# Eosinophils as Regulators of Host Immunity against Influenza Infections

> **NIH NIH R01** · UNIVERSITY OF TENNESSEE HEALTH SCI CTR · 2021 · $380,000

## Abstract

Influenza A virus (IAV) infections have claimed over 50 million lives worldwide during epidemic and pandemics.
Patients with asthma were less likely to suffer from severe influenza during the 2009 influenza pandemic
compared to non-asthmatics for reasons not yet fully elucidated. We have recapitulated these clinical findings
using our innovative mouse model of asthma and influenza co-morbidity, and found that heightened
eosinophilia during influenza infection correlated with reduced lung viral burden. Our preliminary data showed
that eosinophil transfer into lungs of virus-infected animals reduced lung viral burden and led to increased
recruitment of CD8+ T-cells into the airways. Mice in the asthma and influenza co-morbidity model also have
elevated gene expression of resistin-like molecule (RELM)-α and -β, and the administration of these proteins
into the lungs of virus-infected mice led to a reduction in lung viral burden and increased recruitment of CD8+
T-cells. These data led to our central hypothesis that eosinophils in allergic airways promote antiviral immunity
against IAV by activating CD8+ T-cells. The three overlapping aims to be investigated in this project are: (1) To
identify eosinophil granule proteins released during degranulation upon direct contact with IAV and determine
their impact on IAV infectivity, (2) To determine if eosinophils directly enhance CD8+ T-cell responses against
IAV, and (3) To determine the function of eosinophil-derived RELM proteins in enhancing antiviral immunity
against IAV. This project is significant because we propose to identify basic immune mechanisms in host
defense against a prominent human pathogen with an innovative approach of investigating eosinophils as a
regulator of adaptive immunity and mediator of host protection rather than as an end-stage effector cell. These
studies will have a broad impact on eosinophil biology, virology, and may offer novel therapeutic targets to treat
influenza.

## Key facts

- **NIH application ID:** 10102168
- **Project number:** 5R01AI125481-05
- **Recipient organization:** UNIVERSITY OF TENNESSEE HEALTH SCI CTR
- **Principal Investigator:** Amali E Samarasinghe
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $380,000
- **Award type:** 5
- **Project period:** 2017-03-06 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10102168

## Citation

> US National Institutes of Health, RePORTER application 10102168, Eosinophils as Regulators of Host Immunity against Influenza Infections (5R01AI125481-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10102168. Licensed CC0.

---

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