T cells are fundamental effector cells against viruses and cancers that can be divided into different subsets based on their long-term immune protection and immediate immune response effects. The percentage and absolute number of these subsets change with ageing, which leads to a reduced immune response in older individuals. Stem cell memory T cells (TSCM) represent a small population of memory T cells with enhanced proliferation and differentiation properties that are endowed with high potential for maintaining T cell homeostasis. However, whether these cells change with ageing and gender remains unknown. Here, we assayed the distribution of TSCM and other T cell subsets in peripheral blood from 92 healthy subjects (44 females and 48 males) ranging from 3 to 88 years old by flow cytometry. We found that CD4+ and CD8+ TSCM in the circulation have relatively stable frequencies, and the absolute number of CD8+ TSCM decreased with age; however, the ratio of TSCM to the CD4+ or CD8+ naïve population increased with age. Unlike the obvious changes in other T cell subsets with age and gender, the stable level of TSCM in peripheral blood may support their capacity for sustaining long-term immunological memory, while their importance may increase together with ageing.

中文翻译：

---

与年龄有关的人类T细胞亚群的进化和衰老

T细胞是针对病毒和癌症的基本效应细胞，根据其长期的免疫保护作用和即时的免疫反应作用，可以分为不同的亚群。这些子集的百分比和绝对数量随年龄的增长而变化，从而导致老年人的免疫反应降低。干细胞记忆T细胞（TSCM）代表一小群具有增强的增殖和分化特性的记忆T细胞，具有维持T细胞稳态的高潜力。然而，这些细胞是否随着年龄的增长和性别的变化而变化尚不清楚。在这里，我们通过流式细胞仪检测了3至88岁的92位健康受试者（44位女性和48位男性）外周血中TSCM和其他T细胞亚群的分布。我们发现循环中的CD4 +和CD8 + TSCM的频率相对稳定，并且CD8 + TSCM的绝对数量随着年龄的增长而降低。但是，TSCM与纯净CD4 +或CD8 +人口的比例随年龄增长而增加。与其他T细胞亚群随年龄和性别的明显变化不同，外周血中TSCM的稳定水平可能支持其维持长期免疫记忆的能力，而其重要性则随着年龄的增长而增加。