Copper chelation redirects neutrophil function to enhance anti-GD2 antibody therapy in neuroblastoma [scRNA-seq]

Anti-disialoganglioside (GD2) antibody therapy has provided clinical benefit to patients with neuroblastoma however efficacy is likely impaired by the immunosuppressive tumor microenvironment. We have previously defined a link between intratumoral copper levels and immune evasion. Here, we report that adjuvant copper chelation potentiates anti-GD2 antibody therapy to confer durable tumor control in immunocompetent models of neuroblastoma. Mechanistic studies reveal copper chelation creates an immune-primed tumor microenvironment through enhanced infiltration and activity of Fc-receptor-bearing cells, specifically neutrophils which are emerging as key effectors of antibody therapy. Moreover, we report copper sequestration by neuroblastoma attenuates neutrophil function which can be successfully reversed using copper chelation to increase pro-inflammatory effector functions. Importantly, we repurpose the clinically approved copper chelating agent Cuprior as a non-toxic, efficacious immunomodulatory strategy. Collectively, our findings provide robust evidence for the clinical testing of Cuprior as an adjuvant to enhance the activity of anti-GD2 antibody therapy and improve outcomes for patients with neuroblastoma. To examine changes occuring within the tumor microenvironment with treatment at single-cell resolution, Th-MYCN mice (recruited when tumor diameter was 3-4mm) were treated with saline control or TEPA (400mg/kg) for seven days before tumour collection. Tumours (n=2/condition) were freshly dissociated and subjected to red blood cell lysis before tumor, lymphocyte and myeloid compartments were postitively selected for using flow cytometry. Sample sorting was performed using BD FACSAria III (BD Biosciences) and subjected to downstream analysis using the BD Rhapsody single-cell analysis system according to manufacturer's instructions (BD Biosciences).