Abstract Introduction Immune cell death programs are not passive endpoints but active regulators of tissue immunity. Neutrophil extracellular trap (NET) formation is one such program, releasing DNA and granule proteins that can either restrict pathogens or reinforce tumor progression. More broadly, the capacity to induce or redirect death pathways represents a powerful immunotherapeutic tool. We examined how manipulating neutrophil death and NETosis shapes antitumor immunity, situating these findings within the broader context of programmed cell death as a driver of immune reprogramming. Methods We combined genetically engineered pancreatic ductal adenocarcinoma (PDAC) models with thick tissue slice imaging to visualize NET formation in situ. Engineered bacteria were used to selectively induce pyroptosis or apoptosis, while NETosis was modulated through genetic and pharmacologic approaches. Spatial transcriptomics and multiplex immunofluorescence were employed to map neutrophil clusters, death pathway activation, and tumor microenvironmental (TME) remodeling. Results NETosis emerged as a dominant neutrophil fate within PDAC, enriched in clusters that restricted lymphocyte access. Inhibition of NETosis reduced tumor burden and enhanced CD8+ T cell activity. In parallel, bacterial induction of pyroptosis promoted inflammatory myeloid states, whereas apoptosis favored immune resolution. These data highlight that distinct death programs can be selectively manipulated to rewire immune responses. Conclusion Our findings identify NETosis as a targetable suppressive program in cancer and show that engineered manipulation of cell death can redirect the TME toward antitumor immunity. Together, these results position neutrophils as central regulators of immunogenic death and illustrate how programmed cell death pathways can be leveraged as a generalizable strategy for immune intervention. Funding Source NIH R00 Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)
Vivien Maltez (Tue,) studied this question.