Document text
Principal Investigator: M. Kristen Demoruelle
Organization: UNIVERSITY OF COLORADO DENVER
Fiscal Year: 2024
Award: $361,090
Funding agency: National Institute of Arthritis and Musculoskeletal and Skin Diseases
PROJECT SUMMARY/ABSTRACT
Formation of anti-citrullinated protein antibodies (ACPA) is an early step in the development of rheumatoid
arthritis (RA). Serum ACPA are highly predictive of developing RA and can directly promote joint damage. Yet,
there remains a major gap in our understanding of ACPA development, including where and how they are
initially triggered. Importantly, to achieve the NIH's mission of disease/disability prevention in RA, an improved
understanding of the initiating factors and pathways that lead to ACPA is needed as these factors/pathways
would be novel targets for RA prevention. ACPA originate several years prior to the onset of arthritis in RA, and
data support that they may initially develop in the lung mucosa. However, the mechanism by which the lung
contributes to ACPA development is unclear. The overall hypothesis of the proposed project is that neutrophil
extracellular traps (NETs) in the lung trigger ACPA and predict RA. This hypothesis is based on our published
and preliminary data including our finding that NET remnants correlate with ACPA in the lung in subjects At-
Risk for developing RA. Importantly, NET remnants are a composite of NET formation (NETosis) and NET
clearance. This study will establish whether aberrancies in one or both of these processes contribute to ACPA
generation in the lung and development of RA. In this project, induced sputum will be collected from subjects
who are At-Risk for RA (based on known familial or serologic risk factors), healthy controls and subjects with
RA. Using microscopy, the percentage of sputum neutrophils that undergo NETosis following cytokine
stimulation will be calculated. The binding of serum ACPA to proteins on sputum NETs will also be measured.
It is expected that subjects At-Risk for RA will have abnormally increased sputum NETosis following cytokine
stimulation compared to controls. It is also expected that cytokine-induced sputum NETosis will correlate with
sputum ACPA levels and that sputum NETs will express citrullinated proteins that bind serum ACPA from At-
Risk subjects. The proposed project will also measure the degradation of NETs by DNase in sputum and the
clearance of NETs by sputum macrophage phagocytosis. It is expected that both mechanisms of NET
degradation and clearance will be decreased in subjects At-Risk for RA compared to controls and will correlate
with sputum ACPA. In addition, At-Risk subjects will be followed for 3 years. Sputum ACPA and NET remnant
levels will be measured at baseline and yearly to establish the ability of sputum NET remnants to predict which
At-Risk subjects will develop RA. Mass spectrometry will also be used to identify citrullinated proteins present
in sputum that are associated with development of RA. It is expected that increased sputum NET remnants
mediated through sputum ACPA and unique cit-proteins will predict imminent RA in subjects At-Risk for RA.
Ultimately, these findings can lead to novel approaches for RA prevention that target specific mechanisms of
ACPA development (e.g. NET formation and clearance) at the site of initial immune dysregulation (e.g. the
lung) in individuals who are At-Risk for RA.
