IL2/Anti-IL2 Complex Combined with CTLA-4, But Not PD-1, Blockade Rescues Antitumor NK Cell Function by Regulatory T-cell Modulation

Nom de la revue
Cancer Immunology Research
Pamela Caudana, Nicolas Gonzalo Núñez, Philippe De La Rochere, Anaïs Pinto, Jordan Denizeau, Ruby Alonso, Leticia Laura Niborski, Olivier Lantz, Christine Sedlik, Eliane Piaggio

High-dose IL2 immunotherapy can induce long-lasting cancer regression but is toxic and insufficiently efficacious. Improvements are obtained with IL2/anti-IL2 complexes (IL2Cx), which redirect IL2 action to CD8+ T and natural killer (NK) cells. Here, we evaluated the efficacy of combining IL2Cx with blockade of inhibitory immune pathways. In an autochthonous lung adenocarcinoma model, we show that the IL2Cx/anti–PD-1 combination increases CD8+ T-cell infiltration of the lung and controls tumor growth. In the B16-OVA model, which is resistant to checkpoint inhibition, combination of IL2Cx with PD-1 or CTLA-4 pathway blockade reverses that resistance. Both combinations work by reinvigorating exhausted intratumoral CD8+ T cells and by increasing the breadth of tumor-specific T-cell responses. However, only the IL2Cx/anti–CTLA-4 combination is able to rescue NK cell antitumor function by modulating intratumoral regulatory T cells. Overall, association of IL2Cx with PD-1 or CTLA-4 pathway blockade acts by different cellular mechanisms, paving the way for the rational design of combinatorial antitumor therapies.