Lange R, Peng X, Wimmer E, Lipp M, Bernhardt G
Department of Tumor and Immunogenetics, Max-Delbrück-Center for Molecular Medicine, Robert-Rössle Strasse 10, Berlin, 13092, Germany.
Virology. 2001 Jul 5;285(2):218-27. doi: 10.1006/viro.2001.0943.
The human receptor for poliovirus (CD155) is an immunoglobulin-like molecule with unknown normal function(s). Here we provide evidence that CD155 binds specifically to vitronectin with a dissociation constant (K(d)) of 72 nM as determined by surface plasmon resonance. Based on sequence homology to the CD155 gene, three poliovirus receptor-related genes (PRR1, PRR2, and PRR3) were cloned recently. PRR proteins were reported by others to mediate homophilic cell adhesion. Neither PRR1 nor PRR2 binds poliovirus and it is assumed that their physiological functions differ from that of CD155. Indeed, mPRR2 was found to bind to vitronectin only weakly, while its self-adhesion activity is characterized by a K(d) of 310 nM. Moreover, there is no evidence for CD155 self-adhesion. Both CD155 and vitronectin colocalize to follicular dendritic cells and B cells inside the germinal centers of secondary lymphoid tissue (tonsils)-an observation suggesting that the CD155/vitronectin interaction is required for the establishment of a proper immune response in this particular context.
脊髓灰质炎病毒的人类受体（CD155）是一种免疫球蛋白样分子，其正常功能未知。在此，我们提供证据表明，通过表面等离子体共振测定，CD155与玻连蛋白特异性结合，解离常数（K(d)）为72 nM。基于与CD155基因的序列同源性，最近克隆了三个脊髓灰质炎病毒受体相关基因（PRR1、PRR2和PRR3）。其他人报道PRR蛋白介导同种型细胞黏附。PRR1和PRR2均不结合脊髓灰质炎病毒，推测它们的生理功能与CD155不同。实际上，发现mPRR2仅微弱结合玻连蛋白，而其自身黏附活性的特征是K(d)为310 nM。此外，没有证据表明CD155存在自身黏附。CD155和玻连蛋白在二级淋巴组织（扁桃体）生发中心内的滤泡树突状细胞和B细胞中共定位——这一观察结果表明，在这种特定情况下，CD155/玻连蛋白相互作用对于建立适当的免疫反应是必需的。
