Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
Netherlands Proteomics Center, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
Anal Bioanal Chem. 2021 Aug;413(20):5037-5049. doi: 10.1007/s00216-021-03468-4. Epub 2021 Jun 25.
Immunoglobulins are the primary protective products in human milk and are responsible for transferring maternal pathogen memory to the infant, providing protection by binding to recognized pathogens and inhibiting virulence. To better understand potentially protective/anti-infective compounds in human milk, the establishment of human milk-tailored analytical approaches is crucial, as most contemporary analytical methods have been optimized for plasma or serum. One of the most prominent immunoglobulins in human milk is secretory immunoglobulin A (sIgA), which may be relevant for the protection of breastfed infants from harmful pathogens. Advanced sIgA detection methods can help monitor the immune status and development of the mother-infant dyad. We therefore developed an enzyme-linked immunosorbent assay (ELISA) sIgA method for the quantitative analysis of IgA plus secretory component (SC), validated with sIgA standards and substantiated by mass spectrometry (MS)-based proteomics. A very strong correlation was observed between the MS-detected IgA1 and the human milk-specific sIgA ELISA (r = 0.82). Overall, the MS data indicate that the developed human milk sIgA ELISA does not differentiate between sIgA1 and sIgA2 and is, therefore, a reflection of total sIgA. Furthermore, our MS data and the human milk-derived sIgA ELISA data are better correlated than data derived from a standard serum IgA ELISA kit (relative to MS IgA1 r = 0.82 and r = 0.42, respectively). We therefore propose our human milk-specific sIgA ELISA as an ideal quantitative indicator of total sIgA with advantages over current serum IgA ELISA kits.
免疫球蛋白是人类母乳中的主要保护产物，负责将母体病原体记忆传递给婴儿，通过与已识别的病原体结合并抑制其毒性来提供保护。为了更好地了解母乳中潜在的保护/抗感染化合物，建立针对人乳的分析方法至关重要，因为大多数现代分析方法已经针对血浆或血清进行了优化。母乳中最突出的免疫球蛋白之一是分泌型免疫球蛋白 A（sIgA），它可能与保护母乳喂养的婴儿免受有害病原体的侵害有关。先进的 sIgA 检测方法可以帮助监测母婴对子的免疫状态和发育。因此，我们开发了一种酶联免疫吸附测定（ELISA）sIgA 方法，用于定量分析 IgA 加分泌成分（SC），并使用 sIgA 标准品进行验证，并用基于质谱（MS）的蛋白质组学进行证实。观察到 MS 检测到的 IgA1 与母乳特异性 sIgA ELISA 之间存在很强的相关性（r=0.82）。总的来说，MS 数据表明，开发的母乳 sIgA ELISA 不能区分 sIgA1 和 sIgA2，因此反映的是总 sIgA。此外，我们的 MS 数据和母乳衍生的 sIgA ELISA 数据比来自标准血清 IgA ELISA 试剂盒的数据相关性更好（相对于 MS IgA1，r=0.82 和 r=0.42）。因此，我们建议使用我们的母乳特异性 sIgA ELISA 作为总 sIgA 的理想定量指标，其优势超过当前的血清 IgA ELISA 试剂盒。
