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Query: UMLS:C0001511 (
Adhesion
)
5,955
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Human kit ligand (KL), also known as
stem cell factor
(
SCF
), steel factor, or mast cell growth factor, is a recently identified hematopoietic growth factor whose receptor is the product of the c-kit proto-oncogene. Alternative splicing of the pre-mRNA of KL/
SCF
results in secreted and membrane-bound forms of the protein. We and others have recently shown that the c-kit gene product is expressed on human megakaryocytes and that soluble KL/
SCF
in combination with granulocyte-macrophage colony-stimulating factor, interleukin-3 (IL-3), or IL-6 increased megakaryocyte progenitor colony formation (CFU-MEG) and stimulated mature megakaryocytes. Here we show that adhesion of human megakaryocytes to bone marrow stromal fibroblasts, which express the membrane-bound form of KL/
SCF
(mKL/
SCF
), is mediated in part by the interaction between mKL/
SCF
and the c-kit protein. This interaction also results in marrow fibroblast-stimulated proliferation but not an increase in ploidy of megakaryocytes; when the two cell types were separated by a transoluble membrane, proliferation did not occur.
Adhesion
and proliferation of human megakaryocytes to an immortalized murine stromal cell line SI/SI lacking the KL/
SCF
gene was impaired, whereas transfection of SI/SI cells with human mKL/
SCF
significantly increased both adhesion and proliferation. Marrow stromal fibroblast mKL/
SCF
may serve both as an adhesion structure and as a growth-potentiating factor for megakaryocytes in the bone marrow.
...
PMID:Interaction of human bone marrow fibroblasts with megakaryocytes: role of the c-kit ligand. 138 98
Stem cell factor
(
SCF
) or c-kit ligand is a growth factor cytokine produced by stromal cells that is known to influence mast cell proliferation and differentiation. We hypothesized that
SCF
may also influence the adhesion of mast cells to connective tissue matrix. To examine this hypothesis, we stimulated MCP5/L mast cells or murine bone marrow-derived cultured mast cells (BMCMC) with either
SCF
or PMA and observed adhesion to fibronectin (FN). As expected, 80 to 90% of PMA-activated MCP5/L cells or BMCMC adhered to FN. In addition,
SCF
promoted MCP5/L cell or BMCMC adhesion to FN in a dose-response fashion with 50 to 60% of BMCMC adhering to FN at a concentration 10 ng/ml of
SCF
. BMCMC adhesion was observed with as little as 200 pg/ml of
SCF
.
Adhesion
of
SCF
stimulated BMCMC to FN did not require IL-3, but was dependent on the concentration of FN used to coat the assay surface. Mast cell adhesion in the presence of
SCF
appeared to occur through an integrin receptor as adhesion was calcium dependent and could be blocked by an RGD (Ang, Gly, Asp)-containing peptide.
SCF
did not directly mediate adhesion through interaction with c-kit, as FN-coated surfaces exposed to
SCF
before initiation of the adhesion assay did not promote adhesion in the absence of soluble
SCF
. Rather,
SCF
appeared to stimulate adhesion to FN by activating mast cells through its interaction with c-kit. Thus, antibody to
SCF
blocked adhesion, and rat and murine
SCF
stimulated BMCMC adhesion to FN, but human
SCF
, which does not bind to murine c-kit, did not stimulate adhesion. Genistein, which inhibits tyrosine kinase activity, partially inhibited
SCF
-induced adhesion.
SCF
thus stimulates mast cell adhesion and, because
SCF
is produced normally in tissues, it may be a major factor responsible for the adhesion of mast cells to connective tissue matrix under physiologic conditions.
...
PMID:Stem cell factor induces mast cell adhesion to fibronectin. 750 10
The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. During inflammation, an increase in the number of mast cells can be seen, e.g., in the intraepithelial cell layer after a provoked allergic reaction. Such accumulation probably requires directed migration of mature mast cells or their precursors. To study the migration of human mast cells we used as a model the human mast cell line, HMC-1, and
stem cell factor
-dependent (also referred to as mast cell growth factor or Kit ligand) cord blood-derived mast cells. The results show that
stem cell factor
is a potent chemotactic factor for human mast cells in vitro. The chemotactic response to SCF was found to be dose dependent, reaching a maximum at 50 ng/ml. The activity of SCF could be blocked by anti-SCF Abs. We also tested the effect of different intercrines, i.e., IL-8, MIP-1 alpha, MIP-1 beta, RANTES, and MCAF (also referred to as monocyte chemotactic protein 1), on human mast cell migration. Only RANTES was chemotactic for in vitro-developed mast cells. None of the tested intercrines induced migration of HMC-1 cells. For migration, the mast cells were dependent on binding to an extracellular matrix protein. Thus, coating of the filters with fibronectin was required, whereas collagen or laminin did not promote migration.
