# Improving granulocyte transfusion in neutropenia-related infections

> **NIH NIH P01** · BOSTON CHILDREN'S HOSPITAL · 2022 · $681,450

## Abstract

Project Summary
Granulocyte transfusion (aka. neutrophil transfusion or GTX) has been utilized as a therapeutic approach for
the treatment of life-threatening bacterial and fungal infections in severe neutropenic patients, including
hematopoietic cell transplantation (HCT) recipients. Clinical outcomes from GTX are disadvantaged by the
short shelf life and compromised function of donor neutrophils. Spontaneous neutrophil death is
heterogeneous and mediated by multiple pathways. Leveraging mechanistic knowledge and pharmacological
screening, we identified a combined treatment, caspases–lysosomal membrane permeabilization–oxidant–
necroptosis inhibition plus granulocyte colony-stimulating factor (CLON-G), which alters neutrophil fate by
simultaneously targeting multiple cell death pathways. CLON-G treatment significantly prolongs neutrophil ex
vivo survival, increasing their half-life from less than 1 day to greater than 5 days. Compared to freshly isolated
neutrophils, the stored CLON-G-treated neutrophils display normal functions, including chemotaxis, ROS
production, phagocytosis, and bacteria killing. These results led us to hypothesize that CLON-G treatment can
significantly increase the ex vivo shelf life of granulocyte transfusion products without impairing the function of
the neutrophils in the GTX recipients. Due to the prolonged intracellular retention of the drugs, CLON-G
treatment may even improve the survival and increase the half-life of the transfused neutrophils in vivo and
therefore further improve the efficacy of GTX. In this study, we will first test this hypothesis in a clinically
relevant murine model of granulocyte transfusion in neutropenia-related pneumonia. We will determine
whether the stored CLON-G-treated neutrophils can function normally and survive even longer in vivo
compared to freshly isolated neutrophils (Aim 1A). Additionally, we will investigate the survival and function of
transfused human neutrophils in vivo in neutrophil-depleted NSG mice (Aim 1B). Next, we will examine
whether transfusion with stored CLON-G-treated neutrophils can ultimately enhance the inflammatory
response and bactericidal capability of the recipients as effectively as, or even more effectively than,
transfusion with untreated fresh neutrophils (Aim 2). Last, to identify novel CLON-G-inducible factors and
pathways that play critical role in regulating neutrophil death and function, we will perform single-cell RNA
sequencing (scRNA-seq) to reveal the molecular signature of CLON-G reprogrammed neutrophils
(Aim 3)
.
Together, experiments proposed in the three aims will assist us to better understand the molecular and
cellular mechanism leading to neutrophil death and to design novel clinical procedures for the long-term
storage and application of neutrophils in transfusion medicine. This study also provides a new strategy for
treatment of neutropenia-related pneumonia. The ability to utilize GTX through better understanding of
granulocyte func...

## Key facts

- **NIH application ID:** 10494384
- **Project number:** 1P01HL158688-01A1
- **Recipient organization:** BOSTON CHILDREN'S HOSPITAL
- **Principal Investigator:** Hongbo R Luo
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $681,450
- **Award type:** 1
- **Project period:** 2022-08-15 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10494384

## Citation

> US National Institutes of Health, RePORTER application 10494384, Improving granulocyte transfusion in neutropenia-related infections (1P01HL158688-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10494384. Licensed CC0.

---

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