Sidell N, Rieber P, Golub S H
Cell Immunol. 1984 Aug;87(1):118-25. doi: 10.1016/0008-8749(84)90136-9.
We previously reported that retinoic acid (RA) enhances the blastogenic responses of human thymocytes. In this study, we explored the mechanism(s) of this effect by determining the phenotype of cells that show augmented responses to PHA and by analyzing RA effects on regulatory events mediated by interleukin-2 (IL-2). Our results indicate that RA is required early in the PHA activation process and that thymocytes affected by RA treatment already express the "mature" T3 antigen but lack T6 and Fc mu receptors. In the presence of saturating concentrations of exogeneous IL-2, RA caused further enhancement of both unfractionated and T3+ thymocyte proliferation, but could not induce immature T3- cells to become PHA responsive. RA treatment of thymus cells did not affect IL-2 production nor IL-2-dependent T-cell blast growth. RA-induced enhancement appears to induce increased sensitivity of T3+T6-Fc mu- thymocytes to PHA activation, but does not alter either IL-2-dependent proliferation or the accessory cells involved in IL-2 production.
我们先前报道过视黄酸（RA）可增强人胸腺细胞的增殖反应。在本研究中，我们通过确定对PHA反应增强的细胞表型以及分析RA对白细胞介素-2（IL-2）介导的调节事件的影响，探讨了这种作用的机制。我们的结果表明，在PHA激活过程的早期需要RA，并且受RA处理影响的胸腺细胞已经表达“成熟”的T3抗原，但缺乏T6和Fcμ受体。在存在饱和浓度的外源性IL-2的情况下，RA导致未分级的和T3 +胸腺细胞增殖进一步增强，但不能诱导未成熟的T3 -细胞对PHA产生反应。用RA处理胸腺细胞不影响IL-2的产生，也不影响IL-2依赖性T细胞母细胞的生长。RA诱导的增强作用似乎诱导T3 + T6 - Fcμ -胸腺细胞对PHA激活的敏感性增加，但不改变IL-2依赖性增殖或参与IL-2产生的辅助细胞。
