Abstract

Based on the known accumulation of mast cells (MCs) in B cell-dependent inflammatory diseases, including rheumatoid arthritis, we hypothesized that MCs directly modulate B cells. We show here that degranulated, and to a lesser extent naive or IgE-sensitized, MCs activate both naive and B cell receptor-activated B cells. This was shown by increased proliferation, blast formation, and expression of CD19, MHC class II and CD86 in the B cells. Further, MCs stimulated the secretion of IgM and IgG in IgM(+) B cells, indicating that MCs can induce class-switch recombination in B cells. We also show that coculture of MCs with B cells promotes surface expression of L-selectin, a homing receptor, on the B cells. The effects of MCs on B cells were partly dependent on cell-cell contact and both follicular and marginal zone B cells could be activated by MCs. Our findings suggest that degranulated MCs support optimal activation of B cells, a finding that is in line with in vivo studies showing that MCs frequently degranulate in the context of B-cell driven pathologies such as arthritis. Together, our findings show that MCs have the capacity to differentiate B cells to effector cells.

Published in

Scientific Reports
2016, Volume: 6, article number: 20531
Publisher: NATURE PUBLISHING GROUP

SLU Authors

• Garcia Faroldi, Gianni

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Pejler, Gunnar

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Uppsala University

Associated SLU-program

Future Animal Health and Welfare (until Jan 2017)


UKÄ Subject classification

Immunology in the medical area


Publication identifier

DOI: https://doi.org/10.1038/srep20531

Permanent link to this page (URI)

https://res.slu.se/id/publ/79420