Limits...
The chemokine SDF-1 is a chemoattractant for human CD34+ hematopoietic progenitor cells and provides a new mechanism to explain the mobilization of CD34+ progenitors to peripheral blood.

Aiuti A, Webb IJ, Bleul C, Springer T, Gutierrez-Ramos JC - J. Exp. Med. (1997)

Bottom Line: Hematopoietic progenitor cells migrate in vitro and in vivo towards a gradient of the chemotactic factor stromal cell-derived factor-1 (SDF-1) produced by stromal cells.This is the first chemoattractant reported for human CD34+ progenitor cells.Concentrations of SDF-1 that elicit chemotaxis also induce a transient elevation of cytoplasmic calcium in CD34+ cells.

View Article: PubMed Central - PubMed

Affiliation: Center for Blood Research, Inc., Boston, Massachusetts, USA.

ABSTRACT
Hematopoietic progenitor cells migrate in vitro and in vivo towards a gradient of the chemotactic factor stromal cell-derived factor-1 (SDF-1) produced by stromal cells. This is the first chemoattractant reported for human CD34+ progenitor cells. Concentrations of SDF-1 that elicit chemotaxis also induce a transient elevation of cytoplasmic calcium in CD34+ cells. SDF-1-induced chemotaxis is inhibited by pertussis toxin, suggesting that its signaling in CD34+ cells is mediated by seven transmembrane receptors coupled to Gi proteins. CD34+ cells migrating to SDF-1 include cells with a more primitive (CD34+/CD38- or CD34+/DR-) phenotype as well as CD34+ cells phenotypically committed to the erythroid, lymphoid and myeloid lineages, including functional BFU-E, CFU-GM, and CFU-MIX progenitors. Chemotaxis of CD34+ cells in response to SDF-1 is increased by IL-3 in vitro and is lower in CD34+ progenitors from peripheral blood than in CD34+ progenitors from bone marrow, suggesting that an altered response to SDF-1 may be associated with CD34 progenitor mobilization.

Show MeSH

Related in: MedlinePlus

SDF-1 induces calcium fluxes in human CD34+ cells and the  associated chemotaxis is pertussis toxin sensitive. (A) SDF-1 induces calcium fluxes in human CD34+cells. Human BM CD34+ cells were loaded  with the calcium-sensitive dye Fluo-3. Changes in Fluo-3 emission in response to SDF-1 (30 ng/ml, open circles; 300 ng/ml, closed circles) or human  MCP-1 (300 ng/ml, open squares) were monitored over time by flow cytometry. (B) The chemotaxis of human CD34+ to SDF-1 is pertussis  toxin sensitive. The chemotactic response of human BM CD34+ cells to  SDF-1 (300 ng/ml) after a 2-h incubation in 10% FCS IMDM with (100  ng/ml; pert toxin) or without pertussis toxin (control). Results shown are  the mean (and duplicates) of the percentage of the migration of the control samples (which are considered as 100%). Actual percentage of migration in the control ranged from 18–25% of input. Data are representative  of three separate experiments.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2196104&req=5

Figure 3: SDF-1 induces calcium fluxes in human CD34+ cells and the associated chemotaxis is pertussis toxin sensitive. (A) SDF-1 induces calcium fluxes in human CD34+cells. Human BM CD34+ cells were loaded with the calcium-sensitive dye Fluo-3. Changes in Fluo-3 emission in response to SDF-1 (30 ng/ml, open circles; 300 ng/ml, closed circles) or human MCP-1 (300 ng/ml, open squares) were monitored over time by flow cytometry. (B) The chemotaxis of human CD34+ to SDF-1 is pertussis toxin sensitive. The chemotactic response of human BM CD34+ cells to SDF-1 (300 ng/ml) after a 2-h incubation in 10% FCS IMDM with (100 ng/ml; pert toxin) or without pertussis toxin (control). Results shown are the mean (and duplicates) of the percentage of the migration of the control samples (which are considered as 100%). Actual percentage of migration in the control ranged from 18–25% of input. Data are representative of three separate experiments.

Mentions: Mobilization of intracellular calcium is an early event in the response to chemokine signals (38). We tested the ability of SDF-1 to induce modulation of calcium in human BM CD34+cells in a flow cytometric assay. SDF-1 (300 ng/ml) induced a rapid, transient flux of intracellular calcium, which returned to basal levels within 60 s (Fig. 3 A). No response was elicited by human MCP-1 at either 300 ng/ml (Fig. 3 A) or 30 ng/ml (data not shown). The proportion of CD34+ cells fluxing calcium in response to SDF-1 ranged between 15–25% (data not shown). Mobilized PB CD34+ cells also showed a transient rise in intracellular calcium upon SDF-1 stimulation (data not shown). To our knowledge, these results demonstrate that human CD34+ hematopoietic progenitor cells are capable of modulating intracytoplasmatic calcium in response to an external ligand.


