{ "abstract": "Systemic lupus erythematosus (SLE) is characterized by autoantibody production alongside inflammatory manifestations, including nephritis. In SLE, infections are frequent and associated with disease flares, increasing morbidity and mortality. Additionally, dysbiosis, often marked by overgrowth of Pseudomonadota, is a prominent feature of SLE and lupus nephritis. We previously demonstrated that complexes of DNA and curli, an amyloidogenic protein from biofilms of Pseudomonadota, including Salmonella Typhimurium and E. coli, can induce anti-dsDNA and anti-chromatin autoantibody responses. Here, we assessed the effects of curli administration or Salmonella infection on autoimmune manifestations in wild-type and lupus-prone mice. A multiplex autoantibody assay showed increased levels of anti-C1q antibodies in curli-treated C57BL/6 and lupus-prone NZBxW/F1 mice compared to PBS-treated controls. An anti-C1q-specific ELISA confirmed the presence of anti-C1q antibodies in C57BL/6 mice after treatment with curli/DNA, extracted from E. coli or Salmonella biofilms, or infection with Salmonella. Prior to the onset of spontaneous disease, sera from young NZBxW/F1 mice, injected with curli, demonstrated increased anti-dsDNA and anti-C1q antibody responses compared to PBS-treated controls; however, no differences were found in older mice, post-onset, when autoantibody levels were already high. In MRL/lpr mice, curli treatment significantly exacerbated anti-C1q antibody production regardless of age and disease stage, compared to PBS-treated controls. While curli treatment did not significantly affect proteinuria in either model, curli-treatment of MRL/lpr mice significantly increased C1q deposition in glomeruli. This study uncovers a novel mechanism for the induction of anti-C1q autoantibodies and how infection or dysbiosis may exacerbate renal disease in SLE. Author summary: Up to half of patients with systemic lupus erythematosus (SLE) develop lupus nephritis, a major cause of morbidity characterized by immune complex deposition and complement activation within the glomeruli. The deposition of immune complexes is thought to contribute to the development of kidney inflammation and injury. Our previous work found a link between anti-DNA antibody production and exposure to the biofilm matrices of bacteria like Salmonella and E. coli. Such bacterial infections or microbiota species overgrowths are associated with autoimmunity. Here, we found, for the first time, that purified biofilm matrix or Salmonella infection triggers the production of antibodies targeting C1q in both healthy and lupus-prone mouse models. Additionally, we showed that biofilm matrix administration increased C1q deposition in the glomeruli of lupus-prone mice, implicating bacterial biofilms in the exacerbation of lupus nephritis. This work highlights the interplay between environmental insults like bacterial infections, age, and the development or exacerbation of autoimmunity, in genetically predisposed individuals.", "abstract_shown": true, "affiliations": [ "Center for Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, United States of America", "Division of Rheumatology, Department of Medicine, UMass Chan Medical School, Worcester, Massachusetts, United States of America", "Durham VA Medical Center and Duke University Medical Center, Durham, North Carolina, United States of America", "Department of Medicine, NYU Grossman School of Medicine, New York, New York, United States of America" ], "article_type": "Research Article", "arxiv": null, "author_total": 11, "authors": [ { "affs": [ 0 ], "name": "Kaitlyn Grando" }, { "affs": [ 1 ], "name": "Molly Elkins" }, { "affs": [ 2 ], "name": "Lauren Nicastro" }, { "affs": [ 3 ], "name": "Shingo Bessho" }, { "name": "Sophia Olubajo" }, { "name": "Anita Kowal" }, { "name": "Vincent Tam" }, { "name": "Roberto Caricchio" }, { "name": "David Pisetsky" }, { "name": "Gregg J. Silverman" }, { "name": "Çagla Tükel" } ], "bibtex": "https://research.draconitic.com/paper/2g9xsbxv7jj3v.bib", "cited_by": 0, "doi": "10.1371/journal.ppat.1014666", "fulltext_url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014666", "id": "2g9xsbxv7jj3v", "issns": [ "1553-7374" ], "landing_url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014666", "language": null, "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "2745|Systemic Lupus Erythematosus Research" ], [ "plos", "/Biology and life sciences/Anatomy/Renal system/Kidneys" ], [ "plos", "/Biology and life sciences/Biochemistry/Proteins/Immune system proteins/Antibodies" ], [ "plos", "/Biology and life sciences/Biochemistry/Proteins/Immune system proteins/Antibodies/Autoantibodies" ], [ "plos", "/Biology and life sciences/Immunology/Clinical immunology/Autoimmune diseases/Lupus erythematosus/Systemic lupus erythematosus" ], [ "plos", "/Biology and life sciences/Immunology/Immune system proteins/Antibodies" ], [ "plos", "/Biology and life sciences/Immunology/Immune system proteins/Antibodies/Autoantibodies" ], [ "plos", "/Biology and life sciences/Microbiology/Bacteriology/Bacterial biofilms" ], [ "plos", "/Biology and life sciences/Microbiology/Biofilms/Bacterial biofilms" ], [ "plos", "/Biology and life sciences/Physiology/Immune physiology/Antibodies" ], [ "plos", "/Biology and life sciences/Physiology/Immune physiology/Antibodies/Autoantibodies" ], [ "plos", "/Medicine and health sciences/Anatomy/Renal system/Kidneys" ], [ "plos", "/Medicine and health sciences/Clinical medicine/Clinical immunology/Autoimmune diseases/Lupus erythematosus/Systemic lupus erythematosus" ], [ "plos", "/Medicine and health sciences/Immunology/Clinical immunology/Autoimmune diseases/Lupus erythematosus/Systemic lupus erythematosus" ], [ "plos", "/Medicine and health sciences/Immunology/Immune system proteins/Antibodies" ], [ "plos", "/Medicine and health sciences/Immunology/Immune system proteins/Antibodies/Autoantibodies" ], [ "plos", "/Medicine and health sciences/Medical conditions/Infectious diseases/Bacterial diseases/Salmonellosis" ], [ "plos", "/Medicine and health sciences/Rheumatology/Systemic lupus erythematosus" ], [ "plos", "/Research and analysis methods/Animal studies/Experimental organism systems/Animal models/Mouse models" ], [ "plos", "/Research and analysis methods/Animal studies/Experimental organism systems/Model organisms/Mouse models" ], [ "plos", "/Research and analysis methods/Immunologic techniques/Immunoassays/Enzyme-linked immunoassays" ], [ "plos", "/Research and analysis methods/Model organisms/Mouse models" ] ], "openalex": "W7215065301", "pdf_url": "https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1014666&type=printable", "pmcid": null, "pmid": null, "published": "2026-10-01", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/2g9xsbxv7jj3v.ris", "sources": [ { "first_seen": "2026-10-30T12:17:37Z", "native_id": "10.1371/journal.ppat.1014666", "source": "plos", "url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014666" } ], "subjects": [ { "field": "biology", "origin": "plos:immunology", "subfield": "immunology" }, { "field": "medicine", "origin": "plos:anatomy", "subfield": "physiology" } ], "title": "Salmonella infection and biofilms drive anti-C1q and anti-dsDNA autoantibodies in systemic autoimmunity", "title_text": "Salmonella infection and biofilms drive anti-C1q and anti-dsDNA autoantibodies in systemic autoimmunity", "type": "peer-reviewed", "updated_at": "2026-10-30T12:17:37Z", "url": "https://research.draconitic.com/paper/2g9xsbxv7jj3v", "venue": "PLOS Pathogens", "versions": [] }