Follicular dendritic cells control engulfment of apoptotic bodies by secreting Mfge8.

in Journal of Experimental Medicine (2008), 205(6), 1293-302

The secreted phosphatidylserine-binding protein milk fat globule epidermal growth factor 8 (Mfge8) mediates engulfment of apoptotic germinal center B cells by tingible-body macrophages (TBMphis ... [more ▼]

The secreted phosphatidylserine-binding protein milk fat globule epidermal growth factor 8 (Mfge8) mediates engulfment of apoptotic germinal center B cells by tingible-body macrophages (TBMphis). Impairment of this process can contribute to autoimmunity. We show that Mfge8 is identical to the mouse follicular dendritic cell (FDC) marker FDC-M1. In bone-marrow chimeras between wild-type and Mfge8(-/-) mice, all splenic Mfge8 was derived from FDCs rather than TBMphis. However, Mfge8(-/-) TBMphis acquired and displayed Mfge8 only when embedded in Mfge8(+/+) stroma, or when situated in lymph nodes draining exogenous recombinant Mfge8. These findings indicate a licensing role for FDCs in TBMphi-mediated removal of excess B cells. Lymphotoxin-deficient mice lacked FDCs and splenic Mfge8, and suffer from autoimmunity similar to Mfge8(-/-) mice. Hence, FDCs facilitate TBMphi-mediated corpse removal, and their malfunction may be involved in autoimmunity. [less ▲]

Follicular dendritic cells in lymph nodes after x-irradiation.

in International Journal of Radiation Biology and Related Studies in Physics, Chemistry, and Medicine (1982), 42(2), 121-30

Follicular dendritic cells (FDC), non lymphoid cells present in lymph follicles, are characterized by numerous cytoplasmic processes retaining antigen-antibody complexes. Their origin, nature and function ... [more ▼]

Follicular dendritic cells (FDC), non lymphoid cells present in lymph follicles, are characterized by numerous cytoplasmic processes retaining antigen-antibody complexes. Their origin, nature and function are unknown. Mice inguinal lymph nodes after 4.5 or 7.5 Gy X-irradiation were depleted of lymphoid cells. Ultrastructural observations during the first few days post-irradiation show that FDC are unaltered and possess dendritic processes enveloping dense material. Furthermore, they show intense metabolic activity. A lamina densa, never observed so well-developed in other lymph node cells, was detected around the nuclear envelope. The localization of junctions between FDC was analysed. FDC preserve their typical cytoplasmic processes even if lymphoid cells are rare. The latter thus seem not to be responsible for the maintenance of FDC integrity or their development. The possible role of this for antibody production is discussed. Irradiated lymph nodes of lymphoid cells are highly convenient for studying FDC. Isolation of FDC from irradiated lymph organs would seem to be possible. [less ▲]

Follicular dendritic cells in vitro modulate the expression of Fas and Bcl-2 on germinal center B cells.

in Cell & Tissue Research (2000), 299(3), 395-402

Germinal center (GC) B cells are highly susceptible to apoptosis. The cellular mechanism regulating this sensitivity, however, has not yet been fully delineated. To investigate whether follicular ... [more ▼]

Germinal center (GC) B cells are highly susceptible to apoptosis. The cellular mechanism regulating this sensitivity, however, has not yet been fully delineated. To investigate whether follicular dendritic cells (FDC) are capable of regulating the susceptibility to apoptosis of GC B cells, we constructed a GC model in vitro: emperipolesis of tonsillar B cells by FDC. We then analyzed the expressions of apoptosis-related proteins (Bcl-2 and Fas) on the cells by three-color flow cytometry. B cells nonentrapped by FDC decreased rapidly in number owing to early apoptosis in vitro, whereas entrapped B cells were rescued for at least 18 h and showed peculiar regulation of Fas and Bcl-2. GC founder cells (CD38+, IgD+; GCFC) and GC B cells (CD38+, IgD-) showed approximately a twofold increased expression of Fas; in contrast, mantle zone B cells (CD38-, IgD+) and memory B cells (CD38-, IgD-) showed no changes. Bcl-2 expression in mantle zone and memory B cells was reduced by approximately one-half; however, GCFC and GC B cells continued to express little Bcl-2 and this did not change. Our findings strongly suggest that FDC play a part in the modulation of the susceptibility to apoptosis on B cells within GC. [less ▲]

