Kwok A Y, Zu X, Yang C, Alfa M J, Jay F T
Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
Immunology. 1993 May;79(1):131-7.
An antiviral activity-neutralizing monoclonal antibody (mAb), MIF3037, was developed by the immunization of BALB/c mice with recombinant human interferon-gamma (rhuIFN-gamma). Its neutralizing activity suggests that its epitope may be at or adjacent to a functional domain on the huIFN-gamma. MIF3037 was compared with representative mAb of previously identified epitope-specific groups in a competitive binding assay. In an attempt to determine if there are other functional epitopes recognized by mAb developed with different preparations of huIFN-gamma or different hybridoma screening methods, 14 additional mAb contributed by five other laboratories were similarly analysed. Based on their ability to bind to huIFN-gamma, all the neutralizing mAb except MIF3037 may be classified into three previously defined groups: E1, E2 and E1/E2. Monoclonal antibodies of the E1 group do not compete with those of the E2 group for huIFN-gamma binding, indicating that the E1 and E2 epitopes are distinct domains on the huIFN-gamma important for the antiviral function. Monoclonal antibodies of the E1/E2 group compete with some of the mAb of E1 and/or E2 groups and may bind to regions of the huIFN-gamma that partially overlap the E1 and E2 epitopes. MIF3037 demonstrated no competitive binding inhibition with mAb of the previously identified epitope specificity groups and, therefore, must represent a distinct functional epitope, E3. The huIFN-gamma, therefore, must have at least three distinct functional domains; none of these appeared to be responsible for cell surface receptor binding. Based on this finding, the epitope typing scheme must be extended to include the E3 epitope. The epitope specificity relationships of 13 neutralizing mAb developed by five other laboratories were established which allows correlation of results obtained with these mAb by different laboratories. The location of the epitopes of four widely studied mAb, 69B, 73A, 113B and 220A12, have been deduced based on their competition with the E1 mAb which have recently been mapped.
通过用重组人干扰素 -γ（rhuIFN -γ）免疫BALB/c小鼠，研发出一种抗病毒活性中和单克隆抗体（mAb）MIF3037。其中和活性表明其表位可能位于huIFN -γ的功能域或与之相邻。在竞争性结合试验中，将MIF3037与先前确定的表位特异性组的代表性mAb进行了比较。为了确定用不同制备的huIFN -γ或不同杂交瘤筛选方法产生的mAb是否识别其他功能表位，对其他五个实验室提供的另外14种mAb进行了类似分析。基于它们与huIFN -γ结合的能力，除MIF3037外的所有中和mAb可分为先前定义的三个组：E1、E2和E1/E2。E1组的单克隆抗体与E2组的单克隆抗体在结合huIFN -γ时不竞争，这表明E1和E2表位是huIFN -γ上对抗病毒功能重要的不同结构域。E1/E2组的单克隆抗体与E1和/或E2组的一些mAb竞争，并且可能结合到huIFN -γ中与E1和E2表位部分重叠的区域。MIF3037与先前确定的表位特异性组的mAb未表现出竞争性结合抑制，因此，它必定代表一个独特的功能表位E3。因此，huIFN -γ必定至少有三个不同的功能结构域；这些结构域似乎都与细胞表面受体结合无关。基于这一发现，表位分型方案必须扩展以包括E3表位。确定了其他五个实验室研发的13种中和mAb的表位特异性关系，这使得不同实验室用这些mAb获得的结果能够相互关联。基于四种广泛研究的mAb（69B、73A、113B和220A12）与最近已定位图谱的E1 mAb的竞争情况，推断出了它们的表位位置。
