The origin of follicular dendritic cells in the mouse and the mechanism of trapping of immune complexes on them

Abstract

F1----parental bone marrow chimeras between CBA and B10 mice were used to show that even after 1 year follicular dendritic cells (FDC), also termed dendritic reticular cells, are not derived from bone marrow stem cells. However clusters of cells wrapped in the dendritic processes of FDC, isolated by enzyme digestion of the spleen contain B cells originating from donor marrow. This implies that evidence for the presence of antigens such as Ia-like detected by others (Gerdes, J. and Stein, H., Clin. Exp. Immunol. 1982. 48: 348) by immunohistology in or on FDC clusters should be interpreted with caution. Deposition of immune complexes on mouse spleen FDC depends upon the presence of a radio- and cyclophosphamide-sensitive population of cells, although FDC themselves are resistant to such treatments. After whole body irradiation the capacity to localize fluorescein isothiocyanate-labeled aggregated human gamma globulin can be restored by normal or T-deprived spleen cells, but restoration requires an interval of more than 1 though less than 5 days. These findings are compatible with the evidence of Gray et al., Eur. J. Immunol. 1984. 14: 47, that in the rat immune complexes are transported to FDC by a sessile population of marginal zone lymphocytes, as first suggested by Brown et al., Immunology 1973. 24: 955.

Lymphoid Chemokine B Cell-Attracting Chemokine-1 (CXCL13) Is Expressed in Germinal Center of Ectopic Lymphoid Follicles Within the Synovium of Chronic Arthritis Patients

“…Kapasi et al (23) reported that precursors of FDC exist in bone marrow, move into target organs, and differentiate into FDC, while Humphery et al (24) and Yamakawa et al (25) did not support the idea that FDC originate from bone marrow. According to previous reports using knockout mice, lymphotoxin-␣ and TNFRI play a crucial role in establishing FDC in vivo (26 -30).…”

Follicular dendritic cells: origin, function, and different disease-associated patterns

“…Moreover, the ultrastructure, cytology, and immunophenotype of FDCs do not support a hematopoietic origin but favor a mesenchymal origin and raise the issue whether they arise from further differentiation of a local fibroblastic reticular cell [7][8][9] or from a migratory mesenchymal cell, likely from the bone marrow [10,11]. Most ultrastructural studies point to a fibroblastic origin for FDCs in their less differentiated forms; however, the mature FDCs differ from fibroblasts in that they bear a complex network of long branching dendrites that retain an electron-dense material and possess desmosomal and adherent junctions [5].…”

The long-term maintenance of cytotoxic T-cell memory does not require persistence of antigen

“…There exists good evidence that B cell memory requires continuous restimulation by antigen, which is facilitated by follicular dendritic ceils (24,25) presenting the trapped B cell epitope in its original immunogenic form. T cells, however, recognize epitopes consisting of MHC molecules plus processed antigen.…”