scholarly journals Structure-function relationships of stem cell factor: an analysis based on a series of human-murine stem cell factor chimera and the mapping of a neutralizing monoclonal antibody

Blood ◽  
1996 ◽  
Vol 88 (2) ◽  
pp. 437-444 ◽  
Author(s):  
JV Matous ◽  
K Langley ◽  
K Kaushansky
Keyword(s):  
Monoclonal Antibody ◽  
Stem Cell ◽  
Stem Cell Factor ◽  
Functional Organization ◽  
Biological Properties ◽  
Structural Basis ◽  
Gm Csf ◽  
Neutralizing Monoclonal Antibody ◽  
Macrophage Colony ◽  
And Function

Although much is now known about the biological properties of the c-kit receptor and its ligand, stem cell factor (SCF), little is known of the structural basis for the binding and function of this hematopoietic cytokine. By analyzing the activities of chimeric interspecies and homologue muteins and epitope mapping of a monoclonal antibody (MoAb) to the human protein, we have found that three distinct regions of SCF are essential for full biological function. Homologue and interspecies swapping of polypeptide sequences between the amino terminus and G35, between L79 and N97, and between R121 and D128 reduced or eliminated the ability of the chimera to act in synergy with murine granulocyte- macrophage colony-stimulating factor (GM-CSF) to promote hematopoietic colony formation. Moreover, a nonconformation-dependent MoAb that neutralizes human, but not murine SCF, was found to bind to residues within the L79-N97 segment of the human homologue. As these three regions localize to the putative first, third, and fourth helices of the protein, findings remarkably similar to previous studies of cytokines as diverse as growth hormone, GM-CSF, and interleukin (IL)-4, our results suggest that cytokines of multiple classes share a common functional organization.

scholarly journals Cell-to-cell interaction of cytokine-dependent myeloblastic line constitutively expressing membrane-bound stem cell factor abrogates cytokine dependency partially through granulocyte-macrophage colony- stimulating factor production

Blood ◽  
1995 ◽  
Vol 85 (5) ◽  
pp. 1220-1228 ◽  
Author(s):  
K Sasaki ◽  
K Ikeda ◽  
K Ogami ◽  
J Takahara ◽  
S Irino
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Cell Interaction ◽  
Colony Stimulating Factor ◽  
Semisolid Medium ◽  
Gm Csf ◽  
Membrane Bound ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Stem cell factor (SCF) is a cytokine for hematopoietic progenitor cells and plays an important role in megakaryocyte proliferation. The UT-7 cell line was established from a patient with megakaryoblastic leukemia, and its growth and survival are strictly dependent on interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoietin (Epo), or IL-6. In this study, we showed that SCF also supported the growth of UT-7 in the absence of other cytokines and downregulated the cell surface c-kit receptors. Constitutive expression of SCF by introducing SCF expression vector made UT-7 grow factor-independently in liquid medium, but not in semisolid medium. This SCF-expressing factor-independent UT-7 (UT-7scf9) expressed the membrane bound form of SCF on their surface, but did not secrete detectable amounts of soluble SCF. UT-7scf9 formed aggregates as they grew in the absence of cytokines, and this aggregation was inhibited by adding soluble SCF into the medium. UT-7 cultured with SCF and UT-7scf9 cultured without cytokines expressed GM-CSF, and anti-GM-CSF neutralizing antibody partially inhibited their growth. These results suggest that SCF stimulated UT-7 proliferation partially through the autocrine-loop of GM-CSF, and UT-7scf9 expressed SCF mostly as a membrane-bound form, which transduces its growth signal through c-kit receptor as they aggregate by cell-to-cell interaction.

scholarly journals Recombinant human stem cell factor, a c-kit ligand, stimulates hematopoiesis in primates

Blood ◽  
1991 ◽  
Vol 78 (8) ◽  
pp. 1975-1980 ◽  
Author(s):  
RG Andrews ◽  
GH Knitter ◽  
SH Bartelmez ◽  
KE Langley ◽  
D Farrar ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Absolute Number ◽  
Human Stem Cell ◽  
Clinical Role ◽  
Gm Csf ◽  
Macrophage Colony ◽  
Human Stem Cell Factor

