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Query: UNIPROT:P17931 (galectin-3)
 2,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lines of thymic stromal cells have been established. One of these, designated TS-9, has been cloned and studied extensively. This line expresses both acid and alkaline phosphatases. Despite repeated cloning, TS-9 cells remain morphologically heterogeneous. The origin of these cells is not clear. They express low levels of immunologically identifiable cytokeratins, produce laminin, a basement membrane protein, but express antigens typically found on bone marrow stromal cells. The TS-9 cells are MHC Class I+ but Class II-. They express the Thy-1, Pgp-1, and Mac-2 antigens but not other lineage markers of T cells or macrophages. Coculturing TSC with normal thymocytes or with the CTLL-1 cell line leads to a profound inhibition of lectin-induced and/or IL-2 induced T cell proliferation. This requires direct cell-cell contact and ultimately results in the death of the bound lymphocytes. It cannot be reproduced by culturing the thymocytes with TSC culture supernatants. These supernatants do contain hematopoietic growth factor(s) which augment the growth of some T lineage cells and support the growth of monocytic colonies in semi-solid culture medium. Both normal thymocytes and a variety of T cell tumors bind to TSC but only the normal cells are killed as a consequence of this interaction. Neither the binding nor the killing appear to be MHC restricted. We suggest that this killing may provide a model for the effector mechanism of the negative selection imposed by the thymus on developing T cells.
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PMID:Thymic stromal cells in culture. I. Establishment and characterization of a line which is cytotoxic for normal thymocytes and produces hematopoietic growth factor(s). 170 4

This study reports on the earliest stages of mononuclear phagocyte differentiation. A crucial question in this developmental process is whether mature macrophage (M phi) heterogeneity is already appointed at the precursor cell level. For this purpose, we produced clonal populations of mononuclear phagocytes from bone marrow culture by somatic cell hybridization with two hypoxanthine, aminopterin, thymidine-sensitive myeloid cell lines. A panel of 22 stable hybrids was obtained from these fusions. Differentiation stage analysis of the hybrids indicated that all cell lines had immature mononuclear phagocyte characteristics. The hybrids exhibited typical myeloid morphology and mainly nonadherent growth. Mature M phi features, such as expression of the cell surface antigens Mac-1, Mac-2 and F4/80, phagocytosis of latex beads, and expression of nonspecific esterase and acid phosphatase activity, were virtually absent. The immature M phi markers Thy-1, MIV25 and MIV52, on the other hand, were readily expressed, although heterogeneity was observed among different hybrid cell lines. We then analyzed the differentiation potential of seven hybrids by culture of the cells in the presence of post-lipopolysaccharide serum supplemented with interferon-gamma and found that the expression of mature M phi characteristics was induced. However, the various hybrids showed divergent patterns of mature M phi marker induction. R0C2 cells, for instance, showed extensive morphological and phenotypical differentiation without concomitant induction of phagocytosis. In contrast, W1C4 cells showed significant induction of phagocytosis without simultaneous increase of phosphatase and esterase activity. R1C1 cells were unique in the strong induction of Ia antigen expression. Together, our data indicate that (a) early M phi differentiation stages can be rescued by somatic cell hybridization, and that (b) the obtained cell lines are able to mature according to divergent differentiation programs.
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PMID:Murine macrophage precursor characterization. I. Production, phenotype and differentiation of macrophage precursor hybrids. 196 90

The antigenic phenotype of mouse lymph node follicular dendritic cells (FDCs) was studied by immunocytochemical techniques. Indirect fluorescence was used in conjunction with monoclonal antibodies to localize FDC surface antigens on FDC-enriched cell preparations and in cryostat sections. Lymph nodes from rats and mice were also labeled directly for Ia antigens with fluorescein- or peroxidase-conjugated Ia-specific monoclonal antibodies (i.e., MRC Ox4 and 10-2.16, respectively). Lymphoid tissue was also prepared for electron microscopy to allow clear distinction between Ia antigens of B lymphocytes and FDCs in situ. In these experiments, gold-labeled antigen was used to clearly identify FDCs and their processes among the Ia-positive cells of lymph node follicles. The labeling observed by light and electron microscopy showed that FDCs expressed Ia in situ and in vitro. Additional surface determinants shown to be expressed by FDCs included H2-K, common leukocyte antigen, and the receptor for the Fc portion of IgG1 and IgG2b. Neither macrophage antigens, such as Mac-1, Mac-2, Mac-3, and F4/80, nor the lymphocyte markers Ly-1, Ly-2, and Thy-1 were expressed by FDCs. Thus, the antigenic phenotype of FDCs, along with their distinctive dendritic morphology, their nonphagocytic and nonadherent nature, and their ability to trap and retain immune complexes on their plasma membrane, identifies them as a unique cell population.
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PMID:Antigenic phenotyping of isolated and in situ rodent follicular dendritic cells (FDC) with emphasis on the ultrastructural demonstration of Ia antigens. 352 78

