scholarly journals Aplastic anemia: lack of inhibitory effect of bone marrow lymphocytes on in vitro granulopoiesis

Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 625-632 ◽  
Author(s):  
R Sullivan ◽  
PJ Quesenberry ◽  
R Parkman ◽  
KS Zuckerman ◽  
RH Levey ◽  
...  

Abstract Prompted by previous reports that in certain patients with aplastic anemia, cell-mediated autoimmune suppression of myeloid stem cell proliferation may be demonstrable in vitro, we studied the effects of bone marrow lymphocytes from 18 patients with myeloid aplasia on the proliferation of committed granulocytic-monocytic progenitor cells (CFU- C). When assayed in soft agar cultures, marrow suspensions from 10 patients with aplastic anemia contained significantly fewer viable CFU- C than similar cell preparations from control subjects. To deplete marrow cell suspensions of lymphocytes, we employed rabbit anti-human thymocyte serum (ATS), which after multiple adsorptions exhibited marked cytotoxicity for human B and T lymphocytes but had negligible effect on normal CFU-C proliferation. Preincubation of marrow samples from 12 patients with ATS and complement resulted in no inhibition or enhancement of CFU-C growth. In further experiments, marrow cells from 8 patients were incubated with marrow from control subjects prior to CFU-C culture. No suppression of donor CFU-C proliferation was observed in any of these studies, and in 4 cocultures, mixture of the 2 marrow suspensions resulted in stimulation of CFU-C growth. Using these assays, we detected no evidence of cell-mediated inhibition of CFU-C proliferation in any of the 18 patients that we evaluated. Our data support the conclusion that in the majority of patients with aplastic anemia, an absolute deficiency of hemopoietic stem cells is present within the marrow that does not appear to be effected or sustained by suppressor lymphocytes. Whether the reduction of viable stem cells is the cause or the consequence of the process that leads to marrow failure remains unknown.

Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 625-632
Author(s):  
R Sullivan ◽  
PJ Quesenberry ◽  
R Parkman ◽  
KS Zuckerman ◽  
RH Levey ◽  
...  

Prompted by previous reports that in certain patients with aplastic anemia, cell-mediated autoimmune suppression of myeloid stem cell proliferation may be demonstrable in vitro, we studied the effects of bone marrow lymphocytes from 18 patients with myeloid aplasia on the proliferation of committed granulocytic-monocytic progenitor cells (CFU- C). When assayed in soft agar cultures, marrow suspensions from 10 patients with aplastic anemia contained significantly fewer viable CFU- C than similar cell preparations from control subjects. To deplete marrow cell suspensions of lymphocytes, we employed rabbit anti-human thymocyte serum (ATS), which after multiple adsorptions exhibited marked cytotoxicity for human B and T lymphocytes but had negligible effect on normal CFU-C proliferation. Preincubation of marrow samples from 12 patients with ATS and complement resulted in no inhibition or enhancement of CFU-C growth. In further experiments, marrow cells from 8 patients were incubated with marrow from control subjects prior to CFU-C culture. No suppression of donor CFU-C proliferation was observed in any of these studies, and in 4 cocultures, mixture of the 2 marrow suspensions resulted in stimulation of CFU-C growth. Using these assays, we detected no evidence of cell-mediated inhibition of CFU-C proliferation in any of the 18 patients that we evaluated. Our data support the conclusion that in the majority of patients with aplastic anemia, an absolute deficiency of hemopoietic stem cells is present within the marrow that does not appear to be effected or sustained by suppressor lymphocytes. Whether the reduction of viable stem cells is the cause or the consequence of the process that leads to marrow failure remains unknown.


Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1497-1504 ◽  
Author(s):  
VF Quesniaux ◽  
GJ Graham ◽  
I Pragnell ◽  
D Donaldson ◽  
SD Wolpe ◽  
...  

Abstract A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst- forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP- 1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.


Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1671-1678 ◽  
Author(s):  
Jichun Chen ◽  
Karen Lipovsky ◽  
Felicia M. Ellison ◽  
Rodrigo T. Calado ◽  
Neal S. Young

Abstract Infusion of parental lymph node (LN) cells into sublethally irradiated hybrid F1 recipients created a murine model for bone marrow (BM) failure. Affected animals developed fatal pancytopenia within 2 to 3 weeks, accompanied by BM oligoclonal T-cell infiltration and severe marrow hypoplasia indicated by approximately 10-fold declines in total BM cellularity, 15-fold declines in BM Lin-Sca1+c-Kit+ cells, 100-fold declines in spleen colony-forming units, and 100-fold declines in hematopoietic progenitor and stem cells as estimated by irradiation protection in vivo. LN cells of both H2b/b and H2d/d haplotypes were effectors. Serum interferon-γ (IFN-γ) concentration increased 2- to 3-fold. Marrow cells were severely apoptotic, with high proportions of Fas+ and annexin V+ cells. Cotransplantation of 5 × 105 BM cells from clinically affected donors and 106 BM cells from H2 identical healthy mice could not rescue lethally irradiated recipients. Recipients had significantly lower cellularity in peripheral blood and BM, and cell mixtures failed to produce a stromal feeder layer to support marrow cell growth in vitro. Pathogenic T cells from donors after BM failure appeared capable of destroying hematopoietic progenitor, stem, and stromal cells from fully compatible healthy donors as “innocent bystanders.” This effect can be partially abrogated by anti-IFN-γ antibody. (Blood. 2004;104:1671-1678)


2015 ◽  
Vol 137 (1) ◽  
Author(s):  
T. J. Vaughan ◽  
M. Voisin ◽  
G. L. Niebur ◽  
L. M. McNamara

Mechanical loading directs the differentiation of mesenchymal stem cells (MSCs) in vitro and it has been hypothesized that the mechanical environment plays a role in directing the cellular fate of MSCs in vivo. However, the complex multicellular composition of trabecular bone marrow means that the precise nature of mechanical stimulation that MSCs experience in their native environment is not fully understood. In this study, we developed a multiscale model that discretely represents the cellular constituents of trabecular bone marrow and applied this model to characterize mechanical stimulation of MCSs in vivo. We predicted that cell-level strains in certain locations of the trabecular marrow microenvironment were greater in magnitude (maximum ε12 = ∼24,000 με) than levels that have been found to result in osteogenic differentiation of MSCs in vitro (>8000 με), which may indicate that the native mechanical environment of MSCs could direct cellular fate in vivo. The results also showed that cell–cell adhesions could play an important role in mediating mechanical stimulation within the MSC population in vivo. The model was applied to investigate how changes that occur during osteoporosis affected mechanical stimulation in the cellular microenvironment of trabecular bone marrow. Specifically, a reduced bone volume (BV) resulted in an overall increase in bone deformation, leading to greater cell-level mechanical stimulation in trabecular bone marrow (maximum ε12 = ∼48,000 με). An increased marrow adipocyte content resulted in slightly lower levels of stimulation within the adjacent cell population due to a shielding effect caused by the more compliant behavior of adipocytes (maximum ε12 = ∼41,000 με). Despite this reduction, stimulation levels in trabecular bone marrow during osteoporosis remained much higher than those predicted to occur under healthy conditions. It was found that compensatory mechanobiological responses that occur during osteoporosis, such as increased trabecular stiffness and axial alignment of trabeculae, would be effective in returning MSC stimulation in trabecular marrow to normal levels. These results have provided novel insight into the mechanical stimulation of the trabecular marrow MSC population in both healthy and osteoporotic bone, and could inform the design three-dimensional (3D) in vitro bioreactor strategies techniques, which seek to emulate physiological conditions.


Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1497-1504 ◽  
Author(s):  
VF Quesniaux ◽  
GJ Graham ◽  
I Pragnell ◽  
D Donaldson ◽  
SD Wolpe ◽  
...  

A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst- forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP- 1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.


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