Follicular Dendritic Cells - Location and Molecular Markers

Location and Molecular Markers

Follicular DCs are a non-migratory population found in primary and secondary follicles of the B cell areas of lymph nodes, spleen, and mucosa-associated lymphoid tissue (MALT). They form a stable network due to intercellular connections between FDCs processes and intimate interaction with follicular B cells. Follicular DCs network typically forms the center of the follicle and does not extend from the follicle to the interfollicular regions or T- cell zone. Supposedly, this separation from the sites of earliest antigen processing and capture provide a protected environment in which opsonized antigens can be displayed for a long time without being proteolyzed or removed by phagocytic cells. Follicular DCs have high expression of complement receptors CR1 and CR2 (CD 35 and CD 21 respectively) and Fc-receptor FcγRIIb (CD32). Further FDCs specific molecular markers are FDC-M1, FDC-M2 and C4. Unlike other DCs and macrophages, FDCs lack MHC class II antigen molecules and express few pattern-recognition receptors, so they have little ability to capture non-opsonized antigens.