title: Self-Restrained B Cells Arise following Membrane IgE Expression.
abstract: Among immunoglobulins (Igs), IgE can powerfully contribute to antimicrobial immunity and severe allergy despite its low abundance. IgE protein and gene structure resemble other Ig classes, making it unclear what constrains its production to thousand-fold lower levels. Whether class-switched B cell receptors (BCRs) differentially control B cell fate is debated, and study of the membrane (m)IgE class is hampered by its elusive in vivo expression. Here, we demonstrate a self-controlled mIgE+B cell stage. Primary or transfected mIgE+cells relocate the BCRs into spontaneously internalized lipid rafts, lose mobility to chemokines, and change morphology. We suggest that combined proapoptotic mechanisms possibly involving Hax1 prevent mIgE+memory lymphocyte accumulation. By uncoupling in vivo IgE switching from cytokine and antigen stimuli, we show that these features are independent from B cell stimulation and instead result from mIgE expression per se. Consequently, few cells survive IgE class switching, which might ensure minimal long-term IgE memory upon differentiation into plasma cells.
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Brice
authors: B
authors: Laffleur
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Sophie
authors: S
authors: Duchez
authors: INSERM U917, Université de Rennes, Rennes 35000, France.
authors: Karin
authors: K
authors: Tarte
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Nicolas
authors: N
authors: Denis-Lagache
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Sophie
authors: S
authors: Péron
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Claire
authors: C
authors: Carrion
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France.
authors: Yves
authors: Y
authors: Denizot
authors: Université de Limoges, 87000 Limoges, France; CNRS UMR 7276, Institut Universitaire de France, Limoges 87000, France. Electronic address: cogne@unilim.fr.
authors: Michel
authors: M
authors: Cogné