Adhesion
of HMC-1 cells to fibronectin could also be shown in an adhesion assay. In addition, expression of receptors for fibronectin could be detected on the surface of the mast cells. These results show that SCF is not only a growth and differentiation factor for human mast cells in vitro but also a potent chemoattractant for such cells.
...
PMID:Stem cell factor is a chemotactic factor for human mast cells. 752 4
Human fetal livers contain progenitor cells that become mast cells after 4 weeks of culture with recombinant human
stem cell factor
. Expression of cell surface CD29 (beta 1), CD18 (beta 2), CD61 (beta 3), and beta 5 integrins was investigated on such cells by flow cytometry and adhesion measurements. High surface expression of CD49e, CD51, and CD61 along with kit was apparent by 4 weeks of culture, whereas expression of each at day 0 was low to undetectable. CD29 and CD49d were detected on cells from day 0 to 4 weeks of culture; CD49b, CD49c, CD49f, CD18, and CD54 expression was negligible. The fetal liver-derived mast cells spontaneously adhered to vitronectin. No evidence for degranulation was found during vitronectin-dependent adhesion.
Adhesion
occurred in part through the CD61/CD51 receptor. No evidence for adhesion to vitronectin through CD29 and beta 5 integrins was obtained. Almost all of the vitronectin-adherent cells expressed CD51, CD61, kit, and tryptase, and exhibited metachromasia with toluidine blue. Thus, among the fetal liver-derived cells, developing mast cells were selectively adherent to vitronectin. These mast cells and the other cell types present also adhere spontaneously to fibronectin and to laminin, this adhesion being partially inhibited by antibodies against CD61 and CD29 integrins. In conclusion, human mast cells acquire functional vitronectin receptors as they develop from fetal liver progenitors under the influence of rhSCF. This may be important for the recruitment, localization, and retention of developing mast cells.
...
PMID:Human mast cells derived from fetal liver cells cultured with stem cell factor express a functional CD51/CD61 (alpha v beta 3) integrin. 754 4
Human acute myeloid leukemia (AML) cells adhere to bone marrow fibroblasts (BMF) and extracellular matrix proteins including fibronectin.
Adhesion
is increased when fibroblast monolayers are exposed to tumor necrosis factor-alpha (TNF) alone and in combination with interferon-gamma (IFN) or interleukin-4 (IL-4). The combination of TNF and IFN caused enhanced AML cell adhesion to treated BMFs, from a mean of 25.0 +/- 4.1% to 36.3 +/- 5.4% (p = 0.0007). Enhanced binding was partially a result of upregulated vascular cell adhesion molecule-1 expression on BMFs. Intercellular adhesion molecule-1 was also upregulated, but did not appear to play a role in the increased binding to cytokine-stimulated BMFs. In contrast to observed adhesion to resting BMFs, AML cells binding to TNF/IFN-stimulated BMFs rely more heavily on the VLA-4 alpha chain (CD49d). In some cases, alpha4 integrin chain antibody was more effective than beta1 antibody in blocking binding, suggesting that a non-beta1 alpha4 integrin, possibly alpha4 beta7, on AML cells may act as a stromal ligand. The addition of alpha4 antibody to beta1 and beta2 antibodies significantly increased the inhibition of AML cells to stimulated BMFs. The myeloid cytokines granulocyte colony stimulating factor, granulocyte-monocyte colony stimulating factor, interleukin-3 and
stem cell factor
enhanced the adhesion of AML blast cells to BMFs in some cases. The phorbol ester PMA, however, consistently upregulated AML cell-binding to BMFs, the increase being mediated entirely via beta1 and beta2 integrins without altering AML cell integrin expression. Binding of AML cells to marrow stroma can be enhanced by influences on leukemic cell or stroma. Enhanced binding under these conditions occurs via different pathways, illustrating the heterogeneity of mechanisms underlying leukemic cell retention within the bone marrow stroma.
...
