Hematopoietic stem cell transplant into non-myeloablated W/Wv mice to detect steady-state engraftment defects.

Hematopoietic stem cells (HSC) are capable of self-renewal and reconstitution of the lymphoid and myeloid lineages of transplant recipients. Classical assays for HSC function rely on lethal irradiation to prepare the host for donor engraftment. This assay destroys most of the hematopoietic tissue and the vasculature of the bone marrow space, leading to regeneration of the niche in which HSC are intimately dependent for their survival, self-renewal, and lineage differentiation. The non-ablated transplant setting provides a more physiological background for measuring HSC function during steady-state hematopoiesis. In this chapter, we describe methods for assaying HSC function during the steady-state using W/W ( v ) c-Kit mutant mice as recipients. Our previous studies have found that the competition from W/W ( v )allows an additional level of stringency that is not observed in limiting dilution assays of HSC number based on fully ablated recipient competition. The ease of this approach is an advantage, and this method may be particularly useful for teasing apart HSC engraftment phenotypes that are especially dependent on functions related to homing, adhesion, or migration into the niche.