Unit of Immunology and Chronic Disease, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
Atherosclerosis. 2018 Jan;268:36-48. doi: 10.1016/j.atherosclerosis.2017.11.010. Epub 2017 Nov 16.
IgM antibodies against phosphorylcholine (anti-PC) are negatively associated with atherosclerosis, cardiovascular disease (CVD) and systemic lupus erythematosus (SLE), where the risk of CVD and atherosclerosis is high. We here study the effects of IgM anti-PC immune regulation.
Mononuclear leukocytes were isolated from peripheral blood (PBMC) obtained from healthy blood donors, six SLE patients with age- and sex-matched controls, and symptom-giving human atherosclerotic plaques. The proportion of Th17 (CD4CCR6) and Treg (CD4CD25CD127) cells was determined by flow cytometry in CD4T cells after 6 days of culture with Th17 or Treg-polarizing cytokines, with PMA and Ionomycin stimulation. IgM anti-PC were extracted from total IgM, with flow-through IgM as controls. Dendritic cells (DC) were differentiated from PBMC. Antibody peptide/protein characterization was done by a proteomics de novo sequencing approach.
IgM anti-PC increased significantly the proportion of Tregs from healthy donors, SLE patients and atherosclerotic plaque cells while control antibodies did not. T cells from SLE patients had a significantly lower proportion of Tregs and a higher proportion of Th17 cells as compared to matched controls. IgM anti-PC, but not control antibodies, significantly reduced the production of IL-17 and TNF-α in cell cultures from SLE patients and atherosclerotic plaque cells. IgM anti-PC interacted with CD40 and kept DCs in an immature stage, potentially being tolerogenic. We observed differences in the IgM peptide expression levels in anti-PC compared to control antibodies.
IgM anti-PC promote polarization of Tregs, which could represent a novel protective mechanism in atherosclerosis and autoimmune conditions as SLE.
针对磷酸胆碱（抗-PC）的 IgM 抗体与动脉粥样硬化、心血管疾病（CVD）和系统性红斑狼疮（SLE）呈负相关，这些疾病的 CVD 和动脉粥样硬化风险较高。我们在此研究 IgM 抗-PC 免疫调节的作用。
从健康献血者、六名年龄和性别匹配的 SLE 患者和有症状的人动脉粥样硬化斑块中分离外周血单核细胞（PBMC）。在 Th17（CD4CCR6）和 Treg（CD4CD25CD127）细胞用 Th17 或 Treg 极化细胞因子培养 6 天后，通过流式细胞术确定 CD4T 细胞中的比例，并用 PMA 和离子霉素刺激。从总 IgM 中提取 IgM 抗-PC，以流通过 IgM 作为对照。从 PBMC 中分化树突状细胞（DC）。通过从头测序的蛋白质组学方法进行抗体肽/蛋白特征分析。
与对照抗体相比，IgM 抗-PC 显著增加了健康供体、SLE 患者和动脉粥样硬化斑块细胞中 Treg 的比例，而对照抗体则没有。与匹配的对照相比，SLE 患者的 T 细胞中 Treg 的比例显著降低，Th17 细胞的比例显著升高。与对照抗体相比，IgM 抗-PC 显著降低了 SLE 患者和动脉粥样硬化斑块细胞培养物中 IL-17 和 TNF-α 的产生。IgM 抗-PC 与 CD40 相互作用，使 DC 处于不成熟状态，可能具有耐受性。与对照抗体相比，我们观察到 IgM 抗-PC 与抗-PC 相比在 IgM 肽表达水平上存在差异。
IgM 抗-PC 促进 Treg 的极化，这可能代表动脉粥样硬化和自身免疫性疾病（如 SLE）中的一种新的保护机制。
