Hatzubai A, Lerner R A, Klein G, Sulitzeanu D
Lautenberg Center for General and Tumor Immunology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Eur J Immunol. 1988 Aug;18(8):1283-8. doi: 10.1002/eji.1830180820.
Human B lymphocytes transformed by infection with the Epstein-Barr virus (EBV) express a new membrane protein of 63 kDa (latent membrane protein, LMP) encoded by the virus. The function of this protein in the virus-cell interaction is not known. In this work we have identified in EBV- human and mouse cell molecules which cross-react with LMP. Two types of reagents were employed: (a) antibodies against LMP-derived synthetic peptides, affinity purified from antisera against a fusion protein containing the carboxy half of the LMP molecule and (b) antisera prepared by immunizing rabbits directly with the peptide conjugates. Cross-reactions were determined by radioimmunoblotting experiments. At least six molecules (Mr = 110, 85, 63, 53, 45 and 23 kDa), present in a variety of human cells (peripheral blood lymphocytes, B cell lines and epithelial cell lines) were found to cross-react with the LMP-derived peptides. Cross-reacting proteins were also identified in normal mouse tissues. The specificity of the cross-reacting antibodies was confirmed by inhibition experiments with the corresponding peptide. Furthermore, antibodies eluted from individual bands were shown to bind to the same band when reacted with new blots of the same extracts. Our data suggest that normal cells contain a family of highly conserved proteins cross-reacting with the LMP molecule. If, indeed, these proteins share common functions, their study may lead the way to unraveling the function of LMP.
感染爱泼斯坦-巴尔病毒（EBV）后转化的人B淋巴细胞表达一种由该病毒编码的63 kDa新膜蛋白（潜伏膜蛋白，LMP）。该蛋白在病毒与细胞相互作用中的功能尚不清楚。在这项研究中，我们在EBV感染的人和小鼠细胞中鉴定出了与LMP发生交叉反应的分子。使用了两种类型的试剂：（a）针对LMP衍生合成肽的抗体，这些抗体从针对含有LMP分子羧基端一半的融合蛋白的抗血清中亲和纯化得到；（b）通过直接用肽偶联物免疫兔子制备的抗血清。通过放射免疫印迹实验确定交叉反应。在多种人类细胞（外周血淋巴细胞、B细胞系和上皮细胞系）中发现至少六种分子（分子量分别为110、85、63、53、45和23 kDa）与LMP衍生肽发生交叉反应。在正常小鼠组织中也鉴定出了交叉反应蛋白。通过相应肽的抑制实验证实了交叉反应抗体的特异性。此外，从各个条带洗脱的抗体与相同提取物的新印迹反应时，显示会结合到同一条带上。我们的数据表明正常细胞含有与LMP分子发生交叉反应的高度保守蛋白家族。如果这些蛋白确实具有共同功能，对它们的研究可能会为揭示LMP的功能指明方向。
