Mild acid treatment induces cross-reactivity of 4H84 monoclonal antibody specific to nonclassical HLA-G antigen with classical HLA class I molecules
Mild acid treatment induces cross-reactivity of 4H84 monoclonal antibody specific to nonclassical HLA-G antigen with classical HLA class I molecules
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DOI：
10.1016/s0198-8859(02)00777-2
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发表时间：
2003-02-01
期刊：
影响因子：
2.7
通讯作者：
Russ, G
中科院分区：
文献类型：
--
作者：
Poláková, K;Bennink, JR;Russ, G
通过释放β（2）m和抗原肽的弱酸处理使人白细胞抗原（HLA）I类游离重链附着于细胞表面。因此，酸处理允许通过对无HLA重链特异性的单克隆抗体（mAb）检测细胞表面1类抗原。我们发现，酸处理还能够用对HLA-G游离重链特异性的mAb（包括识别所有同种型的4 H84 mAb）检测细胞表面非经典HLA-G I类抗原。此外，我们发现，4 H84单克隆抗体，而不是其他的单克隆抗体特异性HLA-G游离重链，结合8的16个酸处理的白血病细胞系的表面。然而，HLA-G抗原不存在于任何这些白血病细胞中。这通过免疫印迹中4 H84 mAb未能检测到任何抗原以及通过RT-PCR不能检测HLA-G mRNA来证明。在某些酸处理的白血病细胞中，4 H84 mAb识别的抗原通过免疫沉淀被鉴定为45 kDa蛋白。许多观察结果表明，45 kDa蛋白质正是经典的I类重链。因此，酸处理诱导41184 mAb识别某些经典HLA I类分子的能力。值得注意的是，HLA-G上的41184决定簇是线性的，但存在于一些部分折叠的经典HLA I类游离重链上的相应决定簇是构象的。考虑到意外的交叉反应性，必须仔细评估使用该mAb检测HLA-G，以避免错误检测。(C)美国组织相容性和免疫遗传学学会，2003年。出版社：Elsevier Science Inc.
Mild acid treatment by releasing beta(2)m and antigenic peptides leaves human leukocyte antigen (HLA) class I free heavy chains attached to the cell surface. Acid treatment thus allows detection of the cell surface class 1 antigens by monoclonal antibodies (mAbs) specific to HLA-free heavy chains. We found that acid treatment also enables detection of the cell surface non-classical HLA-G class I antigen with mAbs specific for HLA-G free heavy chains, including 4H84 mAb recognizing all isoforms. Furthermore, we found that 4H84 mAb, but not other mAbs specific to HLA-G free heavy chains, binds to the surface of 8 out of 16 acid-treated leukemia cell lines. Nevertheless, HLA-G antigen is not present in any of these leukemia cells. This was demonstrated by failure to detect any antigen with 4H84 mAb in immunoblotting as well as by inability to detect HLA-G mRNA by RT-PCR. The antigen recognized by 4H84 mAb in some acid treated leukemia cells was identified by immunoprecipitation as a 45 kDa protein. A number of observations indicate that 45 kDa proteins are none other than classical class I heavy chains. Acid treatment thus induces the ability of the 41184 mAb to recognize some classical HLA class I molecules. Remarkably, 41184 determinant on HLA-G is linear but corresponding determinant present on some partially folded classical HLA class I free heavy chains is conformational. In view of the unexpected cross-reactivity, detection of HLA-G with this mAb must be carefully evaluated to avoid false detection. (C) American Society for Histocompatibility and Immunogenetics, 2003. Published by Elsevier Science Inc.