Abstract：
Most investigations on the immune cell-activating potency of IgA used purified total IgA and/or specific isolated cell populations. As IgA2 has been reported to be more pro-inflammatory than IgA1, we aimed to employ a fast and convenient whole blood-based assay to individually probe the capacity of the two IgA subclasses to activate immune cells in close physiological conditions. To this end, whole blood from healthy donors (n = 10) was stimulated with immobilized IgA1, IgA2m1 or IgA2m2 (the two main allotypic variants of IgA2). Activation of major leukocyte subsets was measured using a 10-color flow cytometry panel providing access to the expression of 5 activation markers on 6 different immune cell subsets. While capturing some heterogeneity of responses among donors, IgA2m1 and IgA2m2 systematically showed a stronger activation profile compared to IgA1 in a variety of dimensions. For example, both IgA2 allotypes led to stronger modulations of CD54, CD11b, CD62L, CD66b or CD69, on both or either monocytes or neutrophils, indicating a more pronounced pro-inflammatory effect for this subclass than IgA1. By taking into account donor-specific soluble and cellular components this whole blood-based functional approach provides new perspectives to further investigate IgA effector functions in mechanistic studies and/or translational research.
摘要：
关于IgA的免疫细胞激活效力的大多数研究使用纯化的总IgA和/或特定的分离的细胞群体。由于已报道IgA2比IgA1更具促炎性,我们旨在采用快速和方便的基于全血的测定来单独探测两个IgA亚类在接近的生理条件下激活免疫细胞的能力。为此,用固定的IgA1，IgA2m1或IgA2m2（IgA2的两种主要同种异型变体）刺激健康供体（n=10）的全血。使用10色流式细胞术小组测量主要白细胞亚群的活化,该小组提供在6种不同免疫细胞亚群上5种活化标志物的表达。在捕捉捐助者之间反应的一些异质性的同时，与IgA1相比，IgA2m1和IgA2m2在多个维度上系统地显示出更强的激活谱。例如,两种IgA2同种异型导致CD54，CD11b，CD62L,CD66b或CD69，在单核细胞或中性粒细胞上，表明该亚类比IgA1具有更明显的促炎作用。通过考虑供体特异性可溶性和细胞成分，这种基于全血的功能方法提供了新的观点，可以在机理研究和/或转化研究中进一步研究IgA效应子功能。
