# Dissecting innate immune mechanisms of resistance to checkpoint blockade therapy in bladder cancer

> **NIH NIH F30** · ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI · 2024 · $53,974

## Abstract

PROJECT SUMMARY
Bladder cancer is the fifth most common cancer in the United States, accounting for around 47 deaths per day.
Promisingly, five PD-1/PD-L1 immune checkpoint blockade (ICB) therapies were approved for bladder cancer in
2016. Although these ICB treatments have achieved durable clinical responses in a subset of patients (15-25%),
the majority of patients have still not benefitted from this therapy. This clinical urgency to extend the benefits of
ICB to more patients has led to a need to investigate tumor intrinsic mechanisms underlying resistance. Tumor-
promoting inflammation, a hallmark of cancer pathogenesis, is known to contribute to cancer growth in multiple
ways including restraining antitumor immunity. We discovered a gene signature from pre-treatment tumor
associating with myeloid cells that is enriched in inflammation and innate immune genes and predictive of poor
ICB outcomes and survival in two ICB clinical trials. I plan to follow up on this work and dissect the innate immune
landscape of bladder cancer and investigate mechanisms of myeloid-cell mediated resistance to ICB therapy.
Aim 1 seeks to define the landscape of untreated bladder tumors and provide insight into the immune cell
subsets underlying ICB resistance. I will construct a transcriptomic and molecular atlas of bladder cancer at a
single-cell resolution, a resource that does not currently exist. I will build atlases of patients’ tumor, blood, and
urine using single-cell RNA sequencing, Cellular Indexing of Transcriptomes and Epitopes by Sequencing
(CITEseq), spatial transcriptomics, and O-link proteomics and analyze them using Seurat and other R-based
tools. I plan to resolve myeloid cells expressing this resistant gene signature and define their cellular interactions.
In Aim 2, I will delve into the transcriptional pathways in myeloid cells that are contributing to ICB resistance. We
have identified NLRP3 inflammasome activation and IL-1β signaling in tumor monocyte-macrophages (mono-
MΦs) as candidate pathways promoting tumor inflammation and progression. I will model these mono-MΦs by
differentiating peripheral blood monocytes into MΦ using GM-CSF and M-CSF under hypoxic conditions with IL-
1β and NLRP3 inflammasome activators., I will test effects on adaptive immunity by co-culturing these mono-
MΦs with activated autologous CD8+ T cells. I will also use this model to test drug candidates known to modulate
IL-1β and NLRP3 inflammasome activity as potential combinatorial treatments with ICB in bladder cancer.
This proposal combines direct ex vivo single cell genomics with in vitro functional experiments for a thorough
interrogation of the innate immune contribution to ICB resistance in bladder cancer. Combined, these aims will
elucidate innate immune pathway driven resistance to PD-1/PD-L1 ICB therapy in bladder cancer, which can be
used to identify critical predictive clinical biomarkers and inform new combinatorial treatment strategies.

## Key facts

- **NIH application ID:** 10886745
- **Project number:** 5F30CA275269-03
- **Recipient organization:** ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
- **Principal Investigator:** Michelle Alyssa Tran
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $53,974
- **Award type:** 5
- **Project period:** 2022-07-11 → 2026-07-10

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10886745

## Citation

> US National Institutes of Health, RePORTER application 10886745, Dissecting innate immune mechanisms of resistance to checkpoint blockade therapy in bladder cancer (5F30CA275269-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10886745. Licensed CC0.

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