COVID-19 disease is an ongoing global pandemic caused by a new beta-coronavirus SARS-CoV- 2. A major obstacle to battling SARS-CoV-2 is a better understanding of the human innate immune responses that can lead to an uncontrolled hyper-inflammation in the lung and, ultimately, to an acute respiratory distress syndrome (ARDS) in some patients but not others. Due to the rapid emergence of this pandemic, very limited knowledge is available on the lung-specific innate immune responses to SARS-CoV-2 that could lead to ARDS (and in some cases death) or instead elicit a protective antiviral response (e.g., type-I interferons, interferon-stimulated genes). The role of the human innate immune system, particularly the myeloid cells, in initiating a ?cytokine storm? and generalized hyper-inflammation has been reported, but specifically how lung-resident macrophages vs. infiltrating monocytes differentially respond to SARS-CoV-2 and how each myeloid subset contribute to either protective antiviral responses or uncontrolled hyper- inflammation and ARDS remain unknown. Hence, an in-depth study of the myeloid compartment in the lung and blood of severe COVID-19 patients in ICU is critical to better understand the initiation and persistence of ARDS and, most importantly, to the development of more efficient and targeted therapy. Our project?s primary objective is to resolve, at a single-cell level, the specific myeloid subsets, including lung-resident alveolar and interstitial macrophages, dendritic cells, as well as infiltrating blood monocytes, that are responsible for protective antiviral responses (e.g., type-I interferons, interferon-stimulated genes) and/or aberrant hyper-inflammatory responses that lead to ARDS (e.g., ?cytokine storm?, neutrophil recruitment, etc.). Through these studies, we will develop novel insights into the molecular programming and heterogeneity of the human innate immune responses to SARS-CoV-2 infection and identify potential target genes to inform effective treatment strategies.

Public Health Relevance

The ongoing global pandemic caused by the new coronavirus SARS-CoV-2 urgently calls for a strong and sustained research response to quickly gain and apply the knowledge needed to ameliorate the current public health crisis. To contribute to this effort, we propose to conduct a focused investigation of the innate immune responses to SARS-CoV-2 in the lung (endotracheal aspirates) and matching blood of severe COVID-19 patients in intensive care units. Specifically, we will investigate and distinguish the innate immune cells in the lung that elicit either protective antiviral responses or aberrant hyper-inflammation and acute respiratory distress syndrome.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
3R01AI123126-05S1
Application #
10212766
Study Section
Program Officer
Vazquez-Maldonado, Nancy
Project Start
2020-08-24
Project End
2021-01-31
Budget Start
2020-08-24
Budget End
2021-01-31
Support Year
5
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Emory University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
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