Inflammation and immune dysfunction have been increasingly recognized as crucial mechanisms in atherogenesis. Modifications in cell lipid metabolism, plasma dyslipidaemia and particularly low high-density lipoprotein (HDL) levels occur both in atherosclerosis and in autoimmune rheumatic diseases (which are strongly associated with an increased risk of atherosclerosis), suggesting the presence of a crucial link. HDL, the plasma lipoprotein responsible for reverse cholesterol transport, is known for its several protective effects in the context of atherosclerosis. Among these, HDL immunomodulatory effects are possibly the less understood. Through the efflux of cholesterol from plasma cell membranes with the consequent disruption of lipid rafts and the interaction with the cholesterol transporters present in the plasma membrane, HDL affects both the innate and adaptive immune responses. Animal and human studies have demonstrated a predominance of HDL anti-inflammatory effects, despite some pro-inflammatory actions having also been reported. The HDL role on the modulation of the immune response is further suggested by the detection of low levels together with a dysfunctional HDL in patients with autoimmune diseases. Here, we review the current knowledge of the immune mechanisms of atherosclerosis and the modulatory effects HDL may have on them.

中文翻译：

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高密度脂蛋白在免疫反应调节中的作用：对动脉粥样硬化和自身免疫的影响

炎症和免疫功能障碍越来越被认为是动脉粥样硬化形成的关键机制。动脉粥样硬化和自身免疫性风湿性疾病（与动脉粥样硬化风险增加密切相关）中都会发生细胞脂质代谢、血浆血脂异常和特别是低高密度脂蛋白（HDL）水平的改变，这表明存在关键联系。HDL 是一种负责逆转胆固醇转运的血浆脂蛋白，以其在动脉粥样硬化中的多种保护作用而闻名。其中，HDL 的免疫调节作用可能是人们了解较少的。通过胆固醇从浆细胞膜流出，随后破坏脂筏并与质膜中存在的胆固醇转运蛋白相互作用，HDL 影响先天性和适应性免疫反应。动物和人体研究已证明 HDL 具有显着的抗炎作用，尽管也有报道称有一些促炎作用。在自身免疫性疾病患者中检测到低水平的 HDL 以及功能障碍，进一步表明 HDL 在调节免疫反应中的作用。在这里，我们回顾了目前对动脉粥样硬化免疫机制的认识以及高密度脂蛋白对其可能产生的调节作用。