Pieters R H, Albers R, Bleumink R, Snoeij N J, Itoh T, Seinen W, Penninks A H
Research Institute of Toxicology, University of Utrecht, The Netherlands.
Int J Immunopharmacol. 1995 Apr;17(4):329-37. doi: 10.1016/0192-0561(94)00103-u.
In this study, it is examined whether the organotin compound di-n-butyltindichloride (DBTC), which has been shown to inhibit immature thymocyte proliferation, is able to disturb the binding between thymocytes and thymic epithelial cells (TEC). To that end, an enzyme-linked binding assay was developed in which the amount of binding of Thy-1+ (mAb ER4)-thymocytes to the rat-derived TEC-line IT45R1 (IT45R1-TEC) could be detected. It was found that preincubation of thymocytes with 3-5 microM DBTC for 30 min inhibited the binding by 50-60% during a 1 h adhesion period. By extending the preincubation period to 1 h and the adhesion period to 22 h, 0.1 microM DBTC was already sufficient to reduce the binding with 60-80%. Further characterization of the binding revealed that splenic lymphocytes were unable to bind to the MHC class II-negative IT45R1-TEC. Since dextran sulfate inhibited the binding as well, sulfated polysaccharide-binding molecules such as Thy-1 and CD2 are likely to be involved in the binding. Electron microscopy showed filament-containing microvilli at the site of interaction. The results are discussed in relation to the mechanism of DBTC-induced thymus atrophy.
在本研究中，检测了已被证明可抑制未成熟胸腺细胞增殖的有机锡化合物二正丁基二氯化锡（DBTC）是否能够干扰胸腺细胞与胸腺上皮细胞（TEC）之间的结合。为此，开发了一种酶联结合测定法，可检测Thy-1+（单克隆抗体ER4）-胸腺细胞与大鼠来源的TEC系IT45R1（IT45R1-TEC）的结合量。结果发现，胸腺细胞与3-5 microM DBTC预孵育30分钟后，在1小时的黏附期内，结合被抑制了50-60%。将预孵育时间延长至1小时，黏附期延长至22小时，0.1 microM DBTC就足以使结合减少60-80%。对这种结合的进一步表征显示，脾淋巴细胞无法与MHC II类阴性的IT45R1-TEC结合。由于硫酸葡聚糖也抑制这种结合，因此，诸如Thy-1和CD2等硫酸化多糖结合分子可能参与了这种结合。电子显微镜显示，在相互作用部位存在含细丝的微绒毛。结合DBTC诱导胸腺萎缩的机制对这些结果进行了讨论。
