Hevesi Zsofia, Gerges Daniela Anna, Kapps Sebastian, Freire Raimundo, Schmidt Sophie, Pollak Daniela D, Schmetterer Klaus, Frey Tobias, Lang Rita, Winnicki Wolfgang, Schmidt Alice, Harkany Tibor, Wagner Ludwig
Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, 1090 Vienna, Austria.
Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, 1090 Vienna, Austria.
Vaccines (Basel). 2022 Mar 26;10(4):516. doi: 10.3390/vaccines10040516.
First-generation vaccines against SARS-CoV-2 do not provide adequate immune protection. Therefore, we engineered a divalent gene construct combining the receptor-binding domain (RBD) of the spike protein and the immunodominant region of the viral nucleocapsid. This fusion protein was produced in either or a recombinant baculovirus system. Subsequently, the fusion protein was mixed with adjuvant and administered to mice in a prime-booster mode. Mice (72%) produced an IgG response against both proteins (titer: 10-10) 14 days after the first booster injection, which was increased to 100% by a second booster. Comparable IgG responses were detected against the delta, gamma and omicron variants of the RBD region. Durability testing revealed IgGs beyond 90 days. In addition, cytolytic effector cell molecules were increased in lymphocytes isolated from peripheral blood. Ex vivo stimulation of T cells by nucleocapsid and RBD peptides showed antigen-specific upregulation of CD44 among the CD4 and CD8 T cells of vaccinated mice. No side effect was documented in the central nervous system. Cumulatively, these data represent a proof-of-principle approach alternative to existing mRNA vaccination strategies.
第一代抗SARS-CoV-2疫苗不能提供足够的免疫保护。因此，我们构建了一种二价基因构建体，它结合了刺突蛋白的受体结合域（RBD）和病毒核衣壳的免疫显性区域。这种融合蛋白是在大肠杆菌或重组杆状病毒系统中产生的。随后，将融合蛋白与佐剂混合，并以初免-加强模式给小鼠接种。在首次加强注射后14天，小鼠（72%）产生了针对这两种蛋白的IgG反应（滴度：10-10），第二次加强后这一比例增加到100%。针对RBD区域的Delta、Gamma和Omicron变体检测到了类似的IgG反应。耐久性测试显示IgG水平在90天以上。此外，从外周血分离的淋巴细胞中细胞溶解效应细胞分子增加。用核衣壳和RBD肽对T细胞进行体外刺激显示，在接种疫苗小鼠的CD-4和CD-8 T细胞中，CD44出现了抗原特异性上调。中枢神经系统未记录到副作用。总的来说，这些数据代表了一种不同于现有mRNA疫苗接种策略的原理验证方法。