The chemokine SDF-1 is a chemoattractant for human CD34+ hematopoietic progenitor cells and provides a new mechanism to explain the mobilization of CD34+ progenitors to peripheral blood.

Aiuti A, Webb IJ, Bleul C, Springer T, Gutierrez-Ramos JC - J. Exp. Med. (1997)

SDF-1 induces calcium fluxes in human CD34+ cells and the  associated chemotaxis is pertussis toxin sensitive. (A) SDF-1 induces calcium fluxes in human CD34+cells. Human BM CD34+ cells were loaded  with the calcium-sensitive dye Fluo-3. Changes in Fluo-3 emission in response to SDF-1 (30 ng/ml, open circles; 300 ng/ml, closed circles) or human  MCP-1 (300 ng/ml, open squares) were monitored over time by flow cytometry. (B) The chemotaxis of human CD34+ to SDF-1 is pertussis  toxin sensitive. The chemotactic response of human BM CD34+ cells to  SDF-1 (300 ng/ml) after a 2-h incubation in 10% FCS IMDM with (100  ng/ml; pert toxin) or without pertussis toxin (control). Results shown are  the mean (and duplicates) of the percentage of the migration of the control samples (which are considered as 100%). Actual percentage of migration in the control ranged from 18–25% of input. Data are representative  of three separate experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196104&req=5

Figure 3: SDF-1 induces calcium fluxes in human CD34+ cells and the associated chemotaxis is pertussis toxin sensitive. (A) SDF-1 induces calcium fluxes in human CD34+cells. Human BM CD34+ cells were loaded with the calcium-sensitive dye Fluo-3. Changes in Fluo-3 emission in response to SDF-1 (30 ng/ml, open circles; 300 ng/ml, closed circles) or human MCP-1 (300 ng/ml, open squares) were monitored over time by flow cytometry. (B) The chemotaxis of human CD34+ to SDF-1 is pertussis toxin sensitive. The chemotactic response of human BM CD34+ cells to SDF-1 (300 ng/ml) after a 2-h incubation in 10% FCS IMDM with (100 ng/ml; pert toxin) or without pertussis toxin (control). Results shown are the mean (and duplicates) of the percentage of the migration of the control samples (which are considered as 100%). Actual percentage of migration in the control ranged from 18–25% of input. Data are representative of three separate experiments.
Mentions: Mobilization of intracellular calcium is an early event in the response to chemokine signals (38). We tested the ability of SDF-1 to induce modulation of calcium in human BM CD34+cells in a flow cytometric assay. SDF-1 (300 ng/ml) induced a rapid, transient flux of intracellular calcium, which returned to basal levels within 60 s (Fig. 3 A). No response was elicited by human MCP-1 at either 300 ng/ml (Fig. 3 A) or 30 ng/ml (data not shown). The proportion of CD34+ cells fluxing calcium in response to SDF-1 ranged between 15–25% (data not shown). Mobilized PB CD34+ cells also showed a transient rise in intracellular calcium upon SDF-1 stimulation (data not shown). To our knowledge, these results demonstrate that human CD34+ hematopoietic progenitor cells are capable of modulating intracytoplasmatic calcium in response to an external ligand.

Bottom Line: Hematopoietic progenitor cells migrate in vitro and in vivo towards a gradient of the chemotactic factor stromal cell-derived factor-1 (SDF-1) produced by stromal cells.This is the first chemoattractant reported for human CD34+ progenitor cells.Concentrations of SDF-1 that elicit chemotaxis also induce a transient elevation of cytoplasmic calcium in CD34+ cells.

View Article: PubMed Central - PubMed

Affiliation: Center for Blood Research, Inc., Boston, Massachusetts, USA.

ABSTRACT
Hematopoietic progenitor cells migrate in vitro and in vivo towards a gradient of the chemotactic factor stromal cell-derived factor-1 (SDF-1) produced by stromal cells. This is the first chemoattractant reported for human CD34+ progenitor cells. Concentrations of SDF-1 that elicit chemotaxis also induce a transient elevation of cytoplasmic calcium in CD34+ cells. SDF-1-induced chemotaxis is inhibited by pertussis toxin, suggesting that its signaling in CD34+ cells is mediated by seven transmembrane receptors coupled to Gi proteins. CD34+ cells migrating to SDF-1 include cells with a more primitive (CD34+/CD38- or CD34+/DR-) phenotype as well as CD34+ cells phenotypically committed to the erythroid, lymphoid and myeloid lineages, including functional BFU-E, CFU-GM, and CFU-MIX progenitors. Chemotaxis of CD34+ cells in response to SDF-1 is increased by IL-3 in vitro and is lower in CD34+ progenitors from peripheral blood than in CD34+ progenitors from bone marrow, suggesting that an altered response to SDF-1 may be associated with CD34 progenitor mobilization.

Show MeSH
Related in: MedlinePlus