EX-VIVO EXPANSION OF STEM CELLS: DEFINING OPTIMUM CONDITIONS USING VARIOUS CYTOKINES

Abstract

With the increasing information on the number, quality and characteristics of HSC in umbilical cord and placental blood, this material has been found to be efficacious as an alternative source of HSC for transplantation in children. In this study, we aimed at defining the optimal conditions for ex­ vivo expansion of cord blood stem cells. These conditions include the combinations and concentrations of haematopoietic growth factors (SCF, GM-CSF, IL-3, Tpo and IL-6), the duration of culture, and the effect of serum supplementation. In this study two protocols were applied for ex­ vivo expansion of cord blood stem cells. In protocol I, 20 cord blood sampled were expanded in a static, serum added, liquid culture for 7 and II days using five cytokine cocktails. In protocol II, I 0 cord blood samples were expanded for 7 days using cytokines of cocktail I, with and without IL-6, in serum added and serum free. culture media. This was intended to verify the effect of!L-6 and the role of serum supplementation in short term liquid culture. From the present study, it can de concluded that cocktail I is the cocktail of choice for ex-vivo expansion of cord blood stem cells in 7 days, serum free, liquid culture. We can also conclude that 7 days culture is better than II days, as the fold expansion of CD 34+ cells was not significantly increased, even decreased in some of the cocktails used. Moreover, the% of CD 95+ cells (apoptotic cells) was significantly increased in day II compared to day 7 in the cocktails tested.