Enhanced Immunogenicity and Protective Effects against SARS-CoV-2 Following Immunization with a Recombinant RBD-IgG Chimeric Protein

Autor: Mariângela de Oliveira Silva, Maria Fernanda Castro-Amarante, Alexia Adrianne Venceslau-Carvalho, Bianca da Silva Almeida, Isabela Pazotti Daher, Guilherme Antonio de Souza-Silva, Marcio Massao Yamamoto, Gabriela Koike, Edmarcia Elisa de Souza, Carsten Wrenger, Luís Carlos de Souza Ferreira, Silvia Beatriz Boscardin
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Vaccines, Vol 12, Iss 4, p 356 (2024)
Druh dokumentu: article
ISSN: 2076-393X
DOI: 10.3390/vaccines12040356
Popis: The unprecedented global impact caused by SARS-CoV-2 imposed huge health and economic challenges, highlighting the urgent need for safe and effective vaccines. The receptor-binding domain (RBD) of SARS-CoV-2 is the major target for neutralizing antibodies and for vaccine formulations. Nonetheless, the low immunogenicity of the RBD requires the use of alternative strategies to enhance its immunological properties. Here, we evaluated the use of a subunit vaccine antigen generated after the genetic fusing of the RBD with a mouse IgG antibody. Subcutaneous administration of RBD-IgG led to the extended presence of the protein in the blood of immunized animals and enhanced RBD-specific IgG titers. Furthermore, RBD-IgG immunized mice elicited increased virus neutralizing antibody titers, measured both with pseudoviruses and with live original (Wuhan) SARS-CoV-2. Immunized K18-hACE2 mice were fully resistant to the lethal challenge of the Wuhan SARS-CoV-2, demonstrated by the control of body-weight loss and virus loads in their lungs and brains. Thus, we conclude that the genetic fusion of the RBD with an IgG molecule enhanced the immunogenicity of the antigen and the generation of virus-neutralizing antibodies, supporting the use of IgG chimeric antigens as an approach to improve the performance of SARS-CoV-2 subunit vaccines.
Databáze: Directory of Open Access Journals