# The role of decoy receptor IL-1R2 in Treg biology and anti-tumor immunity

> **NIH NIH F31** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2024 · $51,622

## Abstract

Project Summary/Abstract
Interleukin-1B (IL-1B) is a pro-inflammatory cytokine with conflicting roles in mouse and human cancers. The
cytokine enhances tumor growth by promoting angiogenesis, and chronic inflammation mediated by IL-1B can
induce carcinogenesis. At the same time, IL-1 signaling bolsters the adaptive immune system, polarizing CD4+
T cells toward T helper type 1 and 17 lineages and enhancing the effector function of CD8+ T cells to improve
tumor cell killing. A large clinical trial found that anti-IL-1B treatment significantly reduced tumor incidence in
humans, highlighting the effect of IL-1 signaling on human health. IL-1 signaling is well-regulated by both a
receptor antagonist (IL-1RA) and a non-signaling decoy receptor (IL-1R2). IL-1RA acts at the organism level to
suppress systemic inflammation, while IL-1R2 is thought to attenuate local inflammation in tissues.
Using RNA sequencing, we have identified a population of highly activated IL-1R2+ regulatory T cells (Tregs)
in healthy skin and tumor samples from mice and humans. Tregs are critical suppressors of inflammation in
tissues, but tumor infiltrating Tregs can dampen adaptive immunity to promote cancer growth. However, the
function of IL-1R2 in cancer and Treg biology is not well understood. In our hands, deleting IL-1R2 on Tregs
led to increased tumor growth in mice, suggesting that IL-1 signaling enhances Treg activation. This proposal
will test whether Treg expression of IL-1R2 attenuates their activation in a cell intrinsic fashion by
neutralizing local IL-1B. First, we will define the factors that induce IL-1R2 expression on Tregs in mice and
humans (Aim 1). We will then investigate the functional role of IL-1R2 on tumor infiltrating Tregs (Aim 2).
Lastly, we will determine whether IL-1R2 can be used as a target to selectively deplete Tregs in tumors and
bolster anti-tumor immunity (Aim 3). The proposal will not only broaden our understanding of IL-1 signaling in
Tregs but may also establish a new approach for cancer immunotherapy.
This research strategy will be conducted alongside a comprehensive training plan to develop the applicant’s
career as an academic physician-scientist. Training will include structured and rigorous mentorship in technical
skills and experimental design from a highly qualified physician-scientist sponsor, carried out through regular
one-on-one and lab meetings, courses, seminars, journal clubs, and immunology department events. The
research and training will take place at the University of California, San Francisco, which provides an excellent
research environment for immunology alongside an outstanding graduate education in biomedical sciences.

## Key facts

- **NIH application ID:** 10991656
- **Project number:** 5F31CA278371-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Ireneusz Habrylo
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $51,622
- **Award type:** 5
- **Project period:** 2023-07-01 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10991656

## Citation

> US National Institutes of Health, RePORTER application 10991656, The role of decoy receptor IL-1R2 in Treg biology and anti-tumor immunity (5F31CA278371-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10991656. Licensed CC0.

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