Lepri E, Delfino D V, Migliorati G, Moraca R, Ayroldi E, Riccardi C
Department of Clinical and Experimental Medicine, University of Perugia, Italy.
Exp Hematol. 1998 Dec;26(13):1202-8.
In this study we describe the expression and function of Fas in mouse bone marrow (BM) stromal cells (SCs) and cell lines derived from long-term BM cultures. Flow cytometry analysis showed that Fas was expressed on adherent cells from freshly isolated BM and on all cloned SC lines tested. The SC line ME-25 was Fas+ but negative for FasL as detected by reverse transcriptase-polymerase chain reaction. Furthermore, ME-25 was CD44+, VCAM-1+, Mac-3-, Gr-1-, and type IV collagen-. ME-25 treatment with interferon-gamma or tumor necrosis factor-alpha significantly induced upregulation of Fas expression as detected by both flow cytometry and Western blot immunoassay. The same treatment with interleukin (IL)-1, IL-2, or IL-13 had no effect. Functional studies demonstrated that Fas induced a strong increase in apoptosis when engaged with an anti-Fas monoclonal antibody (MoAb). Activated BM T cells induced Fas-dependent cytotoxicity of ME-25 insofar as blocking anti-FasL MoAb inhibited the killing of ME-25 induced by activated BM T cells. These data suggest a possible involvement of Fas-expressing SCs in negative regulatory functions in the BM and provide a starting point for further studies on the role of Fas+ SCs.
在本研究中，我们描述了Fas在小鼠骨髓（BM）基质细胞（SCs）以及源自长期BM培养物的细胞系中的表达和功能。流式细胞术分析表明，Fas在新鲜分离的BM贴壁细胞以及所有测试的克隆SC系中均有表达。通过逆转录聚合酶链反应检测发现，SC系ME-25为Fas阳性，但FasL阴性。此外，ME-25为CD44阳性、VCAM-1阳性、Mac-3阴性、Gr-1阴性且IV型胶原阴性。用γ干扰素或肿瘤坏死因子-α处理ME-25后，通过流式细胞术和蛋白质免疫印迹法检测均发现Fas表达显著上调。用白细胞介素（IL）-1、IL-2或IL-13进行相同处理则无效果。功能研究表明，当Fas与抗Fas单克隆抗体（MoAb）结合时，会强烈诱导细胞凋亡增加。活化的BM T细胞诱导ME-25发生Fas依赖性细胞毒性，因为阻断抗FasL MoAb可抑制活化的BM T细胞诱导的ME-25杀伤作用。这些数据表明，表达Fas的SCs可能参与BM中的负调节功能，并为进一步研究Fas阳性SCs的作用提供了一个起点。
