Bach M A
J Immunol. 1977 Aug;119(2):641-7.
Adult thymectomy, as well as ageing, depressed splenic lymphocyte-mediated cytotoxicity (LMC) in the mouse. Ageing depressed significantly LMC as early as 19 weeks of age, independently of the number of cells used for immunization. Thymectomy affected LMC only when supoptimal numbers of immunizing allogeneic cells were used. This effect peaked at 6 to 12 weeks after thymectomy. No difference between thymectomized and normal mice was observed when LMC was tested 16 to 20 weeks after thymectomy, at an age when normal control mice themselves already showed a lowered LMC due to ageing. The effect of in vivo treatment with a circulating thymic factor (TF), which was shown to disappear with ageing as well as after adult thymectomy, has been tested in adult thymectomized mice and normal young and ageing mice. TF treatment prevented LMC depression in adult thymectomized mice, whereas it depressed paradoxically splenic LMC in normal young and old mice. The possible mechanisms of the effects of adult thymectomy, ageing, and thymic factor on the different T cell subsets involved in allogeneic killer cell generation are discussed.
成年小鼠胸腺切除以及衰老均会使脾脏淋巴细胞介导的细胞毒性（LMC）降低。早在19周龄时，衰老就会显著降低LMC，且与用于免疫的细胞数量无关。只有当使用次优数量的免疫同种异体细胞时，胸腺切除才会影响LMC。这种影响在胸腺切除后6至12周达到峰值。胸腺切除后16至20周进行LMC检测时，未观察到胸腺切除小鼠与正常小鼠之间存在差异，此时正常对照小鼠由于衰老自身的LMC已经降低。已在成年胸腺切除小鼠以及正常年轻和衰老小鼠中测试了循环胸腺因子（TF）体内治疗的效果，该因子已被证明会随着衰老以及成年胸腺切除而消失。TF治疗可预防成年胸腺切除小鼠的LMC降低，而在正常年轻和老年小鼠中，它却反常地降低了脾脏LMC。本文讨论了成年胸腺切除、衰老和胸腺因子对参与同种异体杀伤细胞生成的不同T细胞亚群产生影响的可能机制。
