CULTIVATION AND IDENTIFICATION OF HUMAN HEMATOPOIETIC CELLS

THE OBJECTIVES OF THIS PROJECT ARE TO ESTABLISH THE CONDITIONS NECESSARY FOR THE LONG-TERM CULTURE AND EXPANSIONOF HUMAN HEMATOPOIETIC PROGENITOR CELLS, TO DEVELOP IN VITRO AND IN VIVO ASSAY SYSTEMS FOR SUCH CLONOGENIC PRECURSORS, AND TO DEVELOP MONOCLONAL ANTIBODIES (MABS) FOR THEIR IDENTIFICATION AND PURIFICATION. ESTABLISHMENT OF LONG-TERM CULTURES HAS BEEN INITIATED. CULTURE CONDITIONS CONTINUOUSLY GENERATING NONADHERENT HEMATOPOIETIC CELLS HAVE BEEN IDENTIFIED. THESE CULTURES HAVE BEEN ADAPTED INTO AN ASSAY FOR CLONOGENIC HEMATOLYMPHOID PROGENITOR CELLS. ISOLATION OF HUMAN HEMATOPOIETIC STEM CELLS WILL DEPEND UPON THE IDENTIFICATIONOF CELL SURFACE ANTIGENS THAT MARK CELLS WITH INCREASED PROGENITOR ACTIVITY. MABS WILL BE TESTED FOR THEIR ABILITY TO MARK EITHER PLURIPOTENT STEM CELLS OR MORE COMMITTED PROGENITOR POPULATIONS. BONE MARROW CELLS WILL BE SORTED AND TESTED TODETERMINE THE FREQUENCY OF RESPONDING CELLS AND THEIR PROLIFERATION/DIFFERENTIATION POTENTIAL. THE FEASIBILITY OF USING THE SCID-HU MOUSE AS AN IN VIVO ASSAY WILL BE EXAMINED. THE AVAILABILITY OF SIMULTANEOUS LONG-TERM IN VITRO AND IN VIVO SYSTEMS FOR THE CHARACTERIZATION AND PURIFICATION OF HUMAN PROGENITOR CELLS WILL ALLOW A MORE PRECISE DISSECTION OF THE DEFECTS OBSERVED IN VARIOUS HUMAN IMMUNOLOGIC DEFICIENCIES.