GSK, Via Fiorentina 1, 53100 Siena, Italy.
GSK, 14200 Shady Grove Rd, Rockville, MD 20850, USA.
Int J Mol Sci. 2023 Mar 24;24(7):6183. doi: 10.3390/ijms24076183.
The presentation of viral antigens on nanoparticles in multivalent arrays has emerged as a valuable technology for vaccines. On the nanoparticle surface, highly ordered, repetitive arrays of antigens can mimic their geometric arrangement on virion surfaces and elicit stronger humoral responses than soluble viral antigens. More recently, bacterial antigens have been presented on self-assembling protein nanoparticles and have elicited protective antibody and effective T-helper responses, further supporting the nanoparticle platform as a universal approach for stimulating potent immunogenicity. Here, we present the rational design, structural analysis, and immunogenicity of self-assembling ferritin nanoparticles displaying eight copies of the trimeric adhesin NadA. We engineered constructs consisting of two different NadA fragments, head only and head with stalk, that we fused to ferritin and expressed in . Both fusion constructs self-assembled into the expected nanoparticles as determined by Cryo electron microscopy. In mice, the two nanoparticles elicited comparable NadA antibody levels that were 10- to 100-fold higher than those elicited by the corresponding NadA trimer subunits. Further, the NadAferritin nanoparticles potently induced complement-mediated serum bactericidal activity. These findings confirm the value of self-assembling nanoparticles for optimizing the immunogenicity of bacterial antigens and support the broad applicability of the approach to vaccine programs, especially for the presentation of trimeric antigens.
纳米粒子多价阵列上病毒抗原的呈现已成为疫苗的一种有价值的技术。在纳米粒子表面上，高度有序、重复的抗原阵列可以模拟其在病毒粒子表面上的几何排列，并引发比可溶性病毒抗原更强的体液反应。最近，细菌抗原已被呈现在自组装蛋白纳米粒子上，并引发了保护性抗体和有效的 T 辅助反应，进一步支持纳米粒子平台作为刺激有效免疫原性的通用方法。在这里，我们介绍了展示三聚体粘附素 NadA 八个拷贝的自组装铁蛋白纳米粒子的合理设计、结构分析和免疫原性。我们设计了由两个不同的 NadA 片段组成的构建体，仅头部和带有茎部的头部，我们将其融合到铁蛋白中，并在 中表达。两种融合构建体都自组装成预期的纳米粒子，这是通过低温电子显微镜确定的。在小鼠中，两种纳米粒子引发的 NadA 抗体水平相当，比相应的 NadA 三聚体亚基引发的水平高 10-100 倍。此外，NadA-铁蛋白纳米粒子有力地诱导了补体介导的血清杀菌活性。这些发现证实了自组装纳米粒子在优化细菌抗原免疫原性方面的价值，并支持该方法在疫苗计划中的广泛适用性，特别是对于三聚体抗原的呈现。
