# Innate immune responses to SARS-CoV-2 infection in the olfactory epithelium

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2022 · $586,386

## Abstract

RESEARCH SUMMARY
Sudden-onset of olfactory loss has been recognized as a common COVID-19 symptom. The mechanism of
COVID-19 related olfactory dysfunction is unknown. Whether the degree of olfactory deficit is indicative of any
long-term neurological diseases in COVID-19 has not been evaluated. Recent single-cell RNA-seq analyses
revealed that the receptor for SARS-CoV-2, ACE2, is not expressed by olfactory sensory neurons (OSNs) but
are expressed by supporting sustentacular (Sus) cells in the OE. Therefore, Sus cells may be the entry cell
type for SARS-CoV-2 in the OE. SARS-CoV-2 infection in the OE needs to be further characterized. Current
observations indicate that the viral infection is sparse and localized. Widespread olfactory receptor
downregulation has been reported under viral infection suggesting that there might be a distributed viral impact
from localized viral infection in the OE. We hypothesize that widespread Sus cell mediated inflammatory
response, triggered by SARS-CoV-2, is responsible for COVID-19 associated olfactory loss. In this study, we
will characterize inflammatory responses to SARS-CoV-2 in the olfactory epithelium and identify Sus cell
specific cytokine expressions; we will established a primary Sus cell culture system to examine viral
recognition pathways and transcription factors involved in SARS-CoV-2 induced innate immune responses; we
will further determine SARS-CoV-2 infection induced olfactory sensory neuron functional deficits. Through this
study, we will gain mechanistic insight into COVID-19 associated olfactory loss.

## Key facts

- **NIH application ID:** 10445837
- **Project number:** 1R01DC019769-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Qizhi Gong
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $586,386
- **Award type:** 1
- **Project period:** 2022-04-01 → 2027-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10445837

## Citation

> US National Institutes of Health, RePORTER application 10445837, Innate immune responses to SARS-CoV-2 infection in the olfactory epithelium (1R01DC019769-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10445837. Licensed CC0.

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