First Author | Kitaura Y | Year | 2007 |
Journal | Immunity | Volume | 26 |
Issue | 5 | Pages | 567-78 |
PubMed ID | 17493844 | Mgi Jnum | J:123596 |
Mgi Id | MGI:3718864 | Doi | 10.1016/j.immuni.2007.03.015 |
Citation | Kitaura Y, et al. (2007) Control of the B cell-intrinsic tolerance programs by ubiquitin ligases Cbl and Cbl-b. Immunity 26(5):567-78 |
abstractText | B cell receptor (BCR) signaling plays a critical role in B cell tolerance and activation. Here, we show that mice with B cell-specific ablation of both Cbl and Cbl-b (Cbl-/-Cblb-/-) manifested systemic lupus erythematosus (SLE)-like autoimmune disease. The Cbl double deficiency resulted in a substantial increase in marginal zone (MZ) and B1 B cells. The mutant B cells were not hyperresponsive in terms of proliferation and antibody production upon BCR stimulation; however, B cell anergy to protein antigen appeared to be impaired. Concomitantly, BCR-proximal signaling, including tyrosine phosphorylation of Syk tyrosine kinase, Phospholipase C-gamma2 (PLC-gamma2), and Rho-family GTP-GDP exchange factor Vav, and Ca2+ mobilization were enhanced, whereas tyrosine phosphorylation of adaptor protein BLNK was substantially attenuated in the mutant B cells. These results suggested that the loss of coordination between these pathways was responsible for the impaired B cell tolerance induction. Thus, Cbl proteins control B cell-intrinsic checkpoint of immune tolerance, possibly through coordinating multiple BCR-proximal signaling pathways during anergy induction. |