Orme I M
J Immunol. 1987 Jun 15;138(12):4414-8.
This study employed an experimental mouse model of Mycobacterium tuberculosis infection to investigate the effects of aging on T cell-mediated protective cellular immunity. It was found that although mice of 3 to 18 mo of age were fully resistant to a standard immunizing dose of Mycobacterium tuberculosis, progressive mortality was observed in old (24 to 28 mo) mice. Death of these older animals was associated with an inability to contain or to eliminate the mycobacterial infection in the spleen and liver, and with an inability to prevent the progressive growth of the infection in the lungs. It was then revealed by the use of reciprocal passive cell transfer experiments that the age-related susceptibility of old mice reflected an inability to generate mediator protective T lymphocytes in response to the infection. In contrast, no evidence was obtained to indicate any defect at the effector cell (macrophage) level, as evidenced primarily by the finding that immune T cells from young mice conferred equivalent levels of immunity upon both old and young recipients. The results suggest therefore that T cell-mediated immunity undergoes an age-related decline in terms of its ability to respond to infection with Mycobacterium tuberculosis.
本研究采用结核分枝杆菌感染的实验小鼠模型，以研究衰老对T细胞介导的保护性细胞免疫的影响。结果发现，虽然3至18月龄的小鼠对标准免疫剂量的结核分枝杆菌具有完全抗性，但老年（24至28月龄）小鼠中观察到逐渐增加的死亡率。这些老年动物的死亡与无法控制或消除脾脏和肝脏中的分枝杆菌感染，以及无法阻止肺部感染的进行性发展有关。随后通过相互被动细胞转移实验表明，老年小鼠与年龄相关的易感性反映了其在感染后无法产生介导保护性T淋巴细胞的能力。相比之下，没有证据表明效应细胞（巨噬细胞）水平存在任何缺陷，这主要通过以下发现得到证明：来自年轻小鼠的免疫T细胞给予老年和年轻受体同等水平的免疫力。因此，结果表明，T细胞介导的免疫在应对结核分枝杆菌感染的能力方面经历了与年龄相关的下降。