PMID:Bone marrow fibroblast exposure to the inflammatory cytokines tumor necrosis factor-alpha and interferon-gamma increases adhesion of acute myeloid leukemia cells and alters the adhesive mechanism. 901 13
Leukocyte adhesion deficiency or LAD is a congenital immunodeficiency disease characterized by recurrent bacterial infections in which the leukocytes from affected children fail to adhere to endothelial cells and migrate to the site of infection due to heterogeneous defects in the leukocyte integrin CD18 subunit. To assess the feasibility of human gene therapy of LAD, we transduced granulocyte colony-stimulating factor (G-CSF)-mobilized, CD34+ peripheral blood stem cells derived from a patient with the severe form of LAD using supernatant from the retroviral vector PG13/LgCD18. The highest transduction frequencies (31%) were found after exposure of the cells to retroviral vector on a substrate of recombinant fibronectin fragment CH-296 in the presence of growth factors interleukin-3 (IL-3), IL-6, and
stem cell factor
. When the phenotype of the transduced cells was monitored by fluorescence-activated cell sorting following in vitro differentiation with growth factors G-CSF and granulocyte-macrophage CSF (GM-CSF), CD11a surface expression was detected immediately after transduction. CD11b and CD11c were expressed at low levels immediately following transduction, but increased over 3 weeks in culture.
Adhesion
of the transduced cells was nearly double that of nontransduced cells in a cell adhesion assay using human umbilical vein endothelial cells. Transduced cells also demonstrated the ability to undergo a respiratory burst in response to opsonized zymosan, a CD11/CD18-dependent ligand. These experiments show that retrovirus-mediated gene transfer of the CD18 subunit complements the defect in LAD CD34+ cells resulting in CD11/CD18 surface expression, and that the differentiated myelomonocytic cells derived from the transduced LAD CD34+ cells display CD11/CD18-mediated adhesion function. These results indicate that ex vivo gene transfer of CD18 into LAD CD34+ cells, followed by re-infusion of the transduced cells, may represent a therapeutic approach to LAD.
...
PMID:Retroviral-mediated gene transfer of the leukocyte integrin CD18 into peripheral blood CD34+ cells derived from a patient with leukocyte adhesion deficiency type 1. 947 15
Mast cells are known to adhere to laminin, although there is limited information on the characteristics of this event. To further examine this adhesive interaction, we thus determined the adherence of murine mast cell lines and primary bone marrow cultured mast cells (BMCMC) to murine laminin (mLN), human placental laminin-1 (hLN), merosin (laminin-2) and various laminin fragments, concentrating on activating stimuli, the involvement of integrins, and the effect on mast cell activation. Murine mast cells were found to adhere to both mLN and hLN and to merosin, not only following exposure to phorbol 12-myristate 13-acetate (PMA), but also after Fc epsilon RI aggregation or addition of
stem cell factor
(
SCF
).
Adhesion
to laminin was partially inhibited by soluble E8 and PA22-2, both fragments of laminin that promote mast-cell adhesion when bound on surfaces. Mast-cell lines and BMCMC consistently expressed high levels of alpha 6 integrin. Antibody to alpha 6 blocked spontaneous and inhibited activated mast-cell adhesion to hLN, and inhibited mast-cell adhesion to mLN and its fragment E8. Mast-cell adhesion to both laminin isoforms increased Fc epsilon RI-mediated mast-cell secretion. These observations demonstrate that mast-cell attachment to laminin is promoted by physiological stimuli, is mediated principally by alpha 6 integrin, and results in enhanced cell activation.
...
PMID:Characterization of adhesive interactions between mast cells and laminin isoforms: evidence of a principal role for alpha 6 integrin. 949 98
We evaluated the effect of beta1-integrin receptor engagement on the expression and activity of cell cycle regulatory proteins in CD34(+) cells under conditions that mimic the steady-state marrow microenvironment and in the presence of supraphysiological concentrations of interleukin-3 (IL3) and
stem cell factor
(
SCF
).
