Fucosylation with fucosyltransferase VI or fucosyltransferase VII improves cord blood engraftment.

BACKGROUND AIMS: Advantages associated with the use of cord blood (CB) transplantation include the availability of cryopreserved units, ethnic diversity and lower incidence of graft-versus-host disease compared with bone marrow or mobilized peripheral blood. However, poor engraftment remains a major obstacle. We and others have found that ex vivo fucosylation can enhance engraftment in murine models, and now ex vivo treatment of CB with fucosyltransferase (FT) VI before transplantation is under clinical evaluation (NCT01471067). However, FTVII appears to be more relevant to hematopoietic cells and may alter acceptor substrate diversity. The present study compared the ability of FTVI and FTVII to improve the rapidity, magnitude, multi-lineage and multi-tissue engraftment of human CB hematopoietic stem and progenitor cells (HSPCs) in vivo. METHODS: CD34-selected CB HSPCs were treated with recombinant FTVI, FTVII or mock control and then injected into immunodeficient mice and monitored for multi-lineage and multi-tissue engraftment. RESULTS: Both FTVI and FTVII fucosylated CB CD34⁺ cells in vitro, and both led to enhanced rates and magnitudes of engraftment compared with untreated CB CD34⁺ cells in vivo. Engraftment after treatment with either FT was robust at multiple time points and in multiple tissues with similar multi-lineage potential. In contrast, only FTVII was able to fucosylate T and B lymphocytes. CONCLUSIONS: Although FTVI and FTVII were found to be similarly able to fucosylate and enhance the engraftment of CB CD34⁺ cells, differences in their ability to fucosylate lymphocytes may modulate graft-versus-tumor or graft-versus-host effects and may allow further optimization of CB transplantation.

In Vivo Targeted Magnetic Resonance Imaging of Endogenous Neural Stem Cells in the Adult Rodent Brain.

Neural stem cells in the adult mammalian brain have a significant level of neurogenesis plasticity. In vivo monitoring of adult endogenous NSCs would be of great benefit to the understanding of the neurogenesis plasticity under normal and pathological conditions. Here we show the feasibility of in vivo targeted MR imaging of endogenous NSCs in adult mouse brain by intraventricular delivery of monoclonal anti-CD15 antibody conjugated superparamagnetic iron oxide nanoparticles. After intraventricular administration of these nanoparticles, the subpopulation of NSCs in the anterior subventricular zone and the beginning of the rostral migratory stream could be in situ labeled and were in vivo visualized with 7.0-T MR imaging during a period from 1 day to 7 days after the injection. Histology confirmed that the injected targeted nanoparticles were specifically bound to CD15 positive cells and their surrounding extracellular matrix. Our results suggest that in vivo targeted MR imaging of endogenous neural stem cells in adult rodent brain could be achieved by using anti-CD15-SPIONs as the molecular probe; and this targeting imaging strategy has the advantage of a rapid in vivo monitoring of the subpopulation of endogenous NSCs in adult brains.

An important developmental role for oligosaccharides during early embryogenesis of cyprinid fish.

Derivatives of chitin oligosaccharides have been shown to play a role in plant organogenesis at nanomolar concentrations. Here we present data which indicate that chitin oligosaccharides are important for embryogenesis in vertebrates. We characterize chitin oligosaccharides synthesized in vitro by zebrafish and carp embryos in the late gastrulation stage by incorporation of radiolabeled N-acetyl-D-[U14C]glucosamine and by HPLC in combination with enzymatic conversion using the Bradyrhizobium NodZ alpha-1, 6-fucosyltransferase and chitinases. A rapid and sensitive bioassay for chitin oligosaccharides was also used employing suspension-cultured plant cells of Catharanthus roseus. We show that chitin oligosaccharide synthase activity is apparent only during late gastrulation and can be inhibited by antiserum raised against the Xenopus DG42 protein. The DG42 protein, a glycosyltransferase, is transiently expressed between midblastula and neurulation in Xenopus and zebrafish embryogenesis. Microinjection of the DG42 antiserum or the Bradyrhizobium NodZ enzyme in fertilized eggs of zebrafish led to severe defects in trunk and tail development.