Characterization of EBV-transformed B-cells established from an individual homozygously mutated (G329A) in the FUT7 alpha1,3-fucosyltransferase gene

• The alpha1,3-fucosyltransferase VII (Fuc-TVII) is involved in the biosynthesis of E- and P-selectin ligands such as sialyl Lewis x (SLe(x)) on human leukocytes. Recently, individuals were characterized carrying a missense mutation (G329A; Arg110-Gln) in the FUT7 gene encoding this enzyme. The mutated FUT7 construct produced a Fuc-TVII enzyme with impaired activity compared with the wildtype enzyme. Polymorphonuclear granulocytes from an individual carrying this mutation homozygously also showed a reduced expression of SLe(x). In the present study, we have established Epstein-Barr virus-transformed B-cell lines from this individual (SIGN) and from an individual not carrying the mutation (IWO). The cell lines were confirmed to be of B-cell origin by flow cytometry analysis. IWO cells interacted with E-selectin in an in vitro flow chamber analysis whereas SIGN cell did not. However, when SIGN cell was transiently transfected with wildtype FUT7 cDNA, interaction with E-selectin could be restored. Cell surface expression of the SLe(x)-related epitopes recognized by antibodies CSLEX-1, KM-93 and HECA-452 was elevated on IWO cells compared with that on SIGN cells, consistent with a role of these antigens in E-selectin recognition. These cell lines will be useful in further characterization of E-selectin ligands and encourage further studies on the consequences of the FUT7-G329A mutation in vivo.

Nyckelord

B-Lymphocytes/drug effects/*enzymology/immunology

Carbohydrates/analysis

*Cell Line

Transformed

DNA

Complementary/genetics

E-Selectin/*biosynthesis/pharmacology

Epitopes

B-Lymphocyte/analysis

Fucosyltransferases/*genetics

Gene Expression

Herpesvirus 4

Human/*physiology

Homozygote

Humans

Ligands

Mutation

Missense

Oligosaccharides/analysis

RNA

Messenger/analysis/metabolism

Transfection

MEDICINE

Publikations- och innehållstyp

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