Abstract Recombinant human stem cell factor (SCF) is homologous with recombinant rat SCF (rrSCF) and is a ligand for c-kit. We determined the influence of SCF on hematopoiesis in vitro and in vivo in baboons. In vitro, SCF alone stimulated little growth of hematopoietic colony-forming cells from baboon marrow, but did increase the number of colonies formed in response to erythropoietin (Epo), interleukin-3 (IL-3), and granulocyte- macrophage colony-stimulating factor (GM-CSF). In vivo, SCF caused an increase in the peripheral blood of the number of erythrocytes, neutrophils, lymphocytes, monocytes, eosinophils, and basophils. In marrow, it caused an increase in marrow cellularity and in the absolute number of colony-forming unit-granulocyte-monocyte (CFU-GM) and burst- forming unit-erythroid (BFU-E) in marrow following infusion of SCF. The in vivo stimulation of multiple lymphohematopoietic lineages corroborates previous in vitro studies and suggests a potentially important clinical role for SCF.

Serum Levels of Granulocyte-Macrophage-colony-stimulating Factor and Stem-cell Factor During Liver Regeneration after Partial Hepatectomy in Humans

2020 ◽  
Vol 15 (2) ◽  
pp. 131-136
Author(s):  
Diego Fiume ◽  
Ilaria Lenci ◽  
Martina Milana ◽  
Tommaso M. Manzia ◽  
Renato Massoud ◽  
...  
Keyword(s):  
Stem Cell ◽  
Liver Regeneration ◽  
Liver Tumor ◽  
Stem Cell Factor ◽  
Serum Levels ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Background: Multiple biological functions have been recognized regarding Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) and Stem Cell Factor (SCF). Aim: To evaluate the serum changes of GM-CSF and SCF in patients undergoing surgical resection for liver tumor, in the regenerative phase after surgery in order to identify the possible relationship with the patient, tumor or surgical variables. Methods: Thirty-two consecutive patients (50% male, median age 66), undergoing hepatic resection of liver neoplasm, were evaluated. The liver tumor was Hepatocellular Carcinoma (HCC) in 44% of cases. Other tumors were cholangiocarcinoma and metastasis. Serum levels of GM-CSF and SCF were assessed at baseline and 2 days, 7 days and 4 weeks after surgery. Personal and clinical patient data were also recorded. The statistical analysis was carried out using t-test for unpaired data or ANOVA (repeated measure) for continuous variables and Fisher test for discrete variables. Results: GM-CSF levels remained constant after surgery and were compared to baseline values. SCF levels, on the other hand, increased during the time, after surgery. The evaluation of SCF levels (fold increase) according to surgical, patient and tumor variables evidenced some differences. At day 7 and week 4, SCF levels were statistically increased: i) in patients undergoing a large resection in comparison with others (p<0.05); ii) in patients non-cirrhotic in comparison with cirrhotic ones (p=0.02) and finally; iii) in patients with non-HCC tumor in comparison with HCC ones (p=0.02). Conclusions: During liver regeneration in humans, SCF serum levels are increased allowing to hypothesize a possible role of this chemokine during tissue growth and remodeling.

Secretion of stem cell factor and granulocyte–macrophage colony-stimulating factor by mouse embryos in culture: influence of group culture

Zygote ◽  
2008 ◽  
Vol 16 (4) ◽  
pp. 297-301 ◽  
Author(s):  
A. P. Contramaestre ◽  
F. Sifontes ◽  
R. Marín ◽  
M. I. Camejo
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Culture Medium ◽  
Mouse Embryos ◽  
Colony Stimulating Factor ◽  
Group Culture ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

SummaryPrevious studies showed that the addition of a growth factor to the culture medium could modulate embryo development. The possible secretion of different factors to the culture medium by the embryo itself, however, has been poorly evaluated. The present study was designed to investigate: (1) the influence of single or group culture on the development of 2-cell mouse embryos (strain CD-1) to the blastocyst stage; (2) the release of granulocyte–macrophage colony-stimulating factor (GM-CSF) and stem cell factor (SCF) into the culture medium by the embryo; and (3) the levels of GM-CSF and SCF in the culture medium from both single and group embryos. Two-cell CD-1 mouse embryos were cultured for 96 h singly or in groups of five embryos per drop. GM-CSF and SCF were assayed by ELISA in the complete culture medium. It was found that embryos cultured in groups gave a higher percentage of total blastocyst formation and hatched blastocyst when compared with single embryo culture. The mouse embryos secreted GM-CSF and SCF to the culture medium. The concentration of these cytokines is significantly higher in the group cultures than the level found in single cultures. In conclusion, mouse embryos in culture secrete GM-CSF and SCF to the culture medium and the concentration of these cytokines increases during communal culture. These factors may be operating in both autocrine and paracrine pathways to modulate embryo development during in vitro culture.

