Role of C6ORF120, an N-glycosylated protein, is implicated in apoptosis of CD4＋ T lymphocytes  

作　　者：LI Xin QIAO Yong CHANG Lu-si XIAO Fan LU Lian-he HAO Xiao-hua ZHANG Ren-wen WU Hao WEI Hong-shan 

机构地区：[1]Department of Infectious Disease , Institute of Infectious Disease , Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China [2]Graduate School, Peking University Health Science Center, Beijing 100083, China [3]Department of Infectious Disease, Beijing Youan Hospital, Capital Medical University, Beijing 100069, China

出　　处：《Chinese Medical Journal》2011年第21期3560-3567,共8页中华医学杂志（英文版）

基　　金：This study was supported by grants from the National Natural Science Foundation of China （No. 81071411 and No. 30872243）.

摘　　要：Background Although CD4＋ T cell apoptosis and CD8＋ T cell responses have been extensively studied during HIV infection, how apoptosis signals being initiated in CD4＋ T cells still need to be elucidated. The present study was designed to characterize the function-unknown gene, C6orf120, and elucidates its primary role in tunicamycin-induced CD4＋ T apoptosis. Methods The C6orf120 coding sequence was amplified from peripheral blood mononuclear cells （PBMCs） total RNA of AIDS patients. The DNA fragment was inserted into the pET-32a expression system, transformed into Escherichia coli, and preparation of C6ORF120 recombinant protein. The magnetic cell separation technology was used to prepare primary CD4＋ T cells and CD8＋T cells. The primary T cells were cultured at 1×10^6 cells/ml, treated with 0, 0.1,1, 10, 100 and 200 ng/ml of C6orf120 recombinant protein for 48 hours, then harvested for cell cycle and apoptosis analysis. Tunicamycin （0.5 μmol/L） was used to induce endoplasmic reticulum stress in Jurkat cells. The biomarker 78 KDa glucose-regulated protein （GRp78） and growth arrest and DNA damage （GADD） were used to evaluate endoplasmic reticulum stress of Jurkat cells. Results We prepared C6ORF120 recombinant protein and its polyclonal antibody. Immunohistochemical analysis showed that C6orf120 mainly expressed in hepatocytes and cells in germinal center of lymph node. At concentration of 0.1, 1, 10, 100, and 200 ng/ml, C6orf120 recombinant protein could induce apoptosis of Jurkat cells and primary CD4＊T cells, and promoting G2 phase of its cell cycle. Western blotting analysis showed that C6ORF120 recombinant protein increased the expression of GRp78 and GADD in Jurkat cells in vitro. Conclusion Our results suggested that C6ORF120 could induce apoptosis of CD4＋ T cells, at least in part, mediated with endoplasmic reticulum stress.Background Although CD4＋ T cell apoptosis and CD8＋ T cell responses have been extensively studied during HIV infection, how apoptosis signals being initiated in CD4＋ T cells still need to be elucidated. The present study was designed to characterize the function-unknown gene, C6orf120, and elucidates its primary role in tunicamycin-induced CD4＋ T apoptosis. Methods The C6orf120 coding sequence was amplified from peripheral blood mononuclear cells （PBMCs） total RNA of AIDS patients. The DNA fragment was inserted into the pET-32a expression system, transformed into Escherichia coli, and preparation of C6ORF120 recombinant protein. The magnetic cell separation technology was used to prepare primary CD4＋ T cells and CD8＋T cells. The primary T cells were cultured at 1×10^6 cells/ml, treated with 0, 0.1,1, 10, 100 and 200 ng/ml of C6orf120 recombinant protein for 48 hours, then harvested for cell cycle and apoptosis analysis. Tunicamycin （0.5 μmol/L） was used to induce endoplasmic reticulum stress in Jurkat cells. The biomarker 78 KDa glucose-regulated protein （GRp78） and growth arrest and DNA damage （GADD） were used to evaluate endoplasmic reticulum stress of Jurkat cells. Results We prepared C6ORF120 recombinant protein and its polyclonal antibody. Immunohistochemical analysis showed that C6orf120 mainly expressed in hepatocytes and cells in germinal center of lymph node. At concentration of 0.1, 1, 10, 100, and 200 ng/ml, C6orf120 recombinant protein could induce apoptosis of Jurkat cells and primary CD4＊T cells, and promoting G2 phase of its cell cycle. Western blotting analysis showed that C6ORF120 recombinant protein increased the expression of GRp78 and GADD in Jurkat cells in vitro. Conclusion Our results suggested that C6ORF120 could induce apoptosis of CD4＋ T cells, at least in part, mediated with endoplasmic reticulum stress.

关 键 词：HIV/AIDS C6orf120 APOPTOSIS endoplasmic reticulum stress cell cycle 

分 类 号：Q343.1[生物学—遗传学] S858[农业科学—临床兽医学]