B lymphoblastoid cell lines with normal and defective O-glycosylation
established from an individual with blood group Tn
CG Gahmberg, L Peltokorpi and LC Andersson
Individuals with the Tn blood group contain terminal serine/threonine-
linked N-acetylgalactosamine residues in their blood cells. This is due to
lack of UDP-D-galactose: D-N-acetyl galactosamine beta-D-galactosyl
transferase from part of their red cells and probably from their
leukocytes. We have established B lymphoblastoid cell lines from such an
individual by in vitro infection of his lymphocytes with Epstein- Barr
virus. The original line contained a mixture of cells reactive and
nonreactive with Helix pomatia lectin (Hp). These cells were subcloned
after staining with fluorescent Hp by a fluorescence-activated cell sorter
(FACS) into homogeneous, phenotypically stable lines of Hp- positive (Hp+)
and Hp-negative (Hp-) cells. The molecular differences between the membrane
glycoproteins were characterized by carbohydrate- specific surface labeling
techniques, Hp affinity chromatography, polyacrylamide slab gel
electrophoresis and glycopeptide/oligosaccharide analysis. The major
O-glycosidic membrane glycoprotein (GP105) was retained on Hp-Sepharose
columns only from Hp+ cells, whereas the common leukocyte antigen
(GP160-200) was partially retained on Hp columns from both lines. These
proteins were isolated by immune precipitation with monoclonal antibodies
and characterized. The results show that the GP105 glycoprotein from Hp+
cells contains terminal N-acetylgalactosamine residues but also more
complex oligosaccharides. The common leukocyte antigen showed different
electrophoretic mobilities in Hp+ and Hp- cells. UDP-galactose D-N- acetyl
galactosamine beta-galactosyl transferase was almost absent in the Hp+
cells. These cell lines are useful for studies on the functional role and
regulation of the biosynthesis of O-glycosidic carbohydrates.
Volume 67,
Issue 4,
pp. 973-979,
04/01/1986
Copyright © 1986 by The American Society of Hematology