scholarly journals Recombinant human stem cell factor, a c-kit ligand, stimulates hematopoiesis in primates

Blood ◽  
1991 ◽  
Vol 78 (8) ◽  
pp. 1975-1980 ◽  
Author(s):  
RG Andrews ◽  
GH Knitter ◽  
SH Bartelmez ◽  
KE Langley ◽  
D Farrar ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Absolute Number ◽  
Human Stem Cell ◽  
Clinical Role ◽  
Gm Csf ◽  
Macrophage Colony ◽  
Human Stem Cell Factor

Recombinant human stem cell factor (SCF) is homologous with recombinant rat SCF (rrSCF) and is a ligand for c-kit. We determined the influence of SCF on hematopoiesis in vitro and in vivo in baboons. In vitro, SCF alone stimulated little growth of hematopoietic colony-forming cells from baboon marrow, but did increase the number of colonies formed in response to erythropoietin (Epo), interleukin-3 (IL-3), and granulocyte- macrophage colony-stimulating factor (GM-CSF). In vivo, SCF caused an increase in the peripheral blood of the number of erythrocytes, neutrophils, lymphocytes, monocytes, eosinophils, and basophils. In marrow, it caused an increase in marrow cellularity and in the absolute number of colony-forming unit-granulocyte-monocyte (CFU-GM) and burst- forming unit-erythroid (BFU-E) in marrow following infusion of SCF. The in vivo stimulation of multiple lymphohematopoietic lineages corroborates previous in vitro studies and suggests a potentially important clinical role for SCF.

scholarly journals Tec kinase associates with c-kit and is tyrosine phosphorylated and activated following stem cell factor binding

1994 ◽  
Vol 14 (12) ◽  
pp. 8432-8437
Author(s):  
B Tang ◽  
H Mano ◽  
T Yi ◽  
J N Ihle
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Colony Stimulating Factor ◽  
Hematopoietic Stem ◽  
Gm Csf ◽  
Amino Terminal ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Stem cell factor (SCF) plays a crucial role in hematopoiesis through its interaction with the receptor tyrosine kinase c-kit. However, the signaling events that are activated by this interaction and involved in the control of growth or differentiation are not completely understood. We demonstrate here that Tec, a cytoplasmic, src-related kinase, physically associates with c-kit through a region that contains a proline-rich motif, amino terminal of the SH3 domain. Following SCF binding, Tec is tyrosine phosphorylated and its in vitro kinase activity is increased. Tyrosine phosphorylation of Tec is not detected in the response to other cytokines controlling hematopoiesis, including colony-stimulating factor-1 (CSF-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-3 (IL-3). Conversely, the cytoplasmic kinase JAK2 is activated by IL-3 but not by SCF stimulation. The activation of distinct cytoplasmic kinases may account for the synergy seen in the actions of SCF and IL-3 on hematopoietic stem cells.

scholarly journals Tec kinase associates with c-kit and is tyrosine phosphorylated and activated following stem cell factor binding.

1994 ◽  
Vol 14 (12) ◽  
pp. 8432-8437 ◽  
Author(s):  
B Tang ◽  
H Mano ◽  
T Yi ◽  
J N Ihle
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Colony Stimulating Factor ◽  
Hematopoietic Stem ◽  
Gm Csf ◽  
Amino Terminal ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Stem cell factor (SCF) plays a crucial role in hematopoiesis through its interaction with the receptor tyrosine kinase c-kit. However, the signaling events that are activated by this interaction and involved in the control of growth or differentiation are not completely understood. We demonstrate here that Tec, a cytoplasmic, src-related kinase, physically associates with c-kit through a region that contains a proline-rich motif, amino terminal of the SH3 domain. Following SCF binding, Tec is tyrosine phosphorylated and its in vitro kinase activity is increased. Tyrosine phosphorylation of Tec is not detected in the response to other cytokines controlling hematopoiesis, including colony-stimulating factor-1 (CSF-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-3 (IL-3). Conversely, the cytoplasmic kinase JAK2 is activated by IL-3 but not by SCF stimulation. The activation of distinct cytoplasmic kinases may account for the synergy seen in the actions of SCF and IL-3 on hematopoietic stem cells.

