The primary goal of this R01 proposal is to characterize the interferon-stimulated gene E74-like ETS transcription factor 1 (ELF1), in vivo and in vitro, regarding its role in restricting virus infections. Although hundreds of interferon-stimulated genes (ISGs) execute the antiviral function of interferon (IFN), for the vast majority, the molecular mechanisms remain a mystery. Understanding the mechanisms by which host factors inhibit viral infections may lead to novel antiviral strategies. The project is founded on our recent published discovery that ELF1 exhibits direct antiviral action in inhibiting influenza A virus. Since that initial discovery, our preliminary data show that ELF1 acts after multiple rounds of viral replication and is broadly antiviral. In epithelial cells, ELF1 transcriptionally regulates a vast program of hundreds of genes mostly distinct from those regulated by IFN. ELF1 does not feed forward to produce IFN, and retains its strong antiviral potential even in the absence of further IFN signaling. Intriguingly, at least part of this program confers protection to neighboring cells. Finally, we show that local knockdown of murine Elf1 during IAV infection significantly increases viral lung titers, morbidity, and mortality in vivo. These results opened the door to propose a novel concept for ELF1's role in the IFN response: that this transcription factor is a novel regulator of inflammation and innate antiviral immunity. In addition, our data raise the exciting possibility that ELF1's antiviral program continues protecting cells from viral infections even in the refractory phase post IFN exposure, or when IFN signaling is abrogated by viral antagonists. The main technical innovation of this proposal is the use the versatile tool of confocal high-content imaging to study sub-cellular signaling events during viral infections. Completion of our aims will have major impact on the field, by characterizing a novel transcriptional antiviral program that is as broad and potent, but distinct from IFN.

Public Health Relevance

. There is an unmet need for novel antiviral drug targets, which is particularly true to combat newly emerging viruses. We are studying a host inhibitor for viruses that pose a major health burden, causing severe disease and even death, including yellow fever virus, chikungunya virus, herpes simplex virus, and influenza A virus. A greater understanding of how the host's innate immune system acts against these viruses may lead to novel options for a targeted drug design.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI143639-03
Application #
10077206
Study Section
Immunity and Host Defense (IHD)
Program Officer
Liu, Qian
Project Start
2019-01-23
Project End
2023-12-31
Budget Start
2021-01-01
Budget End
2021-12-31
Support Year
3
Fiscal Year
2021
Total Cost
Indirect Cost
Name
New York University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
121911077
City
New York
State
NY
Country
United States
Zip Code
10016