Abstract IA008: Dissecting innate immune mechanisms of resistance to immune checkpoint blockade therapy in bladder cancer

Abstract

We have explored the TME of bladder cancer (BC) leveraging single-cell RNA sequencing (scRNAseq) and clinical trial data to ascertain the complexity of tumor-infiltrated immune ecllls in BC. As a first step we identify distinct tumor-associated macrophage (TAM) populations associated with immune checkpoint blockade (ICB) response and resistance. Through plasma cytokine profiling, in vitro assays, and spatial analyses, we uncover novel cytokine-driven axes influencing these TAM populations and their impact on T cells, offering insights into enhancing anti-tumor T cell immunity in BC. Second, we investigate the potential of urine-derived cells (UDCs) as surrogates for monitoring the BC TME. Our scRNAseq atlas of BC patient UDCs reveals a diverse composition of immune cell populations, strikingly transcriptionally similar to tumor immune cells and containing immune subsets absent or rare in peripheral blood, suggesting their utility as biomarkers for response to therapeutic intervention. Collectively, these findings provide new insights into the immune landscape of BC and provide putative targets to enhance existing immunotherapy strategies in BC. Citation Format: Nina Bhardwaj. Dissecting innate immune mechanisms of resistance to immune checkpoint blockade therapy in bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr IA008.