AUTOCRINE PRODUCTION OF EXTRACELLULAR CATALASE PREVENTS APOPTOSIS OF THE HUMAN CEM T-CELL LINE IN SERUM-FREE MEDIUM
AUTOCRINE PRODUCTION OF EXTRACELLULAR CATALASE PREVENTS APOPTOSIS OF THE HUMAN CEM T-CELL LINE IN SERUM-FREE MEDIUM
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DOI：
10.1073/pnas.90.10.4708
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发表时间：
1993-05-15
影响因子：
11.1
通讯作者：
BUTTKE, TM
中科院分区：
文献类型：
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作者：
SANDSTROM, PA;BUTTKE, TM
CCRF-CEM是最初从患有急性淋巴细胞白血病的儿童中分离的人类T细胞系。当细胞密度> 2 × 10（5）个细胞/ml时，CEM细胞在无血清培养基中生长，但在较低的细胞密度下，培养物迅速发生凋亡或程序性细胞死亡。低密度CEM细胞的活力可以通过用来自高密度CEM培养物的“条件"培养基补充无血清培养基来保持，但是各种已知的生长因子和淋巴因子无效。分级的条件培养基上的连续层析DEAE-纤维素，丙基琼脂糖，chromatofocusing，和疏水相互作用HPLC导致在分离的60-kDa的蛋白质能够维持CEM生长的情况下，血清。基于其氨基酸序列和组成，活性蛋白被鉴定为人过氧化氢酶，随后显示出过氧化氢酶活性，并且可被人红细胞过氧化氢酶或牛肝过氧化氢酶替代。细胞内过氧化氢酶活性水平与释放到培养基中的量的比较表明，后者占
CCRF-CEM is a human T-cell line originally isolated from a child with acute lymphoblastic leukemia. At cell densities > 2 x 10(5) cells per ml, CEM cells grow in serum-free medium, but at lower cell densities the cultures rapidly undergo apoptosis, or programmed cell death. The viability of low-density CEM cells could be preserved by supplementing the serum-free medium with ''conditioned'' medium from high-density CEM cultures, but a variety of known growth factors and lymphokines were ineffective. Fractionation of conditioned medium by sequential chromatography on DEAE-cellulose, propyl agarose, chromatofocusing, and hydrophobic-interaction HPLC resulted in the isolation of a 60-kDa protein capable of sustaining CEM growth in the absence of serum. The active protein was identified as human catalase based on its amino acid sequence and composition and was subsequently shown to exhibit catalase activity and to be replaceable by human erythrocyte catalase or bovine liver catalase. Comparison of the level of intracellular catalase activity with the amount released into the culture medium demonstrated that the latter accounted for