Rescue of Daudi cell HLA expression by transfection of the mouse beta 2-microglobulin gene.
Rescue of Daudi cell HLA expression by transfection of the mouse beta 2-microglobulin gene.
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DOI：
10.1084/jem.167.2.288
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发表时间：
1988-02-01
期刊：
影响因子：
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通讯作者：
Parnes JR
中科院分区：
文献类型：
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作者：
Seong RH;Clayberger CA;Krensky AM;Parnes JR
Daudi细胞系是来源于伯基特淋巴瘤的b淋巴母细胞样细胞系。尽管细胞内存在I类重链，但Daudi细胞缺乏I类HLA分子的细胞表面表达。它们在编码β 2-微球蛋白（β 2m）的基因上有缺陷，导致这种蛋白质缺乏可翻译的mRNA。人们一直认为这种缺陷是细胞表面I类表达缺乏的原因。然而，最近的数据表明，在缺乏β 2m的情况下，至少有一条小鼠I类重链可以在细胞表面表达。这些结果提出了一个问题，即缺乏β 2m是否是Daudi的唯一缺陷，以及转移该单基因是否可以恢复表面I类表达。我们发现，将小鼠β 2m基因转染到Daudi中，确实挽救了I类HLA分子的细胞表面表达，并且这些分子可以被单态和异体特异性单克隆抗体识别。CTL克隆对HLA-B17或HLA-B17和HLA-A2共有的一个决定因素具有特异性，可杀死转染β 2m基因的Daudi细胞，但对未转染的Daudi细胞或单独转染载体的Daudi细胞没有杀伤作用。转染的小鼠Daudi细胞在人血清中培养时，其上的β 2m能与人β 2m交换。这种交换并没有改变细胞被特定ctl杀死的能力。这些结果表明，缺乏β 2m是Daudi细胞中缺乏表面I类分子的唯一原因，并且β 2m是特定的I类重链Daudi细胞表面表达所必需的。
The Daudi cell line is a B-lymphoblastoid line derived from a Burkitt lymphoma. Daudi cells lack cell surface expression of class I HLA molecules despite the presence of intracellular class I heavy chains. They have a defect in the gene encoding beta 2-microglobulin (beta 2m), resulting in lack of translatable mRNA for this protein. It has been thought that this deficiency is responsible for the lack of cell surface class I expression. However, data have recently been presented demonstrating that at least one mouse class I heavy chain can be expressed on the cell surface in the absence of beta 2m. These results raised the questions of whether the lack of beta 2m is the only defect in Daudi and whether transfer of this single gene could restore surface class I expression. We found that transfection of the mouse beta 2m gene into Daudi indeed rescued cell surface expression of class I HLA molecules, and that these molecules could be recognized both by monomorphic and allospecific mAbs. CTL clones specific for HLA-B17 or a determinant shared by HLA-B17 and HLA-A2 killed the Daudi cells transfected with the beta 2m gene, but not untransfected Daudi or Daudi transfected with vector alone. Mouse beta 2m on the transfected Daudi cells could exchange with human beta 2m when the cells were incubated in human serum. This exchange did not alter the ability of the cells to be killed by the specific CTLs. These results demonstrate that the lack of beta 2m is the sole reason for lack of surface class I molecules in Daudi cells, and that beta 2m is required for cell surface expression of the specific class I heavy chains of Daudi.