Toll-like receptors stimulate human neutrophil function

Blood ◽  
2003 ◽  
Vol 102 (7) ◽  
pp. 2660-2669 ◽  
Author(s):  
Fumitaka Hayashi ◽  
Terry K. Means ◽  
Andrew D. Luster
Keyword(s):  
Immune Cell ◽  
Germ Line ◽  
Quantitative Polymerase Chain Reaction ◽  
Neutrophil Function ◽  
Human Neutrophils ◽  
Toll Like Receptors ◽  
Gm Csf ◽  
Latex Beads ◽  
Macrophage Colony ◽  
And Function

Abstract The first immune cell to arrive at the site of infection is the neutrophil. Upon arrival, neutrophils quickly initiate microbicidal functions, including the production of antimicrobial products and proinflammatory cytokines that serve to contain infection. This allows the acquired immune system enough time to generate sterilizing immunity and memory. Neutrophils detect the presence of a pathogen through germ line-encoded receptors that recognize microbe-associated molecular patterns. In vertebrates, the best characterized of these receptors are Toll-like receptors (TLRs). We have determined the expression and function of TLRs in freshly isolated human neutrophils. Neutrophils expressed TLR1, 2, 4, 5, 6, 7, 8, 9, and 10—all the TLRs except TLR3. Granulocyte-macrophage colony-stimulating factor (GM-CSF) treatment increased TLR2 and TLR9 expression levels. The agonists of all TLRs expressed in neutrophils triggered or primed cytokine release, superoxide generation, and L-selectin shedding, while inhibiting chemotaxis to interleukin-8 (IL-8) and increasing phagocytosis of opsonized latex beads. The response to the TLR9 agonist nonmethylated CpG-motif-containing DNA (CpG DNA) required GM-CSF pretreatment, which also enhanced the response to the other TLR agonists. Finally, using quantitative polymerase chain reaction (QPCR), we demonstrate a chemokine expression profile that suggests that TLR-stimulated neutrophils recruit innate, but not acquired, immune cells to sites of infection. (Blood. 2003;102:2660-2669)

Surfactant metabolism in transgenic mice after granulocyte macrophage-colony stimulating factor ablation

1996 ◽  
Vol 270 (4) ◽  
pp. L650-L658 ◽  
Author(s):  
M. Ikegami ◽  
T. Ueda ◽  
W. Hull ◽  
J. A. Whitsett ◽  
R. C. Mulligan ◽  
...  
Keyword(s):  
Protein A ◽  
Surfactant Protein ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
And Function ◽  
Stimulating Factor ◽  
Deficient Mice ◽  
Surfactant Metabolism

Mice made granulocyte macrophage-colony stimulating factor (GM-CSF)-deficient by homologous recombination maintain normal steady-state hematopoiesis but have an alveolar accumulation of surfactant lipids and protein that is similar to pulmonary alveolar proteinosis in humans. We asked how GM-CSF deficiency alters surfactant metabolism and function in mice. Alveolar and lung tissue saturated phosphatidylcholine (Sat PC) were increased six- to eightfold in 7- to 9-wk-old GM-CSF-deficient mice relative to controls. Incorporation of radiolabeled palmitate and choline into Sat PC was higher in GM-CSF deficient mice than control mice, and no loss of labeled Sat PC occurred from the lungs of GM-CSF-deficient mice. Secretion of radiolabeled Sat PC to the alveolus was similar in GM-CSF-deficient and control mice. Labeled Sat PC and surfactant protein A (SP-A) given by tracheal instillation were cleared rapidly in control mice, but there was no measurable loss from the lungs of GM-CSF-deficient mice. The function of the surfactant from GM-CSF-deficient mice was normal when tested in preterm surfactant-deficient rabbits. GM-CSF deficiency results in a catabolic defect for Sat PC and SP-A.

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