| 1. |
- Wigren, Maria, et al.
(författare)
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Atheroprotective effects of Alum are associated with capture of oxidized LDL antigens and activation of regulatory T cells
- 2009
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Ingår i: Circulation Research. - 0009-7330 .- 1524-4571. ; 104:12, s. e62-70
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Tidskriftsartikel (refereegranskat)abstract
- The immune system represents a promising novel target for prevention of atherosclerosis. Several pilot vaccines that reduce atherosclerosis in experimental animals have been developed. The aluminum hydroxide adjuvant Alum has been shown to have antiatherogenic properties in itself, suggesting that it may be a suitable adjuvant in possible future atherosclerosis vaccines. To characterize the immune pathways mediating this protection, we treated wild-type C57BL/6 and Apoe(-)(/)(-) mice with Alum or PBS. Analyses of splenocytes isolated from 12-week-old mice demonstrated that Alum increased the presence of CD4(+)CD25(+)FoxP3(+) regulatory T cells and downregulated the expression of T cell activation markers CD28 and ICOS in Apoe(-)(/)(-) mice but not in C57BL/6 wild-type mice. A similar immunosuppressive phenotype was found also in 25-week-old Apoe(-)(/)(-) mice and was associated with reduced atherosclerosis. Alum precipitates recovered from the injection site of Apoe(-)(/)(-) mice contained antigens derived from oxidized LDL. These findings demonstrate that treatment of Apoe(-)(/)(-) mice with Alum results in an increase of regulatory T cells and suggest that these are activated by tolerogenic antigen-presenting cells presenting oxidized LDL antigens. Our findings provide improved mechanistic understanding of the atheroprotective properties of aluminum hydroxide adjuvants but also point to the importance of determining if hypercholesterolemia may compromise the efficacy of Alum-containing vaccines used clinically today.
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| 2. |
- Dunér, Pontus, et al.
(författare)
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Immune responses against aldehyde-modified laminin accelerate atherosclerosis in Apoe(-/-) mice.
- 2010
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 212:2, s. 457-465
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: LDL oxidation in the vascular wall is associated with aldehyde modification of surrounding extracellular matrix proteins that may target autoimmune responses against vascular tissues. Here we investigated the possible influence of immunity against a malondialdehyde (MDA)-modified form of the basement membrane protein laminin on atherosclerosis. METHODS AND RESULTS: IgM and IgG autoantibodies were present in human plasma and a prospective clinical study demonstrated that individuals who later suffered from acute cardiovascular events had lower levels of MDA-laminin antibodies compared to those in the control group. Immunohistochemical analysis of atherosclerotic plaques from Apoe(-/-) mice demonstrated co-localization between laminin and MDA epitopes, however MDA-laminin IgG was absent in mouse plasma. To determine the effect of MDA-laminin immunity, Apoe(-/-) mice were immunized with MDA-laminin. Analysis of circulating leukocytes at 12 weeks demonstrated increased T-cell activation, expansion of Th17 cells and a lower fraction of regulatory T cells (Tregs) in mice immunized with MDA-laminin. At 25 weeks, aortic atherosclerosis was increased by more than 60% in mice immunized with MDA-laminin, together with increased levels of MDA-laminin IgG1 and MDA-laminin-specific T-cells expressing IL-2, IL-4 and IL-6 in the spleen. CONCLUSION: The clinical observations suggest that immune responses against MDA-laminin may be involved in the development of cardiovascular disease in humans. Furthermore, observations in mice provide evidence for the presence of aldehyde-modified laminin in atherosclerotic lesions and demonstrate that induction of an immune response against these structures is associated with activation of Th17 cells, reduced fraction of Tregs and a more aggressive development of atherosclerosis.
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| 3. |
- Engelbertsen, Daniel, et al.
(författare)
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High levels of IgM against methylglyoxal-modified apolipoprotein B100 is associated with less coronary artery calcification in patients with type 2 diabetes.
- 2012
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Ingår i: Journal of Internal Medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 271:1, s. 82-89
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Advanced glycation end products (AGE) have been implicated in diabetic vascular complications through activation of pro-inflammatory genes. AGE-modified proteins are also targeted by the immune system resulting in the generation of AGE-specific autoantibodies, but the association of these immune responses with diabetic vasculopathy remains to be fully elucidated. The aim of this study was to determine whether antibodies against apolipoprotein B100 modified by methylglyoxal (MGO-apoB100) are associated with coronary atherosclerosis in patients with type 2 diabetes. Methods. We measured antibodies against MGO-apoB100 in plasma from 497 type 2 diabetic patients without clinical signs of cardiovascular disease. Severity of coronary disease was assessed as coronary artery calcium (CAC) imaging. Immunoglobulin (Ig)M and IgG levels recognizing MGO-apoB100 were determined by enzyme-linked immunosorbent assay. Results. Anti-MGO-apoB100 IgM antibody levels were higher in subjects with a low to moderate CAC score (≤400 Agatston units) than in subjects with a high score (>400 Agatston units; 136.8 ± 4.4 vs. 101.6 ± 7.4 arbitrary units (AU), P < 0.0001) and in subjects demonstrating no progression of CAC during 30 months of follow-up (136.4 ± 5.7 vs. 113.9 ± 6.2 AU in subjects with progression, P < 0.0001). Subjects with a family history of premature myocardial infarction had lower levels of anti-MGO-apoB100 IgM. Female subjects had higher levels of anti-MGO-apoB100 antibodies and lower CAC than men. Accordingly, high levels of IgM against MGO-apoB100 are associated with less severe and a lower risk of progression of coronary disease in subjects with type 2 diabetes. Conclusions. Although conclusions regarding causal relationships based on epidemiological observations need to be made with caution, our findings suggest the possibility that anti-MGO-apoB100 IgM may be protective in diabetic vasculopathy.
