Project description:NOD mice spontaneously develop lacrimal gland inflammation. NOD mice that lack TLR7 or that lack IFNAR1 are protected from developing lacrimal gland inflammation. RNA sequencing studies were performed to compare gene expression profiles in lacrimal glands from wild-type (WT) vs Tlr7 knockout or Ifnar1 knockout nonobese diabetic (NOD) mice to determine disease-relevant gene and pathway profiles upregulated in WT lacrimal glands in either a TLR7- or IFNAR1-dependent manner.
Project description:UNC93B1 is critical for trafficking and function of nucleic acid-sensing Toll-like receptors (TLRs) TLR3, TLR7, TLR8, and TLR9, which are essential for antiviral immunity. Overactive TLR7 signaling induced by recognition of self-nucleic acids has been implicated in systemic lupus erythematosus (SLE). Here, we report UNC93B1 variants (E92G and R336L) in four patients with early-onset SLE. Patient cells or mouse macrophages carrying the UNC93B1 variants produced high amounts of TNF-α and IL-6 and upon stimulation with TLR7/TLR8 agonist, but not with TLR3 or TLR9 agonists. E92G causes UNC93B1 protein instability and reduced interaction with TLR7, leading to selective TLR7 hyperactivation with constitutive type I IFN signaling. Thus, UNC93B1 regulates TLR subtype-specific mechanisms of ligand recognition. Our findings establish a pivotal role for UNC93B1 in TLR7-dependent autoimmunity and highlight the therapeutic potential of targeting TLR7 in SLE.
Project description:Recently, we reported the development of the C57BL/6.NOD-Aec1Aec2 mouse that carries two genetic intervals derived from the NOD mouse capable of conferring Sjogren's syndrome (SjS)-like disease in SjS-non-susceptible C57BL/6 mice. In an attempt to define the molecular bases underlying onset of stomatitis sicca (xerostomia) in this C57BL/6.NOD-Aec1Aec2 mouse model, we have carried out a study utilizing genomic microarray technology. The present study was designed to define the changing gene expression profiles within the Lacrimal glands of C57BL/6.NOD-Aec1Aec2 mice at five time points representing a pre-disease stage (4 weeks), the early pre-clinical stage (8 weeks), the initial influx of leukocytes into the Lacrimal glands (12 weeks), the early clinical phase of autoimmunity (16 weeks), and the early onset of clinical SjS-like disease characterized by secretory dysfunction (20 weeks). The C57BL/6.NOD-Aec1Aec2 mouse is a model of primary SjS in which the Idd3 region of chromosome 3 and the Idd5 region of chromosome 1 derived from the NOD mouse were bred into the non-autoimmune C57BL/6 mouse, resulting in a SjS-like disease susceptibility that mimics both the pathophysiological characteristics and reduced secretory responses observed with NOD mice during development and onset of disease. This SjS-susceptible strain was designated C57BL/6.NOD-Aec1Aec2, where Aec1 corresponds to Idd3 (of chromosome 3) and Aec2 corresponds to Idd5 (of chromosome 1).
Project description:Systemic autoimmune diseases such as lupus and scleroderma are characterized by the loss of tolerance to nuclear antigens, but the mechanisms by which specific autoantibodies are selected are unclear. Here we report that B cells containing the Y-linked autoimmune accelerator (Yaa) locus are intrinsically biased towards nucleolar antigens due to a duplication of TLR genes in the pseudoautosomal region that makes them more responsive to TLR7 ligands and augments the Btk-dependent signaling pathway. These findings provide genetic evidence that naturally occurring differences in expression of TLR7 have a dramatic impact on antigen selection in autoimmunity. Follicular B cells were isolated from spleen of C57BL/6 male and C57BL/6.Yaa male. Four mice from each group using in this analysis were 2 months old. Dye swab labeled RNA had been done in one mice from each group.
Project description:Prior to the onset of autoimmune destruction, type 1 diabetic patients and an animal model thereof, the nonobese diabetic (NOD) mouse, show morphological and functional abnormalities in target organs, which may act as inciting events for leukocyte infiltration. To better understand these abnormalities, but without the complications associated with inflammatory infiltrates, we examined genes expressed in autoimmune target tissues (pancreas, submandibular glands, and lacrimal glands) of NOD/scid mice and of autoimmune-resistant C57BL6/scid mice. Keywords: tissue expression, disease prone versus resistant strain comparison
Project description:Prior to the onset of autoimmune destruction, type 1 diabetic patients and an animal model thereof, the nonobese diabetic (NOD) mouse, show morphological and functional abnormalities in target organs, which may act as inciting events for leukocyte infiltration. To better understand these abnormalities, but without the complications associated with inflammatory infiltrates, we examined genes expressed in autoimmune target tissues (pancreas, submandibular glands, and lacrimal glands) of NOD/scid mice and of autoimmune-resistant C57BL6/scid mice. Experiment Overall Design: Pancreata (6 weeks old mice), submandibular (9 and 15 weeks), and lacrimal glands (15 weeks) from individual NOD-scid and B6-scid mice were isolated for RNA extraction and hybridization on Affymetrix microarrays.
Project description:NOD mice were injected once a week with LTBR-Ig to block the LTBR-pathway, or with control monoclonal antibody MOPC from age 8 to 16 weeks old. Extraorbital lacrimal glands or submaxillary glands were dissected and total mRNA prepared. Each sample was either the combined lacrimals (2) from each mouse or individual salivary glands. There were 4 mice in each treatment group. Total mRNA was isolated and the quality was assessed using the Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA). Reverse transcription to prepare cDNA was performed using Invitrogen M-MLV system. The purpose was to determine changes in gene expression in glands due to blockade of the LTBR-pathway. Differential Gene Expression in NOD mouse lacrimal and salivary glands after LTBR-Ig treatment
Project description:Systemic autoimmune diseases such as lupus and scleroderma are characterized by the loss of tolerance to nuclear antigens, but the mechanisms by which specific autoantibodies are selected are unclear. Here we report that B cells containing the Y-linked autoimmune accelerator (Yaa) locus are intrinsically biased towards nucleolar antigens due to a duplication of TLR genes in the pseudoautosomal region that makes them more responsive to TLR7 ligands and augments the Btk-dependent signaling pathway. These findings provide genetic evidence that naturally occurring differences in expression of TLR7 have a dramatic impact on antigen selection in autoimmunity. Keywords: genetic modification, Yaa locus
Project description:Type I interferon (IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to regulate sterile and infectious immunity. IFNAR1 expression is tightly regulated to prevent autoimmunity although the mechanisms governing this are incompletely understood. We investigated the strategies used by two flaviviruses, tick-borne encephalitis virus and West Nile virus, to antagonize IFN-I signaling. Infection with these viruses resulted in depletion of IFNAR1 associated with the function of the viral IFN-I antagonist, NS5. NS5 function was dependent on its ability to associate with prolidase (PEPD), a cellular dipeptidase. PEPD was required for IFNAR1 maturation and accumulation, as well as gene induction following IFNAR1 stimulation. The relevance of PEPD to human biology was confirmed in fibroblasts derived from patients with genetic prolidase deficiency that expressed low IFNAR1 and exhibited reduced responses to IFNAR1. Thus, by understanding flavivirus IFN-I antagonism, PEPD is revealed as a central regulator of IFN-I responses in humans. RNA was isolated from replicates of 4 cultured dermal fibroblast lines derived from patients with genetic prolidase deficiency (PEPD), as well as from 4 cultured dermal fibroblast lines derived from normal healthy donors. These were run on Agilent microarrays to compare differences in gene expression observed in PEPD fibroblasts compared with normal fibroblasts.