Surface-immobilization of adhesion peptides on substrate for ex vivo expansion of cryopreserved umbilical cord blood CD34+ cells.


Journal Article

The interaction between integrins and extracellular matrix proteins play an important role in the regulation of hematopoiesis. Human hematopoietic progenitor cells express very late antigen-4 (VLA-4) and VLA-5, which mediate their interaction with fibronectin by recognizing the connecting segment-1 (CS-1 and RGD motifs, respectively. In this study, we investigated the ex vivo expansion of human umbilical cord blood (UCB) CD34+ cells on synthetic substrates surface-immobilized with peptides containing the CS-1 binding motif (EILDVPST) and the RGD motif (GRGDSPC). These peptides were covalently conjugated to poly(ethylene terephthalate) (PET) film at a surface density of 2.0-2.3 nmol/cm2. UCB CD34+ cells were cultured for 10 days in serum-free medium supplemented with recombinant human thrombopoietin, stem cell factor, flt3-ligand and interleukin 3. The highest cell expansion fold was observed on the CS-1 peptide-modified surface, where total nucleated cells, total colony forming unit, and long-term culture initiating cells were expanded by 589.6+/-58.6 (mean+/-s.d.), 76.5+/-8.8, and 3.2+/-0.9-fold, respectively, compared to unexpanded cells. All substrates surface-immobilized with peptides, including the control peptides, were more efficient in supporting the expansion of CD34+, CFU-GEMM and LTC-ICs than tissue culture polystyrene surface. Nevertheless, after 10-days of ex vivo expansion from 600 CD34+ cells, only cells cultured on CS-1-immobilized surface yielded positive engraftment, even though the frequency was low. PET surface immobilized with RGD peptide was less efficient than that with CS-1 peptide. Our results suggest that covalently immobilized adhesion peptides can significantly influence the proliferation characteristics of cultured UCB CD34+ cells.

Full Text

Cited Authors

  • Jiang, X-S; Chai, C; Zhang, Y; Zhuo, R-X; Mao, H-Q; Leong, KW

Published Date

  • May 2006

Published In

Volume / Issue

  • 27 / 13

Start / End Page

  • 2723 - 2732

PubMed ID

  • 16376984

Pubmed Central ID

  • 16376984

Electronic International Standard Serial Number (EISSN)

  • 1878-5905

International Standard Serial Number (ISSN)

  • 0142-9612

Digital Object Identifier (DOI)

  • 10.1016/j.biomaterials.2005.12.001


  • eng