Suzuki G, Sawa H, Kobayashi Y, Nakata Y, Nakagawa K i, Uzawa A, Sakiyama H, Kakinuma S, Iwabuchi K, Nagashima K
Divisions of Radiation, The Fifth Research Group, National Institute of Radiological Sciences, Chiba, Japan.
J Immunol. 1999 May 15;162(10):5981-5.
We investigated a role of chemokines in thymocyte trafficking. Genes encoding stromal cell-derived factor-1 and its receptor CXCR4 were detected in the cortex by in situ hybridization. Early immigrant cells did not express CXCR4, whereas their descendant CD44+CD25+CD4-CD8- cells did. CXCR4 expression was down-modulated when CD4+CD8+ double-positive cells became CD4+CD8- or CD4-CD8+ single-positive (SP) cells. Positively selected CD69+CD3intermediate cells gained CCR4, of which ligand, thymus activation-regulated chemokine, was expressed in the medulla. At the next developmental stage, CD69-CD3high cells lost CCR4 but gained CCR7. These results suggest that thymocytes use different chemokines along with their development. Blockade of chemokine receptor-mediated signaling by pertussis toxin perturbed the normal distribution of SP cells and resulted in the accumulation of SP cells in the cortex. Thus, a pertussis toxin-sensitive event controls the trafficking of SP cells across the corticomedullary junction.
我们研究了趋化因子在胸腺细胞迁移中的作用。通过原位杂交在皮质中检测到编码基质细胞衍生因子-1及其受体CXCR4的基因。早期迁入细胞不表达CXCR4，而其后代CD44+CD25+CD4-CD8-细胞则表达。当CD4+CD8+双阳性细胞变为CD4+CD8-或CD4-CD8+单阳性（SP）细胞时，CXCR4表达下调。阳性选择的CD69+CD3中等细胞获得CCR4，其配体胸腺激活调节趋化因子在髓质中表达。在下一个发育阶段，CD69-CD3高细胞失去CCR4但获得CCR7。这些结果表明胸腺细胞在发育过程中使用不同的趋化因子。百日咳毒素对趋化因子受体介导的信号传导的阻断扰乱了SP细胞的正常分布，并导致SP细胞在皮质中积累。因此，百日咳毒素敏感事件控制SP细胞穿过皮质髓质交界处的迁移。
