scholarly journals Observations on the binding and interaction of radioiodinated colony- stimulating factor with murine bone marrow cells in vivo

Blood ◽  
1982 ◽  
Vol 59 (2) ◽  
pp. 408-420
Author(s):  
G Pigoli ◽  
A Waheed ◽  
RK Shadduck

Radioiodinated L-cell-derived colony-stimulating factor (CSF) was used to characterize the binding reaction to murine bone marrow cells. The major increment in cell-associated radioactivity occurred over 24 hr incubation at 37 degrees C, but virtually no binding was observed at 4 degrees C. The reaction was saturable with approximately 1 ng/ml of purified CSF. Unlabeled CSF prevented the binding, whereas a number of other hormones and proteins did not compete for CSF uptake. Further specificity studies showed virtually no binding to human bone marrow, which is unresponsive to this form of murine CSF. Minimal CSF uptake was noted with murine peritoneal macrophages, but virtually no binding was detected with thymic, lymph node, liver, or kidney cells. The marrow cell interaction with tracer appeared to require a new protein synthesis, as the binding was prevented by cycloheximide or puromycin. Preincubation of marrow cells in medium devoid of CSF increased the degree of binding after 1 hr exposure to the tracer. This suggests that CSF binding sites may be occupied or perhaps decreased in response to ambient levels of CSF in vivo. Approximately 70% of the bound radioactivity was detected in the cytoplasm at 24 hr. This material was partially degraded as judged by a decrease in molecular weight from approximately 62,000 to 2 peaks of approximately 32,000 and approximately 49,000, but 72% of the binding activity was retained. After plateau binding was achieved, greater than 80% of the radioactivity released into the medium was degraded into biologically inactive peptides with molecular weights less than 10,000. These findings suggest that the interaction of CSF with marrow cells is characterized by binding with subsequent internalization and metabolic degradation into portions of the molecule that are devoid of biologic activity.

Blood ◽  
1982 ◽  
Vol 59 (2) ◽  
pp. 408-420 ◽  
Author(s):  
G Pigoli ◽  
A Waheed ◽  
RK Shadduck

Abstract Radioiodinated L-cell-derived colony-stimulating factor (CSF) was used to characterize the binding reaction to murine bone marrow cells. The major increment in cell-associated radioactivity occurred over 24 hr incubation at 37 degrees C, but virtually no binding was observed at 4 degrees C. The reaction was saturable with approximately 1 ng/ml of purified CSF. Unlabeled CSF prevented the binding, whereas a number of other hormones and proteins did not compete for CSF uptake. Further specificity studies showed virtually no binding to human bone marrow, which is unresponsive to this form of murine CSF. Minimal CSF uptake was noted with murine peritoneal macrophages, but virtually no binding was detected with thymic, lymph node, liver, or kidney cells. The marrow cell interaction with tracer appeared to require a new protein synthesis, as the binding was prevented by cycloheximide or puromycin. Preincubation of marrow cells in medium devoid of CSF increased the degree of binding after 1 hr exposure to the tracer. This suggests that CSF binding sites may be occupied or perhaps decreased in response to ambient levels of CSF in vivo. Approximately 70% of the bound radioactivity was detected in the cytoplasm at 24 hr. This material was partially degraded as judged by a decrease in molecular weight from approximately 62,000 to 2 peaks of approximately 32,000 and approximately 49,000, but 72% of the binding activity was retained. After plateau binding was achieved, greater than 80% of the radioactivity released into the medium was degraded into biologically inactive peptides with molecular weights less than 10,000. These findings suggest that the interaction of CSF with marrow cells is characterized by binding with subsequent internalization and metabolic degradation into portions of the molecule that are devoid of biologic activity.


Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1923-1928 ◽  
Author(s):  
BD Chen

Abstract Earlier studies suggested the existence of a blood-bone marrow barrier that significantly inhibits the transfer of plasma macrophage colony- stimulating factor (M-CSF) to responsive hematopoietic cells in vivo as indicated by its failure to induce a receptor downregulation in bone marrow cells. In this study, the effect of recombinant human interleukin-1 (rhuIL-1) was investigated. In vivo administration of rhuIL-1, either intraperitoneally (IP) or intravenously (IV), induced a rapid transient loss of M-CSF receptor binding activity in bone marrow cells, with a nadir occurring between 2 to 4 hours while loss of M-CSF receptors by cells in the peritoneal cavity occurred only in animals receiving rhuIL-1 via IP administration. The loss of M-CSF receptor activity after rhuIL-1 treatment was correlated with an elevated level of circulating M-CSF. However, the loss of M-CSF receptors in marrow cells was prevented by dexamethasone (Dex) treatment before rhuIL-1 administration. The fact that Dex treatment also reduced the level of circulating M-CSF after rhuIL-1 administration suggests that the inhibitory effects of IL-1 are mediated through locally produced M-CSF. Administration of rhuM-CSF at higher doses, either IV or IP, also induced a loss of M-CSF receptor of lesser degree in the marrow cells. However, the loss of M-CSF receptors by the peritoneal cells was induced only in mice receiving rhuM-CSF through IP administration. Taken together, these results indicate the existence of a unidirectional barrier that prevents the transfer of blood M-CSF and IL- 1 to peritoneal cavity but not vice versa.


Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1923-1928
Author(s):  
BD Chen

Earlier studies suggested the existence of a blood-bone marrow barrier that significantly inhibits the transfer of plasma macrophage colony- stimulating factor (M-CSF) to responsive hematopoietic cells in vivo as indicated by its failure to induce a receptor downregulation in bone marrow cells. In this study, the effect of recombinant human interleukin-1 (rhuIL-1) was investigated. In vivo administration of rhuIL-1, either intraperitoneally (IP) or intravenously (IV), induced a rapid transient loss of M-CSF receptor binding activity in bone marrow cells, with a nadir occurring between 2 to 4 hours while loss of M-CSF receptors by cells in the peritoneal cavity occurred only in animals receiving rhuIL-1 via IP administration. The loss of M-CSF receptor activity after rhuIL-1 treatment was correlated with an elevated level of circulating M-CSF. However, the loss of M-CSF receptors in marrow cells was prevented by dexamethasone (Dex) treatment before rhuIL-1 administration. The fact that Dex treatment also reduced the level of circulating M-CSF after rhuIL-1 administration suggests that the inhibitory effects of IL-1 are mediated through locally produced M-CSF. Administration of rhuM-CSF at higher doses, either IV or IP, also induced a loss of M-CSF receptor of lesser degree in the marrow cells. However, the loss of M-CSF receptors by the peritoneal cells was induced only in mice receiving rhuM-CSF through IP administration. Taken together, these results indicate the existence of a unidirectional barrier that prevents the transfer of blood M-CSF and IL- 1 to peritoneal cavity but not vice versa.


Blood ◽  
1983 ◽  
Vol 62 (6) ◽  
pp. 1197-1202
Author(s):  
RK Shadduck ◽  
G Pigoli ◽  
C Caramatti ◽  
G Degliantoni ◽  
V Rizzoli ◽  
...  

Binding of radiolabeled L-cell colony-stimulating factor (CSF) was studied using murine bone marrow and fetal liver cells. With 10(7) cells, saturation of binding was seen with approximately 500,000 cpm of 125I-CSF. Minimal binding was detected after one hour incubation with tracer at 37 degrees C; however, marked cellular uptake of radioactivity was noted after 24-hr exposure to CSF. As judged by autoradiographs, small numbers of myeloblasts, promyelocytes, and large mononuclear cells were labeled with 1-hr exposure to tracer. By 6 hr of incubation, 50%-70% of myeloblasts and promyelocytes and small numbers of late granulocytic cells were labeled. Virtually all myeloblasts and promyelocytes and approximately 50% of myelocytes, metamyelocytes, polymorphonuclear granulocytes, and monocytes were labeled after 24-hr exposure to the radioiodinated CSF. Label was not detected on erythroblasts, eosinophils, or megakaryocytes. Suspensions of fetal liver cells had lower uptake of radioactivity than bone marrow cells. This appeared to result from a lesser concentration of granulocytic cells in fetal liver, as labeling of individual cells was similar with both tissues. In additional experiments, CSF binding to marrow cells was assessed after 30-min exposure to tracer at 0 degrees C. Uptake of 125I-CSF exceeded that observed after 24-hr incubation at 37 degrees C. With this technique, cellular label was also confined to granulocytic and monocytic cells. These findings suggest that purified CSF reacts with and may stimulate immature and mature cells of the granulocytic and monocytic lineages.


Blood ◽  
1999 ◽  
Vol 94 (3) ◽  
pp. 950-958 ◽  
Author(s):  
Feng-Chun Yang ◽  
Kohichiro Tsuji ◽  
Atsushi Oda ◽  
Yasuhiro Ebihara ◽  
Ming-jiang Xu ◽  
...  

