Genetic manipulation of HSCs and generation of thymocytes.

<p>(A). Schematic illustrating the isolation of CD34+ cells from fetal liver by cell sorting (1), transduction of progenitor cells with lentiviral vector containing the SL9-specific TCR (2), and implantation of these cells in the thymic tissue implanted in sub-lethally irradiated SCID-hu mice. Following 3–12 weeks to allow T cell development to occur from HSCs, TCR expression was analyzed and functional assays performed (3). At four (B) and seven (C) weeks following implantation with TCR transduced HSCs, human thymic tissue was biopsied and cells were analyzed by flow cytometry for cell size (forward scatter—denoted “Size”) and SL9 specific tetramer staining. Mock treated mice (top panels) and mice receiving TCR transduced cells (bottom panels) are indicated. The numbers on the left panels illustrate total SL9 tetramer staining cells. SL9-tetramer+ cells were gated and the frequency of cells expressing CD4 and/or CD8 are provided in the right panels.