B and T Lymphocyte Attenuator Suppresses IL-21 Production from Follicular Th Cells and Subsequent Humoral Immune Responses

摘要: We recently showed that mice lacking B and T lymphocyte attenuator (BTLA), a third inhibitory coreceptor expressed on cells cells, exhibit an increased Ag-specific IgG response gradually develop hyper-γ–globulinemia autoantibody production. Recent studies revealed follicular Th (Tfh) which are non-Th1, non-Th2 effector express CXCR5 provide help for to produce Ig, also BTLA. However, the role of BTLA in Tfh cell function remains unknown. In this study, we examined regulatory development cells. found CXCR5+ higher levels than did CXCR5− conventional CD4+ adoptive transfer BTLA−/− stimulated under cell-inducing conditions (Tfh-like cells), wild-type (WT) induced more IgG2a IgG2b production compared with WT Tfh-like By contrast, another adoptive-transfer experiment using as recipients expression was not involved regulation cell-mediated responses. Moreover, IL-21–producing significantly Furthermore, responses were abolished when IL-21R−/− used recipients. These results suggest signaling suppresses IL-21 from subsequent