Publications by authors named "Benjamin Umiker"

Common variable immunodeficiency (CVID) is an immune defect characterized by hypogammaglobulinemia and impaired development of B cells into plasma cells. As follicular helper T cells (T) play a central role in humoral immunity, we examined T cells in CVID, and investigated whether an inducible T cell co-stimulator (ICOS) agonist, vopratelimab, could modulate T, B cell interactions and enhance immunoglobulin production. CVID subjects had decreased T and increased T subsets; this was associated with increased transitional B cells and decreased IgG B and IgDIgMCD27 memory B cells.

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Crohn's disease (CD) is a chronic disorder of the gastrointestinal tract characterized by inflammation and intestinal epithelial injury. Loss of function mutations in the intracellular bacterial sensor NOD2 are major risk factors for the development of CD. In the absence of robust bacterial recognition by NOD2 an inflammatory cascade is initiated through alternative PRRs leading to CD.

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Ficolins are a group of oligomeric defense proteins assembled from collagen-like stalks and fibrinogen-like domains that have common biochemical specificity for N-acetyl-d-glucose amine (GlcNAc) and can function as opsonins. In this report, GlcNAc-binding protein (GBP) purified from porcine nonimmune serum was biochemically characterized as ficolin-α. Ficolin-α was used as an immunogen to generate both rabbit polyclonal and murine monoclonal anti-ficolin-α antibodies, which are not yet commercially available.

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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of anti-nuclear antibodies. SLE is one of many autoimmune disorders that have a strong gender bias, with 70-90% of SLE patients being female. Several explanations have been postulated to account for the severity of autoimmune diseases in females, including hormonal, microbiota, and gene dosage differences.

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Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of pathogenic IgG antinuclear antibodies. Pathogenic IgG autoantibody production requires B-cell activation, leading to the production of activation-induced deaminase (AID) and class switching of IgM genes to IgG. To understand how and when B cells are activated to produce these IgG autoantibodies, we studied cells from 564Igi, a mouse model of SLE.

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Systemic lupus erythematosus (SLE) is an autoimmune disease with a high incidence in females and a complex phenotype. Using 564Igi mice, a model of SLE with knock-in genes encoding an autoreactive anti-RNA Ab, we investigated how expression of Toll-like receptors (TLRs) in B cells and neutrophils affects pathogenesis. We established that TLR signaling through MyD88 is necessary for disease.

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Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of antinucleic acid autoantibodies, high levels of circulating type I interferon (IFN-I), and an IFN-I-dependent elevated expression of activating FcγR. Increases in neutrophils and monocytes are often observed in clinical SLE, but how these contribute to autoantibody and IFN-I production is poorly understood. Here, we analyzed SLE pathogenesis in 564Igi mice, an SLE-model strain carrying gene-targeted heavy and light chain antibody genes encoding an anti-RNA autoantibody in a C57BL/6 background.

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