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 α‐1,6‐ and β‐1,4‐linked galactose terminals was used to facilitate cell separation. A VP containing an α‐1,4‐linked glucose terminal (α‐1,4‐Glu‐VP) was also synthesized as a control for α‐1,6‐ and β‐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 β‐1,4‐Gal‐VP–coated microbeads, but not to α‐1,4‐Glu‐VP–coated microbeads. When peripheral or cord blood cells were cultured on α‐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 α‐1,6‐Gal‐VP and SBA might be useful for separation of blood cells according to their stage of differentiation and lineage.