Terms: <(TNF)-α><3-10C><7S Gamma Globulin><AMCF-I><Ab response><Address><Affect><Anti-CCP antibody><Anti-citrullinated autoantibody><Anti-citrullinated cyclic protein antibody><Anti-citrullinated peptide antibody><Anti-citrullinated protein antibody><Anti-citrullinated protein autoantibody><Anti-cyclic citrullinated peptide antibody><Antibody Formation><Antibody Production><Antigens><Arthritis><Atrophic Arthritis><Autoimmune Status><Autoimmunity><B cell differentiation factor><B cell stimulating factor 2><B-Cell Differentiation Factor><B-Cell Differentiation Factor-2><B-Cell Stimulatory Factor-2><BCDF><BSF-2><BSF2><Basic Research><Basic Science><Binding><Binding Proteins><Biological Markers><Blood Neutrophil><Blood Plasma><Blood Polymorphonuclear Neutrophil><Blood Serum><CTLA-8><CTLA-8 Gene><CTLA8><CTLA8 Gene><CXCL8><Cachectin><Cell Body><Cells><Clinical><Cytotoxic T-Lymphocyte-Associated Antigen 8><Cytotoxic T-Lymphocyte-Associated Antigen 8 Gene><Cytotoxic T-Lymphocyte-Associated Serine Esterase 8><Cytotoxic T-Lymphocyte-Associated Serine Esterase 8 Gene><DNA Nucleases><DNase><Data><Deoxyribonucleases><Development><Disability prevention><Disease><Disorder><ELISA><Enzyme-Linked Immunosorbent Assay><GCP1><Generations><Goals><HPGF><Health Care Costs><Health Costs><Healthcare Costs><Hepatocyte-Stimulating Factor><Hybridoma Growth Factor><IFN-beta 2><IFNB2><IL-17><IL-17 Gene><IL-17A><IL-17A Gene><IL-6><IL-8><IL17><IL17 Protein><IL17 gene><IL17A><IL17A Gene><IL6 Protein><IL8><IL8 gene><IgG><Immune><Immunes><Immunoglobulin G><Incubated><Individual><Ingestion><Initiation Factors><Interleukin 17 (Cytotoxic T-Lymphocyte-Associated Serine Esterase 8)><Interleukin 17 (Cytotoxic T-Lymphocyte-Associated Serine Esterase 8) Gene><Interleukin 17 Precursor><Interleukin 17 Precursor Gene><Interleukin-17><Interleukin-6><Intervention><Intervention Strategies><K60><Label><Ligand Binding Protein><Ligand Binding Protein Gene><Lung><Lung Respiratory System><MGI-2><Macrophage><Macrophage-Derived TNF><Marrow Neutrophil><Mass Photometry/Spectrum Analysis><Mass Spectrometry><Mass Spectroscopy><Mass Spectrum><Mass Spectrum Analyses><Mass Spectrum Analysis><Measures><Mediating><Methods><Microscopy><Mission><Molecular Interaction><Monocyte-Derived TNF><Morbidity><Morbidity - disease rate><Mucosa><Mucosal Tissue><Mucous Membrane><Myeloid Differentiation-Inducing Protein><Mφ><NIH><National Institutes of Health><Neutrophilic Granulocyte><Neutrophilic Leukocyte><Pathogenesis><Pathway interactions><Peptide Initiation Factors><Phagocytosis><Plasma><Plasma Serum><Plasmacytoma Growth Factor><Polymorphonuclear Cell><Polymorphonuclear Leukocytes><Polymorphonuclear Neutrophils><Population><Preventing disabilities><Prevention><Prevention trial><Process><Protein Binding><Proteins><Publishing><Reporting><Reticuloendothelial System, Serum, Plasma><Rheumatoid Arthritis><Risk><Risk Factors><Role><SCYB8><Serology><Serum><Site><Sputum><Synovia><Synovial Fluid><TNF><TNF A><TNF Alpha><TNF gene><TNF-α><TNFA><TNFα><TSG-1><Translation Initiation Factor><Translational Initiation Factor><Translational Research><Translational Science><Tumor Necrosis Factor><Tumor Necrosis Factor-alpha><United States National Institutes of Health><Work><anti-citrullinated protein Abs><antibody biosynthesis><arthritic><b-ENAP><bio-markers><biologic marker><biomarker><bound protein><citrullinated protein><cohort><compare to control><comparison control><cytokine><developmental><enzyme linked immunoassay><extracellular><immunogen><immunoglobulin biosynthesis><improved><ingest><inhibitor><interferon beta 2><interventional strategy><joint damage><joint injury><joint trauma><mortality><multidisciplinary><neutrophil><new approaches><novel><novel approaches><novel strategies><novel strategy><pathway><peripheral blood><prevent><preventing><pulmonary><rheumatic arthritis><social role><societal costs><translation research><translational investigation>