Genetically Modified Mouse Models for Hematopoietic Stem Cell Research

Congenic C57BL/6 WT mice were used as donors (CD45.2⁺) and recipients (CD45.1⁺) for all the experiments. Ifnar1^−/−, Trp53^−/−, Foxo3a^−/−, and BakBax^cKO mice have been described previously (Donehower et al., 1992 (link); Müller et al., 1994 (link); Castrillon et al., 2003 (link); Warr et al., 2013 (link)). Transplantation of purified HSCs and generation of WT:Ifnar1^−/− BM chimeric mice were performed as previously described (Santaguida et al., 2009 (link)). For poly I:C treatment, 6–12 wk-old age- and gender-matched mice were injected i.p. with 10 µg/g body mass of poly I:C (GE Healthcare) in PBS at 2-d intervals for up to 30 d. For in vivo IFN-α treatment, mice were injected subcutaneously with 1 × 10⁴ U IFN-α4 (eBioscience) every 12 h until BM harvest. For in vivo HSC proliferation assays, mice were injected i.p. with 1 mg BrdU (Sigma-Aldrich) in d-PBS 3 h before BM harvest. For myeloablation treatment, mice were injected i.p. with 150 mg/kg of 5-FU (Sigma-Aldrich) in PBS, and PB was collected via the retroorbital vein into K₂EDTA-coated collection tubes (BD) for complete blood counts (CBC) performed on a Hemavet950 analyzer (DREW Scientific). All mouse experiments were performed in accordance with the Institutional Animal Care and Use Committee at the University of California, San Francisco.