McCullagh P
Aust J Exp Biol Med Sci. 1976 Oct;53(5):413-20. doi: 10.1038/icb.1975.46.
The role of thymus-derived cells in controlling the process of immunological maturation in the neonatal rat has been examined. Thymectomy performed on the day of birth resembled irradiation given at this time in that it permitted adoptive immune responses to sheep erythrocytes to be initiated in the neonatal host. Whereas the consequences of irradiation could be demonstrated if antigenic challenge was given of the following day, adoptive responses were not sustained unless an interval in excess of 24 h had elapsed after thymectomy, suggesting that extra-thymic suppressor cells persist for at least this period. Suppression of adoptive responses was achieved in irradiated hosts with thymus cells obtained from rats on their day of birth but not with cells from older donors. Using the transfer of allogeneic lymphocytes as a stimulus, antibody-forming cell precursors were shown to be plentiful in the newborn rat and it was accordingly suggested that thymic suppressor cells are reponsible for the poor responsiveness of newborn rats to antigenic challenge.
胸腺来源的细胞在新生大鼠免疫成熟过程中的作用已得到研究。出生当天进行胸腺切除术类似于此时进行的照射，因为它能使新生宿主启动对绵羊红细胞的过继免疫反应。如果在次日给予抗原刺激，照射的后果可以显现出来，而过继反应则不会持续，除非胸腺切除术后已经过了超过24小时的间隔，这表明胸腺外抑制细胞至少在这段时间内持续存在。用出生当天大鼠的胸腺细胞可在受照射宿主中实现对过继反应的抑制，但用年龄较大供体的细胞则不行。以同种异体淋巴细胞的转移作为刺激，抗体形成细胞前体在新生大鼠中被证明是丰富的，因此有人认为胸腺抑制细胞是新生大鼠对抗原刺激反应不佳的原因。
