👤 M N Bernabé Kleijn

Atherosclerosis has an auto-immune component driven by self-reactive T and B cells. Identifying their antigenic drivers may lead to new diagnosis and treatment approaches. Here, we aim to identify immunogenic T cell epitopes derived from atherosclerosis-relevant proteins such as ApoB100 by studying the repertoire of peptides presented by HLA in human plaques. We used immunopeptidomics to identify peptides presented by HLA-DR molecules from plaques of patients that underwent endarterectomy surgery. We selected a set of 20 peptides derived from ApoB100 and studied the presence and cytokine profile of ApoB100-specific CD4 revealed significant CD4 We show that immunopeptidomics can be a valid approach to new discover antigens in atherosclerosis. Show less

There is a need for effective tools to stratify and modify cardiovascular risk associated with elevated lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPL). The objective of this analysis was to explore the modifying effects of low-grade inflammation on Lp(a)- and OxPL-associated risk in a secondary prevention cohort. Levels of Lp(a), OxPL associated with apolipoprotein(a) (OxPL-apo[a]) and apolipoprotein B (OxPL-apoB) were determined in the placebo-arm of the low-dose colchicine 2 trial. Patients were between 35 and 82 years, had established chronic coronary syndrome (CCS), and were clinically stable for at least six months prior to randomization. The outcome was the incidence of the composite endpoint of spontaneous myocardial infarction, ischemic stroke, or ischemia-driven coronary revascularization stratified by biomarker levels using a Cox regression model. There was a significant interaction between Lp(a) and IL-6 <3.2 ng/L (median) and IL-6 ≥3.2 ng/L for the composite endpoint (HR 0.90; 95 %CI 0.78-1.03 vs HR 1.18; 95 %CI 1.01-1.39, P In patients with CCS, Lp(a), OxPL-apo(a) and OxPL-apoB associated cardiovascular risk was only pertinent in those with elevated IL-6 but not hsCRP levels. Show less

Inflammatory lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPLs) on lipoproteins convey residual cardiovascular disease risk. The low-dose colchicine 2 (LoDoCo2) trial showed that colchicine reduced the risk of cardiovascular events occurring on standard therapies in patients with chronic coronary syndrome (CCS). We explored the effects of colchicine on Lp(a)- and oxidized lipoprotein-associated risk in a LoDoCo2 biomarker subpopulation. Lipoprotein(a) and OxPLs on apolipoprotein(a) [OxPL-apo(a)] and apolipoprotein B-100 (OxPL-apoB) levels were determined in the biomarker population of the LoDoCo2 trial (n = 1777). The Cox regression analysis was used to compare the risk of the primary endpoint, consisting of myocardial infarction, ischaemic stroke, or ischaemia-driven revascularization by biomarker levels. Interactions between treatment, Lp(a), and OxPL levels were evaluated. Lipoprotein(a), OxPL-apo(a), and OxPL-apoB levels were similar between the colchicine and placebo groups. Consistent risk reduction by colchicine was observed in those with Lp(a) < 125 nmol/L and ≥125 nmol/L and the highest OxPL-apo(a) tertile compared with the lowest (Pinteraction = 0.92 and 0.66). The absolute risk reduction for those with Lp(a) ≥ 125 nmol/L appeared higher compared with those with Lp(a) < 125 nmol/L (4.4% vs. 2.4%). A treatment interaction for colchicine was found in those with the highest OxPL-apoB tertile vs. the lowest (Pinteraction = 0.04). In patients with CCS, colchicine reduces cardiovascular disease risk in those with and without elevated Lp(a) but absolute benefits appeared higher in those with Lp(a) ≥ 125 nmol/L. Patients with higher levels of OxPL-apoB experienced greater benefit of colchicine, suggesting that colchicine may be more effective in subjects with heightened oxidation-driven inflammation. Show less

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 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 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

Myocardial infarction (MI) triggers a potent inflammatory response via the release of circulatory mediators, including extracellular vesicles (EVs) by damaged cardiac cells, necessary for myocardial healing. Timely repression of inflammatory response are critical to prevent and minimize cardiac tissue injuries, nonetheless, progression in this aspect remains challenging. The ability of EVs to trigger a functional response upon delivery of carried bioactive cargos, have made them clinically attractive diagnostic biomarkers and vectors for therapeutic interventions. Using label-free quantitative proteomics approach, we compared the protein cargo of plasma EVs between patients with MI and from patients with stable angina (NMI). We report, for the first time, the proteomics profiling on 252 EV proteins that were modulated with >1.2-fold after MI. We identified six up-regulated biomarkers with potential for clinical applications; these reflected post-infarct pathways of complement activation (Complement C1q subcomponent subunit A (C1QA), 3.23-fold change, p = 0.012; Complement C5 (C5), 1.27-fold change, p = 0.087), lipoprotein metabolism (Apoliporotein D (APOD), 1.86-fold change, p = 0.033; Apolipoprotein C-III (APOCC3), 2.63-fold change, p = 0.029) and platelet activation (Platelet glycoprotein Ib alpha chain (GP1BA), 9.18-fold change, p < 0.0001; Platelet basic protein (PPBP), 4.72-fold change, p = 0.027). The data have been deposited to the ProteomeXchange with identifier PXD002950. This novel biomarker panel was validated in 43 patients using antibody-based assays (C1QA (p = 0.005); C5 (p = 0.0047), APOD (p = 0.0267); APOC3 (p = 0.0064); GP1BA (p = 0.0031); PPBP (p = 0.0465)). We further present that EV-derived fibrinogen components were paradoxically down-regulated in MI, suggesting that a compensatory mechanism may suppress post-infarct coagulation pathways, indicating potential for therapeutic targeting of this mechanism in MI. Taken together, these data demonstrated that plasma EVs contain novel diagnostic biomarkers and therapeutic targets that can be further developed for clinical use to benefit patients with coronary artery diseases (CADs). Show less