激发型4-1BBL抗体促进原代急性髓细胞白血病细胞的增殖和MMP-9分泌

Provocative anti-4-1BBL mAb stimulates proliferation of primary blast cells of human acute myeloid leukemia in vitro

目的:研究共刺激分子4-1BBL分子逆向信号对原代急性髓细胞白血病细胞的促增殖作用及其生物学效应。方法:用流式细胞术(FCM)检测4-1BBL分子在26例初诊急性髓细胞白血病(AML)患者白血病细胞表面的表达,分离AML患者的白血病细胞并加入激发型4-1BBL抗体(1F1单抗)共培养,同时设置IgG1同型对照组,Alamar Blue法检测4-1BBL单抗1F1促AML原代细胞的增殖。收集培养细胞的上清液,用ELISA方法检测基质金属蛋白酶-9(MMP-9)的水平。结果:FCM测得初诊AML患者的白血病细胞上存在4-1BBL分子的表达,26例AML患者中4-1BBL分子的阳性表达率为46.15%;1F1单抗能明显促进4-1BBL+-AML细胞的生长,4-1BBL+-AML组刺激指数明显高于4-1BBL--AML组(P<0.01)。1F1与4-1BBL+-AML细胞共培养48 h后,用ELISA法检测其上清液中MMP-9含量显著高于IgG1同型对照组[(965.06±229.94)vs(596.49±129.28)pg/ml,P<0.01],而4-1BBL--AML组的MMP-9与IgG1组无显著差异(P>0.05)。结论:部分AML患者的白血病细胞可以表达4-1BBL分子,1F1单抗与AML细胞上4-1BBL分子交联后,可以促进AML细胞的生长,同时促进MMP-9的分泌。

Objective：To study proliferation and biological functions of 4-1BBL reverse signals in the primary blast cells of human acute myeloid leukemia（AML）.Methods：Twenty-six AML patients were enrolled.The expression of 4-1BBL protein was detected by FACS in human primary AML cells.Anti-4-1BBL mAb（1F1） was used to stimulate primary human myeloid blast cells.Cell proliferation was determined using Alamar Blue assay.The production of cytokine matrix metalloproteinase 9（MMP-9） in the culture supernatants of AML cells.was determined by a cytokine-specific ELISA.Results：FACS analysis showed that 4-1BBL molecule was constitutively expressed on AML cells.Among the 26 cases,46.15% expressed 4-1BBL molecule.Anti-4-1BBL mAb 1F1 stimulated the proliferation of 4-1BBL positive AML cells.The level of MMP-9 in the culture supernatants of AML cells treated with 1F1 and isotype IgG1 for 48 hours were（965.06 ± 229.94） pg / ml and（596.49 ± 129.28） pg / ml,respectively（P〈0.01）.Conclusion：4-1BBL molecule is constitutively expressed on human AML cells.4-1BBL reverse signaling plays a critical role in AML cells survival and growth,and contributes to MMP-9 release.