Interleukin-17A Promotes Lung Tumor Progression through Neutrophil Attraction to Tumor Sites and Mediating Resistance to PD-1 Blockade.


Tumors in IL-17:KrasG12D mice grew more rapidly, resulting in a significantly shorter survival as compared with that of KrasG12D mice. IL-6, granulocyte colony-stimulating factor (G-CSF), milk fat globule-EGF factor 8 protein, and C-X-C motif chemokine ligand 1 were increased in the lungs of IL17:Kras mice. Time course analysis revealed that levels of tumor-associated neutrophils were significantly increased, and lymphocyte recruitment was significantly reduced in IL17:KrasG12D mice as compared with in KrasG12D mice. In therapeutic studies PD-1 blockade was not effective in treating IL-17:KrasG12D tumors. In contrast, blocking IL-6 or depleting neutrophils with an anti-Ly-6G antibody in the IL17:KrasG12D tumors resulted in a clinical response associated with T-cell activation. In tumors from patients with lung cancer with KRAS mutation we found a correlation between higher levels of IL-17A and colony- stimulating factor 3 and a significant correlation among high neutrophil and lower T-cell numbers. Here we have shown that an increase in a single cytokine, IL-17A, without additional mutations can promote lung cancer growth by promoting inflammation, which contributes to resistance to PD-1 blockade and sensitizes tumors to cytokine and neutrophil depletion.

In Journal Thorac Oncol.

Contribution: Analysis of expression data.