IgE actions on CD4+ T cells, mast cells, and macrophages participate in the pathogenesis of experimental abdominal aortic aneurysms.
Bottom Line: Immunoglobulin E (IgE) activates mast cells (MCs).This study demonstrates that CD4+ T cells express IgE receptor FcεR1, at much higher levels than do CD8+ T cells.IgE induces CD4+ T-cell production of IL6 and IFN-γ, but reduces their production of IL10.
Affiliation: Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.Show MeSH
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Mentions: We have previously shown that IgE activates human macrophages, SMCs, and ECs, and induces their apoptosis (Wang et al, 2011). The present study suggested a role of IgE stimulation of CD4+ T cells, MCs, and macrophages in experimental AAA formation. Inflammatory cells in human AAA lesions might also express IgE receptor FcεR1 and bind for IgE. Indeed, CD68-positive macrophages demonstrated expression of FcεR1 and IgE in consecutive frozen sections of human AAAs. Consistent with our prior study (Wang et al, 2011), IgE-positive and FcεR1-positive macrophages in human AAA lesions also underwent apoptosis as shown by TUNEL-positivity (Fig 8A). IgE binding to macrophages also triggers cytokine expression from these cells (Wang et al, 2011) as in CD4+ T cells. Immunofluorescent staining colocalized the expression of both IgE and FcεR1 on CD4+ T cells in human AAA lesions (Fig 8B).
Affiliation: Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.