunomodulation could lead to novel treatment strategies for metabolic disease-associated autoimmunity. Show less
