Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.148 (Thy1)
 1,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human hematopoietic stem cells are thought to express the CD34 stem cell antigen, low numbers of HLA-DR and Thy1 antigens, but no lineage commitment antigens, CD38, or CD45RA antigens. However, fluorescence-activated cell sorted CD34+ subpopulations contain not more than 1% to 5% primitive progenitors capable of initiating and sustaining growth in long-term bone marrow culture initiating cells (LTBMC-ICs). We have recently shown that culture of fresh human marrow CD34+/HLA-DR- cells separated from a stromal layer by a microporous membrane ("stroma-noncontact" culture) results in the maintenance of 40% of LTBMC-ICs. We hypothesized that reselection of CD34+ subpopulations still present after several weeks in stroma-noncontact cultures may result in the selection of cells more highly enriched for human LTBMC-ICs. Fresh marrow CD34+/HLA-DR- cells were cultured for 2 to 3 weeks in stroma-noncontact cultures. Cultured progeny was then sorted on the basis of CD34, HLA-DR, or CD33 antigen expression, and sorted cells evaluated for the presence of LTBMC-ICs by limiting dilution analysis. We show that (1) LTBMC-ICs are four times more frequent in cultured CD34+/HLA-DR- cells (4.6% +/- 1.7%) than in cultured CD34+/HLA-DR- cells (1.3% +/- 0.4%). This suggests that HLA-DR antigen expression may depend on the activation status of primitive cells rather than their lineage commitment. We then sorted cultured cells on the basis of the myeloid commitment antigen, CD33. (2) These studies show that cultured CD34+/CD33- cells contain 4% to 8% LTBMC-ICs, whereas cultured CD34+/CD33+bright cells contain only 0.1% +/- 0.03% LTBMC-ICs. Because LTBMC-ICs are maintained significantly better in stroma-noncontact cultures supplemented with macrophage inflammatory protein 1 alpha (MIP-1 alpha) and interleukin-3 (IL-3) (Verfaillie et al, J Exp Med 179:643, 1994), we evaluated the frequency of LTBMC-ICs in CD34+/CD33- cells present in such cultures. (3) CD34+/CD33- cells present in MIP-1 alpha + IL-3-supplemented cultures contain up to 30% LTBMC-ICs. The increased frequency of LTBMC-ICs in cultured CD34+ subpopulations may be the result of terminal differentiation of less primitive progenitors, loss of cells that fail to respond to the culture conditions or recruitment of quiescent LTBMC-ICs. The capability to select progenitor populations containing up to 30% LTBMC-ICs should prove useful in studies examining the growth requirements, self-renewal, and multilineage differentiation capacity of human hematopoietic stem cells at the single-cell level.
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PMID:CD34+/CD33- cells reselected from macrophage inflammatory protein 1 alpha+interleukin-3--supplemented "stroma-noncontact" cultures are highly enriched for long-term bone marrow culture initiating cells. 752 Jul 71

Most in vitro studies in the CNS require pure cultures of astrocytes. Astrocytes from the human optic nerve head (ONH, type 1B) represent a specialized population of astrocytes. Primary cells grown from human optic nerve head explants were cultured for 3-4 weeks. To select astrocytes by immunopanning, cell suspensions were placed on a P100 panning dish coated with C5 anti-neuroepithelial antibody and allowed to attach for 30 min. Nonadherent cells were plated on a second dish coated with anti-Thy1.1 antibody to deplete microglia and meningeal cells. Finally, remnant nonadherent cells were plated on a noncoated dish. Purified cells were immunostained with astrocyte markers: GFAP, vimentin, Pax2, A2B5, nestin and NCAM. Other cell types were characterized by HLA-DR for microglia and smooth muscle actin for vascular smooth muscle. The proportion of GFAP+ astrocytes in the cultures was determined by flow cytometry. About 95% of the cells that adhered to the C5 dish were GFAP+ astrocytes. GFAP+ astrocytes expressed vimentin, Pax2, nestin and NCAM, but not A2B5. From the Thy1.1 dish, 60-75% cells were GFAP+ astrocytes and the remainder cells were GFAP- cells. Using cloning rings, we eliminated fibroblast-like cells, smooth muscle and meningeal cells from astrocyte cultures. Smooth muscle cells and fibroblasts grew on the noncoated dish. In conclusion, immunopanning is an efficient method to get high yields of viable type 1B astrocytes from adult human ONH. The current described culture system may provide a valuable tool in studying human optic nerve head biology and disease.
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PMID:Purification of astrocytes from adult human optic nerve heads by immunopanning. 1461 7

This study was aimed to investigate the biological characteristics of osteoblasts and their hematopoietic supportive function by using human fetal osteoblastic cell line 1.19 (hFOBs) as a model. The pluripotency markers (Oct-4, Rex-1, hTERT) of hFOBs were analyzed by RT-PCR, the multilineage differentiation experiments were conducted in vitro. Flow cytometry (FCM) was used to identify the surface markers of hFOBs, and RT-PCR was used to analyze their hematopoietic cytokine expression in comparison with bone marrow mesenchymal stem cell (BM-MSC). The results showed that hFOBs expressed several ESC pluripotency markers including Oct-4 and Rex-1, except hTERT. Moreover, hFOBs could also undergo multilineage differentiation into the mesodermal lineages of adipocytic cell types in addition to its predetermined pathway, the mature osteoblast. Both hFOBs and BM-MSC expressed CD44, CD73 (SH3), CD105 (SH2) and CD90 (Thy1), and lack expression of CD34, CD45, or HLA-DR surface molecules. In addition, both hFOBs and BM-MSC expressed SCF, IL-6, and SDF-1alpha mRNA, but only hFOBs could express GM-CSF and G-CSF. It is concluded that human fetal osteoblastic cell line 1.19 may provide a good model to study the osteoblastic regulation role in hematopoiesis in vitro.
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PMID:[Biological characteristics of human fetal osteoblastic 1.19 cell line]. 1842 61