基因多态性与异基因造血干细胞移植后Epstein-Barr病毒感染的研究

Epstein-Barr virus (EBV)-associated diseases have become a major complication and cause of death after allogeneic hematopoietic stem cell transplantation (allo-HSCT).The incidence of EBV-associated diseases varies greatly in different areas. In this study, the association between gene polymorphisms (including HLA polymorphisms and cytokine gene single nucleotide polymorphisms [SNPs]) and EBV infection as well as EBV-associated diseases will be evaluated in order to explore the effect of polymorphisms on EBV-associated diseases and provide plausible explanation of the different incidence in different areas. To provide a possible mechanism to explain the link between gene polymorphisms and EBV-associated diseases, EBV-specific cytotoxic T lymphocytes (EBV-CTL) response restricted through different alleles will be studies. Transcriptional activity of different cytokine gene SNPs in promoter will be studied using luciferase reporter gene systems and electrophoretic mobility shift assays, and protein levels of different cytokine gene SNPs in exon will be tested using western-blotting. Human peripheral blood leukocytes derived from donors with different alleles will be injected to severe-combined immunodeficient mice to test the hypothesis that gene polymorphisms associates with the development of EBV-associated disease.

目前异基因造血干细胞移植（allo-HSCT）后Epstein-Barr病毒（EBV）相关疾病已经成为移植后的重要并发症与死亡原因之一，但不同地域人群发病率差异较大。本研究拟①通过研究HLA多态性和细胞因子基因单核苷酸多态性（SNPs）与allo-HSCT后EBV感染/再激活、EBV相关疾病的关联，探讨基因多态性对EBV相关疾病的影响，揭示不同地域人群发病率差异的原因；②检测不同基因型个体EBV特异性的细胞毒性T细胞（EBV-CTL）的水平和效应能力，探讨基因多态性影响EBV相关疾病的机制；③检测细胞因子基因启动子区域SNPs对转录能力的影响和外显子区域SNPs对蛋白表达水平的影响，探讨细胞因子基因SNPs参与EBV相关疾病的机制；④采用具有不同基因型的EBV血清学阳性供者的外周血单个核细胞诱导严重免疫缺陷小鼠发生EBV相关肿瘤，验证不同基因多态性对EBV相关疾病发生的影响。

研究背景.EB病毒（EBV）是异基因造血干细胞移植（allo-HSCT）后病毒感染主要病原体。目前鲜见allo-HSCT 后EBV感染/再激活以及相关疾病与基因多态性的报道，且影响机制尚不清楚。.主要研究内容.①HLA基因多态性与EBV感染/再激活及相关疾病的关联性研究；.②细胞因子基因SNPs与EBV感染/再激活及相关疾病的关联性研究；.③从不同HLA基因型患者EBV-CTL重建情况，探讨基因多态性影响EBV感染/疾病的机理。.重要结果及关键数据.①EBV感染/再激活组患者HLA-B44的频率高于非感染/再激活组。EBV疾病组患者HLA-B44的频率高于非EBV疾病组；供者HLA-C03位点在疾病组中的频率低于非疾病组。.②EBV感染/再激活组供者IL-1β-511 TT基因型、供者IL-4 -590 TT基因型、患者TNF-α -308 GG基因型的频率高于非感染/再激活组。而EBV感染/再激活组供者IL-1β-511 CC基因型、供者IL-1RN +11100 TT基因型、供者IL-2 -330 TT基因型、供者IL-4 -590 CC基因型、患者TNF-α -308 GA基因型的频率低于非感染/再激活组。EBV疾病组供者IFN-γ +874 AT基因型高于非疾病组。而EBV疾病组供者IL-1β-511 CC基因型、供者IL-10 -592AA基因型、供者IL-12+1188 AA基因型、供者IFN-γ +874 AA基因型的频率低于非疾病组。危险因素分析显示：ATG预防、供者IL-4 -590TT基因型、患者TNF-α -308GG基因型是移植后EBV感染/再激活的危险因素；供者IL-1RN +11100TT基因型是移植后EBV感染/再激活的保护因素。.③IL-1β-511、 IL-1RN +11100、 IL-2 -330 、 IL-10 -592、 TGF-β1 +869 位点SNPs可能影响allo-HSCT后EBV-CTL重建。.科学意义.①探讨HLA基因、细胞因子基因多态性与接受allo-HSCT的患者EBV感染/再激活、EBV相关疾病的发生的关联。.②通过检测不同基因型EBV-CTLs的差异，初步探讨基因多态性影响EBV感染/再激活、EBV相关疾病发生的机制。