Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
J Virol. 2024 Sep 17;98(9):e0079524. doi: 10.1128/jvi.00795-24. Epub 2024 Aug 29.
While investigating methods to target gene delivery vectors to specific cell types, we examined the potential of using a nanobody against the SARS-CoV-2 Spike protein receptor-binding domain to direct lentivirus infection of Spike-expressing cells. Using four different approaches, we found that lentiviruses with surface-exposed nanobody domains selectively infect Spike-expressing cells. Targeting is dependent on the fusion function of the Spike protein, and conforms to a model in which nanobody binding to the Spike protein triggers the Spike fusion machinery. The nanobody-Spike interaction also is capable of directing cell-cell fusion and the selective infection of nanobody-expressing cells by Spike-pseudotyped lentivirus vectors. Significantly, cells infected with SARS-CoV-2 are efficiently and selectively infected by lentivirus vectors pseudotyped with a chimeric nanobody protein. Our results suggest that cells infected by any virus that forms syncytia may be targeted for gene delivery by using an appropriate nanobody or virus receptor mimic. Vectors modified in this fashion may prove useful in the delivery of immunomodulators to infected foci to mitigate the effects of viral infections.IMPORTANCEWe have discovered that lentiviruses decorated on their surfaces with a nanobody against the SARS-CoV-2 Spike protein selectively infect Spike-expressing cells. Infection is dependent on the specificity of the nanobody and the fusion function of the Spike protein and conforms to a reverse fusion model, in which nanobody binding to Spike triggers the Spike fusion machinery. The nanobody-Spike interaction also can drive cell-cell fusion and infection of nanobody-expressing cells with viruses carrying the Spike protein. Importantly, cells infected with SARS-CoV-2 are selectively infected with nanobody-decorated lentiviruses. These results suggest that cells infected by any virus that expresses an active receptor-binding fusion protein may be targeted by vectors for delivery of cargoes to mitigate infections.
在研究针对特定细胞类型的基因传递载体的方法时，我们研究了使用针对 SARS-CoV-2 刺突蛋白受体结合域的纳米抗体来指导慢病毒感染表达刺突蛋白的细胞的潜力。通过四种不同的方法，我们发现表面暴露纳米抗体结构域的慢病毒选择性感染表达刺突蛋白的细胞。靶向作用取决于 Spike 蛋白的融合功能，符合纳米抗体与 Spike 蛋白结合触发 Spike 融合机制的模型。纳米抗体-Spike 相互作用还能够指导细胞-细胞融合和 Spike 假型慢病毒载体对表达纳米抗体的细胞的选择性感染。重要的是，用嵌合纳米抗体蛋白假型化的 SARS-CoV-2 感染细胞可被慢病毒载体有效且选择性地感染。我们的结果表明，任何形成合胞体的病毒感染的细胞都可以通过使用适当的纳米抗体或病毒受体模拟物来进行基因传递。以这种方式修饰的载体可能有助于将免疫调节剂递送到感染病灶，以减轻病毒感染的影响。
我们发现，用针对 SARS-CoV-2 刺突蛋白的纳米抗体修饰表面的慢病毒选择性感染表达刺突蛋白的细胞。感染依赖于纳米抗体的特异性和 Spike 蛋白的融合功能，并符合反向融合模型，其中纳米抗体与 Spike 的结合触发 Spike 融合机制。纳米抗体-Spike 相互作用还可以驱动细胞-细胞融合和表达 Spike 蛋白的病毒感染表达纳米抗体的细胞。重要的是，感染 SARS-CoV-2 的细胞可被纳米抗体修饰的慢病毒选择性感染。这些结果表明，任何表达活性受体结合融合蛋白的病毒感染的细胞都可以被载体靶向，以递送电镜来减轻感染。
