# Engineering RIG-I Activating Nanoparticles for Glioblastoma Immunotherapy

> **NIH NIH F32** · VANDERBILT UNIVERSITY · 2024 · $73,828

## Abstract

Glioblastoma (GBM) is a form of brain cancer with no cure and a five-year survival rate below 10%.
Immunotherapies such as immune checkpoint blockade (ICB) have shown great promise in other solid tumors
but have demonstrated no clinical benefits for GBM patients. In part due to a highly immunosuppressive tumor
microenvironment that inhibits T cell activation and infiltration. There is consequently an urgent unmet need to
engineer new immunotherapies for GBM. Retinoic acid-inducible gene I (RIG-I) is a promising target for cancer
immunotherapy. RIG-I is an RNA sensing pattern recognition receptor in the cytosol that leads to downstream
production of type I interferon, which can lead to CD8+ T cell infiltration into tumors. However, RNA delivery to
the cytosol is a challenge because the negative charge of RNA prevents internalization. Therapeutics that
activate RIG-I have been demonstrated to improve response to ICB in several preclinical models of solid tumors
but have yet to be explored in GBM. This proposal aims to design and test a biomaterial therapy that locally
delivers a RIG-I agonist, 5’-triphosphorylated double-stranded RNA (3pRNA), via a polymeric nanocarrier to elicit
a pro-inflammatory response in mouse models of GBM. RIG-I is an unstudied target for treating GBM, and we
will deliver a unique stem-loop 3pRNA (SLR) to activate the pathway. SLR will be delivered in pH responsive
nanocarriers that destabilize the endosome and release SLR into the cytosol. An α-CD11b nanobody will be
conjugated to the nanoparticle to drive uptake by antigen presenting cells, including resident microglia and
infiltrating dendritic cells and macrophages. We propose two specific aims to 1) Engineer RANs for GBM
immunotherapy and 2) determine their immunological consequences. We will test the aims using the
following experiments: Aim 1) SLR will be covalently conjugated to polymeric nanoparticles, followed by click
chemistry to attach an α-CD11b nanobody. We will verify RNA activity and uptake in vitro using interferon reporter
cell lines and bone marrow-derived dendritic cells. The efficacy of our engineered nanoparticles will be tested in
the GL261 and CT2A immunocompetent models of GBM using intracranial injection of the nanoparticles. We will
determine if combination therapy with ICB leads to enhanced efficacy, as RIG-I activating nanoparticles will
create a more immunogenic tumor microenvironment. Aim 2) Studies will determine the immunological
mechanism of treatment. We will evaluate immune cell frequency and activation state in the tumor and brain.
We will determine T cell dependence, if infiltrating T cells are necessary for efficacy, and if therapy creates
memory T cells in the brain. We hypothesize that our polymer therapeutic will activate antigen presenting cells,
leading to CD8+ T cell infiltration into the tumor. This project will improve the knowledge in the field of
neuroimmunology through insight gained about the role of RIG-I activation in GB...

## Key facts

- **NIH application ID:** 10826789
- **Project number:** 1F32CA288044-01
- **Recipient organization:** VANDERBILT UNIVERSITY
- **Principal Investigator:** Alexander Kwiatkowski
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $73,828
- **Award type:** 1
- **Project period:** 2024-06-01 → 2027-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10826789

## Citation

> US National Institutes of Health, RePORTER application 10826789, Engineering RIG-I Activating Nanoparticles for Glioblastoma Immunotherapy (1F32CA288044-01). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10826789. Licensed CC0.

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