# Perforin 2 controls unconventional cytokine release from mucosal APC

> **NIH NIH U01** · UNIVERSITY OF PENNSYLVANIA · 2024 · $89,577

## Abstract

Perforin 2 controls unconventional cytokine release from mucosal APC
Project Summary
How professional antigen presenting cell (APC) populations focally deliver cytokines to T cells for shaping the
pro-inflammatory vs. anti-inflammatory status of mucosal tissue remains incompletely understood. In particular,
cytokines that lack N-terminal peptide sequence such as the IL-1 family cytokine IL-33 can't access conventional
protein secretion pathways, which has led to the prevailing view that cell death is responsible for IL-33 release.
This project is built upon an exciting set of preliminary data demonstrating that mucosal conventional dendritic
cell (cDC) subsets, in both humans and mice, express the transmembrane pore-forming protein Perforin-2, which
at least in mice, facilitates IL-33 secretion. While in human cDC, we find Perforin-2 expression primarily in an
interferon regulatory factor 4 (IRF4) subset indicating the cDC2 lineage, in mouse cDC, we find Perforin-2 in the
CD103+ cDC1 subset known to express the transcription factors Irf8 and Batf3. Irrespective of this lineage
distinction, both human and mouse CD11c+ cells in the respiratory mucosa contain cytoplasmic IL-33 protein.
Our data demonstrate that inhibition of Perforin-2 activity prevents IL-33 release from cDC and inhibits the
proliferative expansion of a poorly understood ST2+GATA3+Foxp3+Treg subset. Given that Perforin-2 has been
shown to also regulate Type 1 IFN signaling through controlling IFNAR responsiveness, we propose an important
regulatory mechanism exists in humans and mice that is dependent upon mucosal APC that express Perforin-2.
This project tests the central hypothesis that APC require Perforin-2 as an inducible plasma membrane
conduit for unconventional cytokine delivery at the mucosal interface. Three specific aims (SA) will be
investigated. SA1 will determine whether Perforin-2+ APC predict Treg subset abundance in sinonasal mucosa
and define the transcriptional landscape of Perforin-2+ APC. SA2 will define the Perforin-2 domains required for
IL-33 release, the diversity of Perforin-2-dependent secreted molecules, and the requisite intracellular trafficking
machinery responsible for Perforin-2 plasma membrane localization during APC-T cell interactions. SA3 will
directly test whether cDC1 and/or cDC2 subsets preferentially use Perforin-2 for driving pathogen-specific T cell
responses in mouse models of respiratory virus or helminth infection. Taken together, this MIST project stands
to uncover a new paradigm for understanding how cDC instruct immunity within the respiratory mucosa.

## Key facts

- **NIH application ID:** 11052033
- **Project number:** 3U01AI163062-04S1
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** De'Broski R Herbert
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $89,577
- **Award type:** 3
- **Project period:** 2021-08-20 → 2024-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11052033

## Citation

> US National Institutes of Health, RePORTER application 11052033, Perforin 2 controls unconventional cytokine release from mucosal APC (3U01AI163062-04S1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/11052033. Licensed CC0.

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