Fig. 7: In vivo anti-tumor efficacy and toxicity of BP-αCD3-αEGFR-ARC Exos.

A Schematic of the animal study for BP-αCD3-αEGFR-ARC Exos in mice with BT-20 tumors. The left hindlimbs of NSG mice were inoculated with BT-20 cells via para-tibial injections (n = 5 or 7 per group). Expanded human PBMCs were intravenously injected on days 10 and 16 after cancer cells inoculation. One day post the first PBMCs injections, mice were administered (i.v.) with PBS, native exosomes (10 mg kg⁻¹), BP-ARC Exos (10 mg kg⁻¹), αCD3-αEGFR Exos (10 mg kg⁻¹), a combination of BP-ARC Exos (10 mg kg⁻¹) and αCD3-αEGFR Exos (10 mg kg⁻¹), CD9-CD38/αCD3-αEGFR Exos (10 mg kg⁻¹), or BP-αCD3-αEGFR-ARC Exos (10 mg kg⁻¹) every other day for six times. B Bioluminescence images of mice from all groups after the start of treatment. C Bioluminescence intensities of the treatment groups after the start of treatment (n = 5 or 7 per group; ^***p  =  0.0009 and ^****p < 0.0001). Data are shown as mean ± SEM. Plasma levels of calcium (D; ^***p = 0.0004) and TRAcP 5b (E; ^***p = 0.0002) for each group of mice at the end of study (n = 5 or 7 per group). Data are presented as mean ± SD. F Bone mineral density (BMD) of left hindlimb bones for each group of mice at the end of study as quantified by micro-CT scanning (n = 3 per group; ^**p = 0.0030). Data are shown as mean ± SD. G Representative micro-CT 3D images of left hindlimbs for each group of mice at the end of study. H Average body weights for each group of mice during the treatment study (n = 5 or 7 per group). Data are presented as mean ± SD. Plasma levels of creatinine (I) and ALT (J) for each group of mice at the end of study (n = 5 or 7 per group). Data are shown as mean ± SD. K Representative immunohistofluorescence images of tumor sections and quantitative analysis of tumor-infiltrating T cells for each group of mice at the end of study (n = 40 per group; ^****p < 0.0001). Blue: nuclei stained with DAPI. Green: CD3⁺ T cells stained with the anti-human CD3 antibody. Scale bars: 50 µm. Numbers of T cells were quantified with 20 fields of view per region and two mice per group. Data are shown in box-and-whisker plots with the line in the box as median and the lower and upper edge of the box as first and third quartile, respectively. Whiskers extending from the box represent the overall spread of the data. Statistical analysis was performed using two-way ANOVA with Dunnett’s multiple comparison test for (C) and (H) or ordinary one-way ANOVA with Dunnett’s multiple comparison test for (D–F) and (I–K). Significance of finding was defined as follows, ns = not significant p > 0.05, ^**p < 0.01, ^***p < 0.001, and ^****p < 0.0001. Source data are provided as a Source Data file.