Scientific and Educational Center, Molecular Bases of Interaction of Microorganisms and Human of the World-Class Research Center, Center for Personalized Medicine, FSBSI, IEM, 197376 Saint Petersburg, Russia.
Int J Mol Sci. 2023 Dec 22;25(1):215. doi: 10.3390/ijms25010215.
Following the conclusion of the COVID-19 pandemic, the persistent genetic variability in the virus and its ongoing circulation within the global population necessitate the enhancement of existing preventive vaccines and the development of novel ones. A while back, we engineered an orally administered probiotic-based vaccine, L3-SARS, by integrating a gene fragment that encodes the spike protein S of the SARS-CoV-2 virus into the genome of the probiotic strain L3, inducing the expression of viral antigen on the surface of bacteria. Previous studies demonstrated the efficacy of this vaccine candidate in providing protection against the virus in Syrian hamsters. In this present study, utilizing laboratory mice, we assess the immune response subsequent to immunization via the gastrointestinal mucosa and discuss its potential as an initial phase in a two-stage vaccination strategy. Our findings indicate that the oral administration of L3-SARS elicits an adaptive immune response in mice. Pre-immunization with L3-SARS enhances and prolongs the humoral immune response following a single subcutaneous immunization with a recombinant S-protein analogous to the S-insert of the coronavirus in L3.
随着 COVID-19 大流行的结束，病毒持续的遗传变异性及其在全球人群中的持续传播，需要增强现有的预防疫苗并开发新的疫苗。不久前，我们通过将编码 SARS-CoV-2 病毒刺突蛋白 S 的基因片段整合到益生菌菌株 L3 的基因组中，构建了一种口服益生菌疫苗 L3-SARS，从而诱导细菌表面表达病毒抗原。先前的研究表明，这种疫苗候选物在保护叙利亚仓鼠免受病毒感染方面具有功效。在本研究中，我们利用实验室小鼠评估了通过胃肠道黏膜免疫后的免疫反应，并讨论了其作为两阶段疫苗接种策略初始阶段的潜力。我们的研究结果表明，口服 L3-SARS 可在小鼠中引发适应性免疫反应。用 L3-SARS 进行预免疫可增强和延长单次皮下免疫重组 S 蛋白（类似于 L3 中的冠状病毒 S-插入物）后的体液免疫反应。
