Abstract 2879: Cell-autonomous Cxcl1 sustains tolerogenic circuitries and stromal inflammation via neutrophil-derived TNF in pancreatic cancer
Authors: Bianchi Anna , Silva Iago De Castro , Deshpande Nilesh , Singh Samara , Mehra Siddharth , Garrido Vanessa , Ogobuiro Ifeanyichukwu , Amirian Haleh , Rafie Christine , Zhou Zhiqun , Nagathihalli Nagaraj , Villarino Alejandro , Merchant Nipun , Datta Jashodeep 
Published: April 2023

Abstract
Objective: We have shown that KRAS-TP53 genomic co-alteration is associated with immune-excluded microenvironments, chemoresistance, and poor survival in pancreatic ductal adenocarcinoma (PDAC) patients. By treating KRAS-TP53 cooperativity as a model for high-risk biology, we sought to define how cancer cell-autonomous transcriptional programs orchestrate tolerogenic circuitries and stromal inflammation to mediate chemoresistance.
Methods: Spatial neighborhood analysis via Imaging Mass Cytometry (IMC) was performed in human PDAC sections. Immune profiling and RNA-seq in whole tumors, bulk-RNA-seq in intratumoral neutrophilic(PMN)-MDSCs in orthotopic KPC tumors with/without CRISPR/Cas9 editing of Cxcl1 was performed. Effect of TNFR2 inhibition via etanercept on ex vivo co-cultures of intratumoral PMN-MDSC with KPC tumor cells/CAFs and T-cells, as well as in orthotopic KPC models in vivo with/without gemcitabine+paclitaxel was examined.
Results: Interrogation of cancer cell transcriptomes and IMC architecture in human tumors reveals enrichment of Cxcl1 in KRAS-TP53 co-altered PDAC. IMC-enabled spatial neighborhood analysis in KRAS-TP53 co-altered human tumors demonstrate spatial contiguity between PanCK+CXCL1+ tumor islands and cognate CD15+CXCR2+ PMN-MDSCs, with exclusion of CD8+ T-cells from tumor cell:MDSC communities. In murine orthotopic models, silencing of cancer cell-intrinsic Cxcl1 reprograms trafficking and functional dynamics of CXCR2+ PMN-MDSCs to overcomes T-cell exclusion, and controls tumor growth in a CD8+ T-cell dependent manner. Transcriptomes from KPC-Cxcl1KO tumors reveal enrichment in pathways encoding for T-cell effector activity, and attenuation in pathways related to innate immunoregulatory function. Mechanistically, neutrophil-derived TNF emerges as a central regulator of this immunologic rewiring, with transcriptomes from intratumoral KPC-Cxcl1KO PMN-MDSCs revealing a novel MAPK-reliant Cxcr2-Ikk-Map3k8-Tnf axis. Neutrophil-derived TNF instigates feed-forward Cxcl1 overproduction from tumor cells and CAFs, T-cell dysfunction, and inflammatory CAF polarization via transmembraneTNF-TNFR2 interactions. Systemic TNFR2 inhibition via etanercept augments T-cell activation, and mitigates tumor-wide Cxcl1 production, stromal inflammation, and CAF:tumor cell IL6-STAT3 signaling to improve sensitivity to chemotherapy in vivo.
Conclusion: By decoding the link between high-risk cancer cell genotypes, cell-autonomous inflammatory programs, and myeloid-enriched and T-cell-excluded contexts, we identify a previously unrecognized role of neutrophil-derived TNF in sustaining tolerogenic circuitries and stromal inflammation in the PDAC TME. Our data suggest that targeting context-dependent TNF signaling may overcome hallmarks of therapeutic resistance in PDAC.
Citation Format: Anna Bianchi, Iago De Castro Silva, Nilesh Deshpande, Samara Singh, Siddharth Mehra, Vanessa Garrido, Ifeanyichukwu Ogobuiro, Haleh Amirian, Christine Rafie, Zhiqun Zhou, Nagaraj Nagathihalli, Alejandro Villarino, Nipun Merchant, Jashodeep Datta. Cell-autonomous Cxcl1 sustains tolerogenic circuitries and stromal inflammation via neutrophil-derived TNF in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2879.