Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA.
Division of Epidemiology, University of California Berkeley, Berkeley, CA 94720, USA.
J Immunol Res. 2016;2016:5371050. doi: 10.1155/2016/5371050. Epub 2016 Feb 10.
Telomeres, the protective DNA-protein complexes at the ends of linear chromosomes, are important for genome stability. Leukocyte or peripheral blood mononuclear cell (PBMC) telomere length is a potential biomarker for human aging that integrates genetic, environmental, and lifestyle factors and is associated with mortality and risks for major diseases. However, only a limited number of studies have examined longitudinal changes of telomere length and few have reported data on sorted circulating immune cells. We examined the average telomere length (TL) in CD4+, CD8+CD28+, and CD8+CD28- T cells, B cells, and PBMCs, cross-sectionally and longitudinally, in a cohort of premenopausal women. We report that TL changes over 18 months were correlated among these three T cell types within the same participant. Additionally, PBMC TL change was also correlated with those of all three T cell types, and B cells. The rate of shortening for B cells was significantly greater than for the three T cell types. CD8+CD28- cells, despite having the shortest TL, showed significantly more rapid attrition when compared to CD8+CD28+ T cells. These results suggest systematically coordinated, yet cell type-specific responses to factors and pathways contribute to telomere length regulation.
端粒是线性染色体末端的保护性 DNA-蛋白质复合物，对于基因组的稳定性非常重要。白细胞或外周血单核细胞 (PBMC) 的端粒长度是人类衰老的潜在生物标志物，它综合了遗传、环境和生活方式等因素，并与死亡率和主要疾病的风险相关。然而，只有少数研究检查了端粒长度的纵向变化，并且很少有研究报告关于分类循环免疫细胞的数据。我们在一组绝经前妇女中，同时进行了横断面和纵向研究，检查了 CD4+、CD8+CD28+和 CD8+CD28- T 细胞、B 细胞和 PBMC 的平均端粒长度 (TL)。我们报告说，在同一参与者中，这三种 T 细胞类型之间的 18 个月内的 TL 变化相关。此外，PBMC TL 的变化也与这三种 T 细胞类型和 B 细胞的变化相关。B 细胞的缩短速度明显大于三种 T 细胞类型。与 CD8+CD28+ T 细胞相比，尽管 CD8+CD28- 细胞的 TL 最短，但细胞损耗的速度明显更快。这些结果表明，系统性协调但又具有细胞类型特异性的对因素和途径的反应有助于端粒长度的调节。
