Selection of hematopoietic stem cells with a combination of galactose-bound vinyl polymer and soybean agglutinin, a galactose-specific lectin.

BACKGROUND: Selection of hematopoietic stem cells can be used to prevent graft-versus-host disease (GVHD) after allograft transplantation. The purpose of the study was to examine a novel cell separation system comprising a galactose-bound vinyl polymer (Gal-VP) and soybean agglutinin (SBA), a galactose-specific lectin. STUDY DESIGN AND METHODS: A vinyl polymer (VP) containing alpha-1,6- and beta-1,4-linked galactose terminals was used to facilitate cell separation. A VP containing an alpha-1,4-linked glucose terminal (alpha-1,4-Glu-VP) was also synthesized as a control for alpha-1,6- and beta-1,4-Gal-VP. Peripheral blood samples were collected from healthy volunteers and umbilical cord blood cells were collected after normal labor.
RESULTS: The sugar-VP was adsorbed on the surface of various materials. In the presence of SBA, T lymphocytes bound to beta-1,4-Gal-VP-coated microbeads, but not to alpha-1,4-Glu-VP-coated microbeads. When peripheral or cord blood cells were cultured on alpha-1,6-Gal-VP-coated plates, most red blood cells, lymphocytes, granulocytes, and monocytes adhered to the plate in the presence of 300 mg per mL SBA, whereas few CD34+ cells attached, even with 800 mg per mL SBA.
CONCLUSION: SBA binds selectively to blood cells by recognizing cell-surface sugars, which are dependent on the extent of cellular differentiation. Therefore, the combination of alpha-1,6-Gal-VP and SBA might be useful for separation of blood cells according to their stage of differentiation and lineage.