# TLR7/8 agonist design and delivery for effective anticancer immune response

> **NIH NIH R01** · TEMPLE UNIV OF THE COMMONWEALTH · 2021 · $374,075

## Abstract

Agonists of toll like receptors (TLRs) are promising anticancer vaccine adjuvants because of their ability to
induce proinflammatory cytokines necessary to generate a robust immune response. However, currently available
TLR agonists suffer from a number of limitations including self-regulatory immunosuppression and unfavorable
local pharmacokinetics resulting in poor availability within dendritic cells. Further, current TLR agonist-based
anticancer vaccines generate a robust cytotoxic CD8 T cell response but not CD4 Th 1 helper T cell response,
which is critical for inducing effective, long-term antitumor immunity. We will address these important challenges
through a synergistic combination of drug discovery and drug delivery efforts. Our team has developed a suite
of highly substituted imidazoquinolines, which activate TLR7 and/or 8 and induce significantly higher levels of
cytokines compared to imiquimod, an FDA approved TLR7 agonist. Our studies show the balance between proinflammatory
and immunosuppressive cytokines can be tuned through structural modifications. Encapsulation of
these novel agonists in acidic pH responsive nanoparticles (NPs) resulted in robust activation of CD4 and COB
T cells as well as natural killer (NK) cells, leading to a stronger anticancer immune response than free agonist
or that encapsulated in non-pH responsive NPs. Importantly, intradermal delivery of NP vaccine using a hollow
microneedle platform led to an enhanced Th1 immune response, which is essential for effective induction of
long-term antitumor immunity. We will build on these exciting findings and further optimize the new agonists for
efficient encapsulation in pH responsive NPs, tune the NP properties for improved targeting of dendritic cells
following delivery via hollow microneedles, and investigate potentiation of NK cell-mediated antibody-mediated
cellular cytotoxicity. The Specific Aims of this revised R01 grant application include:
Aim 1: Design and synthesize TLR7/8 agonists that are optimized for NP encapsulation
Aim 2: Optimize pH responsive NP formulation for hollow microneedle-assisted ID delivery
Aim 3: Determine anticancer efficacy of NP vaccine following hollow microneedle-assisted ID delivery
We expect our studies will identify new design principles and delivery strategies for TLR agonists that overcome
the limitations of current anticancer vaccines and further advance the field of cancer immunotherapy.

## Key facts

- **NIH application ID:** 10312341
- **Project number:** 1R01CA260825-01A1
- **Recipient organization:** TEMPLE UNIV OF THE COMMONWEALTH
- **Principal Investigator:** Jayanth Panyam
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $374,075
- **Award type:** 1
- **Project period:** 2021-06-08 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10312341

## Citation

> US National Institutes of Health, RePORTER application 10312341, TLR7/8 agonist design and delivery for effective anticancer immune response (1R01CA260825-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10312341. Licensed CC0.

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