Breitbart Eyal, Wang Xiaowei, Leka Lynette S, Dallal Gerard E, Meydani Simin Nikbin, Stollar B David
Department of Biochemistry, Tufts University School of Medicine, and the Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts 02111, USA.
J Gerontol A Biol Sci Med Sci. 2002 Aug;57(8):B304-11. doi: 10.1093/gerona/57.8.b304.
Previous studies of age-associated immune system changes revealed alterations in expressed immunoglobulin heavy chain variable domain repertoires, and variability in the fraction of expressed heavy chain variable domain genes with mutations. To test whether the latter finding reflected a variation in memory B-cell numbers, we measured circulating memory B cells of 11 healthy elderly subjects, 173 nursing-home residents, and 34 healthy young adults. A large fraction of old adults have low values for memory cells both as a percentage of all B cells and as an absolute memory B-cell concentration. The range of both values is much wider in old adults than in young adults, and it is much wider than the range of T-cell concentrations. Memory B-cell concentration, which was positively correlated with memory T-cell concentrations but inversely related to in vitro T-cell responses to mitogens, may reflect highly individual rates of immune senescence, and it may serve as an amplified marker of underlying T-cell function.
先前关于年龄相关免疫系统变化的研究揭示了表达的免疫球蛋白重链可变区库的改变，以及带有突变的表达重链可变区基因比例的变异性。为了测试后一发现是否反映了记忆B细胞数量的变化，我们测量了11名健康老年人、173名疗养院居民和34名健康年轻人的循环记忆B细胞。很大一部分老年人的记忆细胞无论是占所有B细胞的百分比还是绝对记忆B细胞浓度都较低。这两个值在老年人中的范围比年轻人中的范围宽得多，并且比T细胞浓度的范围宽得多。记忆B细胞浓度与记忆T细胞浓度呈正相关，但与体外T细胞对有丝分裂原的反应呈负相关，可能反映了高度个体化的免疫衰老速率，并且它可能作为潜在T细胞功能的放大标志物。
