Hypocrates is a genetically encoded fluorescent biosensor for (pseudo)hypohalous acids and their derivatives

January 18, 2022

Title

Hypocrates is a genetically encoded fluorescent biosensor for (pseudo)hypohalous acids and their derivatives

Author

Alexander I. Kostyuk, Maria-Armineh Tossounian, Anastasiya S. Panova, Marion Thauvin, Roman I. Raevskii, Daria Ezerina, Khadija Wahni, Inge Van Molle, Anastasia D. Sergeeva, Didier Vertommen, Andrey Yu. Gorokhovatsky, Mikhail S. Baranov, Sophie Vritz, Joris Messens, Dmitry S. Bilan & Vsevolod V. Belousov

Year

2022

Journal

Nature Communications

Abstract

The receptor binding domain (RBD) of the Spike protein from SARS-CoV-2 is a promising candidate to develop effective COVID-19 vaccines since it can induce potent neutralizing antibodies. We have previously reported the highly efficient production of RBD in Pichia pastoris, which is structurally similar to the same protein produced in mammalian HEK-293T cells. In this work we designed an RBD multimer with the purpose of increasing its immunogenicity. We produced multimeric particles by a transpeptidation reaction between RBD expressed in P. pastoris and Lumazine Synthase from Brucella abortus (BLS), which is a highly immunogenic and very stable decameric 170 kDa protein. Such particles were used to vaccinate mice with two doses 30 days apart. When the particles ratio of RBD to BLS units was high (6–7 RBD molecules per BLS decamer in average), the humoral immune response was significantly higher than that elicited by RBD alone or by RBD-BLS particles with a lower RBD to BLS ratio (1–2 RBD molecules per BLS decamer). Remarkably, multimeric particles with a high number of RBD copies elicited a high titer of neutralizing IgGs. These results indicate that multimeric particles composed of RBD covalent coupled to BLS possess an advantageous architecture for antigen presentation to the immune system, and therefore enhancing RBD immunogenicity. Thus, multimeric RBD-BLS particles are promising candidates for a protein-based vaccine.

Instrument

J-715

Keywords

COVID-19, RBD, protein-based vaccine