Dailey R W, Eun S Y, Russell C E, Vogel L A
Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA.
Cell Immunol. 2001 Dec 15;214(2):99-109. doi: 10.1006/cimm.2001.1894.
Increased dysfunction of the immune system with age can be attributed to developmental changes in cell types critical for proper immune responses. Previous studies have shown defects in humoral responses of aged individuals, but have not distinguished between aged T-cell/microenvironment and intrinsic B-cell defects. Here adoptive transfer of antigen-specific transgenic B cells compared early immunopoeisis from young and aged donors in a young recipient environment. B cells from aged donors demonstrated decreased antigen-induced expansion, particularly in the lymph nodes; however, they acquired a germinal center phenotype at frequencies similar to B cells from young donors. Additionally, aged B cells produced equivalent levels of antigen-specific antibody that underwent affinity maturation and isotype switching and demonstrated similar numbers of antibody-secreting cells of switched isotype. Thus, the ability of aged B cells to respond appropriately to T-dependent antigens and differentiate into high-affinity, isotype-switched, antibody-secreting cells appears to be intact.
免疫系统功能障碍随年龄增长而增加，这可能归因于对适当免疫反应至关重要的细胞类型的发育变化。先前的研究表明老年个体的体液反应存在缺陷，但未区分老年T细胞/微环境和内在B细胞缺陷。在这里，通过抗原特异性转基因B细胞的过继转移，比较了年轻受体环境中年轻和老年供体的早期免疫发生情况。老年供体的B细胞表现出抗原诱导的扩增减少，特别是在淋巴结中；然而，它们获得生发中心表型的频率与年轻供体的B细胞相似。此外，老年B细胞产生的抗原特异性抗体水平相当，这些抗体经历了亲和力成熟和同种型转换，并显示出相似数量的转换同种型的抗体分泌细胞。因此，老年B细胞对T依赖性抗原做出适当反应并分化为高亲和力、同种型转换的抗体分泌细胞的能力似乎是完整的。
