Neta R, MacVittie T J, Schwartz G N, Douches S D
Cell Immunol. 1985 Sep;94(2):480-90. doi: 10.1016/0008-8749(85)90272-2.
The restorative effect of thymosin fraction 5 (TF5) on the thymus of gamma-irradiated mice was examined. Four different mouse strains were used in this study since earlier work determined that the degree of response to TF5 is strain dependent. The responsiveness to comitogenic effect of interleukin 1 (IL-1) was used to measure the rate of recovery of immunocompetent cells in the thymus, since only more mature PNA-, Lyt-1+-2- medullary cells respond to this monokine. Contrary to several earlier reports that radioresistant cells repopulating the thymus within the first 10 days after irradiation are mature, corticosteroid resistant, immunocompetent cells, the thymic cells from irradiated mice in all strains used had greatly reduced responses to IL-1. Daily intraperitoneal injections of TF5 increased significantly the responses of thymic cells to IL-1 in 10- to 13-weeks-old C57Bl/KsJ, C57Bl/6, C3H/HeJ, and DBA/1 mice. Older mice, 5 months or more in age, of DBA/1 strain did not respond to treatment with TF5. However, C3H/HeJ mice of the same age were highly responsive. In conclusion, (1) cells repopulating the thymus within 12 days after irradiation contain lower than normal fraction of mature IL-1 responsive cells, (2) thymic hormones increase the rate of recovery of immunocompetent cells in the thymus, and (3) the effect of thymic hormones is strain and age dependent.
研究了胸腺素组分5（TF5）对γ射线照射小鼠胸腺的恢复作用。本研究使用了四种不同的小鼠品系，因为早期研究确定对TF5的反应程度具有品系依赖性。由于只有更成熟的PNA +、Lyt-1 + -2 - 髓质细胞对这种单核因子有反应，因此使用对白细胞介素1（IL-1）促有丝分裂作用的反应性来测量胸腺中免疫活性细胞的恢复率。与早期的一些报道相反，即照射后前10天内重新填充胸腺的抗辐射细胞是成熟的、抗皮质类固醇的、免疫活性细胞，所有使用品系的受照射小鼠的胸腺细胞对IL-1的反应都大大降低。每天腹腔注射TF5可显著提高10至13周龄的C57Bl/KsJ、C57Bl/6、C3H/HeJ和DBA/1小鼠胸腺细胞对IL-1的反应。5个月或以上的DBA/1品系老年小鼠对TF5治疗无反应。然而，相同年龄的C3H/HeJ小鼠反应强烈。总之，（1）照射后12天内重新填充胸腺的细胞中成熟的IL-1反应性细胞比例低于正常水平，（2）胸腺激素可提高胸腺中免疫活性细胞的恢复率，（3）胸腺激素的作用具有品系和年龄依赖性。
