Sadeghi H M, Schnelle J F, Thoma J K, Nishanian P, Fahey J L
Center for Interdisciplinary Research in Immunology and Disease and the Jonsson Comprehensive Cancer Center, UCLA School of Medicine, Los Angeles, CA 90024-1747, USA.
Exp Gerontol. 1999 Dec;34(8):959-70. doi: 10.1016/s0531-5565(99)00065-0.
Aging is associated with impairment of immune functions. Age-dependent alterations in T-cells are well known. Although the pivotal role of monocytes in immune regulation by their production of proinflammatory and inhibitory cytokines is acknowledged, limited information is available on monocyte changes in aging. The present study focused on phenotypic changes in circulating monocytes in elderly subjects and in the level of cytokines they produce. The results demonstrated a significant expansion of CD14dim/CD16bright circulating monocytes in elderly. In contrast, the majority of circulating monocytes of healthy young individuals were CD14bright/CD16dim. The CD14dim/CD16bright monocytes are considered to have phenotypic evidence for activation. Furthermore, significant increases of constitutive production of monocytic cytokines including interleukin (IL)-1beta. IL-1 receptor antagonist, and IL-6 by nonstimulated monocytes from elderly was also indicative of activation. This was also observed when monocytes from elderly were cultured with autologous lymphocytes. However, after stimulation, significantly lowered IL-1beta production was observed and IL-6 and IL-10 tended to be higher in the elderly. Collectively, these results indicate that monocytes of aged individuals, in contrast to a younger population exhibit in vivo activation as well as imbalanced production of cytokines. Such age-related alterations in monocytes may contribute to impaired immune competence of aging.
衰老与免疫功能受损相关。T细胞随年龄的变化是众所周知的。尽管单核细胞通过产生促炎和抑制性细胞因子在免疫调节中的关键作用已得到认可，但关于衰老过程中单核细胞变化的信息有限。本研究聚焦于老年受试者循环单核细胞的表型变化及其产生的细胞因子水平。结果表明，老年人循环中CD14dim/CD16bright单核细胞显著增多。相比之下，健康年轻人的大多数循环单核细胞为CD14bright/CD16dim。CD14dim/CD16bright单核细胞被认为具有激活的表型证据。此外，老年人未受刺激的单核细胞组成性产生的单核细胞因子（包括白细胞介素（IL）-1β、IL-1受体拮抗剂和IL-6）显著增加，这也表明存在激活。当老年人的单核细胞与自体淋巴细胞共培养时也观察到了这种情况。然而，刺激后，老年人的IL-1β产生显著降低，而IL-6和IL-10则趋于升高。总体而言，这些结果表明，与年轻人群相比，老年人的单核细胞在体内表现出激活以及细胞因子产生失衡。单核细胞的这种与年龄相关的变化可能导致衰老过程中免疫能力受损。
