Experimental Models of Mouse and Human Hematopoietic Stem Cell Transplantation

Experimental hematopoietic stem cell transplantation (HSCT) is an invaluable tool in determining the function and characteristics of hematopoietic stem cells (HSC) from experimental mouse and human donor groups. These groups could include, but are not limited to, genetically altered populations (gene knockout/knockin models), ex vivo manipulated cell populations, or in vivo modulated cell populations. The basic fundamentals of this process involve taking cells from a mouse/human donor source and putting them into another mouse (recipient) after preconditioning of the recipient with either total body irradiation (TBI) for mouse donor cells or into sublethally irradiated immune-deficient mice for human donor cells. Then, at pre-determined time points post-transplant, sampling a small amount of peripheral blood (PB) and at the termination of the evalaution, bone marrow (BM) to determine donor contribution and function by phenotypic analysis. Exploiting the congenic mouse strains of C57BL/6 (CD45.1^- CD45.2⁺), BoyJ (CD45.1⁺ CD45.2^-), and their F1-crossed hybrid C57BL/6 × BoyJ (CD45.1⁺ CD45.2⁺), we are able to quantify donor, competitor, and recipient mouse cell contributions to the engraftment state. Human donor cell engraftment (e.g., from the cord blood [CB], mobilized PB, or BM) is assessed by human cell phenotyping in sublethally irradiated immune-deficient mouse recipients (e.g., NOD scid gamma mice that are deficient in B cells, T cells, and natural killer cells and have defective dendritic cells and macrophages). Engraftment of cells from primary mouse recipients into secondary mice allows for an estimation of the self-renewal capacity of the original donor HSC. This chapter outlines concepts, methods, and techniques for mouse and human cell models of HSCT and for assessment of donor cells collected and processed in hypoxia versus ambient air.