Generation of Immunodeficient Mice Bearing Human Immune Systems by the Engraftment of Hematopoietic Stem Cells v2

Immunodeficient mice are being used as recipients of human hematopoietic stem cells (HSC) for in vivo analyses of human immune system development and function. The development of several stocks of immunodeficient Prkdc scid ( scid ), or recombination activating 1 or 2 gene ( Rag1 or Rag2 ) knockout mice bearing a targeted mutation in the gene encoding the IL2 receptor gamma chain ( IL2r γ) have greatly facilitated the engraftment of human HSC and enhanced the development of functional human immune systems. These “humanized” mice are being used to study human hematopoiesis, human-specific immune therapies, human-specific pathogens, and human immune system homeostasis and function. The establishment of these model systems is technically challenging, and levels of human immune system development reported in the literature are variable between laboratories. The use of standard protocols for optimal engraftment of HSC and for monitoring the development of the human immune systems would enable more direct comparisons between humanized mice generated in different laboratories. Here we describe a standard protocol for the engraftment of human HSC into 21-day old NOD-scid IL2r γ ( NSG) mice using an intravenous injection approach. The multi-parameter flow cytometry used to monitor human immune system development and the kinetics of development are described. ACKNOWLEDGEMENT This work was supported by National Institutes of Health Grants AI046629, AI112321, DK104218, CA034196, and OD018259 and grants from the Helmsley Charitable Trust and the Juvenile Diabetes Research Foundation. The authors would like to thank to TUBITAK (The Scientific and Technological Research Council of Turkey) for the research support (2214A). MAB and DLR are consultants for the Jackson Laboratory (Bar Harbor, ME).The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of the National Institutes of Health.