Abstract A014: Engineered neutrophils for intratumoral delivery and targeting

Abstract Immunotherapy has improved outcomes for renal cell cancer patients, but tumor recurrence and therapeutic toxicity remain challenges. Unlike systemically administered therapy, neutrophils can infiltrate solid tumors including their hypoxic core. Unfortunately, such neutrophils typically cause local immunosuppression, facilitate tumor metastasis, and reduce cytotoxic T-cell killing of tumor cells. Although tumor-associated neutrophils have been investigated in other tumor models, renal cell carcinoma, known to be significantly impacted by neutrophil infiltration, has had limited investigation into characterizing pro-and anti-tumor neutrophils and assessing mechanisms of intratumor neutrophil reprogramming. We aim to engineer neutrophil progenitors to produce neutrophils that uniquely augment immunologic tumor killing as well as neutrophils that can secrete antitumor therapeutics directly into the tumor microenvironment. We have previously developed conditionally immortalized murine neutrophil progenitors (NPs) allowing in vitro expansion and viral infection with artificial plasmids. Uniquely, these neutrophil progenitors engraft into bone marrow of donor mice without the need for bone marrow ablative therapies such as chemotherapy or radiation, facilitating the use of engineered NPs as cell therapy. We infect NPs with either a plasmid encoding an inflammation-inducible promoter-driven immune checkpoint inhibitor antibody with a signal peptide to allow for antibody secretion or plasmids encoding the CRISPR-Cas9 gene-editing system with a guide RNA specific to the transforming growth factor-beta receptor, which has been shown to be involved in protumor neutrophil reprogramming in other tumors. Engineered neutrophils are assessed in vitro and in vivo in the RENCA renal cell carcinoma tumor model in syngeneic immunocompetent mice. Experiments are currently underway to identify novel cell surface markers for engineered protumor and antitumor neutrophils in renal cell carcinoma, confirm the significance of similar cytokine receptor-mediated neutrophil reprogramming as in other tumors, and demonstrate the ability to develop neutrophils with tumor-inducible secretion of artificial therapeutics directly into tumor deposits. We aim to show conditionally immortalized neutrophils can be engineered to be off-the-shelf cell therapies for solid tumors that can penetrate hypoxic tumor microenvironments and cause tumor-specific cytotoxicity by both direct and indirect action. Citation Format: Anirudh Udutha, Craig Lefort. Engineered neutrophils for intratumoral delivery and targeting abstract. In: Proceedings of the AACR Special Conference in Cancer Research: Innovations in Kidney Cancer Research: From Molecular Insights to Therapeutic Breakthroughs; 2026 Mar 13-16; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86 (5Suppl₂): Abstract nr A014.