B cells with regulatory properties (Bregs) were identified in human and in mice among different B-cell subsets. Their regulatory properties rely mainly on the production of anti-inflammatory cytokines, in particular IL10, IL-35 and TGFβ, and were extensively studied in mouse models of autoimmune and inflammatory diseases. However, the exact nature of the stimulatory signals conferring regulatory properties to B cells is still not clear. We serendipitously observed that fluorescein isothiocyanate (FITC) binds to a significant proportion of naïve mouse B cells. Binding of FITC to the B-cell surface implicated at least in part the B-cell receptor. It triggered IL-10 production and allowed the endocytosis of FITC-coupled antigens followed by their presentation to CD4+ T cells. In particular, B cells incubated with FITC-OVA polarized OTII T cells towards a Tr1/Th2 phenotype in vitro. Further, the adoptive transfer of B cells incubated with FITC-labeled myelin oligodendrocyte glycoprotein peptide protected mice from experimental autoimmune encephalomyelitis, a T-cell-dependent autoimmune model. Together, the data show that FITC-stimulated B cells polarize immune responses towards Tr1/Th2 and acquire immuno-modulatory properties.
Bibliographical noteFunding Information:
This work was supported by INSERM, CNRS, Sorbonne Université and by a grant from LFB (Les Ulis, France). We wish to express our gratitude to Christophe Sirac (UMR CNRS 7276/INSERM U1262, Université de Limoges) and Christian Vosshenrich ( Institut Pasteur , Paris, France) for sharing LMP2 mice and OTII mice, respectively.
Copyright 2020 Elsevier B.V., All rights reserved.
- Experimental autoimmune encephalitis
- Immuno-modulatory B cells
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