While HAART has reduced the incidence of HIV-related morbidity and mortality, increasing evidence suggests that chronic inflammatory medical illnesses, including cardiovascular disease, diabetes mellitus, chronic kidney and liver disease, osteoporosis, and cancer occur more frequently and/or at earlier ages in HIV infected individuals. Chronic HCV is similarly associated with liver inflammation and increased risk of diabetes mellitus, kidney disease, and cancer. HIV co-infection with HCV results in enhanced progression of inflammation-linked liver and kidney pathology relative to HCV infection alone. However, the pathogenesis of HIV-1 and HCV-related chronic inflammation is complex and incompletely understood. Inflammation in infection is orchestrated by innate immune cell signaling receptors that detect microbial molecules. A subset of intracellular immune receptors can assemble into multi-protein complexes called """"""""inflammasomes"""""""". Inflammasomes integrate two pathogen-triggered signaling cascades (signal 1 and 2), ultimately leading to secretion of the active, mature forms of the pro-inflammatory cytokines interleukin (IL)-18 and IL-1?. Elevated serum IL-18 levels are associated with diabetes, with kidney disease and liver inflammation, and with increased atherosclerosis progression. We recently discovered that HIV and HCV virions assemble inflammasomes in monocytes and macrophages and that a subset of antibodies directed against envelope proteins from either virus can prevent monocyte IL-18 and IL-1? release in response to cognate virus. The mechanism through which antibodies specific for HIV or HCV prevent activation of the inflammasome by cognate virus and what antibody characteristics are critical for the process are unknown. Given the increased rates of inflammatory diseases in HIV infected people, our overall goal is to improve our understanding of mechanisms of inflammasome suppression to enhance control of HIV-associated inflammation.
In Aim 1, we will test whether co-infection increases inflammasome activation relative to monoinfection by comparing IL-18, IL-1?, and other proinflammatory cytokine levels in plasma from HIV infected, HCV infected, HIV/HCV co-infected, and uninfected subjects. Using a novel model system, we will assess the effect of HIV and HCV specific-antibodies on monocyte inflammasome activation with both viruses present.
In Aim 2, we will determine if envelope antibodies block one or both signals in the pathogen-triggered signaling cascades and correlate the degree of inflammasome inhibition to inhibition of the two signals.
In Aim 3, we will determine the role of the constant region (Fc) of anti-envelope antibodies in inflammasome inhibition. These studies will break new ground by revealing mechanisms of stimulation and modulation of inflammation triggered by chronic viruses, potentially explaining increased inflammation of the liver, kidney, and other organs and providing new therapeutic targets for modulation of that inflammation.

Public Health Relevance

People with HIV infection develop heart disease, diabetes mellitus, chronic kidney and liver disease, osteoporosis, and cancer more frequently and/or at earlier ages than people without HIV. We will study how a pathway implicated in the development of these diseases is activated by viral infection. Determining the cause of this increased risk of heart and other disease in those with HIV infection and understanding how to reduce the risk is important.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI108403-02
Application #
8695289
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Brobst, Susan W
Project Start
2013-07-03
Project End
2018-06-30
Budget Start
2014-07-01
Budget End
2015-06-30
Support Year
2
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Wood, Emily Turner; Ercan, Ece; Sati, Pascal et al. (2017) Longitudinal MR spectroscopy of neurodegeneration in multiple sclerosis with diffusion of the intra-axonal constituent N-acetylaspartate. Neuroimage Clin 15:780-788
Vergara, C; Thio, C; Latanich, R et al. (2017) Genetic basis for variation in plasma IL-18 levels in persons with chronic hepatitis C virus and human immunodeficiency virus-1 infections. Genes Immun 18:82-87
Veenhuis, Rebecca T; Freeman, Zachary T; Korleski, Jack et al. (2017) HIV-antibody complexes enhance production of type I interferon by plasmacytoid dendritic cells. J Clin Invest 127:4352-4364
Veenhuis, Rebecca T; Astemborski, Jacquie; Chattergoon, Michael A et al. (2017) Systemic Elevation of Proinflammatory Interleukin 18 in HIV/HCV Coinfection versus HIV or HCV Monoinfection. Clin Infect Dis 64:589-596
Patel, Eshan U; Cox, Andrea L; Mehta, Shruti H et al. (2016) Use of Hepatitis C Virus (HCV) Immunoglobulin G Antibody Avidity as a Biomarker to Estimate the Population-Level Incidence of HCV Infection. J Infect Dis 214:344-52
Chattergoon, Michael A; Latanich, Rachel; Quinn, Jeffrey et al. (2014) HIV and HCV activate the inflammasome in monocytes and macrophages via endosomal Toll-like receptors without induction of type 1 interferon. PLoS Pathog 10:e1004082
Serti, Elisavet; Werner, Jens M; Chattergoon, Michael et al. (2014) Monocytes activate natural killer cells via inflammasome-induced interleukin 18 in response to hepatitis C virus replication. Gastroenterology 147:209-220.e3
Cox, Andrea L; Siliciano, Robert F (2014) HIV: Not-so-innocent bystanders. Nature 505:492-3
Cox, Andrea L; Siliciano, Robert F (2013) Making sense of HIV innate sensing. Immunity 39:998-1000