The long term objective of this project is to characterize the most primative adult stem cells - those with the most repopulating ability over the longest time. Such cells continuously populate the hemopoietic and immune systems and are the essential element in clinical marrow transplantation. They are assayed by directly measuring repopulating ability in competition with a standard dose of simultaneously grafted, genetically marked stem cells. Optimal conditions for this assay will be defined, using congenic mouse strains that are identical except for the genetic markers, defining optimal cell numbers, calibrating the assay with standard frozen cell types, and repeating proliferative stimuli over the recipient's life to make the assay as rigorous as possible. Deleterious effects of transplanting stem cells are of major concern in clinical marrow grafts. The degree to which these effects are caused by proliferative exhaustion, irradiation, stem cell displacement, excessive stimuli to differentiate, and handling will be determined by removing possible causes. Mutant mice defective in either erythropoietic or immune stem cells will be studied to determine whether the same stem cell produces both. Other mutants with hemolytic anemias requiring over 50 times normal rates of erythrocyte production will be tested for proliferative exhaustion from fetal life through old age. Tetraparental mice will be used to determine whether newly synthesized erythrocytes arise from few or many stem cells. Variabilities among irradiated recipients of identical marrow mixtures and among recipients with a constant portion of bone shielded, will be used to estimate stem cell numbers with the binomial equation. Both stimulatory and inhibitory effects of immune responses on stem cell repopulation will be studied, and antigens causing each will be characterized with monoclonal antibodies. Stem cells will be purified, or treated with antibody, to remove regulatory cells and analyze their effects. Long-term repopulation assays will be used to assess stem cell growth in vitro and to evaluate assays for stem cells in vitro. Currently used tissue culture procedures will be tested, and improved procedures will be developed for stem cell growth and analysis. The ability to assay, or even to grow, the most primative human stem cells in vitro might have clinical importance.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK025687-14
Application #
3227528
Study Section
Immunobiology Study Section (IMB)
Project Start
1979-12-01
Project End
1989-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
14
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Jackson Laboratory
Department
Type
DUNS #
042140483
City
Bar Harbor
State
ME
Country
United States
Zip Code
04609
Harrison, D E; Zhong, R K; Jordan, C T et al. (1997) Relative to adult marrow, fetal liver repopulates nearly five times more effectively long-term than short-term. Exp Hematol 25:293-7
Zhong, R K; Astle, C M; Harrison, D E (1996) Distinct developmental patterns of short-term and long-term functioning lymphoid and myeloid precursors defined by competitive limiting dilution analysis in vivo. J Immunol 157:138-45
Zhong, R K; Donnenberg, A D; Edison, L et al. (1996) The appearance of Thy-1- donor T cells in the peripheral circulation 3-6 weeks after bone marrow transplantation suggests an extrathymic origin. Int Immunol 8:171-6
Jordan, C T; Astle, C M; Zawadzki, J et al. (1995) Long-term repopulating abilities of enriched fetal liver stem cells measured by competitive repopulation. Exp Hematol 23:1011-5
Harrison, D E; Zsebo, K M; Astle, C M (1994) Splenic primitive hematopoietic stem cell (PHSC) activity is enhanced by steel factor because of PHSC proliferation. Blood 83:3146-51
Gardner, R V; Lerner, C; Astle, C M et al. (1993) Assessing permanent damage to primitive hematopoietic stem cells after chemotherapy using the competitive repopulation assay. Cancer Chemother Pharmacol 32:450-4
Harrison, D E; Jordan, C T; Zhong, R K et al. (1993) Primitive hemopoietic stem cells: direct assay of most productive populations by competitive repopulation with simple binomial, correlation and covariance calculations. Exp Hematol 21:206-19
Harrison, D E; Zhong, R K (1992) The same exhaustible multilineage precursor produces both myeloid and lymphoid cells as early as 3-4 weeks after marrow transplantation. Proc Natl Acad Sci U S A 89:10134-8
Harrison, D E (1992) Evaluating functional abilities of primitive hematopoietic stem cell populations. Curr Top Microbiol Immunol 177:13-30
Harrison, D E; Lerner, C P (1991) Most primitive hematopoietic stem cells are stimulated to cycle rapidly after treatment with 5-fluorouracil. Blood 78:1237-40

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