B-Cell Epitopes-Based Chimeric Protein from SARS-CoV-2 N and S Proteins Is Recognized by Specific Antibodies in Serum and Urine Samples from Patients

Fernanda F Ramos; Isabela A G Pereira; Mariana M Cardoso; Raquel S Bandeira; Daniela P Lage; Rahisa Scussel; Rafaela S Anastacio; Victor G Freire; Marina F N Melo; Joao A Oliveira-da-Silva; Vivian T Martins; Grasiele S V Tavares; Danniele L Vale; Camila S Freitas; Ana Thereza Chaves; Júlia F M Caporali; Paula F Vassallo; Cecilia G Ravetti; Vandack Nobre; Flavio G Fonseca; Myron Christodoulides; Ricardo A Machado-de-Ávila; Eduardo A F Coelho; Fernanda Ludolf

doi:10.3390/v15091877

B-Cell Epitopes-Based Chimeric Protein from SARS-CoV-2 N and S Proteins Is Recognized by Specific Antibodies in Serum and Urine Samples from Patients

Viruses. 2023 Sep 5;15(9):1877. doi: 10.3390/v15091877.

Authors

Fernanda F Ramos¹, Isabela A G Pereira¹, Mariana M Cardoso¹, Raquel S Bandeira¹, Daniela P Lage¹, Rahisa Scussel², Rafaela S Anastacio², Victor G Freire², Marina F N Melo¹, Joao A Oliveira-da-Silva¹, Vivian T Martins¹, Grasiele S V Tavares¹, Danniele L Vale¹, Camila S Freitas¹, Ana Thereza Chaves¹, Júlia F M Caporali^{1

3}, Paula F Vassallo³, Cecilia G Ravetti³, Vandack Nobre^{1

3}, Flavio G Fonseca^{4

5}, Myron Christodoulides⁶, Ricardo A Machado-de-Ávila², Eduardo A F Coelho^{1

7}, Fernanda Ludolf^{1

8}

Affiliations

¹ Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte 30130-100, Minas Gerais, Brazil.
² Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma 88806-000, Santa Catarina, Brazil.
³ Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte 30130-100, Minas Gerais, Brazil.
⁴ Centro de Tecnologia de Vacinas (CT Vacinas), BH-Tec, UFMG, Belo Horizonte 31270-901, Minas Gerais, Brazil.
⁵ Laboratório de Virologia Molecular e Aplicada, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
⁶ Neisseria Research Group, Molecular Microbiology, School of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton SO16 6YD, UK.
⁷ Departamento de Patologia Clínica, COLTEC, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
⁸ Programa de Pós-Graduação em Ciências da Saúde, Faculdade Ciências Médicas de Minas Gerais, Belo Horizonte 30130-110, Minas Gerais, Brazil.

Abstract

The impact of the COVID-19 pandemic caused by the SARS-CoV-2 virus underscored the crucial role of laboratorial tests as a strategy to control the disease, mainly to indicate the presence of specific antibodies in human samples from infected patients. Therefore, suitable recombinant antigens are relevant for the development of reliable tests, and so far, single recombinant proteins have been used. In this context, B-cell epitopes-based chimeric proteins can be an alternative to obtain tests with high accuracy through easier and cheaper production. The present study used bioinformatics tools to select specific B-cell epitopes from the spike (S) and the nucleocapsid (N) proteins from the SARS-CoV-2 virus, aiming to produce a novel recombinant chimeric antigen (N4S11-SC2). Eleven S and four N-derived B-cell epitopes were predicted and used to construct the N4S11-SC2 protein, which was analyzed in a recombinant format against serum and urine samples, by means of an in house-ELISA. Specific antibodies were detected in the serum and urine samples of COVID-19 patients, which were previously confirmed by qRT-PCR. Results showed that N4S11-SC2 presented 83.7% sensitivity and 100% specificity when using sera samples, and 91.1% sensitivity and 100% specificity using urine samples. Comparable findings were achieved with paired urine samples when compared to N and S recombinant proteins expressed in prokaryotic systems. However, better results were reached for N4S11-SC2 in comparison to the S recombinant protein when using paired serum samples. Anti-N4S11-SC2 antibodies were not clearly identified in Janssen Ad26.COV2.S COVID-19-vaccinated subjects, using serum or paired urine samples. In conclusion, this study presents a new chimeric recombinant antigen expressed in a prokaryotic system that could be considered as an alternative diagnostic marker for the SARS-CoV-2 infection, with the potential benefits to be used on serum or urine from infected patients.

Keywords: B-cell epitopes; SARS-CoV-2; chimeric protein; diagnosis; serum; urine.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ad26COVS1
COVID-19* / diagnosis
Epitopes, B-Lymphocyte
Humans
Pandemics
Recombinant Fusion Proteins / genetics
Recombinant Proteins / genetics
SARS-CoV-2* / genetics

Substances

Epitopes, B-Lymphocyte
Ad26COVS1
Recombinant Proteins
Recombinant Fusion Proteins

Grants and funding

This work was supported by Secretaria de Educação Superior do Ministério da Educação (SESU/MEC), grant 04/2020, Enfrentamento da COVID-19 (to V.N.); Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG), grant APQ-02167-21 (to E.A.F.C.); and Brazilian agencies Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and CNPq fellowships/scholarships (to F.L., F.F.R., I.A.G.P., M.M.C., R.S.B., D.P.L., R.S., R.S.A., V.G.F., M.F.N.M., V.T.M., G.S.V.T., D.L.V., C.S.F., A.T.C., J.F.M.C. and P.F.V.).