Harber J, Bernhardt G, Lu H H, Sgro J Y, Wimmer E
Department of Molecular Genetics and Microbiology, State University of New York, Stony Brook 11794-5222, USA.
Virology. 1995 Dec 20;214(2):559-70. doi: 10.1006/viro.1995.0067.
Several mouse cell lines expressing hybrid human poliovirus receptors (hPVRs) bearing mutations in the first immunoglobulin-like domain were previously characterized for their defective binding and replication of poliovirus type 1 Mahoney (G. Bernhardt, J. Harber, A. Zibert, M. DeCrombrugghe, and E. Wimmer, Virology, 203, 344-356, 1994). Here we report that these mutant hPVRs were utilized to explore differences in the binding behavior of the three serotypes of poliovirus. Type 3 polioviruses (both Sabin and the neurovirulent Leon strain) clearly bound to the hPVR mutant Q130G/GD, but were incapable of initiating infection. Also, binding at 25 degrees of poliovirus types 2 and 3 to cell lines expressing the hPVR mutants P84SYS/HPGA, L99GAE/AAAA, and D117F was greater than type 1 poliovirus. Further study of the serotype-specific interaction with mutant hPVRs was accomplished with antigenic hybrid viruses. Improved binding by antigenic hybrid viruses demonstrated that serotype-specific binding to mutant hPVRs is, in part, determined by the amino acid sequence of neutralization antigenic sites (NAgs) and the probable conformational rearrangement of amino acids adjacent to the NAg sites. Finally, site-directed mutants of poliovirus were utilized to determine the relative contributions, to hPVR interactions, of individual amino acids with solvent accessible side chains in the viral canyon. Of the 18 viable virus mutants produced, 3 (D1226A, I1089A, and VPEK1166HPGA) expressed impaired replication phenotypes on the mutant hPVR cell lines P84SYS/HYSA and D117F. A location at the rim of the poliovirus canyon was implicated for the interaction of the amino terminal domain of the poliovirus receptor with conserved and serotype-specific viral surface amino acids. The possible involvement of elements of neutralization antigenic sites in receptor binding may explain, in part, why poliovirus exists in only three serotypes.
先前已对几种表达在第一个免疫球蛋白样结构域带有突变的人源脊髓灰质炎病毒受体（hPVR）的小鼠细胞系进行了表征，它们对1型马奥尼脊髓灰质炎病毒的结合和复制存在缺陷（G. 伯恩哈特、J. 哈伯、A. 齐伯特、M. 德克伦布吕赫和E. 维默，《病毒学》，203卷，344 - 356页，1994年）。在此我们报告，利用这些突变的hPVR来探究三种血清型脊髓灰质炎病毒结合行为的差异。3型脊髓灰质炎病毒（无论是萨宾株还是神经毒性的莱昂株）能明显结合hPVR突变体Q130G/GD，但无法引发感染。此外，2型和3型脊髓灰质炎病毒在25摄氏度时与表达hPVR突变体P84SYS/HPGA、L99GAE/AAAA和D117F的细胞系的结合能力强于1型脊髓灰质炎病毒。通过抗原性杂交病毒对与突变hPVR的血清型特异性相互作用进行了进一步研究。抗原性杂交病毒结合能力的提高表明，与突变hPVR的血清型特异性结合部分取决于中和抗原位点（NAgs）的氨基酸序列以及NAg位点附近氨基酸可能的构象重排。最后，利用脊髓灰质炎病毒的定点突变体来确定病毒峡谷中具有溶剂可及侧链的单个氨基酸对hPVR相互作用的相对贡献。在产生的18个活病毒突变体中，有3个（D1226A、I1089A和VPEK1166HPGA）在突变hPVR细胞系P84SYS/HYSA和D117F上表现出复制表型受损。脊髓灰质炎病毒峡谷边缘的一个位置与脊髓灰质炎病毒受体的氨基末端结构域与保守的和血清型特异性的病毒表面氨基酸的相互作用有关。中和抗原位点的元件可能参与受体结合，这在一定程度上可以解释为什么脊髓灰质炎病毒仅存在三种血清型。
