Development, maturation and subsequent activation of follicular dendritic cells (FDC): immunohistochemical observation of human fetal and adult lymph nodes

Abstract

To elucidate the processes involved in development and activation of human follicular dendritic cells (FDC), immunohistochemistry was performed on paraffin sections of fetal lymph nodes (FLN) obtained from archived autopsy material, and of adult reactive lymph nodes (ARLNs) excised for diagnostic purpose, using a panel of antibodies. Our study showed that tiny clusters of CNA.42(+ )KiM4p(+) cells, surrounded by some B-lymphocytes, initially arose in the cortical area of underdeveloped FLN around the 20th gestational week. No co-expression of CD21 and CD35 was found. In the relatively developed FLN of the same gestational age, small eddies of immature FDC, which expressed CD21, CD35, and nerve growth factor receptor (NGFR), as well as CNA.42 and KiM4p, were observed within ill-defined aggregations of B-lymphocytes. As gestation progressed, more B-lymphocytes assembled in a compact manner and formed primary lymphoid follicles containing an extending web of mature FDC, which expressed CNA.42, KiM4p, CD21, CD35, NGFR, and sometimes CD23 and X-11. In well-developed secondary follicles of ARLNs, activated FDC expressed additional molecules such as CD55, CD106, and S100alpha. Our observations identified the processes of phenotypic alteration of human FDC and established practical indicators determining their developmental stage and functional phase.

Modeling emergent tissue organization involving high-speed migrating cells in a flow equilibrium

“…More specifically, the motility properties of the cells could be adjusted to in vivo motility data of lymphocytes in lymphoid follicles. The model generates homeostatic follicles in a flow equilibrium of reasonable size of few 100 µm [50,[92][93][94][95] demonstrating that the model architecture is able to describe systems that are in a cell flow equilibrium of fast migrating cells.…”

IgM memory B cells: a mouse/human paradox

“…Germinal centers were analyzed by confocal microscopy of two spleen samples, one from a 4-year-old child, one from a young adult. The IgD marker was used, together with CNA.42 that marks follicular dendritic cells (FDC) throughout their development, and CD55 that marks FDCs in reactive lymphoid tissues [59]. CD38 marks GC B cells.…”

Serum and Tissue CD23, IL‐15, and FasL in Cow's‐Milk Protein–sensitive Enteropathy and in Coeliac Disease

“…Immunoreaction for CD23 was always present in the germinal centres (Fig. 3A), where dendritic reticulum cells show a constant expression (23,24), and have recently been shown to be a dynamic population with ample apoptosis (24). Because the presence of germinal centres in mucosa correlates with endoscopical LNH, a feature clearly connected with CMSE (4)(5)(6)8,15,25), the presence and extent of LNH would have been a plausible explanation for the increase of sCD23; however, our finding that sCD23 concentrations in patients with CMSE were not related to the absence or presence of LNH favours the idea that increase in sCD23 does not originate from the abundant mucosal lymphatic tissue.…”