Granulocyte-colony stimulating factor (G-CSF) has been found to act on the neutrophilic lineage. We recently showed that human G-CSF (hG-CSF) has effects similar to early-acting cytokines such as interleukin-3 (IL-3) in the development of multipotential hematopoietic progenitors in transgenic (Tg) mice expressing receptors (R) for hG-CSF. In the present study, we examined the effects of hG-CSF on more mature hematopoietic cells committed to megakaryocytic lineage in these Tg mice. The administration of hG-CSF to the Tg mice increased the numbers of both platelets in peripheral blood and megakaryocytes in the spleen, indicating that hG-CSF stimulates megakaryopoiesis in the Tg mice in vivo. The stimulatory effect of hG-CSF was also supported by the results of studies in vitro. hG-CSF supported megakaryocyte colony formation in a dose-dependent fashion in clonal cultures of bone marrow cells derived from the Tg mice. Direct effects of hG-CSF on megakaryocytic progenitors in the Tg mice were confirmed by culture of single-cell sorted from bone marrow cells. hG-CSF showed a stronger effect on maturation of megakaryocytes in the Tg mice than that of IL-3 alone, but weaker than that of TPO alone. In addition, hG-CSF induced phosphorylation of STAT3 but not Jak2 or STAT5, while TPO induced phosphorylation of both. In contrast to TPO, hG-CSF did not enhance ADP-induced aggregation. Thus, hG-CSF has a wide variety of functions in megakaryopoiesis of hG-CSFR-Tg mice, as compared with other megakaryopoietic cytokines, but the activity of hG-CSF in megakaryocytes and platelets does not stand up to a comparison with that of TPO. Specific signals may be required for the full maturation and activation of platelets.


Blood ◽  
1983 ◽  
Vol 62 (6) ◽  
pp. 1197-1202 ◽  
Author(s):  
RK Shadduck ◽  
G Pigoli ◽  
C Caramatti ◽  
G Degliantoni ◽  
V Rizzoli ◽  
...  

Abstract Binding of radiolabeled L-cell colony-stimulating factor (CSF) was studied using murine bone marrow and fetal liver cells. With 10(7) cells, saturation of binding was seen with approximately 500,000 cpm of 125I-CSF. Minimal binding was detected after one hour incubation with tracer at 37 degrees C; however, marked cellular uptake of radioactivity was noted after 24-hr exposure to CSF. As judged by autoradiographs, small numbers of myeloblasts, promyelocytes, and large mononuclear cells were labeled with 1-hr exposure to tracer. By 6 hr of incubation, 50%-70% of myeloblasts and promyelocytes and small numbers of late granulocytic cells were labeled. Virtually all myeloblasts and promyelocytes and approximately 50% of myelocytes, metamyelocytes, polymorphonuclear granulocytes, and monocytes were labeled after 24-hr exposure to the radioiodinated CSF. Label was not detected on erythroblasts, eosinophils, or megakaryocytes. Suspensions of fetal liver cells had lower uptake of radioactivity than bone marrow cells. This appeared to result from a lesser concentration of granulocytic cells in fetal liver, as labeling of individual cells was similar with both tissues. In additional experiments, CSF binding to marrow cells was assessed after 30-min exposure to tracer at 0 degrees C. Uptake of 125I-CSF exceeded that observed after 24-hr incubation at 37 degrees C. With this technique, cellular label was also confined to granulocytic and monocytic cells. These findings suggest that purified CSF reacts with and may stimulate immature and mature cells of the granulocytic and monocytic lineages.


Blood ◽  
1996 ◽  
Vol 87 (10) ◽  
pp. 4136-4142 ◽  
Author(s):  
I Kawashima ◽  
ED Zanjani ◽  
G Almaida-Porada ◽  
AW Flake ◽  
H Zeng ◽  
...  

Using in utero transplantation into fetal sheep, we examined the capability of human bone marrow CD34+ cells fractionated based on Kit protein expression to provide long-term in vivo engraftment. Twelve hundred to 5,000 CD34+ Kit-, CD34+ Kit(low), and CD34+ Kit(high) cells were injected into a total of 14 preimmune fetal sheep recipients using the amniotic bubble technique. Six fetuses were killed in utero 1.5 months after bone marrow cell transplantation. Two fetuses receiving CD34+ Kit(low) cells showed signs of engraftment according to analysis of CD45+ cells in their bone marrow cells and karyotype studies of the colonies grown in methylcellulose culture. In contrast, two fetuses receiving CD34+ Kit(high) cells and two fetuses receiving CD34+ Kit- cells failed to show evidence of significant engraftment. Two fetuses were absorbed. A total of six fetuses receiving different cell populations were allowed to proceed to term, and the newborn sheep were serially examined for the presence of chimerism. Again, only the two sheep receiving CD34+ Kit(low) cells exhibited signs of engraftment upon serial examination. Earlier in studies of murine hematopoiesis, we have shown stage-specific changes in Kit expression by the progenitors. The studies of human cells reported here are in agreement with observations in mice, and indicate that human hematopoietic stem cells are enriched in the Kit(low) population.


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