MHCII类反式激活蛋白调控肿瘤细胞HLA分子的表达

MHC Class II Transactivator (CIITA) Regulates the Expression of HLA Molecules in Tumor Cells

为研究肿瘤细胞MHCII类分子表达及对IFN γ诱导HLA分子表达的反应性与CIITA表达的关系 ,本文采用Westernblot、免疫组化和流式细胞术检测肿瘤细胞HLA分子表达 ,以RT PCR检测肿瘤细胞CIITA基因表达。肿瘤细胞HLAII类分子表达与CIITA表达一致 ;组成性或诱导性表达CIITA的肿瘤细胞 ,经IFN γ作用后其HLAI、II类分子表达增高 ;IFN γ诱导后仍不表达CIITA的肿瘤细胞 ,其对IFN γ促HLA表达的作用不反应。提示 ,某些肿瘤细胞对IFN γ不能诱导HLA分子表达与CIITA诱导性表达缺陷有关。表面CIITA参与调控肿瘤细胞HLAI、II类分子表达。

To investigate the role of class II transactivator(CIITA) in constitutive or IFN γ inducible expression of HLA molecules in tumor cells, the expression of HLA molecules was detected by Western blot, immunohistochemistry and flow cytometry,and the expression of CIITA gene was determined by RT PCR It was found that the HLA class II positive tumor cells expressed the CIITA quite well, and IFN γ could induce the expression of HLA class I and II molecules only if the tumor cells were able to express CIITA constitutively or in a IFN γ induced manner, suggesting a correlation between the inability of the tumor cells in response to IFN γ for HLA expression and the deficiency in the inducible expression of CIITA It suggests that CIITA is a critical factor responsible for the expression of HLA class I and II molecules in tumor cells