Radic M Z, Mascelli M A, Erikson J, Shan H, Weigert M
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111.
J Immunol. 1991 Jan 1;146(1):176-82.
An Ig H chain expression vector has been constructed by using the V region of 3H9, an antibody that binds ssDNA, dsDNA, and cardiolipin. The H chain construct was transfected into six hybridoma cell lines expressing Ig L chains. All resulting H and L chain combinations had at least some affinity for ssDNA, whereas five also bound dsDNA to a similar degree as 3H9. The loss of dsDNA binding was correlated with a single amino acid difference between two V kappa 8 L chains. A further characteristic of 3H9, its immunofluorescent staining pattern, was shared by four of the recombinant antibodies, whereas its specificity for cardiolipin was shared with five. The transfections reported here show that a V kappa 3 L chain confers specificity for an RNA-associated epitope and that a V kappa 21E L chain prevents cardiolipin binding. These experiments suggest that the 3H9 H chain contributes essential determinants required for binding to DNA as well as cardiolipin but that L chains can modulate or prevent this binding. L chains may also expand the specificity of a recombinant antibody.
通过使用3H9的V区构建了一种Ig H链表达载体，3H9是一种能结合单链DNA、双链DNA和心磷脂的抗体。将H链构建体转染到六个表达Ig L链的杂交瘤细胞系中。所有产生的H链和L链组合对单链DNA都至少有一定亲和力，而其中五种对双链DNA的结合程度与3H9相似。双链DNA结合能力的丧失与两种Vκ8 L链之间的一个氨基酸差异相关。3H9的另一个特征，即其免疫荧光染色模式，在四种重组抗体中也有体现，而其对心磷脂的特异性在五种抗体中也有体现。此处报道的转染实验表明，Vκ3 L链赋予了对RNA相关表位的特异性，而Vκ21E L链则阻止了心磷脂结合。这些实验表明，3H9 H链为与DNA以及心磷脂的结合提供了必需的决定簇，但L链可以调节或阻止这种结合。L链也可能扩展重组抗体的特异性。
