【摘要】 目的　探讨Ⅱ类主要组织相容性复合物 (MHCⅡ )激活因子 (CⅡTA)的反义cDNA对细胞表面MHCⅡ类分子表达的抑制。方法　克隆 3条CⅡTA反义片段 (arⅡ 1、arⅡ 2、arⅡ 3) ,并稳定转染Hela细胞。免疫组化、流式细胞术检测细胞核内CⅡTA蛋白及其调控的经典MHCⅡ (HLA DR、 DP、 DQ)类抗原表达 ,RT PCR法检测CⅡTA、经典MHCⅡ及恒定链的mRNA水平。结果　三种反义片段中arⅡ 2效果最佳。在重组人IFN γ诱导下 ,arⅡ 2阳性Hela细胞与正义链组比较 ,CⅡTA蛋白抑制率达87.2 3% ,HLA DR、 DP及 DQ抗原诱导型表达分别降低了 79.2 1%、90 .31%及 4 8.30 % ;同时CⅡTA、经典的MHCⅡ及恒定链的mRNA含量明显减少 (P <0 .0 5 )。结论　CⅡTA反义片段抑制了自身mRNA含量 ,从而阻止其调控的MHCⅡ分子的表达 ,为预防移植物抗宿主病提供了一种新思路。更多还原

【Abstract】 Objective To investigate the inhibiting effect of classⅡ major histocompatibility complex transactivator (CⅡTA) anti-sense cDNA on MHCⅡ molecules expression. Methods CⅡTA antisense cDNAs (arⅡ1,arⅡ2 and arⅡ3) were obtained from Raji cell by RT-PCR, and then inserted into the pcDNA3.1B plasmid. The stable transfectants of Hela cell were tested for CⅡTA protein by immunohistochemistry, and classic MHCⅡ molecules (HLA-DR,-DP,-DQ) induction through recombinant human IFN-γ by flow cytometry. mRNAs of CⅡTA, invariant chain and classic MHCⅡ molecules were detected by RT-PCR. Results The effect of arⅡ2 was the best. When induced with IFN-γ, the expression of CⅡTA protein was inhibited by 87.23%, and that of HLA-DR, -DP and -DQ was almost totally inhibited on arⅡ2 positive Hela cells. The mRNA contents of CⅡTA, HLA-DR,-DP, -DQ and invariant chain were decreased significantly (P<0.05). Conclusions arⅡ2 inhibits CⅡTA and thus the family of MHCⅡmolecules regulated by CⅡTA, therefore, it provides a novel approach to graft versus host disease study in hematopoietic stem cell transplantation.更多还原