Abstract
Coronavirus disease 2019 (COVID-19) vaccination programs rolled out in an attempt to stop the COVID-19 pandemic. Besides neutralising antibodies, effective T cell responses are also crucial for protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19 disease severity. To assess SARS-CoV-2-specific T cell immunity, we developed an interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISpot) that can be deployed in research and diagnostic settings. We optimised our ELISpot by testing multiple antigen concentrations to stimulate peripheral blood mononuclear cells of SARS-CoV-2-unexposed, COVID-19 convalescent and COVID-19 vaccinated volunteers. Also, we developed an ELISpot plate reader-free method to detect and quantify spots, which we compared to manual spot counting and automated analysis by an ELISpot plate reader. We observed strong SARS-CoV-2-reactive T cell responses in COVID-19 convalescent, and COVID-19 vaccinated volunteers but absent or only weak responses in unexposed volunteers. Overall, antigens with concentrations from 0.1 to 5.0 μg/mL per peptide elicited similar T cell responses. Also, our plate reader-free detection method reliably detected and quantified SARS-CoV-2-specific T cells, demonstrated by an excellent reliability when compared to manual analysis and automated analysis by an ELISpot plate reader.
Keywords: COVID-19; Diagnostic; ELISpot; SARS-CoV-2; T cells.
【저자키워드】 COVID-19, SARS-CoV-2, T cells, diagnostic, ELISPOT, 【초록키워드】 coronavirus disease, Coronavirus disease 2019, coronavirus, vaccination, Immunity, reliability, T cells, COVID-19 pandemic, Neutralising Antibodies, Infection, peptide, severe acute respiratory syndrome Coronavirus, Antigen, COVID-19 disease, Peripheral blood, T cell, response, T cell responses, Research, Peripheral blood mononuclear cells, antigens, automated, ELISPOT, respiratory, convalescent, volunteers, T cell response, SARS-CoV-2-specific T cells, IFN-γ, Interferon-gamma, Concentration, Analysis, mononuclear cells, mononuclear cell, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, enzyme, enzyme-linked immunospot, COVID-19 disease severity, Volunteer, effective, plate reader, detect, demonstrated, elicited, stimulate, quantified, multiple antigen, 【제목키워드】 development,