Sonic hedgehog is produced by follicular dendritic cells and protects germinal center B cells from apoptosis.

Wnt5a is secreted by follicular dendritic cells to protect germinal center B cells via Wnt/Ca2+/NFAT/NF-κB-B cell lymphoma 6 signaling.

Follicular dendritic cells (FDCs) protect germinal center (GC) B cells from rapid apoptosis to allow their survival and maturation. In this article, we show that FDCs normally produce and secrete Wnt5a to protect GC B cells. Wnt5a production is upregulated by polyI:C. Purified Wnt5a protects GC B cells from apoptosis in a dose-dependent manner. GC B cells are protected by FDC coculture or condi...

Germinal center B cell apoptosis requires both caspase and cathepsin activity.

Follicular dendritic cells (FDCs) select B cells during germinal center (GC) reactions. The B cells that are able to bind to the FDCs receive a signal that leads to the termination of endonuclease activity in the nuclei of those B cells. This signal must be in addition to the signals transferred through the cross-linkage of the B cell receptors and signals resulting from the interactions of the...

Biology of germinal centers in lymphoid tissue.

Germinal centers in lymphoid tissue are the sites of generation of memory B cells undergoing isotype switching and somatic mutation in their Ig genes. Their formation cannot be induced by stimuli other than immunogenic ones. It seems likely that in the function and possibly also in the formation of germinal centers, one important factor is the localization of immune complexes with fixed complem...

Cells from Apoptosis Dendritic Cells Protect Germinal Center B Notch Ligands Expressed by Follicular

Follicular dendritic cells inhibit apoptosis in human B lymphocytes by a rapid and irreversible blockade of preexisting endonuclease

During germinal center reactions, a minority of B lymphocytes are selected after successful binding to follicular dendritic cells (FDCs). The majority of the B cells, however, die by apoptosis. One of the characteristics of apoptosis is rapid fragmentation of DNA by an endogenous endonuclease. The regulation of apoptosis and endonuclease activity in germinal center (GC) B cells is largely unkno...