Agonists and Antagonists of Neuropsychiatric Lupus Project Summary Neuropsychiatric systemic lupus erythematosus (NPSLE) is a common and potentially lethal form of lupus. Two abnormalities have consistently been linked to NPSLE: the presence of autoantibodies and the presence of pro-inflammatory cytokines. However, the role of individual autoantibodies as well as specific cytokines remains controversial and the relationship between these two abnormalities is relatively unexplored. In our previously funded R21 proposal, we hypothesized that cell death coupled with the release of nucleoproteins resulted in the formation of immune complexes that stimulate Toll like receptors (TLRs) to produce high local concentrations of type 1 IFN (and perhaps other cytokines). In preliminary data, we have indeed observed that cerebrospinal fluid (CSF) from NPSLE patients have significantly higher interferon (IFN)-a inducing potential compared to controls and that, normalized for IgG concentrations, the IFN inducing activity was 800-fold higher than serum. The high IFN inducing activity of autoantibodies in CSF relative to serum was explained by the low concentration of certain protein inhibitors in CSF. In the current proposal, we will ask the following questions: 1) Does the IFN-a or other cytokine inducing activity of immune complexes correlate with autoantibody specificity, disease subsets or CNS injury in patients with NPSLE? Cytokine inducing capacity of serum and CSF from well characterized NPSLE patients will be compared between the 19 case definitions of NPSLE, between different autoantibody specificities as determined by a proteomic array and correlations determined with markers of brain cell injury. In the pediatric population, we will examine whether IFN-a inducing activity is associated with neurocognitive defects or MRI changes. 2) In the second Aim, we ask what are the mechanisms whereby two identified serum factors inhibit IFG activity? At least two serum factors have been identified that suppress IFN-a inducing activity by autoantibodies in CSF. We will identify the cell type and receptors that the inhibitors act on and then investigate the mechanism of inhibition. Relevance: Even when the most common (but least specific) subtypes of NPSLE are excluded, NPSLE occurs in about half of pediatric cases of SLE and a high proportion of cases with adult SLE. We have documented the potent inflammatory potential of autoantibodies in the CSF of NPSLE patients and have identified protein inhibitors. The ready availability of these inhibitors will allow us to consider therapeutic uses in the future.

Public Health Relevance

Agonists and Antagonists of Neuropsychiatric Lupus Project Narrative The cause(s) of most cases of lupus affecting the brain are unknown, but there is good evidence to suggest that certain types of antibodies may play a role. We have documented that these antibodies in brain fluid can cause the production of certain inflammatory proteins. Here, we determine which types of neurological disease are associated with specific inflammatory proteins and we determine how certain protein inhibitors can be used to dampen the inflammation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS065933-01
Application #
7696866
Study Section
Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section (HAI)
Program Officer
Utz, Ursula
Project Start
2009-07-15
Project End
2013-06-30
Budget Start
2009-07-15
Budget End
2010-06-30
Support Year
1
Fiscal Year
2009
Total Cost
$349,440
Indirect Cost
Name
University of Washington
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Colonna, Lucrezia; Lood, Christian; Elkon, Keith B (2014) Beyond apoptosis in lupus. Curr Opin Rheumatol 26:459-66
Wiedeman, Alice E; Santer, Deanna M; Yan, Wei et al. (2013) Contrasting mechanisms of interferon-? inhibition by intravenous immunoglobulin after induction by immune complexes versus Toll-like receptor agonists. Arthritis Rheum 65:2713-23
Sun, Xizhang; Wiedeman, Alice; Agrawal, Nalini et al. (2013) Increased ribonuclease expression reduces inflammation and prolongs survival in TLR7 transgenic mice. J Immunol 190:2536-43
Elkon, Keith B; Wiedeman, Alice (2012) Type I IFN system in the development and manifestations of SLE. Curr Opin Rheumatol 24:499-505
Santer, Deanna M; Wiedeman, Alice E; Teal, Thomas H et al. (2012) Plasmacytoid dendritic cells and C1q differentially regulate inflammatory gene induction by lupus immune complexes. J Immunol 188:902-15
Elkon, Keith B; Silverman, Gregg J (2012) Naturally occurring autoantibodies to apoptotic cells. Adv Exp Med Biol 750:14-26
Elkon, Keith B; Santer, Deanna M (2012) Complement, interferon and lupus. Curr Opin Immunol 24:665-70
Elkon, Keith B; Stone, Vivian V (2011) Type I interferon and systemic lupus erythematosus. J Interferon Cytokine Res 31:803-12
Santer, Deanna M; Hall, Brian E; George, Thaddeus C et al. (2010) C1q deficiency leads to the defective suppression of IFN-alpha in response to nucleoprotein containing immune complexes. J Immunol 185:4738-49