1. Functional neutralization of anti-IFN-γ autoantibody in patients with nontuberculous mycobacteria infection
- Author
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Yuarn Jang Lee, Po Chun Tseng, Dyah Ika Krisnawati, Yung Ching Liu, Yun Ting Wang, Chia Ling Chen, and Chiou Feng Lin
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0301 basic medicine ,THP-1 Cells ,Mycobacterium Infections, Nontuberculous ,lcsh:Medicine ,Peptide binding ,Article ,Epitope ,Cell Line ,Interferon-gamma ,Jurkat Cells ,03 medical and health sciences ,0302 clinical medicine ,Blood serum ,Immune system ,Cell Line, Tumor ,medicine ,Humans ,lcsh:Science ,Immunodeficiency ,Autoantibodies ,Multidisciplinary ,biology ,business.industry ,lcsh:R ,Autoantibody ,Nontuberculous Mycobacteria ,biology.organism_classification ,medicine.disease ,Antibodies, Neutralizing ,030104 developmental biology ,Immunology ,biology.protein ,lcsh:Q ,Nontuberculous mycobacteria ,Antibody ,business ,030217 neurology & neurosurgery - Abstract
Interferon (IFN)-γ is crucial for normal immune surveillance and exhibits immunomodulatory, antimicrobial, and anticancer activity. Patients with nontuberculous mycobacteria (NTM) infection commonly express high levels of anti-IFN-γ autoantibodies (autoAbs) and suffer from recurrent infections due to adult-onset immunodeficiency with defects in IFN-γ immune surveillance. In this study, we developed the methods for determination of anti-IFN-γ autoAbs and then characterized their neutralizing activity in patients with NTM infection. A modified sandwich ELISA-based colorimetric assay followed by immunoblot analysis detected the presence of autoAbs in three out of five serum samples. Serum levels of IFN-γ were decreased. Synthetic peptide binding assay showed variable patterns of epitope recognition in patients positive for anti-IFN-γ autoAbs. Functional tests confirmed that patient serum blocked IFN-γ-activated STAT1 activation and IRF1 transactivation. Furthermore, IFN-γ-regulated inflammation, chemokine production and cytokine production were also blocked. These results provide potentially useful methods to assay anti-IFN-γ autoAbs and to characterize the effects of neutralizing autoAbs on IFN-γ signaling and bioactivity.
- Published
- 2019
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