Related Experiment Videos
Cell interactions influencing murine marrow megakaryocytes: nature of the potentiator cell in bone marrow
Abstract:
Auxiliary bone marrow cells are required for optimal murine megakaryocyte colony formation in addition to progenitor cells and a colony stimulating activity (CSA) present in WEHI-3 cell conditioned medium. These auxiliary cells are adherent, with a sedimentation rate of 5.8 mm hr-1 and buoyant density of 1.065-1.078 gcm-3. The activity from bone marrow cells is loss at irradiation doses above 900 rad. Bone marrow cells with these characteristics, and supernatants from lung, bone shafts, and peritoneal exudate cells were all active in enhancing megakaryocyte colony incidences in mouse bone marrow cultures above those stimulated by an obligatory activity in WEHI-3 cell conditioned medium. Certain macrophage cell lines (J774, P388D1) could elaborate the activity. This study confirms that a potentiation activity enhances CSA stimulation of megakaryocyte colony formation. The potentiator is elaborated by bone marrow cells in limiting amounts requiring either high cell concentrations or an exogenous source of the activity for optimal colony growth.
Insights
Auxiliary bone marrow cells enhance megakaryocyte colony formation by potentiating colony stimulating activity (CSA). This crucial helper cell activity requires specific physical characteristics and is sensitive to irradiation.
Area of Science:
- Hematology
- Cell Biology
- Stem Cell Research
Background:
- Optimal megakaryocyte colony formation in murine bone marrow cultures requires progenitor cells and colony stimulating activity (CSA).
- An additional auxiliary cell activity from bone marrow cells is necessary for maximal colony development.
Purpose of the Study:
- To characterize the auxiliary bone marrow cells involved in enhancing megakaryocyte colony formation.
- To identify the source and nature of the potentiating activity that synergizes with CSA.
Main Methods:
- Characterization of auxiliary bone marrow cells by sedimentation rate and buoyant density.
- Assessment of activity loss following irradiation.
- Testing supernatants from various tissues and cell lines for potentiating effects on megakaryocyte colony formation.
Main Results:
- Auxiliary bone marrow cells are adherent, with specific sedimentation rates and densities, and their activity is lost above 900 rad irradiation.
- Supernatants from bone marrow, lung, bone shafts, peritoneal exudate cells, and macrophage cell lines (J774, P388D1) demonstrated potentiating activity.
- This potentiator enhances CSA stimulation, but is elaborated in limiting amounts by bone marrow cells.
Conclusions:
- A potentiation activity, distinct from CSA, significantly enhances megakaryocyte colony formation.
- This potentiator is produced by bone marrow cells and other cell types, but requires high cell concentrations or exogenous supply for optimal results.