# Developing an in vivo toolbox to interrogate the intracellular trafficking and killing of Aspergillus spores

> **NIH NIH R21** · CLEMSON UNIVERSITY · 2022 · $224,491

## Abstract

Project Summary/Abstract
Fungal pathogens, including Aspergillus fumigatus, cause life-threatening infections in more than 2 million
immunocompromised people worldwide per year. Healthy people encounter and successfully combat A.
fumigatus every day, but we do not fully understand the immune pathways that promote fungal clearance. In
particular, the function of macrophages in killing A. fumigatus spores inside of infected hosts is unclear. The
overarching goal of the proposed research is to delineate the cellular pathways through which
macrophages phagocytose, endosomally traffick, and kill A. fumigatus spores. These experiments will
be performed in larval zebrafish which allow for imaging of subcellular host-pathogen dynamics in live, intact
hosts throughout a multi-day infection. A larval zebrafish model of A. fumigatus infection recapitulates the
pathogenesis of infections in human patients. In this model we find that only ~50% of spores are killed by
macrophages and the remaining spores can persist inside of these cells. We hypothesize that spore killing
correlates with localization of spores to specific phagosomal compartments and that modulation of this
localization by mutation of compartment-defining genes will alter this killing. Targeting a panel of 15 candidate
genes/proteins shown to associate with fungal phagosomes in vitro, I first propose to fluorescently-tag each
protein in macrophages in larval zebrafish and use live imaging to quantify colocalization with spores
throughout infection to define the compartments through which spores are trafficked. Second, I propose to
systematically mutate each of the 15 candidate genes using a CRISPR pipeline and test the requirement for
each gene in macrophage-mediated spore killing and host survival. Altogether, this research will identify
intracellular mechanisms that promote killing of A. fumigatus spores by macrophages and open up future
opportunities to modulate these pathways to increase fungal killing.

## Key facts

- **NIH application ID:** 10453136
- **Project number:** 1R21AI164363-01A1
- **Recipient organization:** CLEMSON UNIVERSITY
- **Principal Investigator:** Emily Rosowski
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $224,491
- **Award type:** 1
- **Project period:** 2022-02-09 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10453136

## Citation

> US National Institutes of Health, RePORTER application 10453136, Developing an in vivo toolbox to interrogate the intracellular trafficking and killing of Aspergillus spores (1R21AI164363-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10453136. Licensed CC0.

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