Fig. 1

Preparation of PD-1 stably blocked CART19 cells. a Schematic representation of dual promoter lentivirus vectors and CAR structure. b Anti-mouse Fab antibody and PE conjucted second antibody were used to detect CAR. A strict one-to-one correspondence between the expression of CAR and ZsGreen was demonstrated. c In ZsGreen positive sorted Jurkat cells, S3 and S4 presented effective PD-1 knockdown efficiency, while S6 showed no significant effect. d From the fourth day after infection, S3 and S4 showed significant PD-1 knockdown efficiency in CAR-T cells. CAR-T e the expressions of PD-1 in different CAR-T cell populations (9 days after virus infection) were tested before and after 24 h co-culture with Raji cells. During co-culture, S3 and S4 significantly decreased the expression of PD-1. 0.01 < *P < 0.05; **P < 0.01. Statistical significance was determined using the ANOVA method for multiple comparisons. Data represent the mean ± SEM of triplicates and are representative of at least 3 independent experiments or are plotted as individual points