Burns E A, Lum L G, Seigneuret M C, Giddings B R, Goodwin J S
Department of Medicine, University of Wisconsin School of Medicine, Milwaukee.
Mech Ageing Dev. 1990 Apr 30;53(3):229-41. doi: 10.1016/0047-6374(90)90041-d.
The rise in rates of infection in adults over the age of 60 is accompanied by a decreased ability of older adults to make specific immune responses after immunization with a variety of specific antigens (Ag). This investigation delineates age-related changes in Ag-specific humoral immunity, comparing adults over age 60 to young adults aged 18-40, using tetanus toxoid (TT) as an immunologic probe. A culture system which does not require TT booster immunizations of study subjects was used to induce in vitro specific antibody responses. The amount of anti-TT antibody (Ab) produced in serum and in culture was measured by a TT-specific enzyme-linked immunosorbent assay (ELISA). The numbers of anti-TT Ab-secreting B cells were measured by a TT-specific ELISA-plaque assay. The TT-specific responses of old subjects were significantly less than that seen for young control subjects in the following measures: (1) serum anti-TT Ab titers (mean +/- S.E. log 2 titer = 3.3 +/- 1.1 vs. 9.5 +/- 1.4, P less than 0.01); (2) anti-TT Ab produced by peripheral blood lymphocytes (PBL) in cultures stimulated with TT (6 +/- 2.1 ng/ml vs. 22 +/- 8.4 ng/ml, P less than 0.01); (3) numbers of anti-TT Ab secreting B cells per million cells cultured (6.7 +/- 3.4 vs. 26.6 +/- 7.6, P less than 0.001) and (4) mean ng Ab secreted per anti-TT Ab-secreting B cell (0.6 +/- 0.4 ng vs. 12.7 +/- 7.8 ng, P less than 0.01). This study shows that both decreased numbers of Ag-specific immune B cells and decreased potency on a per cell basis contribute to the impaired immune responses to immunizations in older adults.
60岁以上成年人感染率上升的同时，老年人在用多种特异性抗原（Ag）免疫后产生特异性免疫反应的能力下降。本研究以破伤风类毒素（TT）作为免疫探针，比较了60岁以上成年人与18 - 40岁年轻人，描绘了与年龄相关的Ag特异性体液免疫变化。使用一种无需对研究对象进行TT加强免疫的培养系统来诱导体外特异性抗体反应。通过TT特异性酶联免疫吸附测定（ELISA）测量血清和培养物中产生的抗TT抗体（Ab）量。通过TT特异性ELISA空斑试验测量分泌抗TT Ab的B细胞数量。在以下指标中，老年受试者的TT特异性反应明显低于年轻对照受试者：（1）血清抗TT Ab滴度（平均±标准误log₂滴度 = 3.3±1.1 vs. 9.5±1.4，P＜0.01）；（2）用TT刺激培养的外周血淋巴细胞（PBL）产生的抗TT Ab（6±2.1 ng/ml vs. 22±8.4 ng/ml，P＜0.01）；（3）每百万培养细胞中分泌抗TT Ab的B细胞数量（6.7±3.4 vs. 26.6±7.6，P＜0.001）和（4）每个分泌抗TT Ab的B细胞分泌的平均ng Ab（0.6±0.4 ng vs. 12.7±7.8 ng，P＜0.01）。这项研究表明，Ag特异性免疫B细胞数量减少和单个细胞效力降低都导致了老年人免疫接种免疫反应受损。