The present study investigated whether transformed macrophage cell lines represent certain stages in macrophage differentiation. Cell surface markers linked to macrophage differentiation were characterized in 11 murine macrophage cell lines and compared with markers on isolated resident and exudate peritoneal macrophages. Furthermore, the capacity of the cell lines to phagocytose latex microspheres was analyzed. This analysis indicated that cell lines arrested at an early differentiation stage were characterized by the expression of the 'immature' markers Thy-1 and MIV 113, and the lack of expression of 'mature' macrophage markers such as Mac-1, Mac-2, and F4/80. More mature cell lines, which do not express 'immature' markers, show an increase in the expression of 'mature' macrophage markers. Furthermore, the expression of the 'mature' markers was found to be correlated with the phagocytic capacity of the cells. We have ordered the cell lines in a linear differentiation sequence based on these data. We propose that this sequence represents various stages in the differentiation of macrophages. This panel of cell lines provides a new model of early macrophage differentiation.
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PMID:Murine macrophage cell lines can be ordered in a linear differentiation sequence. 379 3

Antigen-retaining follicular dendritic cells (FDC) have been identified and studied in sections of lymph nodes and spleen, but studies of these cells in culture have been extremely limited. The purpose of this study was to establish techniques to release these fragile cells from mouse lymph nodes in a viable state and to identify these cells routinely in lymph node cell suspensions. FDC were obtained from passively or actively immunized popliteal lymph nodes of mice injected in the footpads with 125I-labeled human serum albumin (HSA) or horseradish peroxidase (HRP). Lymph nodes were removed 1 hr after the footpads had been injected with collagenase. After another hour of incubation in vitro with collagenase, protease, and deoxyribonuclease, FDC were released by gentle teasing and enriched by centrifugation on a low density bovine serum albumin (BSA) or Percoll gradient. Most FDC with the associated radiolabel floated at densities greater than 1.06 g/ml on BSA or Percoll gradients. Slides of the FDC-enriched fraction were prepared, using a cytobucket which allowed the cells to be affixed to glass slides by centrifugation in a less disruptive manner than by cytocentrifugation. FDC that were air-dried and fixed with 3% glutaraldehyde had a characteristic pink acidophilic cytoplasm after Wright's staining, and had a faintly basophilic euchromatic nucleus frequently with peripherally-clumped chromatin. In addition, these cells were large and irregularly shaped (up to 60 micron long). Fixation of FDC with 0.6% paraformaldehyde/ 0.9% glutaraldehyde on poly-L-lysine-coated slides resulted in a preservation of FDC which made possible visualization of long dendritic processes by Nomarski optics. Antigen presence on the cell surface was confirmed by autoradiography and, in the case of HRP, was also visualized enzymatically using diaminobenzidine. In contrast to resident peritoneal macrophages or some contaminating lymph node macrophages present on the same slides, FDC did not phagocytize opsonized sheep red blood cells (SRBC) or adhere to plastic surfaces although they did form rosettes with opsonized SRBC. Cell marker studies indicated FDC have a distinctive phenotype. They were positive for Ia, Fc receptor, and leukocyte common antigen, but negative for Thy-1, Ly-1, Ly-2, endogenous Ig, Mac-1, Mac-2, Mac-3, and F4/80, and negative to weakly positive for nonspecific esterase. Cultured FDC remained viable and retained radiolabeled antigen-antibody complexes on their surfaces and were significantly enriched for FDC.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Follicular dendritic cells in suspension: identification, enrichment, and initial characterization indicating immune complex trapping and lack of adherence and phagocytic activity. 396 23

