Katsube Y, Suzuki H, Muryoi T, Sasaki T
Department of Rheumatology, Insutitute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki 305, Japan.
Int J Mol Med. 1998 May;1(5):863-8. doi: 10.3892/ijmm.1.5.863.
Although contribution of light chain to DNA reactivity of some murine anti-DNA antibodies (Abs) has been demonstrated, similar studies on human anti-DNA Abs are limited. To investigate this contribution, we reproduced Fab molecules on the surface of phages from a human B cell line producing IgM anti-DNA monoclonal Ab (NE-1) by an Ab-phage display technique. Expressed Fab molecules (p4-1 clone) were similar to the parental mAb in their binding activities and idiotypic expression. We constructed a light chain shuffled library containing Vkappa genes derived from peripheral blood lymphocytes of a patient with systemic lupus erythematosus (SLE) in combination with the NE-1 heavy chain gene. After panning to ss- or dsDNA, 7 Fab-phage clones which showed significant bindings to ss- or dsDNA were isolated. Many other Fab-phage clones from the library did not bind to ss- nor dsDNA. Sequence analysis revealed that light chains of the 7 clones are derived from diverse Vkappa germline genes including rarely used ones such as the L5 and A30. Most of the Vk germline genes have been used for previously reported anti-DNA antibodies. These findings suggest that diverse Vkappa genes can pair with the NE-1 heavy chain for anti-DNA Ab activity. In addition, kappa light chains seem to modulate DNA binding activities in various ways.
尽管已证明轻链对某些鼠抗DNA抗体（Abs）的DNA反应性有贡献，但对人抗DNA Abs的类似研究有限。为了研究这种贡献，我们通过抗体-噬菌体展示技术，从产生IgM抗DNA单克隆抗体（NE-1）的人B细胞系中，在噬菌体表面重现了Fab分子。表达的Fab分子（p4-1克隆）在结合活性和独特型表达方面与亲本单克隆抗体相似。我们构建了一个轻链改组文库，该文库包含来自系统性红斑狼疮（SLE）患者外周血淋巴细胞的Vκ基因，并与NE-1重链基因结合。在用单链或双链DNA淘选后，分离出7个与单链或双链DNA有显著结合的Fab-噬菌体克隆。文库中的许多其他Fab-噬菌体克隆不与单链或双链DNA结合。序列分析表明，这7个克隆的轻链源自多种Vκ种系基因，包括很少使用的如L5和A30等基因。大多数Vκ种系基因已被用于先前报道的抗DNA抗体。这些发现表明，多种Vκ基因可与NE-1重链配对以产生抗DNA Ab活性。此外，κ轻链似乎以多种方式调节DNA结合活性。
