Abstract
Background: Rapid tests to evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cell responses are urgently needed to decipher protective immunity and aid monitoring vaccine-induced immunity.
Methods: Using a rapid whole blood assay requiring a minimal amount of blood, we measured qualitatively and quantitatively SARS-CoV-2-specific CD4 T-cell responses in 31 healthcare workers using flow cytometry.
Results: 100% of COVID-19 convalescent participants displayed a detectable SARS-CoV-2-specific CD4 T-cell response. SARS-CoV-2-responding cells were also detected in 40.9% of participants with no COVID-19-associated symptoms or who tested PCR-negative. Phenotypic assessment indicated that, in COVID-19 convalescent participants, SARS-CoV-2 CD4 responses displayed an early differentiated memory phenotype with limited capacity to produce interferon (IFN)-γ. Conversely, in participants with no reported symptoms, SARS-CoV-2 CD4 responses were enriched in late differentiated cells, coexpressing IFN-γ and tumour necrosis factor-α and also Granzyme B.
Conclusions: This proof-of-concept study presents a scalable alternative to peripheral blood mononuclear cell-based assays to enumerate and phenotype SARS-CoV-2-responding T-cells, thus representing a practical tool to monitor adaptive immunity due to natural infection or vaccine trials.
【초록키워드】 COVID-19, SARS-CoV-2, Necrosis, Adaptive immunity, Vaccine, coronavirus, adaptive, Immunity, T-cell Response, T-cells, interferon, Symptom, severe acute respiratory syndrome Coronavirus, CD4, healthcare worker, flow cytometry, memory, Peripheral blood, Whole blood, cells, protective immunity, response, Rapid, phenotype, respiratory, convalescent, natural infection, trials, Blood, T-cell responses, Rapid tests, IFN-γ, Vaccine-induced immunity, acute respiratory syndrome, Participants, Differentiated cells, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, participant, PCR-negative, MONITOR, granzyme, reported symptoms, tumour necrosis factor, Cell, CD4 T-cell, tumour necrosis factor-α, tested, evaluate, indicated, detectable, representing, 【제목키워드】 Rapid, phenotype, T-cell,