Follicular dendritic cells (FDCs) are specialized cells found within the follicles of secondary lymphoid organs, particularly in lymph nodes and spleen. These cells play a crucial role in the immune response by facilitating the development and function of B cells.
FDCs are stellate-shaped cells with long, finger-like projections called dendrites. These dendrites extend into the follicular network where they form a complex network of interconnected processes. FDCs are unique among other dendritic cell subsets, as they lack the ability to initiate an immune response by presenting antigens to T cells. Instead, they primarily interact with B cells and aid in their activation, maturation, and maintenance.
One of the key functions of FDCs is to trap and retain antigens, particularly immune complexes formed by the binding of antibodies to foreign pathogens. FDCs capture these immune complexes using their dendritic processes and store them within specialized compartments called immune complexes or germinal centers. This provides a localized environment for B cells to encounter the antigens and initiate an immune response.
Furthermore, FDCs play a crucial role in the formation and maintenance of germinal centers, which are vital for the development of an effective immune response. These structures serve as sites for B cell proliferation, somatic hypermutation, antibody class switching, and affinity maturation.
In summary, follicular dendritic cells are specialized cells found within secondary lymphoid organs that primarily interact with B cells. Their main functions include trapping and retaining antigens, aiding in the formation of germinal centers, and supporting the development and maintenance of an effective humoral immune response.
