Increase of CXCR4 expression on expanded non-enriched cord blood CD34+cells using MSCs

ABSTRACT

A number of potential cell adhesion molecules, which mediate essential cell-to-cell or cell-to-matrix interactions, are expressed on the surface of CD34+ hematopoietic progenitor cells [HPCs], including integrins, CD44, and CXCR4. These molecules are essential for homing process. In this study, we compared the changes of expression of CD44 and CXCR4 on the CD34+ hematopoietic progenitor cells expanded on MSCs in the presence of cytokines. Cord blood CD34+ cells were expanded using human bone marrow mesenchymal stem cells and cytokines [TPO, SCF, FLt-3, IL-6, and IL-3], and then expression of CD44 and CXCR4 on CD34+ cells were evaluated by flow cytometric analysis. After 2 weeks of serum free culture of CD34+ cells in the presence of cytokines, the expression of CXCR4 on CD34+ cells was decreased 3.4 fold [p<0.05]. In contrast, the expression of CXCR4 on CD34+ cells expanded on hMSCs was increased [p<0.05]. The expression of CD44 on expanded CD34+ cells in both methods did not differ significantly. Our results indicated that co-culture of cord blood stem cells on hMSCs significantly increased CXCR4 expression on cord blood CD34+ cells