MicroRNA-155 (miR-155) regulates antibody responses and subsequent B-cell effector functions to exogenous antigens. However, the role of miR-155 in systemic autoimmunity is not known. Using the death receptor deficient (Fas(lpr)) lupus-prone mouse, we show here that ablation of miR-155 reduced autoantibody responses accompanied by a decrease in serum IgG but not IgM anti-dsDNA antibodies and a reduction of kidney inflammation. MiR-155 deletion in Fas(lpr) B cells restored the reduced SH2 domain-containing inositol 5'-phosphatase 1 to normal levels. In addition, coaggregation of the Fc γ receptor IIB with the B-cell receptor in miR-155(-/-)-Fas(lpr) B cells resulted in decreased ERK activation, proliferation, and production of switched antibodies compared with miR-155 sufficient Fas(lpr) B cells. Thus, by controlling the levels of SH2 domain-containing inositol 5'-phosphatase 1, miR-155 in part maintains an activation threshold that allows B cells to respond to antigens.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864325 | PMC |
http://dx.doi.org/10.1073/pnas.1317632110 | DOI Listing |
Int J Mol Sci
December 2024
Departments of Genetics, Microbiology and Immunology, Center for Research on Harmful Effects of Biological and Chemical Hazards, Faculty of Medical Sciences, University of Kragujevac, 69 Svetozara Markovica Street, 34000 Kragujevac, Serbia.
Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by the infiltration of lymphocytes on salivary and lacrimal glands, resulting in their dysfunction. Patients suffering from severe pSS have an increased risk of developing multi-organ dysfunction syndrome due to the development of systemic inflammatory response, which results in immune cell-driven injury of the lungs, kidneys, liver, and brain. Therapeutic agents that are used for the treatment of severe pSS encounter various limitations and challenges that can impact their effectiveness.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
Military breachers are routinely exposed to repetitive low-level blast overpressure, placing them at elevated risk for long-term neurological sequelae. Mounting evidence suggests that circulating brain-reactive autoantibodies, generated following CNS injury, may serve as both biomarkers of cumulative damage and drivers of secondary neuroinflammation. In this study, we compared circulating autoantibody profiles in military breachers ( = 18) with extensive blast exposure against unexposed military controls ( = 19).
View Article and Find Full Text PDFBiomedicines
December 2024
Unit of Epidemiology & Statistical Medicine, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy.
: While post-acute COVID-19 syndrome is well known and extensively studied, the post-acute COVID vaccination syndrome (PACVS) is a more recent nosological entity that is poorly defined at the immunopathological level, although it shares many symptoms with the sequelae of viral infections. : This single-center retrospective study reports a case series of 17 subjects vaccinated with mRNA or adenoviral vector vaccines who were healthy before vaccination and had never been infected with SARS-CoV-2 but who presented with symptoms similar to PACVS for a median time of 20 months (min 4, max 32). The medical records of all patients referred to our outpatient clinic over a one-year period were retrospectively analyzed.
View Article and Find Full Text PDFBiomedicines
December 2024
Immunology Department and IdISSC, Hospital Clínico San Carlos, 28040 Madrid, Spain.
: Emerging evidence suggests that SARS-CoV-2 infection and vaccines may trigger autoimmune responses in predisposed individuals. Idiopathic inflammatory myopathies (IIMs) are diseases with diverse clinical manifestations, often associated with myositis autoantibodies (MAs). Diagnosing IIM is challenging due to limitations in classification criteria and diagnostic assays.
View Article and Find Full Text PDFAntioxidants (Basel)
December 2024
Unit of Nephrology, Dialysis and Transplantation and Laboratory of Molecular Nephrology, Core Facilities-Proteomics Laboratory, 16147 Genoa, Italy.
Historically, oxidants have been considered mechanisms of glomerulonephritis, but a direct cause-effect correlation has never been demonstrated. Several findings in the experimental model of autoimmune conditions with renal manifestations point to the up-regulation of an oxidant/anti-oxidant system after the initial deposition of autoantibodies in glomeruli. Traces of oxidants in glomeruli cannot be directly measured for their rapid metabolism, while indirect proof of their implications is derived from the observation that Superoxide Oxidase 2 (SOD2) is generated by podocytes after autoimmune stress.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!