Journal: Science translational medicine
Article Title: IFN-γ-resistant CD28 CAR-T cells demonstrate increased survival, efficacy, and durability in multiple murine tumor models
doi: 10.1126/scitranslmed.adp8166
Figure Lengend Snippet: (A) Schematic diagram of genetic constructs used to generate human chimeric antigen receptor (CAR)-T cells with a CD19 single-chain fragment variable (scFv), CD28 costimulatory domain, and CRISPR/Cas9 editing of T cell receptor A constant region locus ( TRAC ; CAR CD19 ), TRAC and IFNG (IFNγKO CAR CD19 ), or TRAC and IFNGR (IFNγRKO CAR CD19 ). (B) Expression of CD3 (Allophycocyanin, APC; left ), IFNγR (Alexa Fluor 647, AF647; middle ) and phosphoSTAT1 (pSTAT1) signaling (AF647; right ) following exposure to recombinant human IFNγ on resting CAR-T cells and donor-matched untransduced (UTD) T cells) with representative histograms from 3 biological replicates. (C) IFNγ (Brilliant Violet 510, BV510) expression on CAR-T cells was assessed by flow cytometry following four-hour activation with phorbol myristate acetate (PMA) and ionomycin; (n=3 biological replicates). Y-axis is an empty channel. (D) CD4 and CD8 expression on CAR-T cells and UTD T cells were determined using flow cytometry; n=6 biological replicates. Data are shown as mean ± SEM with P values determined by two-way ANOVA with Tukey’s multiple comparisons test. (E) CAR-T cells were activated overnight with CD19 antigen and secreted cytokines were measured by Luminex; bubble plot represents average cytokine expression (ng/ml) from 3 biological replicates. (F) Expansion of CD28 CAR-T cells in response to Nalm6 cells was monitored using real-time Incucyte imaging. Average expansion (±SEM) was measured over 72 hours. Data represents 4 biological replicates which were analyzed by one-way ANOVA with Tukey’s multiple comparisons analysis at 24, 48, and 72 hours. Significance of IFNγKO CAR CD19 vs. CAR CD19 ( pink * ) or IFNγRKO CARCD19 vs. CAR CD19 (turquoise *,**) is shown. (G) Schematic diagram of constructs used to generate control, IFNγKO, and IFNγRKO CAR-T cells with a CD19 scFv and 4–1BB costimulatory domain. (H) Representative histograms of CD3 (APC; left ) and IFNγR (AF647; middle ) expression on resting CAR-T cells and donor-matched UTD T cells measured by flow cytometry alongside IFNγ following a four-hour activation with PMA and Ionomycin (BV510; right ). Data was analyzed from 3 biological replicates. (I) Expansion of 4–1BB CAR-T cells in response to Nalm6 cells was monitored using real-time Incucyte imaging. Average expansion (±SEM) was measured over 72 hours. Data represents 3 biological replicates which were analyzed by one-way ANOVA. * P <0.05, ** P <0.01, **** P <0.0001; ns, not significant.
Article Snippet: For functional assessment, CAR-T cells were activated for four hours using Cell Activation Cocktail with Brefeldin A (BioLegend; Cat. 423302) or 18 hours with plate-bound CD19 (Recombinant Human CD19 Fc Chimera Protein, CF; R&D Systems Cat. 9269-CD-050), mesothelin (Recombinant Human Mesothelin; PeproTech Cat. 100–63), or EGFR (Recombinant Human EGF Receptor (EGFR); PeproTech Cat. 100–15R) prior to staining.
Techniques: Knock-Out, In Vitro, Construct, CRISPR, Expressing, Recombinant, Flow Cytometry, Activation Assay, Luminex, Imaging, Control