Jagged2 targeting in lung cancer activates anti-tumor immunity via Notch-induced functional reprogramming of tumor-associated macrophages

Signaling through Notch receptors intrinsically regulates tumor cell development and growth. However, whether Notch ligands on cancer cells impact anti-tumor immunity remains unclear. We demonstrate that deletion of Notch ligand Jagged2, but not Jagged1, in lung cancer cells attenuates tumor growth and activates anti-tumor T cell responses. Jagged2 deletion in cancer cells incites intra-tumor accumulation of macrophages with elevated capacity to uptake, process, and present antigens. Also, transfer of Jagged2KO tumors-related macrophages into mice provokes lymphocyte-mediated anti-tumor actions, while macrophage ablation in mice restores Jagged2KO tumor growth. Jagged2 deletion on lung tumors induces Notch ligands DLL1/4, which signal through Notch1-2 on macrophages to stimulate IRF4-driven anti-tumor responses. Intercepting DLL1/4 in tumors or IRF4 in myeloid cells blunts macrophage expansion and reinstates Jagged2KO tumor growth. Therapeutically, anti-Jagged2 treatments restrict tumor growth and augment immunotherapy effectiveness. Findings elucidate how cancer cell Jagged2 promotes immune-evasion and identify Jagged2-targeting immunotherapy to activate anti-tumor immunity. Lewis Lung Carcinoma (LLC) GFP cells with either Scramble or sgRNA for JAG2 (JAG2KO) were injected into the flanks of mice. At endpoint, mice were euthanized and tumors were collected, dissociated with Liberase, and stained with CD45 and DAPI. 400,000 GFP+/CD45-/DAPI-cells were flow sorted directly into RLT Lysis Buffer. Using the QIAGEN RNeasy kit, RNA was extracted and submitted for RNAseq.