The fluctuating phenotype of the lymphohematopoietic stem cell with cell cycle transit - PubMed (original) (raw)

The fluctuating phenotype of the lymphohematopoietic stem cell with cell cycle transit

H K Habibian et al. J Exp Med. 1998.

Abstract

The most primitive engrafting hematopoietic stem cell has been assumed to have a fixed phenotype, with changes in engraftment and renewal potential occurring in a stepwise irreversible fashion linked with differentiation. Recent work shows that in vitro cytokine stimulation of murine marrow cells induces cell cycle transit of primitive stem cells, taking 40 h for progression from G0 to mitosis and 12 h for subsequent doublings. At 48 h of culture, progenitors are expanded, but stem cell engraftment is markedly diminished. We have investigated whether this effect on engraftment was an irreversible step or a reversible plastic feature correlated with cell cycle progression. Long-term engraftment (2 and 6 mo) of male BALB/c marrow cells exposed in vitro to interleukin (IL)-3, IL-6, IL-11, and steel factor was assessed at 2-4-h intervals of culture over 24-48 h using irradiated female hosts; the engraftment phenotype showed marked fluctuations over 2-4-h intervals, with engraftment nadirs occurring in late S and early G2. These data show that early stem cell regulation is cell cycle based, and have critical implications for strategies for stem cell expansion and engraftment or gene therapy, since position in cell cycle will determine whether effective engraftment occurs in either setting.

PubMed Disclaimer

Figures

Figure 1

Engraftment of cytokine-treated male BALB/c cells into irradiated female hosts: male BALB/c marrow cells cultured in IL-3, IL-6, IL-11, and steel factor were analyzed at 2–4-h intervals for their capacity to competitively engraft into irradiated female BALB/c mice (650– 1,000 cGy) when competed with equal numbers (based on starting input) of normal, noncultured female cells. (A) In one of five experiments in which marrow engraftment was assessed 8 wk after cell infusion, Southern blot shows PY2-labeled male sequence in DNA from female BALB/c host marrow. Each band represents marrow from an individual mouse. Percent engraftment is derived from phosphorimaging of original blots. The low-level engraftment seen at 32 h was significantly different from levels at 28 h (P = 0.009) or 0 h (P = 0.009). Similarly, values at 44 and 48 h were significantly different from those at 40 and 0 h (P = 0.007 and 0.01), respectively. (B) One of two experiments in which marrow was assessed 6 mo after cell infusion. The engraftment level at 28 h was significantly lower than that at 26 h (P = 0.03) and at 0 h (P = 0.01), and that seen at 48 h was different from 44 h (P = 0.09) and 0 h (P = 0.01).

Figure 1

Figure 2

Graphic representation of mean ± 1 SD for the time of first nadir and mean ± 1 SD for the time of first recovery for male BALB/c marrow cells cultured in IL-3, IL-6, IL-11, and steel factor, analyzed for competitive engraftment (competed with equal starting equivalents of fresh female marrow) in 1,000 cGy–irradiated female hosts, and superimposed on cell cycle parameters separately determined for BALB/c lineage–negative rhodaminelo Hoechstlo purified stem cells cultured under identical conditions. Cell cycle parameters were determined by tritiated thymidine labeling and cell count doublings. (A) Summary of five experiments analyzed 8 wk after cell infusion. (B) Summary of two experiments analyzed 6 mo after cell infusion.

Figure 3

Engraftment of BALB/c marrow cells cultured for 80 h under serum-free condition at 3.6 × 106 cells/ml with IL-3, IL-6, IL-11, and steel factor and analyzed 8 wk after transplantation. 106 cultured male BALB/c cells in cytokines were competed against 106 noncultured female cells. Southern blots show PY2-labeled male sequence in DNA from female BALB/c host marrow. Analysis is as described in the legend to Fig. 1, A and B. The low levels of engraftment seen at 28 and 32 h were significantly different from levels at 24 h (P = 0.005 for both) and 0 h (P = 0.005 for both). Similarly, values at 48 h were significantly different from those at 40 h (P = 0.008) and 0 h (P = 0.008).

References

1. Quesenberry, P.J. 1994. Hemopoietic stem cells, progenitor cells and cytokines. In Williams Textbook of Hematology, 5th ed. M. Lichtman and T. Kipps, editors. McGraw-Hill Inc., New York. 211–228.
1. Monette FC, DeMello JB. The relationship between stem cell seeding efficiency and position in cell cycle. Cell Tissue Kinet. 1979;12:161–175. - PubMed
1. Quesenberry PJ. The effect of endotoxin on murine stem cells. J Cell Physiol. 1973;82:239–244. - PubMed
1. Fleming WM. Functional heterogeneity is associated with the cell cycle status of murine hematopoietic stem cells. J Cell Biol. 1993;122:897–902. - PMC - PubMed
1. Peters SO, Kittler EL, Ramshaw HS, Quesenberry PJ. Murine marrow cells expanded in culture with IL-3, IL-6, IL-11, and SCF acquire an engraftment defect in normal hosts. Exp Hematol. 1995;23:461–469. - PubMed

The fluctuating phenotype of the lymphohematopoietic stem cell with cell cycle transit - PubMed (original) (raw)