Bruun Theodora U J, Do Jonathan, Weidenbacher Payton A-B, Utz Ashley, Kim Peter S
Sarafan ChEM-H, Stanford University, Stanford, California 94305, United States.
Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305, United States.
ACS Cent Sci. 2024 Sep 17;10(10):1871-1884. doi: 10.1021/acscentsci.4c00722. eCollection 2024 Oct 23.
The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is the main target of neutralizing antibodies. Although they are infrequently elicited during infection or vaccination, antibodies that bind to the conformation-specific cryptic face of the RBD display remarkable breadth of binding and neutralization across . Here, we employed the immunofocusing technique PMD (protect, modify, deprotect) to create RBD immunogens (PMD-RBD) specifically designed to focus the antibody response toward the cryptic-face epitope recognized by the broadly neutralizing antibody S2X259. Immunization with PMD-RBD antigens induced robust binding titers and broad neutralizing activity against homologous and heterologous strains. A serum-depletion assay provided direct evidence that PMD successfully skewed the polyclonal antibody response toward the cryptic face of the RBD. Our work demonstrates the ability of PMD to overcome immunodominance and refocus humoral immunity, with implications for the development of broader and more resilient vaccines against current and emerging viruses with pandemic potential.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白的受体结合域（RBD）是中和抗体的主要靶点。尽管在感染或疫苗接种过程中很少产生，但结合RBD构象特异性隐蔽面的抗体在 范围内显示出显著的结合广度和中和能力。在这里，我们采用免疫聚焦技术PMD（保护、修饰、去保护）来创建RBD免疫原（PMD-RBD），其专门设计用于使抗体反应聚焦于被广泛中和抗体S2X259识别的隐蔽面表位。用PMD-RBD抗原免疫可诱导产生针对同源和异源 毒株的强大结合效价和广泛中和活性。血清去除试验提供了直接证据，表明PMD成功地使多克隆抗体反应偏向RBD的隐蔽面。我们的工作证明了PMD克服免疫优势和重新聚焦体液免疫的能力，这对开发针对具有大流行潜力的当前和新出现病毒的更广泛、更具弹性的疫苗具有重要意义。
