Rapid, scalable assessment of SARS-CoV-2 cellular immunity by whole-blood PCR

• Published in: Nature biotechnology 2022-11, Vol.40 (11), p.1680-1689
• Main Authors: Schwarz, Megan, Torre, Denis, Lozano-Ojalvo, Daniel, Tan, Anthony T., Tabaglio, Tommaso, Mzoughi, Slim, Sanchez-Tarjuelo, Rodrigo, Le Bert, Nina, Lim, Joey Ming Er, Hatem, Sandra, Tuballes, Kevin, Camara, Carmen, Lopez-Granados, Eduardo, Paz-Artal, Estela, Correa-Rocha, Rafael, Ortiz, Alberto, Lopez-Hoyos, Marcos, Portoles, Jose, Cervera, Isabel, Gonzalez-Perez, Maria, Bodega-Mayor, Irene, Conde, Patricia, Oteo-Iglesias, Jesús, Borobia, Alberto M., Carcas, Antonio J., Frías, Jesús, Belda-Iniesta, Cristóbal, Ho, Jessica S. Y., Nunez, Kemuel, Hekmaty, Saboor, Mohammed, Kevin, Marsiglia, William M., Carreño, Juan Manuel, Dar, Arvin C., Berin, Cecilia, Nicoletti, Giuseppe, Della Noce, Isabella, Colombo, Lorenzo, Lapucci, Cristina, Santoro, Graziano, Ferrari, Maurizio, Nie, Kai, Patel, Manishkumar, Barcessat, Vanessa, Gnjatic, Sacha, Harris, Jocelyn, Sebra, Robert, Merad, Miriam, Krammer, Florian, Kim-schulze, Seunghee, Marazzi, Ivan, Bertoletti, Antonio, Ochando, Jordi, Guccione, Ernesto
• Format: Article
• Language: English
• Subjects: 631/250/2152/1566; 631/337/2019; 631/61/24; 692/53/2421; 692/700/139; Agriculture; Bioinformatics; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biomedicine; Biotechnology; COVID-19; Humans; Immunity, Cellular; Life Sciences; Polymerase Chain Reaction; SARS-CoV-2 - genetics; T-Lymphocytes
• ISSN: 1087-0156; 1546-1696; 1546-1696
• DOI: 10.1038/s41587-022-01347-6

Fast, high-throughput methods for measuring the level and duration of protective immune responses to SARS-CoV-2 are needed to anticipate the risk of breakthrough infections. Here we report the development of two quantitative PCR assays for SARS-CoV-2-specific T cell activation. The assays are rapid, internally normalized and probe-based: qTACT requires RNA extraction and dqTACT avoids sample preparation steps. Both assays rely on the quantification of CXCL10 messenger RNA, a chemokine whose expression is strongly correlated with activation of antigen-specific T cells. On restimulation of whole-blood cells with SARS-CoV-2 viral antigens, viral-specific T cells secrete IFN-γ, which stimulates monocytes to produce CXCL10 . CXCL10 mRNA can thus serve as a proxy to quantify cellular immunity. Our assays may allow large-scale monitoring of the magnitude and duration of functional T cell immunity to SARS-CoV-2, thus helping to prioritize revaccination strategies in vulnerable populations. The T cell response to SARS-CoV-2 is detected by a PCR assay on whole blood.