Fig. 4: PHOX2B-specific PC-CAR T cells induce potent tumour killing in vitro and in vivo and break conventional HLA restriction.
From: RETRACTED ARTICLE: Cross-HLA targeting of intracellular oncoproteins with peptide-centric CARs
a–c, The CAR 10LH induces specific killing and IFN-γ release in neuroblastoma cells expressing HLA-A*24:02 and HLA-A*23:01 and PHOX2B (SKNAS, NBSD and SKNFI), but not in HLA-A*24:02 PHOX2B− non-neuroblastoma tumour cells (SW620, HEPG2 and KATO III), unless PHOX2B peptide is added. No T cell activity was observed in SW620 when pulsed with 10 μM of the predicted cross-reactive peptides ABCA8 or MYO7B (b, c). Cytotoxicity was visualized by T cell clustering and cleaved caspase (a), relative loss of confluence measured by loss of green fluorescence in GFP-transduced cancer cells in (b), and IFN-γ release measured by ELISA (c). UT denotes untransduced T cells. Assays performed using T cells from n = 3 donors, each in triplicate; data are mean ± s.d. d, Pulsing HLA-A*24:02 PHOX2B− cell line SW620 with 5 μM PHOX2B induces complete cell killing when co-cultured with 10LH CAR, but no killing when pulsed with 50 μM CHRNA3. Repeated across 3 experiments. e, 10LH CAR specifically and specifically kills SW620 control cells transduced with PHOX2B, but not with PRAME. f, Staining cancer cells with tetramerized 10LH scFv enables detection of PHOX2B pMHC on neuroblastoma cells but not in HLA-matched controls. g, PHOX2B-specific PC-CAR T cells induce potent tumour killing in mice engrafted with neuroblastoma PDX tumours, including the extremely fast-growing line COG-564x and HLA-A*23:01 line NBSD. n = 6 mice enrolled per arm (individual plots shown in Extended Data Fig. 17); data are representative from one of two independent in vivo studies for each PDX line; data are mean ± s.d. h, Treatment with 10LH and 302LH PC-CARs potently upregulate HLA expression in PDX tumours collected from lone mice in each arm reaching tumour burden compared with mice treated with untransduced T cells (COG-564x collected 11 days after treatment; NBSD collected 14 days after treatment for untransduced cells and 17 days after treatment for 10LH and 302LH; both tumours collected from one experiment). Created with BioRender.com.
