The Bioactive Peptide SL-13R Expands Human Umbilical Cord Blood Hematopoietic Stem and Progenitor Cells In Vitro

Area of Science:

• Hematology
• Stem Cell Biology
• Biotechnology

Background:

• Hematopoietic stem and progenitor cell (HSPC) transplantation is a key treatment for hematological disorders.
• Umbilical cord blood (UCB) offers a promising HSPC source, but limited cell numbers hinder its application.
• Ex vivo expansion of UCB HSPCs is crucial for overcoming dose limitations.

Purpose of the Study:

• To develop an efficient method for expanding UCB HSPCs ex vivo.
• To investigate the efficacy of a novel bioactive peptide, SL-13R, for HSPC expansion.
• To assess the long-term functionality of SL-13R-expanded HSPCs.

Main Methods:

• UCB CD34+ cells were cultured with SL-13R in an animal component-free medium with a cytokine cocktail.
• Cell expansion was quantified by enumerating total cells, CD34+ cells, CD38- cells, and HSC-enriched populations.
• Transplantation into immunodeficient mice (NOD/Shi-scid/IL-2Rγ knockout) evaluated long-term reconstitution and self-renewal.
• Gene knockdown of interacting proteins (AHNAK, ANXA2, PLEC) assessed their role in SL-13R function.

Main Results:

• SL-13R culture significantly increased UCB CD34+ cell numbers, including HSC-enriched populations, after 9 days.
• Transplanted cells showed robust long-term hematopoietic reconstitution and self-renewal capacity in vivo.
• Knockdown of AHNAK, ANXA2, and PLEC reduced hematopoietic colony formation, confirming their interaction with SL-13R.

Conclusions:

• The novel bioactive peptide SL-13R effectively promotes the expansion of UCB CD34+ cells.
• SL-13R-expanded HSPCs retain long-term reconstitution and self-renewal abilities.
• SL-13R holds significant potential for clinical applications in hematopoietic stem cell therapies.