Effective chimeric antigen receptor T cells against SARS-CoV-2.

Current therapies to treat coronavirus disease 2019 (COVID-19) involve vaccines against the spike protein S1 of SARS-CoV-2. Here, we outline an alternative approach involving chimeric antigen receptors (CARs) in T cells (CAR-Ts). CAR-T recognition of the SARS-CoV-2 receptor-binding domain (RBD) peptide induced ribosomal protein S6 phosphorylation, the increased expression of activation antigen, CD69 and effectors, interferon-γ, granzyme B, perforin, and Fas-ligand on overlapping subsets of CAR-Ts. CAR-Ts further showed potent killing of target cells loaded with RBD, S1 peptide, or expressing the S1 protein. The efficacy of killing varied with different sized hinge regions, whereas time-lapse microscopy showed CAR-T cluster formation around RBD-expressing targets. Cytolysis of targets was mediated primarily by the GZMB/perforin pathway. Lastly, we showed killing of S1-expressing cells by our SARS-CoV-2 CAR-Ts in mice. The successful generation of SARS-CoV-2 CAR-Ts represents a living vaccine approach for the treatment of COVID-19.