Jill Henault, Jeffrey M Riggs, Jodi L Karnell, Vladimir M Liarski, Jianqing Li, Lena Shirinian, Linda Xu, Kerry A Casey, Michael A Smith, Deepak B Khatry, Liat Izhak, Lorraine Clarke, Ronald Herbst, Rachel Ettinger, Michelle Petri, Marcus R Clark, Tomas Mustelin, Roland Kolbeck, Miguel A Sanjuan
Canonically, immunoglobulin E (IgE) mediates allergic immune responses by triggering mast cells and basophils to release histamine and type 2 helper cytokines. Here we found that in human systemic lupus erythematosus (SLE), IgE antibodies specific for double-stranded DNA (dsDNA) activated plasmacytoid dendritic cells (pDCs), a type of cell of the immune system linked to viral defense, which led to the secretion of substantial amounts of interferon-α (IFN-α). The concentration of dsDNA-specific IgE found in patient serum correlated with disease severity and greatly potentiated pDC function by triggering phagocytosis via the high-affinity FcɛRI receptor for IgE, followed by Toll-like receptor 9 (TLR9)-mediated sensing of DNA in phagosomes...
February 2016: Nature Immunology