Engineered glycoforms of an antineuroblastoma IgG1 with optimized antibody-dependent
cellular cytotoxic activity
Pablo Umaña2, Joël Jean−Mairet2, Radmila Moudry1, Hanspeter Amstutz1
& James E. Bailey2
1
ZLB Central Laboratory, Blood Transfusion Service, Swiss Red Cross, CH−3000 Bern 22, Switzerland.
2
Institute of Biotechnology, ETH Zürich, CH−8093, Zürich, Switzerland.
Correspondence should be addressed to James E. Bailey (bailey@biotech.biol.ethz.ch).glycosylationeffector functionantitumor antibodytetracycline
The glycosylation pattern of chCE7, an antineuroblastoma chimeric IgG1,
was engineered in Chinese hamster ovary cells with tetracycline−regulated
expression of (1,4)−N−acetylglucosaminyltransferase
III (GnTIII), a glycosyltransferase catalyzing formation of bisected oligosaccharides
that have been implicated in antibody−dependent cellular cytotoxicity
(ADCC). Measurement of the ADCC activity of chCE7 produced at different tetracycline
levels showed an optimal range of GnTIII expression for maximal chCE7 in vitro
ADCC activity, and this activity correlated with the level of constant region−associated,
bisected complex oligosaccharides determined by matrix−assisted laser
desorption/ionization time−of−flight mass spectrometry. The new
optimized variants of chCE7 exhibit substantial ADCC activity and, hence,
may be useful for treatment of neuroblastoma. The strategy presented here
should be applicable to optimize the ADCC activity of other therapeutic IgGs.
(1,4)−N−acetylglucosaminyltransferase
III (GnTIII), a glycosyltransferase catalyzing formation of bisected oligosaccharides
that have been implicated in antibody−dependent cellular cytotoxicity
(ADCC). Measurement of the ADCC activity of chCE7 produced at different tetracycline
levels showed an optimal range of GnTIII expression for maximal chCE7 in vitro
ADCC activity, and this activity correlated with the level of constant region−associated,
bisected complex oligosaccharides determined by matrix−assisted laser
desorption/ionization time−of−flight mass spectrometry. The new
optimized variants of chCE7 exhibit substantial ADCC activity and, hence,
may be useful for treatment of neuroblastoma. The strategy presented here
should be applicable to optimize the ADCC activity of other therapeutic IgGs.
