Follicular Dendritic Cells (B Lymphocyte Stimulating)

Follicular dendritic cells (FDCs) are unique immune system cells that contribute to the maintenance of humoral (i.e. antibody) immune responses. These cells are located in the follicles of secondary lymphoid tissues (e.g. lymph nodes and spleen), where they trap and retain antigens in the form of highly immunogenic immune complexes (ICs). FDC-ICs are composed of antigen plus specific antibody and/or complement proteins. These trapped antigens, combined with other soluble and membrane-bound signals contributed by FDCs, are essential to the development and maintenance of the germinal centre reaction and IgG and IgE responses respectively. FDCs also appear to contribute to initial IgM responses. In addition to their positive effects on humoral immunity, FDCsmay promote diseases includingHIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome), prion diseases and follicular lymphomas. A better understanding of FDCs should permit better regulation of antibody responses and may also allow the amelioration of some disease states.