Evaluation of Nonviral piggyBac and lentiviral Vector in Functions of CD19chimeric Antigen Receptor T Cells and Their Antitumor Activity for CD19(+) Tumor Cells.

Nonviral transposon piggyBac (PB) and lentiviral (LV) vectors have been used to deliver chimeric antigen receptor (CAR) to T cells. To understand the differences in the effects of PB and LV on CAR T-cell functions, a CAR targeting CD19 was cloned into PB and LV vectors, and the resulting pbCAR and lvCAR were delivered to T cells to generate CD19pbCAR and CD19lvCAR T cells. Both CD19CAR T-cell types were strongly cytotoxic and secreted high IFN-γ levels when incubated with Raji cells. TNF-α increased in CD19pbCAR T cells, whereas IL-10 increased in CD19lvCAR T cells. CD19pbCAR and CD19lvCAR T cells showed similar strong anti-tumor activity in Raji cell-induced mouse models, slightly reducing mouse weight while enhancing mouse survival. High, but not low or moderate, concentrations of CD19pbCAR T cells significantly inhibited Raji cell-induced tumor growth in vivo. These CD19pbCAR T cells were distributed mostly in mesenteric lymph nodes, bone marrow of the femur, spleen, kidneys, and lungs, specifically accumulating at CD19-rich sites and CD19-positive tumors, with CAR copy number being increased on day 7. These results indicate that pbCAR has its specific activities and functions in pbCAR T cells, making it a valuable tool for CAR T-cell immunotherapy.

Lin Z ，Liu X ，Liu T ，Gao H ，Wang S ，Zhu X ，Rong L ，Cheng J ，Cai Z ，Xu F ，Tan X ，Lv L ，Li Z ，Sun Y ，Qian Q ... -  《Frontiers in Immunology》

Transferrin epitope-CD19-CAR-T cells effectively kill lymphoma cells in vitro and in vivo.

Valentine M ，Li L ，Zhou H ，Xu S ，Sun J ，Liu C ，Harto H ，Berahovich R ，Golubovskaya V ，Wu L ... -  《-》

PiggyBac Transposon-Mediated CD19 Chimeric Antigen Receptor-T Cells Derived From CD45RA-Positive Peripheral Blood Mononuclear Cells Possess Potent and Sustained Antileukemic Function.

The quality of chimeric antigen receptor (CAR)-T cell products, namely, memory and exhaustion markers, affects the long-term functionality of CAR-T cells. We previously reported that piggyBac (PB) transposon-mediated CD19 CAR-T cells exhibit a memory-rich phenotype that is characterized by the high proportion of CD45RA+/C-C chemokine receptor type 7 (CCR7)+ T-cell fraction. To further investigate the favorable phenotype of PB-CD19 CAR-T cells, we generated PB-CD19 CAR-T cells from CD45RA+ and CD45RA- peripheral blood mononuclear cells (PBMCs) (RA+ CAR and RA- CAR, respectively), and compared their phenotypes and antitumor activity. RA+ CAR-T cells showed better transient gene transfer efficiency 24 h after transduction and superior expansion capacity after 14 days of culture than those shown by RA- CAR-T cells. RA+ CAR-T cells exhibited dominant CD8 expression, decreased expression of the exhaustion marker programmed cell death protein-1 (PD-1) and T-cell senescence marker CD57, and enriched naïve/stem cell memory fraction, which are associated with the longevity of CAR-T cells. Transcriptome analysis showed that canonical exhaustion markers were downregulated in RA+ CAR-T, even after antigen stimulation. Although antigen stimulation could increase CAR expression, leading to tonic CAR signaling and exhaustion, the expression of CAR molecules on cell surface after antigen stimulation in RA+ CAR-T cells was controlled at a relatively lower level than that in RA- CAR-T cells. In the in vivo stress test, RA+ CAR-T cells achieved prolonged tumor control with expansion of CAR-T cells compared with RA- CAR-T cells. CAR-T cells were not detected in the control or RA- CAR-T cells but RA+ CAR-T cells were expanded even after 50 days of treatment, as confirmed by sequential bone marrow aspiration. Our results suggest that PB-mediated RA+ CAR-T cells exhibit a memory-rich phenotype and superior antitumor function, thus CD45RA+ PBMCs might be considered an efficient starting material for PB-CAR-T cell manufacturing. This novel approach will be beneficial for effective treatment of B cell malignancies.

Suematsu M ，Yagyu S ，Nagao N ，Kubota S ，Shimizu Y ，Tanaka M ，Nakazawa Y ，Imamura T ... -  《Frontiers in Immunology》

Preclinical Assessment of Efficacy and Safety Analysis of CAR-T Cells (ISIKOK-19) Targeting CD19-Expressing B-Cells for the First Turkish Academic Clinical Trial with Relapsed/Refractory ALL and NHL Patients.

Taştan C ，Kançağı DD ，Turan RD ，Yurtsever B ，Çakırsoy D ，Abanuz S ，Yılancı M ，Seyis U ，Özer S ，Mert S ，Kayhan CK ，Tokat F ，Açıkel Elmas M ，Birdoğan S ，Arbak S ，Yalçın K ，Sezgin A ，Kızılkılıç E ，Hemşinlioğlu C ，İnce Ü ，Ratip S ，Ovalı E ... -  《-》

Anti-CD19 CAR T cells potently redirected to kill solid tumor cells.

Ambrose C ，Su L ，Wu L ，Dufort FJ ，Sanford T ，Birt A ，Hackel BJ ，Hombach A ，Abken H ，Lobb RR ，Rennert PD ... -  《-》