Function of Eosinophils from Eosinophilic pneumonia : Purification and Analysis of Tcell-derived eosinophil chemotactic factor

虽然我们没有成功发现T细胞来源的嗜酸性粒细胞趋化因子的结构，但在这段时间里我们得到了一个有趣的结果。用免疫组织化学和原位杂交法检测嗜酸性粒细胞增多性血管淋巴样增生症皮损和外周血嗜酸粒细胞(E-Eos)中Galectin-9的表达。此外，还观察了Galectin-9对嗜酸性粒细胞表达的调节以及Galectin-9对嗜酸性粒细胞凋亡的影响。许多渗入部位的嗜酸性粒细胞Galectin-9呈阳性。E-Eos细胞表面和细胞内Galectin-9免疫反应较N-Eos明显。当嗜酸性粒细胞与IL-5共同培养时，E-Eos表面Galectin-9的表达显著下调，而N-Eos的表面Galectin-9表达不受影响。地塞米松或抗Fas抗体处理嗜酸粒细胞后，E-Eos表面Galectin-9的表达明显上调。相反，地塞米松有争议地下调N-Eos表面Galectin-9的表达，尽管抗Fas抗体未能影响其表面Galectin-9的表达。我们还发现，重组Galectin-9显著抑制E-Eos的凋亡，而明显促进N-Eos的凋亡。此外，Galectin-9可显著抑制地塞米松诱导的N-Eos的凋亡，而Galectin-9对地塞米松诱导的E-Eos的凋亡无明显影响。相反，Galectin-9可增强抗Fas抗体诱导的N-Eos和E-Eos的细胞凋亡。这些结果表明Galectin-9是由嗜酸性粒细胞产生的，Galectin-9对嗜酸性粒细胞表现出异质性作用和动力学，这可能是嗜酸性粒细胞炎症的关键因素之一。

Although we couldn't success the finding of structure of eosinophil chemotactic factor derived from T-cell, we could get an interesting result during this time. We assessed the expression of galectin-9 with immunostaining and in situ hybridization both in the lesion of angiolymphoid hyperplasia with eosinophilia, and peripheral blood eosinophils of eosinophilic patients (E-Eos) in comparison with those of normal volunteers (N-Eos). Regulation of expression of galectin-9 on eosinophils and the effect of galectin-9 on apoptosis of eosinophil were also evaluated. Many eosinophils infiltrating the site were positive for galectin-9. Surface and intracellular immunoreactive galectin-9 was more evident in E-Eos than N-Eos. When eosinophils were cultured with IL-5 in vitro, the surface galectin-9 expression of E-Eos was significantly, down-regulated, although that of N-Eos was not affected. Treatment of eosinophils with dexarnethasone or anti-Fas antibody significantly up-regulated the surface galectin-9 expression of E-Eos. In contrast, dexamethasone controversially down-regulated the surface galectin-9 of N-Eos, although anti-Fas antibody failed to affect on the surface galectin-9 expression. We also found that recombinant galectin-9 significantly suppressed apoptosis of E-Eos, whereas it apparently enhanced apoptosis of N-Eos. Furthermore, dexamethasone-induced apoptosis of N-Eos was significantly suppressed by galectin-9, whereas galectin-9 failed to induce significant change in dexamethasoneinduced apoptosis of E-Eos. In contrast, apoptosis induced by anti-Fas antibody in both N-Eos and E-Eos was enhanced by galectin-9. These findings suggested that galectin-9 was produced by eosinophils, and galectin-9 showed heterogeneous effects and kinetics to eosinophils, and this factor might be one of crucial factors in eosinophilic inflammation.