Department of Medicine, University of Toledo, Ohio 43614, USA.
J Infect Dis. 2013 Jul;208(1):101-8. doi: 10.1093/infdis/jit139. Epub 2013 Apr 1.
The phenotype of B cells that respond to vaccination with the purified pneumococcal polysaccharide (PPS) has been a topic of debate. We have recently identified the phenotype of cells from healthy young volunteers as CD27(+)IgM(+) B cells. However, the PPS-responding B-cell population has not yet been identified in high-risk populations, such as elderly individuals. Previous studies have shown that elderly individuals have a lower percentage of immunoglobulin M memory B cells than healthy young adults. In this study, we directly characterized the phenotype of PPS-specific B cells before and after vaccination with PPS vaccine (PPV) in elderly adults, using fluorescently labeled PPS14 and PPS23F. In contrast to our observations in healthy young volunteers, the PPS-responding B-cell population consisted primarily of switched memory (CD27(+)IgM(-)) B cells. In concurrence with these findings, postvaccination immunoglobulin M concentrations were not significantly increased in this population, and the opsonophagocytic response was decreased, compared with that in young adults. These findings identify a significant shift in the phenotype of the B-cell population in response to PPV among elderly individuals.
接种纯化肺炎球菌多糖（PPS）疫苗后对 B 细胞表型的反应一直是一个有争议的话题。我们最近确定了来自健康年轻志愿者的细胞表型为 CD27(+)IgM(+)B 细胞。然而，高危人群（如老年人）中的 PPS 反应性 B 细胞群体尚未被确定。先前的研究表明，老年人的免疫球蛋白 M 记忆 B 细胞百分比低于健康的年轻成年人。在这项研究中，我们使用荧光标记的 PPS14 和 PPS23F，直接描述了老年人接种 PPS 疫苗（PPV）前后 PPS 特异性 B 细胞的表型。与我们在健康年轻志愿者中的观察结果相反，PPS 反应性 B 细胞群体主要由转换记忆（CD27(+)IgM(-)）B 细胞组成。与这些发现一致的是，与年轻人相比，该群体的接种后免疫球蛋白 M 浓度并没有显著增加，调理吞噬作用的反应也降低了。这些发现确定了老年人对 PPV 反应的 B 细胞群体表型发生了显著变化。
