异基因造血干细胞移植术后CD4+T细胞中缺乏SIRT1诱发急性移植物抗宿主病

目的：研究异基因造血干细胞移植患者外周血CD4+T细胞中SIRT1基因表达水平与急性移植物抗宿主病 (acute graft-versus-host disease，aGVHD)的关系。方法：收集40例行同胞全相合异基因造血干细胞移植患者的血液样 本，采用实时定量PCR和Western印迹检测各组患者SIRT1的表达水平；采用Western印迹检测各组患者STAT3乙酰化 及磷酸化水平；采用免疫共沉淀和Western印迹检测各组患者SIRT1和STAT3结合水平；aGVHD患者CD4+T细胞过表 达SIRT1后采用Western印迹检测STAT3乙酰化及磷酸化水平，采用实时定量PCR检测Th17相关基因RORγt，IL-17A， IL-17F的表达。结果：与未发生aGVHD患者比较，aGVHD患者外周血CD4+T细胞中SIRT1表达水平明显降低；STAT3 表达水平、乙酰化及磷酸化水平均明显升高，且STAT3乙酰化与磷酸化水平呈明显正相关(r=0.69，P<0.01)；STAT3 与SIRT1结合显著减少。aGVHD患者外周血CD4+T细胞中过表达SIRT1后，STAT3乙酰化及磷酸化水平均明显降低， RORγt，IL-17A，IL-17F的表达明显减少(P<0.05)。结论：CD4+T细胞中SIRT1表达不足是异基因造血干细胞移植术后 患者STAT3高度乙酰化及磷酸化，介导Th 17的相关基因表达升高，进而诱发aGVHD的重要因素。

SIRT1 deficiency in CD4+T cells induces acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Objective: To study the relationship between acute graft-versus-host disease (aGVHD) and the SIRT1 expression in peripheral blood CD4+T cells from patients after allogeneic hematopoieticstem cell transplantation (allo-HSCT). Methods: We collected 40 patients who underwent allo-HSCT from human leukocyte antigen (HLA)-identical sibling donors. SIRT1 expression level in CD4+T cells was measured by real-time PCR and Western blot. Acetylation and phosphorylation of STAT3 in CD4+T cells were detected by Western blot. The binding level between SIRT1 and STAT3 in CD4+T cells was analyzed by coimmunoprecipitation and Western blot. Over-expression of SIRT1 in aGVHD CD4+T cells, as well as STAT3 acetylation and phosphorylation were measured by Western blot. The mRNA levels of RORγt, IL-17A, IL-17F related to Th17 were detected by real-time PCR. Results: SIRT1 expression was significantly down-regulated, while STAT3 expression, acetylation and phosphorylation levels were significantly up-regulated in patients with aGVHD compared with patients without aGVHD. The STAT3 acetylation was positively correlated with STAT3 phosphorylation (r=0.69, P<0.01). Less SIRT1-STAT3 complexes were found in CD4+T cells from patients with aGVHD compared with patients without aGVHD. After SIRT1 over-expression in aGVHD CD4+T cells, the STAT3 acetylation and phosphorylation, and the expression of RORγt, IL-17A, and IL-17F related to Th17 were significantly down-regulated (P<0.05). Conclusion: SIRT1 deficiency in CD4+T cells plays a crucial role in up-regulation of STAT3 acetylation and phosphorylation, the increase of Th17 related gene expression, and induction of aGVHD after allogeneic hematopoietic stem cell transplantation.