Objectives: The generation of systemic lupus erythematosus (SLE)-related autoantibodies have been shown to be T cell dependent and antigen driven with HLA-DR restriction. In this study, the initiating antigen(s) and the mechanism of autoantibody diversification were investigated.
Methods: T cell epitopes (T-epitopes) of SmD1 (SmD) were mapped by T-T hybridomas generated from DR3AE mice immunised with SmD and with SmD overlapping peptides. TCRs from the reactive hybridomas were sequenced. The core epitopes were determined. Bacterial mimics were identified by bioinformatics. Sera from DR3AE mice immunised with SmD peptides and their mimics were analysed for their reactivity by ELISA and immunohistochemistry. Samples of blood donors were analysed for HLA-DR and autoantibody specificities.
Results: Multiple HLA-DR3 restricted T-epitopes within SmD were identified. Many T-T hybridomas reacted with more than one epitope. Some of them were cross-reactive with other snRNP peptides and with proteins in the Ro60/La/Ro52 complex. The reactive hybridomas used unique TCRs. Multiple T-epitope mimics were identified in commensal and environmental bacteria. Certain bacterial mimics shared both T and B cell epitopes with the related SmD peptide. Bacterial mimics induced autoantibodies to lupus-related antigens and to different tissues. HLA-DR3 blood donors made significantly more SLE-related autoantibodies.
Conclusions: The unique antigenic structures of the lupus-related autoantigens provide the basis for being targeted and for T and B cell epitope spreading and autoantibody diversification with unique patterns. SLE-related autoantibodies are likely generated from responses to commensal and/or environmental microbes due to incomplete negative selection for autoreactive T cells. The production of SLE-related antibodies is inevitable in normal individuals. The findings in this investigation have significant implications in autoimmunity in general.
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http://dx.doi.org/10.1136/annrheumdis-2018-214125 | DOI Listing |
Neurol Neuroimmunol Neuroinflamm
March 2025
Neuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy.
Background And Objectives: Antibodies to proteolipid protein-1 (PLP1-IgG), a major central myelin protein also expressed in the peripheral nervous system (PNS) as the isoform DM20, have been previously identified mostly in patients with multiple sclerosis (MS), with unclear clinical implications. However, most studies relied on nonconformational immunoassays and included few patients with non-MS CNS autoimmune demyelinating disorders (ADDs). We aimed to investigate conformational PLP1-IgG in the whole ADD spectrum.
View Article and Find Full Text PDFDiabetes
January 2025
Barbara Davis Center for Diabetes, University of Colorado, Aurora, CO, USA.
Increasing evidence shows that pathogenic T cells in type 1 diabetes (T1D) that may have evaded negative selection recognize post-translational modified (PTM) epitopes of self-antigens. We have investigated the profiles of autoantibodies specifically targeting the deamidated epitopes of insulinoma antigen-2 extracellular domain (IA-2ec) to explore their relationship with T1D development. We compared the characteristics of autoantibodies targeting the IA-2ec Q>E epitopes (PTM IA-2ecA) as well as those targeting the IA-2ec unmodified epitopes (IA-2ecA) in participants across different stages of T1D development and in individuals with other types of diabetes and other kinds of autoimmunity.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
January 2025
Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No, 2508, C.P. 07360, Mexico City, Mexico.
One of the most significant bacteriophage technologies is phage display, in which heterologous peptides are exhibited on the virion surface. This work describes the display of λ decorative protein D linked to the E protein domain III of Zika virus (D-ZE), to the GFP protein (D-GFP), or to different domain III epitopes of the E protein (D-TD), exhibited on the surface of an in vitro evolved lambda phage (λ). This phage harbors a gene D deletion and was subjected to directed evolution using Escherichia coli W3110/pD-ZE as background.
View Article and Find Full Text PDFPLoS One
January 2025
Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh.
Streptococcus pneumoniae (SPN) is a significant pathogen causing pneumonia and meningitis, particularly in vulnerable populations like children and the elderly. Available pneumonia vaccines have limitations since they only cover particular serotypes and have high production costs. The emergence of antibiotic-resistant SPN strains further underscores the need for a new, cost-effective, broad-spectrum vaccine.
View Article and Find Full Text PDFCurr Pharm Biotechnol
January 2025
Center for Vaccine Innovation, La Jolla Institute for Immunology (LJI), La Jolla, CA 92037, USA.
The SARS-CoV-2 pandemic has highlighted the need for society, as a whole, to be prepared against potential pandemics caused by a variety of different viral families of concern. Here, we describe a roadmap towards the identification and validation of conserved T cell epitope regions from Viral Families of Pandemic Potential (VFPP). For each viral family, we select a prototype virus, the sequence of which could be utilized in epitope identification screens.
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