Shackelford P G, Granoff D M, Nelson S J, Scott M G, Smith D S, Nahm M H
J Immunol. 1987 Jan 15;138(2):587-92.
The polysaccharide (PS) capsule of Haemophilus influenzae type b (Hib) is a "simple" antigen, polyribosylribitolphosphate. Although similar carbohydrate antigens have been reported to elicit IgG antibodies relatively restricted to the IgG2 subclass in man, we report here that Hib PS elicits substantial quantities of both IgG1 and IgG2 serum antibodies in most individuals. Because the determination of IgG subclass distribution can be technically difficult, we used four different approaches to establish our finding. First, we used an IgG subclass-specific, antigen-specific "sandwich assay." Second, we measured IgG subclasses of purified antibodies to Hib PS. Third, we showed that significant amounts of IgG anti-PS can be absorbed with a monoclonal anti-IgG1 affinity column. Fourth, we showed that IgG1 and IgG2 fractions of immune sera have clonally restricted anti-Hib PS antibodies that are easily distinguishable by their isoelectric points. The data indicate that both IgG1 and IgG2 contribute substantially to the IgG antibody response of most adults to immunization with Hib PS.
b型流感嗜血杆菌（Hib）的多糖（PS）荚膜是一种“简单”抗原，即多聚核糖基核糖醇磷酸。尽管据报道，类似的碳水化合物抗原在人体内引发的IgG抗体相对局限于IgG2亚类，但我们在此报告，在大多数个体中，Hib PS能引发大量的IgG1和IgG2血清抗体。由于IgG亚类分布的测定在技术上可能具有挑战性，我们采用了四种不同的方法来证实我们的发现。首先，我们使用了一种IgG亚类特异性、抗原特异性的“夹心测定法”。其次，我们测定了针对Hib PS的纯化抗体的IgG亚类。第三，我们表明，大量的IgG抗PS抗体可被单克隆抗IgG1亲和柱吸收。第四，我们表明，免疫血清的IgG1和IgG2组分具有克隆限制性的抗Hib PS抗体，通过它们的等电点很容易区分。数据表明，IgG1和IgG2在大多数成年人对Hib PS免疫的IgG抗体反应中都起了重要作用。
