Coronin 1 Is Essential for IgM-Mediated Ca2+ Mobilization in B Cells but Dispensable for the Generation of Immune Responses In Vivo

Coronin 1 is a leukocyte specific regulator of Ca2+-dependent signaling and is essential for the survival of peripheral T lymphocytes, but its role in B cells is unknown. In this study, we show that coronin 1 is essential for intracellular Ca2+ mobilization and proliferation upon triggering of the BCR. However, the presence of costimulatory signals rendered coronin 1 dispensable for B cell signaling, consistent with the generation of normal immune responses against a variety of Ags in coronin 1-deficient mice. We conclude that coronin 1, while being essential for T cell function and survival, is dispensable for B cell function in vivo. The Journal of Immunology, 2009, 182: 1954-1961.