Bone marrow stroma in humans: anti-nerve growth factor receptor antibodies selectively stain reticular cells in vivo and in vitro

Abstract

Two anti-nerve growth factor receptor (LNGFR or p75NGFR) antibodies, Me20.4 and Me8211, label stromal cells with dendritic features in fresh smears and in formalin-fixed, paraffin-embedded human bone marrow (BM). The LNGFR+ cells have an oval nucleus, a scanty cytoplasm with long dendrites that intermingle with the hematopoietic cells, line the abluminal side of sinus endothelial cells, and provide the scaffold for the hematopoietic marrow. At the electron microscopy level, the immunogold tag labels the body and the long branching dendrites of fibroblast-like cells with scanty cytoplasm containing mitochondria, endoplasmic reticulum, and dense bodies. The LNGFR+ cells are positive for alkaline phosphatase, reticulin, collagen III, vimentin, TE-7, and CD13 but negative for endothelial (vWF, CD34, Pal-E), neural (CD56, neurofilament) and leukocyte markers (CD45, CD68). The LNGFR+ stromal cells appear in the fetal BM before the hematopoietic activity begins, originate from the vessel adventitia, and radiate in the Bm cavity. Long-term BM culture (LTBMC) in vitro contain LNGFR+ stromal cells. We document the presence of RNA message for the low- (LNGFR) and the high- affinity NGF receptor (NTRK1) by using RT-PCR on fresh BM aspirate and on LTBMC. BM biopsies from patients with hematologic fibrogenic diseases and in cytokine-treated cancer patients are evaluated for LNGFR+ cells: the amount of stained cells is correlated with the traditional reticulin stain in cases of myelofibrosis, therapy-related myelodysplasia, leukemia, and detected an increase of stromal cells in cytokine-treated patients. The anti-LNGFR antibodies represent a specific membrane marker for the adventitial reticular cells (ARC) of the human marrow and allow precise evaluation and quantitation of this important BM microenvironment component in vivo and in vitro.

The stromal composition of malignant lymphoid aggregates in bone marrow: variations in architecture and phenotype in different B‐cell tumours

“…LNGFR is a member of the tumour necrosis factor receptor family that binds the neurotrophin group of growth factors (Johnson et al, 1986;Raffioni et al, 1993). LNGFR is widely expressed on neural cells and in a diverse array of mesenchymal cell types, including FDC of the lymph node and bone marrow ARC (Thompson et al, 1989;Cattoretti et al, 1993;Labouyrie et al, 1999). Strong LNGFR expression is characteristic of nodal FDC (Dorfman & Shahsafaei, 1996).…”

“…The morphology and immunophenotype of different stromal populations in normal bone marrow has been previously investigated in monolayer cultures and in bone marrow aspiration and core biopsy samples (Wilkins & Jones, 1995. Distinct stromal populations have been identified, including reticular cells expressing the cell surface molecules low-affinity nerve growth factor receptor (LNGFR), vascular cell adhesion molecule (VCAM-1) and CD105/endoglin (Cattoretti et al, 1993;Caneva et al, 1995;Wilkins & Jones, 1995. A number of studies have compared expression of extracellular matrix components, including tenascin, collagen IV and collagen VI, in these stromal populations (Wilkins & Jones, 1995.…”

KLF2+ stemness maintains human mesenchymal stem cells in bone regeneration

“…Several in vivo markers have been reported to characterize MSCs, including Gli 1, SSEA-4, CD271, and CD146. [49][50][51][52] The classical markers of MSCs in vitro include CD73, CD90, and CD105, but few of these can be used to represent their unique properties, such as stemness and pluripotency. 3,53 Here, we identified KLF2 as a marker of MSCs related to their stemness.…”

Further Characterization of Cells Expressing STRO-1 in Cultures of Adult Human Bone Marrow Stromal Cells

“…(46) In situ, expression of the low affinity NGFR has been localized to a subset of marrow stromal cells that possess long processes and in some species express ALP. (47,48) These reticular or "Westen Bainton" cells are thought to participate in the regulation of hematopoiesis and to be capable of giving rise to cells of other marrow stromal lineages, including osteoblasts. (49) Expression of the NGFR has also been detected on freshly isolated STRO-1 + CFU-F. (20) In this investigation, expression of the NGFR was detected on only a minority of BMSCs in primary cultures, the majority of which were STRO-1 − .…”