Persistent viral infections are among the greatest health concerns worldwide. By definition, immune escape is required for viral persistence, and many of the suppressive factors involved are being identified. Yet, it is still unclear how prolonged virus replication leads to the expression of the many and mechanistically diverse suppressive factors, pathways and cells that inhibit immunity during persistent viral infections. Type I interferons (IFN-I) are well known for their antiviral activity during virus infection. However, using the lymphocytic choriomeningitis virus (LCMV) system, we discovered that in addition to their critical antiviral role throughout viral persistence, sustained IFN-I production ed to many of the suppressive mechanisms and immune dysfunctions associated with persistent viral infections. Antibody blockade of IFN-I signaling decreased immunosuppression, restored immune competence and facilitated immune mediated control of the persistent infection. In the current proposal, we will mechanistically define how IFN-I functions as the mediator of the multiple and diverse parameters of immunosuppression that ultimately potentiate viral persistence. We will then test the hypothesis that the distinct antiviral and suppressive aspects of IFN-I signaling can be uncoupled to specifically inhibit the negative while maintaining the critical positive functions of IFN-I to restore immunity and control infection. These studies will provide critical biologic insight into how IFN-I simultaneously induces antiviral and suppressive functions and will potentially guide the way we therapeutically target IFN-I to treat disease. Finally, we will investigate a novel IFN-I induced mechanism of immunosuppression to define how IFN-I implements secondary down-stream effectors to promote viral persistence. Ultimately, our study will provide fundamental insight into a new aspect of IFN-I biology and facilitate the first understanding of a newly described mechanism of immunosuppression potentiating viral persistence.

Public Health Relevance

Therapies to treat many persistent virus infections are needed. The experiments outlined in this proposal will investigate a newly defined mechanism of immunosuppression that facilitates persistent viral infection. Ultimately, identification of the mechanisms that undermine immunity will aid in the design of restorative therapies to amplify the immune response to control persistent viral infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI085043-09
Application #
9207122
Study Section
Immunity and Host Defense (IHD)
Program Officer
Singleton, Kentner L
Project Start
2009-12-01
Project End
2020-01-31
Budget Start
2017-02-01
Budget End
2018-01-31
Support Year
9
Fiscal Year
2017
Total Cost
$270,000
Indirect Cost
$20,000
Name
University Health Network
Department
Type
DUNS #
208469486
City
Toronto
State
ON
Country
Canada
Zip Code
M5 2-M9
Clemente-Casares, Xavier; Hosseinzadeh, Siyavash; Barbu, Iulia et al. (2017) A CD103+ Conventional Dendritic Cell Surveillance System Prevents Development of Overt Heart Failure during Subclinical Viral Myocarditis. Immunity 47:974-989.e8
Zhen, Anjie; Rezek, Valerie; Youn, Cindy et al. (2017) Targeting type I interferon-mediated activation restores immune function in chronic HIV infection. J Clin Invest 127:260-268
Cunningham, Cameron R; Champhekar, Ameya; Tullius, Michael V et al. (2016) Type I and Type II Interferon Coordinately Regulate Suppressive Dendritic Cell Fate and Function during Viral Persistence. PLoS Pathog 12:e1005356
Snell, Laura M; Osokine, Ivan; Yamada, Douglas H et al. (2016) Overcoming CD4 Th1 Cell Fate Restrictions to Sustain Antiviral CD8 T Cells and Control Persistent Virus Infection. Cell Rep 16:3286-3296
Walsh, Nicole C; Waters, Lynnea R; Fowler, Jessica A et al. (2015) LKB1 inhibition of NF-?B in B cells prevents T follicular helper cell differentiation and germinal center formation. EMBO Rep 16:753-68
York, Autumn G; Williams, Kevin J; Argus, Joseph P et al. (2015) Limiting Cholesterol Biosynthetic Flux Spontaneously Engages Type I IFN Signaling. Cell 163:1716-29
Snell, Laura M; Brooks, David G (2015) New insights into type I interferon and the immunopathogenesis of persistent viral infections. Curr Opin Immunol 34:91-8
Yamada, Douglas H; Elsaesser, Heidi; Lux, Anja et al. (2015) Suppression of Fc?-receptor-mediated antibody effector function during persistent viral infection. Immunity 42:379-390
Osokine, Ivan; Snell, Laura M; Cunningham, Cameron R et al. (2014) Type I interferon suppresses de novo virus-specific CD4 Th1 immunity during an established persistent viral infection. Proc Natl Acad Sci U S A 111:7409-14
Wilson, Elizabeth B; Brooks, David G (2013) Decoding the complexity of type I interferon to treat persistent viral infections. Trends Microbiol 21:634-40

Showing the most recent 10 out of 23 publications