It is important to understand how viruses subvert host immunity to persist so that strategies can be developed to effectively target and purge them. T cells are critical to control persistent virus infections and the bulk of research has focused on how they achieve (or fail to achieve) this goal. However, antibodies are also a central component of the antiviral immune response against virus infections and are critical to control persistent viruses. Antibodies limit virus infection by blocking de novo cell infection and by killng infected cells; thus, suppression of antibody effector activity could severely hinder immune control of persistent virus infections. Yet, to date, specific suppression of antibody activity itslf has not been identified. Using the lymphocytic choriomeningitis virus (LCMV) model of persistent infection, we recently made the discovery that antibody effector function is suppressed during viral persistence. As a result, otherwise highly efficacious antibody mediated killing is ineffective during a persistent virus infection. Thus, we have uncovered a novel mechanism of immunosuppression during persistent infection and we hypothesize that by impeding killing of infected cells, the suppression of antibody activity facilitates viral persistece. The proposed study will (1) identify the cellular mechanisms underlying the loss of antibody effector function; (2) define how inhibition of function differentially impacts neutralizing and no-neutralizing antiviral antibodies to kill infected cells and control persistent virus infection; an (3) develop a strategy to restore antibody effector activity in vivo. Ultimately, these studies will define a previously unrecognized mechanism of immunosuppression during viral persistence and design an approach to restore antibody function to fight persistent virus infection.

Public Health Relevance

Persistent viral infections represent one of the greatest health concerns worldwide. The proposed experiments will define a mechanism of immunosuppression during viral persistence that limits otherwise effective antibody function. Our study has important implications for the design of therapies to restore antibody activity to fight persistent viruses.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
7R21AI109627-02
Application #
8874100
Study Section
Immunity and Host Defense Study Section (IHD)
Program Officer
Park, Eun-Chung
Project Start
2014-07-01
Project End
2016-08-31
Budget Start
2015-09-28
Budget End
2016-08-31
Support Year
2
Fiscal Year
2015
Total Cost
$135,000
Indirect Cost
$10,000
Name
University Health Network
Department
Type
DUNS #
208469486
City
Toronto
State
ON
Country
Canada
Zip Code
M5 2-M9
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
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