Adhesion
of CD34(+) progenitors to fibronectin (FN) was similar whether IL3 or
SCF
was present or absent. Engagement of beta1-integrins blocked S-phase entry of CD34(+) cells in the absence of IL3 or
SCF
, whereas addition of 10 ng/mL IL3 or
SCF
prevented such a block in S-phase entry. In the absence of IL3 or
SCF
, cyclin-E levels were significantly lower and p27(KIP1) levels significantly higher in FN-adherent than in FN-nonadherent cells, or than in poly-L-lysine (PLL)-adherent or (PLL)-nonadherent cells. Cyclin-dependent-kinase (cdk)-2 activity was decreased and levels of cyclin-E-cdk2 complexes were lower in FN-adherent than in PLL-adherent cells. In contrast, cyclin-E and p27(KIP1) protein levels and cdk2 activity in cells adherent to FN in the presence of IL3 or
SCF
were similar to those in PLL-adherent and FN-nonadherent or PLL-nonadherent cells. In conclusion, under physiological cytokine conditions, integrin engagement prevents S-phase entrance of CD34(+) cells, which is associated with elevated levels of the contact-dependent cyclin kinase inhibitor p27(KIP1). Supraphysiological concentrations of IL3 or
SCF
prevent p27(KIP1) elevation and override the integrin-mediated inhibition of entry into S phase.
...
PMID:Opposing effects of engagement of integrins and stimulation of cytokine receptors on cell cycle progression of normal human hematopoietic progenitors. 1064 95
Recent studies suggested that trafficking of hematopoietic progenitor cells is related to cell cycle status. We studied whether adhesion of progenitor cells to extracellular matrix proteins was modulated by cell cycle transit. Mobilized peripheral blood CD34+ cells were stimulated ex vivo for 48 hours with
stem cell factor
, flt-3 ligand, and thrombopoietin and fractionated by adhesion to fibronectin or vascular cell adhesion molecule-1 (VCAM-1). Adherent and nonadherent cells were assayed for cell cycle status, long-term culture-initiating cell frequency, and integrin function. Binding to fibronectin, but not to VCAM-1, displayed a cell cycle selectivity as the adherent fraction to fibronectin was enriched in cycling CD34+ cells and in cycling long-term culture-initiating cells compared to the nonadherent fraction. Combined cell cycle and phenotypic analysis showed that the expression of VLA-5 was upregulated during S/G2+M but that of VLA-4 remained constant. The selective binding of cycling CD34+ cells to fibronectin was reverted by anti-VLA-5 but not by anti-VLA-4 blocking antibodies. Also, cycling CD34+ cells preferentially adhered to the VLA-5 binding domain but not to the VLA-4 binding domain of fibronectin.
Adhesion
of cycling CD34+ cells to fibronectin was a reversible process modulated by cell cycle progression, because adherent cells could exit the cell cycle and return to a nonadhesive state within an additional 48-hour culture period. The results indicate that the enhanced binding capacity of cycling progenitor cells to fibronectin is mediated by VLA-5.
...
PMID:Cell cycle activation of hematopoietic progenitor cells increases very late antigen-5-mediated adhesion to fibronectin. 1130 Nov 92
Mast cells are inflammatory and immunoregulatory cells resident in tissues. They develop from bone marrow-derived progenitor cells that enter the tissue through the blood circulation. The specific localization and migration of mast cells in tissues is dependent on their interaction with extracellular matrix (ECM) proteins.
Adhesion
of human mast cells isolated from intestinal mucosa and cultured in the presence of
stem cell factor
(
SCF
) to ECM proteins is analyzed. It was observed that
SCF
is a unique cytokine enhancing mast cell adhesion to all tested ECM proteins (fibronectin, laminin, collagen I, III, IV, VI, XIV) up to 5-fold, particularly to fibronectin (54% +/- 12% of mast cells) and to denatured collagens (40% +/- 12% on cyanogen bromide-cleaved peptides of collagen I). Most noteworthy, preculture of mast cells with interleukin-4 (IL-4), in addition to
SCF
, reduced their potency to adhere to ECM proteins to one third compared to mast cells cultured with
SCF
alone. Mast cell adhesion was preferentially mediated by beta1 integrins, and most cells expressed the ECM-binding integrins alpha2beta1, alpha3beta1, alpha4beta1, alpha5beta1, and alphaVbeta3.
SCF
-induced mast cell adhesion was totally blocked by wortmannin and apigenin, indicating an involvement of phosphatidylinositol 3-kinase and mitogen-activated protein kinase, and it was related to an up-regulation of the HUTS-21 beta1 epitope, which is associated with an activated conformation of beta1. In conclusion, these data indicate that
SCF
induces the adhesion of cultured mast cells to ECM proteins, whereas IL-4 may promote detachment from the ECM.
...
PMID:Regulatory effects of stem cell factor and interleukin-4 on adhesion of human mast cells to extracellular matrix proteins. 1180
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