Fascin-positive dendritic cells and fibroblastic reticulum cells build a framework of T-cell areas in lymph nodes
ABSTRACT Fascin, a 55-kDa actin-bundling protein, and alpha-smooth muscle actin (ASMA) were immunohistochemically examined in murine normal and stimulated lymph nodes. In specific pathogen-free young female mice, a few fascin-positive cells (FPCs) were located in the sinus and surrounding tissues, but ASMA-positive cells were undetectable. Following a subcutaneous injection of sheep red blood cells, the numbers of FPCs and their dendrites increased in the paracortex, with the accumulation of activated lymphocytes. Fibroblastic reticulum cells (FRCs), endothelial cells, histiocytic cells and lymphocytes in various stages of maturation were all fascin negative. These results indicated that fascin could be a reliable marker of paracortical dendritic cells in murine lymph nodes. However, FRCs became ASMA positive. Immunoelectron microscopy showed that the FPCs were interdigitating cells and that they closely contacted with FRCs. These two types of cells and reticular fiber formed a network in the paracortex and contacted with each other. In active paracortical response, both FPCs and FRCs are also stimulated and might play a significant role in the maturation of the lymphocytes.
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ABSTRACT: Experimental autoimmune neuritis (EAN) is a well-known animal model of human demyelinating polyneuropathies and is characterized by inflammation and demyelination in the peripheral nervous system. Fascin is an evolutionarily highly conserved cytoskeletal protein of 55 kDa containing two actin binding domains that cross-link filamentous actin to hexagonal bundles. Here we have studied by immunohistochemistry the spatiotemporal accumulation of Fascin + cells in sciatic nerves of EAN rats. A robust accumulation of Fascin + cell was observed in the peripheral nervous system of EAN which was correlated with the severity of neurological signs in EAN, CONCLUSION: Our results suggest a pathological role of Fascin in EAN.Virtual slides: The virtual slides for this article can be found here: http://www.diagnosticphatology.diagnomx.eu/vs/6734593451114811.Diagnostic Pathology 12/2013; 8(1):213. DOI:10.1186/1746-1596-8-213 · 2.41 Impact Factor
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ABSTRACT: The lymphoepithelial symbiosis (LES) of the human palatine tonsil is composed of spindle- or star-shaped epithelial cells forming a loose meshwork, containing numerous lymphocytes and dendritic cells (DCs). In the present study, we immunohistochemically characterized DCs in the LES (LES-DCs). LES-DCs were phenotypically immature DCs that were S100beta+, fascin-, HLA-DR+, CD1a-, CD80-, CD83-, CD86-, and CD123-. The most characteristic feature of LES-DCs was that they contacted many B cells, which were mostly IgM+ IgD+ resting naive B cells. Langerhans cells (LCs) located in the nonsymbiotic squamous epithelium were immature DCs that were S100beta+, fascin-, and CD1a+ and did not contact lymphocytes. In contrast to LES-DCs, interdigitating dendritic cells (IDCs) in the T zone were mature DCs that were HLA-DR+, CD1a-, fascin+, CD80+, CD83+, and CD86+ and contacted numerous CD4+ T cells. Two subsets of IDC, S100beta+ fascin+ IDC (IDC-1) and S100beta- fascin+ IDC (IDC-2), were identified, and the majority of IDCs are IDC-2. In contrast to IDCs, which were distributed in the T-cell area in groups, LES-DCs were distributed along the crypt as if forming a barrier. These findings suggest that LES-DCs are a novel type of DC playing an important role in the induction of humoral immune response against incoming air- or food-borne pathogenic antigens.Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 06/2006; 448(5):623-9. DOI:10.1007/s00428-005-0085-1 · 2.56 Impact Factor
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ABSTRACT: We previously reported the expression of cyclooxygenase (COX)-2 in draining lymph nodes during carrageenin-induced pleurisy of rats. Here, we analyzed histological and immunohistochemical characteristics of COX-2-expressing cells. After carrageenin administration into the pleural cavity of rats, parathymic lymph nodes were enlarged beginning at 8h and peaking from 24 to 48h. Lymphatic follicles disappeared 16h after injection, and numerous macrophages and fibroblasts were observed in the cortical region. COX-2-expressing cells in the cortical region showed characteristic dendritic processes from 16 to 48h and primarily co-localized with stromal fibroblastic reticular cell markers, α-smooth muscle actin (α-SMA), and desmin. Expression of α-SMA increased following COX-2 expression. Nimesulide, a COX-2 inhibitor, increased the dendritic processes of COX-2-expressing cells as well as expression of both COX-2 and α-SMA. These results suggest that COX-2-expressing cells may be stromal fibroblastic cells, which negatively self-regulate their proliferation and modulate tissue remodeling of draining lymph nodes at inflammatory sites.Prostaglandins & other lipid mediators 04/2013; DOI:10.1016/j.prostaglandins.2013.04.001 · 2.86 Impact Factor