Death-receptor contribution to the germinal-center reaction.

Both helper T cells and follicular dendritic cells play crucial roles in the germinal-center (GC) reaction. One of their key functions is to provide GC B cells with anti-apoptotic signals during their growth, diversification of antibody repertoire and positive selection. Dysregulation of the mechanisms that control B-cell apoptosis in the GC could cause hyperplasia, endanger self-tolerance or impair dramatically the efficiency of the humoral response. This article discusses how the death receptor Fas and components of its signaling machinery contribute to the GC reaction.