Youngnak Pornpan, Kozono Yuko, Kozono Haruo, Iwai Hideyuki, Otsuki Noriko, Jin Hisayo, Omura Ken, Yagita Hideo, Pardoll Drew M, Chen Lieping, Azuma Miyuki
Department of Molecular Immunology, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
Biochem Biophys Res Commun. 2003 Aug 1;307(3):672-7. doi: 10.1016/s0006-291x(03)01257-9.
Programmed death-1 (PD-1) is a negative regulatory receptor expressed on activated T and B cells. Two ligands for PD-1, B7-H1 (PD-L1) and B7-DC (PD-L2), have been identified, but their binding properties have not been characterized yet. In this study, we generated soluble Ig fusion proteins of these molecules and examined the kinetics and relative affinities of the interactions between B7-H1 or B7-DC and PD-1 by flow cytometry and surface plasmon resonance. The interaction of B7-DC/PD-1 exhibited a 2-6-fold higher affinity and had different association/dissociation kinetics compared with the interaction of B7-H1/PD-1. Our results suggest that the differential binding properties of B7-H1 and B7-DC may be responsible for differential contributions of these two PD-1 ligands to immune responses.
程序性死亡蛋白1（PD-1）是一种在活化的T细胞和B细胞上表达的负性调节受体。已鉴定出PD-1的两种配体，即B7-H1（PD-L1）和B7-DC（PD-L2），但它们的结合特性尚未得到表征。在本研究中，我们制备了这些分子的可溶性Ig融合蛋白，并通过流式细胞术和表面等离子体共振检测了B7-H1或B7-DC与PD-1之间相互作用的动力学和相对亲和力。与B7-H1/PD-1的相互作用相比，B7-DC/PD-1的相互作用表现出高2至6倍的亲和力，并且具有不同的结合/解离动力学。我们的结果表明，B7-H1和B7-DC的不同结合特性可能是这两种PD-1配体对免疫反应的不同贡献的原因。
