# Development of a technique for specific labelling phagosome-derived membranous structures in dendritic cells

> **NIH NIH R03** · FLORIDA STATE UNIVERSITY · 2022 · $71,058

## Abstract

PROJECT SUMMARY/ABSTRACT
 Dendritic cells (DCs) are immune cells that play a critical role in establishing adaptive immunity
through a process termed cross-presentation. A major route of cross-presentation starts with the
phagocytosis of a particulate pathogen by a DC into an intracellular vacuole called phagosome. The
phagosome is a site for assembling major histocompatibility complex class 1 (MHC-I) and antigenic
peptides into MHC-I:peptide complexes and initiating the transport of the MHC-I:peptide complexes to
the cell surface. How the MHC-I:peptide complexes are transported from the phagosome to the cell
surface is not well understood but probably through shedding membranous structures by the phagosome.
However, existing live-cell imaging techniques cannot provide a comprehensive picture of this process.
The long-term goal of this proposed research is to develop a new technique capable of specifically
labelling all membranous structures derived from a pathogen-containing phagosome in a DC undergoing
cross-presentation. This proposed technique uses highly engineered microparticles crafted to mimic
particulate pathogens while carrying a releasable membrane dye. The most innovative feature of this
proposed technique is the use of a special material to first hold the dye in the microparticle before the
microparticle is phagocytosed and then release the dye after the phagocytosis. The central hypothesis
of this study is that by delivering a membrane dye solely into a phagosome with a microparticle and
rendering the dye releasable from the microparticle, the membranous structures derived from the
phagosome can be stained by the dye. This hypothesis has been formulated on the basis of our own
preliminary results. The objective of this application, which is the next step toward attainment of the long-
term goal, is to determine whether the microparticles can be used to specifically label phagosome-derived
membranous structures in model DCs. The specific aims are to (1) establish a protocol for fabricating the
microparticles, and (2) determine whether the microparticles can be phagocytosed by model DCs and
whether the microparticle-laden phagosome can disseminate membranous structures stained by the dye.
Success of this project will prove the feasibility of this technique and lay a foundation for its further
development. The fully developed version of this technique promises to significantly advance our
understanding of cross-presentation.

## Key facts

- **NIH application ID:** 10508764
- **Project number:** 1R03AI171974-01
- **Recipient organization:** FLORIDA STATE UNIVERSITY
- **Principal Investigator:** Jingjiao Guan
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $71,058
- **Award type:** 1
- **Project period:** 2022-08-01 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10508764

## Citation

> US National Institutes of Health, RePORTER application 10508764, Development of a technique for specific labelling phagosome-derived membranous structures in dendritic cells (1R03AI171974-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10508764. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*