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| 4. |
- Engelbertsen, Daniel, et al.
(författare)
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Low Levels of IgM Antibodies against an Advanced Glycation Endproduct-Modified Apolipoprotein B100 Peptide Predict Cardiovascular Events in Nondiabetic Subjects.
- 2015
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 195:7, s. 3020-3025
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Tidskriftsartikel (refereegranskat)abstract
- Increased glucose levels are associated with the generation of advanced glycation endproduct (AGE) modifications. Interaction between AGE-modified plaque components and immune cells is believed to have an important role in the development of vascular complications in diabetes. Methylglyoxal (MGO) is one type of reactive aldehyde that gives rise to AGE modification. The present study analyzed whether autoantibodies against MGO-modified epitopes of the low-density lipoprotein apolipoprotein B (apoB) 100 predict cardiovascular events. A library consisting of 302 peptides comprising the complete apoB100 molecule was screened to identify peptides targeted by MGO-specific autoantibodies. Peptide (p) 220 (apoB amino acids 3286-3305) was identified as a major target. Baseline IgM and IgG against MGO-peptide 220 (p220) were measured in 700 individuals from the Malmö Diet and Cancer Cohort. A total of 139 cardiovascular events were registered during the 15-y follow-up period. Controlling for major cardiovascular risk factors demonstrated that subjects in the lowest tertile of MGO-p220 IgM had an increased risk for cardiovascular events (hazard ratio [95% confidence interval]: 2.07 [1.22-3.50]; ptrend = 0.004). Interestingly, the association between MGO-p220 IgM and cardiovascular events remained and even tended to become stronger when subjects with prevalent diabetes were excluded from the analysis (2.51 [1.37-4.61]; ptrend = 0.002). MGO-p220 IgM was inversely associated with blood glucose, but not with oxidized low-density lipoprotein. Finally, we demonstrate that anti-MGO-p220 IgM is produced by B1 cells. These data show that subjects with low levels of IgM recognizing MGO-modified p220 in apoB have an increased risk to develop cardiovascular events and that this association is present in nondiabetic subjects.
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| 5. |
- Rattik, Sara, et al.
(författare)
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Elevated circulating effector memory T cells but similar levels of regulatory T cells in patients with type 2 diabetes mellitus and cardiovascular disease
- 2019
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Ingår i: Diabetes and Vascular Disease Research. - : SAGE Publications. - 1479-1641 .- 1752-8984. ; 16:3, s. 270-280
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes mellitus is associated with an elevated risk of cardiovascular disease, but the mechanism through which diabetes contributes to cardiovascular disease development remains incompletely understood. In this study, we compared the association of circulating regulatory T cells, naïve T cells, effector memory T cells or central memory T cells with cardiovascular disease in patients with and without type 2 diabetes mellitus. Percentage of circulating T cell subsets was analysed by flow cytometry in type 2 diabetes mellitus subjects with and without prevalent cardiovascular disease as well as in non-diabetic subjects with and without prevalent cardiovascular disease from the Malmö SUMMIT cohort. Subjects with type 2 diabetes mellitus had elevated percentages of effector memory T cells (CD4+CD45RO+CD62L–; 21.8% ± 11.2% vs 17.0% ± 9.2% in non-type 2 diabetes mellitus, p < 0.01) and central memory T cells (CD4+CD45RO+CD62L+; 38.0% ± 10.7% vs 36.0% ± 9.5% in non-type 2 diabetes mellitus, p < 0.01). In contrast, the frequency of naïve T cells was reduced (CD4+CD45RO–CD62L+, 35.0% ± 16.5% vs 42.9% ± 14.4% in non-type 2 diabetes mellitus, p < 0.001). The proportion of effector memory T cells was increased in type 2 diabetes mellitus subjects with cardiovascular disease as compared to those without (26.4% ± 11.5% vs 18.4% ± 10.2%, p < 0.05), while no difference in regulatory T cells was observed between these two patient groups. This study identifies effector memory T cells as a potential cellular biomarker for cardiovascular disease among subjects with type 2 diabetes mellitus, suggesting a state of exacerbated immune activation in type 2 diabetes mellitus patients with cardiovascular disease.
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