The repopulating potential of bone marrow cells that have been subjected either to cryoprotective or to cryodestructive treatments were assayed by the spleen colony technique. There were four treatments. For each treatment group the ultrastructure of aliquots of the cell suspensions was studied, and an attempt was made to identify the cells responsible for hematopoietic repopulation. The repopu...

AIM The effect of lung irradiation on reduction of lung stem cells and repopulation with bone marrow-derived cells was measured. MATERIALS AND METHODS Expression of green fluorescent protein positive cells (GFP(+)) in the lungs of thoracic irradiated FVB/NHsd mice (Harlan Sprague Dawley, Indianapolis, IN, USA) was determined. This was compared to the repopulation of bone marrow-derived cells ...

Mice lacking the chemokine stromal cell-derived factor/pre-B cell growth stimulating factor or its primary physiological receptor CXCR4 revealed defects in B lymphopoiesis and bone marrow myelopoiesis during embryogenesis. We show here that adoptive transfer experiments reveal a deficiency in long-term lymphoid and myeloid repopulation in adult bone marrow by CXCR4-/- fetal liver cells, althoug...

Fractionation of mouse bone marrow by adherence to tissue culture plastic was used to characterize the adhesive properties of hematopoietic stem (HS) cells capable of long-term reconstitution. The adherent fraction that represents approximately 13% of the total marrow population was virtually devoid of in vitro colony-forming cells and spleen colony-forming cells but did contain approximately 3...

Microglia are highly dynamic components of the innate immune system. In this issue of Neuron, Elmore et al. (2014) report that global depletion of microglia triggers mobilization of latent microglial progenitors throughout the CNS, resulting in rapid repopulation.

Several studies have suggested that the cyclin-dependent kinase (CDK) inhibitor p21 plays a crucial role in regulating hematopoietic stem and progenitor pool size. To allow assessment of long-term stem cell functioning in vivo, we have backcrossed a p21 null allele to C57BL/6 (B6) mice, the most commonly used mouse strain in hematopoietic stem cell research. In various in vitro assays, the homo...

The radiation dose-survival of various hematopoietic cell subsets in murine bone marrow (BM) was determined in the cobblestone area forming cell (CAFC) assay under conditions of single-, split-, and multiple-dose irradiation. A greater recovery in cell survival with decreasing dose per fraction, or increasing fraction number, was observed for primitive CAFC day-28 and day-35 than for CAFC day-6...

Previous work has shown that the 0.02-0.05% of adult mouse bone marrow cells that bear the cell surface phenotype Thy-1loLin-Sca-1+ are enriched 1000- to 2000-fold for hematopoietic stem-cell activity in a variety of assays. When 50-100 cells of this phenotype are injected into an irradiated animal, they can permanently repopulate the entire hematopoietic system. In the present study, limiting-...

Neutralizing injurious stimuli, proinflammatory mediator catabolism, and polymorphonuclear leukocyte (PMN) clearance are determinants of inflammatory resolution. To this, we recently added innate-type lymphocyte repopulation as being central for restoring postinflammation tissue homeostasis with a role in controlling innate immune-mediated responses to secondary infection. However, although mac...

Forty-four out of 258 allogeneic BMT were performed across the major ABO barrier. Donor erythrocyte repopulation could be evaluated in 30 cases. Fifty-eight patients transplanted with an ABO compatible or minor incompatible graft served as the control group. All patients received a marrow graft depleted of lymphocytes by counterflow centrifugation. Less than 10(8) residual erythrocytes were pre...