Transcriptional responses of T cells activated via CD22-specific T cell receptor compared to CD22-specific chimeric antigen receptor

Chimeric antigen receptor (CAR) T cells are effective against B-cell malignancies but are associated with cytokine-driven inflammatory toxicities such as cytokine release syndrome (CRS). Historically, T cell receptor (TCR) engineered T cell therapies are rarely associated with CRS. However, it is challenging to compare diverse cell products utilized in different clinical contexts and against different antigens. In this study, TCR and CAR were made to target the same source of antigen, CD22, expressed by B-cell malignancies: the TCR recognizes CD22-derived peptide processed and presented in the context of HLA-A*02:01, and the CAR recognizes CD22 protein expressed on the cell surface. In vivo studies comparing the CD22 TCR-T cells to CD22 CAR-T cells demonstrated that the TCR-T cells could clear leukemia without inducing systemic proinflammatory cytokine elevation, whereas CD22 CAR-T cells induced high levels of circulating proinflammatory cytokine reminiscent of CRS. T cells activated through either the TCR or CAR by an identical leukemia cell line demonstrated differential transcriptional responses. T cells activated via the CAR had disproportionate and significant upregulation of inflammatory gene sets compared to T-cells activated via the TCR.