Tempest P R, Barbanti E, Bremner P, Carr F J, Ghislieri M, Rifaldi B, Marcucci F
Scotgen Biopharmaceuticals Inc., Aberdeen, Scotland, UK.
Hybridoma. 1994 Jun;13(3):183-90. doi: 10.1089/hyb.1994.13.183.
We have constructed several humanized versions of a monoclonal antibody (MAb78) against human tumor necrosis factor-alpha (huTNF-alpha) retaining the complementarity-determining regions (CDR) of the original mouse MAb with or without a variable number of original framework region (FR) residues. All versions, except one, showed a loss of binding affinity and neutralizing potency of at least 10-fold compared to the original mouse MAb or its chimeric equivalent. In some cases, however, the decrease in neutralizing potency was significantly greater than the decrease in binding affinity. Two humanized versions showing the greatest dissociation between these two parameters were studied for their capacity to inhibit the neutralizing activity of chimeric or murine MAb78 when used at concentrations that bound but only partially neutralized huTNF-alpha. One humanized version (MAb78D) was indeed able to do so, whereas the other (MAb78C) was not found to exert any inhibitory activity at all concentrations tested. The antagonistic effect of MAb78D was concentration dependent and could be overcome by increasing the concentrations of chimeric or murine MAb78. Two different models of MAb78-huTNF-alpha interaction that may help explain the antagonist activity of humanized MAb78D are discussed.
我们构建了几种抗人肿瘤坏死因子-α（huTNF-α）单克隆抗体（MAb78）的人源化版本，保留了原始小鼠单克隆抗体的互补决定区（CDR），并带有或不带有可变数量的原始框架区（FR）残基。除了一个版本外，所有版本与原始小鼠单克隆抗体或其嵌合等效物相比，结合亲和力和中和效力均至少损失了10倍。然而，在某些情况下，中和效力的下降明显大于结合亲和力的下降。研究了在结合但仅部分中和huTNF-α的浓度下使用时，这两个参数之间解离度最大的两个人源化版本抑制嵌合或鼠源MAb78中和活性的能力。其中一个人源化版本（MAb78D）确实能够做到这一点，而另一个（MAb78C）在所有测试浓度下均未发现有任何抑制活性。MAb78D的拮抗作用是浓度依赖性的，可以通过增加嵌合或鼠源MAb78的浓度来克服。讨论了两种不同的MAb78 - huTNF-α相互作用模型，它们可能有助于解释人源化MAb78D的拮抗活性。