The demonstration of thymic nurse cells (TNC), complexes between stromal cells and thymocytes, in cell suspensions of murine thymuses, prompted us to investigate (1) the relationship of TNC to other thymic stromal cell types defined in situ, and (2) the maturation stage of the enclosed thymocytes. To this purpose we incubated frozen sections of TNC suspensions with various monoclonal antisera directed to T cells and stromal cell types, using immunohistology. This approach enabled us to study antigen expression on the "nursing" cell itself and to analyze the phenotype of the enclosed lymphocytes in cross sections of TNC. The results show that lymphocytes enveloped by TNC express high levels of Thy-1, moderate levels of T200, and variable amounts of Lyt-1. Due to enzymatic degradation Lyt-2 expression could not be studied. The enveloped cells also bear PNA receptors, but no detectable I-A/E antigens. Expression of H-2K antigens on enclosed thymocytes varied from weak to absent. The "nursing" cells react with ER-TR4, a monoclonal antibody which detects cortical epithelial-reticular cells. In addition TNC express I-A/E and H-2K antigens. In contrast, TNC do not react with ER-TR 5 and 7, monoclonal antibodies, which detect medullary epithelial cells and reticular fibroblasts, respectively. TNC do not express the macrophage antigens Mac-1 and Mac-2. We conclude that TNC in vitro represent the in vivo association of epithelial-reticular cells with cortical thymocytes. However, the enclosed thymocytes do not constitute a phenotypically distinct subset of subcapsular or outer cortical cells.
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PMID:Immunohistology of thymic nurse cells. 620 71

The present paper reports the distribution of lymphoid and non-lymphoid cell types in the thymus of mice. To this purpose, we employed scanning electron microscopy and immunohistology. For immunohistology we used the immunoperoxidase method and incubated frozen sections of the thymus with 1) monoclonal antibodies detecting cell-surface-differentiation antigens on lymphoid cells, such as Thy-1, T-200, Lyt-1, Lyt-2, and MEL-14; 2) monoclonal antibodies detecting the major histocompatibility (MHC) antigens, H-2K, I-A, I-E, and H-2D; and 3) monoclonal antibodies directed against cell-surface antigens associated with cells of the mononuclear phagocyte system, such as Mac-1, Mac-2, and Mac-3. The results of this study indicate that subsets of T lymphocytes are not randomly distributed throughout the thymic parenchyma; rather they are localized in discrete domains. Two major and four minor subpopulations of thymocytes can be detected in frozen sections of the thymus: 1) the majority of cortical thymocytes are strongly Thy-1+ (positive), strongly T-200+, variable in Lyt-1 expression, and strongly Lyt-2+; 2) the majority of medullary thymocytes are weakly Thy-1+, strongly T-200+, strongly Lyt-1+, and Lyt-2- (negative); 3) a minority of medullary cells are weakly Thy-1+, T-200+, strongly Lyt-1+, and strongly Lyt-2+; 4) a small subpopulation of subcapsular lymphoblasts is Thy-1+, T-200+, and negative for the expression of Lyt-1 and Lyt-2 antigens; 5) a small subpopulation of subcapsular lymphoblasts is only Thy-1+ but T-200- and Lyt-; and 6) a small subpopulation of subcapsular lymphoblasts is negative for all antisera tested. Surprisingly, a few individual cells in the thymic cortex, but not in the medulla, react with antibodies directed to MEL-14, a receptor involved in the homing of lymphocytes in peripheral lymphoid organs. MHC antigens (I-A, I-E, H-2K) are mainly expressed on stromal cells in the thymus, as well as on medullary thymocytes. H-2D is also expressed at a low density on cortical thymocytes. In general, anti-MHC antibodies reveal epithelial-reticular cells in the thymic cortex, in a fine dendritic staining pattern. In the medulla, the labeling pattern is more confluent and most probably associated with bone-marrow-derived interdigitating reticular cells and medullary thymocytes. We discuss the distribution of the various lymphoid and non-lymphoid subpopulations within the thymic parenchyma in relation to recently published data on the differentiation of T lymphocytes.
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PMID:Immunohistology of lymphoid and non-lymphoid cells in the thymus in relation to T lymphocyte differentiation. 633 20

Serine phosphorylation of the beta-galactoside-binding protein galectin-3 (Gal-3) impacts nuclear localization but has unknown consequences for extracellular activities. Herein, we reveal that the phosphorylated form of galectin-3 (pGal-3), adsorbed to substratum surfaces or to heparan sulphate proteoglycans, is instrumental in promoting axon branching in cultured hippocampal neurons by local actin destabilization. pGal-3 interacts with neural cell adhesion molecule L1, and enhances L1 association with Thy-1-rich membrane microdomains. Concomitantly, membrane-actin linker proteins ezrin-radixin-moesin (ERM) are recruited to the same membrane site via interaction with the intracellular domain of L1. We propose that the local regulation of the L1-ERM-actin pathway, at the level of the plasma membrane, underlies pGal-3-induced axon branching, and that galectin phosphorylation in situ could act as a molecular switch for the axon response to Gal-3.
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PMID:Phosphorylation of adhesion- and growth-regulatory human galectin-3 leads to the induction of axonal branching by local membrane L1 and ERM redistribution. 2012 15