Advanced Centre for Bio Separation Technology, Vellore Institute of Technology, Vellore, India.
CRMSB UMR5536, CNRS, Université de Bordeaux, Bordeaux, France.
J Immunol Methods. 2019 Nov;474:112637. doi: 10.1016/j.jim.2019.112637. Epub 2019 Aug 3.
High density lipoproteins (HDL) are considered cardio protective. Apolipoprotein A-I (apoA-I), a major component of HDL helps in reverse cholesterol transport, whose function is greatly affected during atherosclerosis due to oxidation by myeloperoxidase. Amino acid tyrosine residue of apoA-I at position 192 and 166 are sensitive to oxidation by myeloperoxidase resulting in the generation of chlorinated and nitrated apoA-I and they are believed to be present in atherosclerotic plaques and in circulation. These oxidized apoA-I have been suggested as potential indicator(s) of CVD risks in humans. To detect the levels of oxidized apoA-I there is a need for developing monoclonal antibodies (mAbs) with high specificity and sensitivity that could be utilized routinely in clinical immune based assays for blood plasma or for in vivo imaging. In this study, chemically chlorinated apoA-I (chlorinated tyrosine- apoA-I) and a short synthetic peptide, containing the corresponding chlorinated tyrosine residue, conjugated to keyhole limpet hemocyanin (KLH) carrier protein were used for immunization. Stable hybridoma clones F7D5 and G11E3 were found to be highly sensitive and reactive towards chlorinated tyrosine- apoA-I. Interestingly, these mAbs also displayed positive reaction with atherosclerotic plaques obtained from mouse and human biopsies. In vitro or in vivo diagnostic tests could be developed either by detecting oxidized apoA-I in human plasma or by directly imaging atheroma plaques as both mAbs were shown to stain human atheroma. The anti-chlorinated tyrosine- apoA-I mAbs described in this study may have a high diagnostic potential in predicting CVD risks.
高密度脂蛋白（HDL）被认为具有心脏保护作用。载脂蛋白 A-I（apoA-I）是 HDL 的主要成分之一，有助于胆固醇逆向转运，但其在动脉粥样硬化过程中的功能由于髓过氧化物酶的氧化而受到极大影响。apoA-I 位于 192 位和 166 位的氨基酸酪氨酸残基容易被髓过氧化物酶氧化，导致产生氯化和硝化的 apoA-I，并且它们被认为存在于动脉粥样硬化斑块和循环中。这些氧化的 apoA-I 被认为是人类心血管疾病风险的潜在指标之一。为了检测氧化 apoA-I 的水平，需要开发具有高特异性和灵敏度的单克隆抗体（mAbs），这些 mAbs 可以常规用于临床免疫测定法，用于检测血浆或活体成像中的apoA-I。在这项研究中，使用化学氯化的 apoA-I（氯化酪氨酸-apoA-I）和含有相应氯化酪氨酸残基的短合成肽与血蓝蛋白（KLH）载体蛋白缀合进行免疫。发现稳定的杂交瘤克隆 F7D5 和 G11E3 对氯化酪氨酸-apoA-I 具有高度的敏感性和反应性。有趣的是，这些 mAbs 还与从小鼠和人类活检中获得的动脉粥样硬化斑块呈阳性反应。可以通过检测人血浆中的氧化 apoA-I 或直接对动脉粥样硬化斑块进行成像来开发体外或体内诊断测试，因为这两种 mAbs 都显示出对人动脉粥样硬化斑块的染色。本研究中描述的抗氯化酪氨酸-apoA-I mAbs 可能具有很高的预测心血管疾病风险的诊断潜力。
