A human cell line selected for resistance to adenovirus infection has reduced levels of the virus receptor
A human cell line selected for resistance to adenovirus infection has reduced levels of the virus receptor
复制标题
DOI：
10.1128/jvi.70.6.4081-4085.1996
复制
发表时间：
1996-06
影响因子：
5.4
通讯作者：
P. Freimuth
中科院分区：
文献类型：
--
作者：
P. Freimuth
为了研究宿主细胞对感染的易感性的决定因素，从罕见的细胞中选择了部分抵抗感染的细胞，这些细胞在用 Ad2RAE 感染 A549 细胞培养物后仍保持贴壁，Ad2RAE 是 2 型腺病毒的突变体，其顶点壳粒缺乏介导野生型病毒与整合素结合的 Arg-Gly-Asp (RGD) 序列。整合素促进附着的病毒粒子的内化，而吸附本身是病毒纤维与未知细胞受体结合的结果。经过三轮选择后，建立了持续感染的培养物，其中约 5% 的细胞中检测到病毒复制。未感染的细胞很容易从培养物中克隆出来，这表明在任何特定时间培养物中的大多数细胞都未被感染。与亲本 A549 细胞系相比，未感染细胞的一个克隆对感染的抵抗力与这些细胞上纤维受体浓度降低 10 倍相关，表明病毒吸附效率取决于受体浓度。令人惊讶的是，宿主细胞内化 RGD 阴性病毒的速度也强烈依赖于纤维受体浓度。虽然整合素与五邻体碱基 RGD 序列的结合促进了野生型病毒的内化，但这些结果表明病毒也可以通过需要病毒粒子与多个纤维受体结合的替代途径进入细胞。
To investigate determinants of host cell susceptibility to infection, cells partially resistant to infection were selected from the rare cells which remained adherent after infection of a culture of A549 cells with Ad2RAE, a mutant of adenovirus type 2 whose vertex capsomers lack an Arg-Gly-Asp (RGD) sequence which mediates binding of wild-type virus to integrins. Integrins promote the internalization of attached virions, whereas adsorption itself results from binding of the viral fibers to an unidentified cellular receptor. Following three rounds of selection, a persistently infected culture was established in which virus replication was detected in approximately 5% of the cells. Uninfected cells were readily cloned from the culture, indicating that at any particular time the majority of cells in the culture were uninfected. The resistance of one clone of uninfected cells to infection was correlated with a 10-fold reduction in the concentration of fiber receptors on these cells compared with the parental A549 cell line, indicating that efficiency of virus adsorption depends on the receptor concentration. Surprisingly, the rate at which host cells internalized RGD-negative virus also was strongly dependent on the fiber receptor concentration. While internalization of wild-type virus is promoted by the binding of integrins to the penton base RGD sequence, these results suggest that virus also can enter cells by an alternate pathway which requires binding of virions to multiple fiber receptors.