Bacillus subtilis spores displaying RBD domain of SARS-CoV-2 spike protein

Bacillus subtilis spores are considered to be efficient and useful vehicles for the surface display and delivery of heterologous proteins. In this study, we prepared recombinant spores with the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein displayed on their surface in fusion with the CotZ or CotY spore coat proteins as a possible tool for the development of an oral vaccine against the SARS-CoV-2 virus. The RBD was attached to the N-terminus or C-terminus of the coat proteins. We also directly adsorbed non-recombinantly produced RBD to the spore surface. SDS-PAGE, western blot and fluorescence microscopy were used to analyze RBD surface expression on purified spores. Results obtained from both display sys-tems, recombinant and non-recombinant, demonstrated that RBD was present on the spore surfaces.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of Research Network of Computational and Structural Biotechnology. This is an open access article under the CC BY-NC-ND license (http://creative-commons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, recombinant spores displaying the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein on their surface were prepared as a possible tool for developing an oral vaccine against the SARS-CoV-2 virus. The RBD was attached to the spore coat proteins and its surface expression was confirmed using SDS-PAGE, western blot, and fluorescence microscopy.