Members of Dr. John Dick’s laboratory demonstrated that female NOD/SCID/IL-2Rg_cnull (NSG) mice are far superior to their male counterparts in engrafting and detecting single human hematopoietic stem cells (HSC), published March 5 in the journal, Blood.

HSC have self-renewal and differentiation capacities and are capable of long-term multilineage engraftment. HSCs from cord blood were intrafemorally transplanted, in equal doses, into sublethally irradiated adult male and female NSG mice, and their engraftment potential was assessed using flow cytometry. When non-limiting cell doses were used, female mice demonstrated a modest trend for increased engraftment. In comparison to male mice, however, when limiting-dilution cell dose transplants were performed with a single human HSC, female mice displayed a 5-fold increase in sensitivity in detecting human HSCs.

While the mechanism is not understood, it is possible that female NSG mice are more immunodeficient than males, or that gender associated factors, such as steroid hormones, may influence human HSCs. This report identifies that recipient gender is a critical variable that must be taken into account when designing and interpreting stem cell transplantation studies.

Engraftment of human hematopoietic stem cells is more efficient in female NOD/SCID/IL-2Rg_cnull recipients. Notta F, Doulatov S, Dick JE. Blood. 2010 March 5. [Abstract]

Congratulations go out to Dr. John Dick this month for the successful renewal of his Tier1 Canada Research Chair in Stem Cell Biology as well as for the Ontario Institute for Cancer Research (OICR)'s Cancer Stem Cell Program, led by Dr. Dick, which received a total of $235,000 in equipment funding from the OICR.

The 2010 Gairdner International Award recipients have been announced. They include Dr. Pierre Chambon, for elucidating the fundamental mechanisms of transcription in animal cells and the discovery of a nuclear receptor superfamily and Dr.William A. Catterall, for the discovery and characterization of voltage-gated sodium channel and calcium-channel proteins. Drs. William G. Kaelin Jr, Peter J. Ratcliffe and Gregg L. Semenza are also recognized for their studies identifying the molecular mechanisms of oxygen sensing in the cell. The Gairdner Foundation Toronto Symposium will take place during the week of October 25, 2010.