Follicular dendritic cells isolated from human tonsils.

in Advances in Experimental Medicine and Biology (1985), 186

Follicular dendritic cells: isolation procedures, short and long term cultures.

in Advances in Experimental Medicine and Biology (1993), 329

Follicular dendritic cells: whose children?

in Immunology Today (1994), 15(5), 201-4

At the recent Germinal Centre Conference in Spa*, over 200 immunologists gathered to study the fate of lymph follicles, B- and T-cell selection, cell migration, accessory cells, and pathological ... [more ▼]

At the recent Germinal Centre Conference in Spa*, over 200 immunologists gathered to study the fate of lymph follicles, B- and T-cell selection, cell migration, accessory cells, and pathological conditions such as lymphoproliferative diseases and AIDS. Here, Ernst Heinen and Alain Bosseloir report on this fascinating field. [less ▲]

Follow-up de 190 nouveau-nés а risque : résultats préliminaires

Conference (1992)

Follow-up of COLL2-1, COLL2-1NO2 and myeloperoxidase serum levels in marathon runners

Poster (2007)

Follow-up of COLL2-1, COLL2-1NO2 and myeloperoxydase in dogs after transection of the cruciate ligament of the knee

Poster (2009, May 23)

Purpose: To determine the profile of Coll2-1, Coll2-1NO2 and myeloperoxydase (MPO) serum concentrations in experimental knee OA induced in the dog by transection of the anterior cruciate ligament. Methods ... [more ▼]

Purpose: To determine the profile of Coll2-1, Coll2-1NO2 and myeloperoxydase (MPO) serum concentrations in experimental knee OA induced in the dog by transection of the anterior cruciate ligament. Methods: Surgical transection of the ACL of the right knee was performed on 16 adult crossbred dogs. The dogs were sacrificed 8 weeks after the surgical procedure. Coll2-1, Coll2-1NO2 and MPO were measured by specific immunoassays in 16 dogs at baseline and every 2 weeks during the 8 weeks. The results were expressed as median (range). Results: Immunostainings with D3 and D37, the antiserum recognizing Coll2-1 and Coll2-1NO2, respectively, labelled extracellular matrix in the superficial layer of fibrillated cartilage. After the transection of the ACL, the concentration of 3 biomarkers increased significantly (Friedman test: p<0.001). The concentrations of Coll2-1 and MPO were significantly increased at week 2 compared to baseline [Coll2-1 baseline: 281.57 (131.02-384.67) nM vs Coll2-1 week 2: 345.52 (181.15-589.25) nM (p<0.01) and MPO baseline: 5.16 (<0.4-14.7) ng/ml vs MPO week 2: 14.54 (3.28-31.50) ng/ml (p<0.001)] and remained stable until week 8 [Coll2-1 week 8:318.89 (117.95-492.28) nM and MPO week 8: 11.55 (2.87-42.94) ng/ml]. The Coll2-1NO2 concentration increased significantly at weeks 6 and 8 compared to baseline [Coll2-1NO2 baseline: 0.54 (0.29-1.48) nM vs Coll2-1NO2 week 6: 0.64 (0.40-1.9) nM (p<0.001) vs week 8: 0.61 (0.37-1.79) nM]. Conclusions: These findings suggest that Coll2-1 is a relevant marker for the detection of early structural changes in OA dogs. Interestingly, MPO and Coll2-1NO2 are increased in OA dogs indicating that an oxidative stress occurs in this OA model. [less ▲]

Follow-up of iron microalbuminuria in hypertensive patients: a belgian promise survey

in Acta Clinica Belgica (2003), 58-3(4), 328