Summary

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in clinical patients remains unexplored. Here, we longitudinally profiled the transcriptomes of 55,488 T cells including CAR-T products, CAR-T cells, and endogenous T cells at the peak and remission phases in a plasma cell leukemia (PCL) patient treated with BCMA CAR-T cells by single-cell transcriptomic analysis. Our results showed distinct CAR-T and endogenous T cell subsets indicating stage-specific expression in proliferation, cytotoxicity, and intercellular signaling pathways. Furthermore, we found that CAR-T cells at peak phase gradually convert to a highly cytotoxic state from a highly proliferative state along a development trajectory. Moreover, re-analysis of a single cell study from CD8+ CD19 CAR-T confirmed our findings. These commonalities suggest conserved mechanisms for CAR-T treatment across hematological malignancies. Taken together, our current study provides insight into CAR-T cell dynamics during CAR-T therapy and proves that both BCMA CAR-T and CD19 CAR-T have similar transcriptional characteristics, especially at the CAR-T peak phase.

Overall design

Single-cell RNA sequencing samples were collected at three phases: CAR-T products before infusion, CAR-T on day 8 after infusion, and CAR-T on day 15 after infusion. After obtaining the PBMCs for each phase, CAR-T and endogenous T cells were collected by fluorescence-activated cell sorting with anti-Mouse IgG Biotin, FITC Streptavidin, and anti-human CD3 APC.

Contributors

Xue Li 1, Xin Guo 1, Yuqing Zhu 2, Guoqing Wei 3, Yanlei Zhang 4, Xia Li 1, Huijun Xu 1, Jiazhen Cui 1, Wenjun Wu 3, Jingsong He 3, Matthew E Ritchie 5, Taylor M Weiskittel 6, Hu Li 6, Hua Yu 2, Lijuan Ding 1, Mi Shao 1, Qian Luo 1, Xiaoxiao Xu 1, Xinyi Teng 1, Alex H Chang 4, Jin Zhang 7, He Huang 8, Yongxian Hu 9

Contact

1313016@zju.edu.cn.(Yongxian Hu)