Figure 5. B7-H3 nanoCAR-T cells control tumor growth in vivo but are associated with toxicity events. (A) Graphical overview of in vivo experimental set-up. (B) Bioluminescent images at day 3 post inoculation. (C) Thy1.1 expression of expanded CAR-T cell products at day 10 post-transduction. (D) Tumor growth curves over time (left) and tumor images at 28 days post inoculation, shown for all conditions (right). (E) Flow cytometry data of blood from mice, processed at 1 and 3 weeks of CAR-T cell treatment, showing % of circulating human CD45 cells gated within all living blood cells and Thy1.1 positive cells within the human CD45^pos cell population. (F) Weight curves over time. (G) Images of spleens dissected from B7-H3 nanoCAR-treated mice. Data represent mean±SD n=4 mice per group. ****p≤0.0001. Two-way ANOVA with Bonferroni’s multiple comparisons test was used to determine statistical significance in panel D. Statistical significance shown on the graph at 28 days post inoculation. 5T2Id, 5T2 multiple myeloma idiotype; ACT, adoptive cell transfer; ANOVA, analysis of variance; B7-H3, B7 homolog 3; BLI, bioluminescence imaging; CAR, chimeric antigen receptor; HER2, human epidermal growth factor receptor 2; i.v., intravenously; nanoCAR, nanobody-based chimeric antigen receptor; s.c., subcutaneously.