title: Na-butyrate increases the production and alpha2,6-sialylation of recombinant interferon-gamma expressed by alpha2,6- sialyltransferase engineered CHO cells.
abstract: A non-human like glycosylation pattern in human recombinant glycoproteins expressed by animal cells may compromise their use as therapeutic drugs. In order to correct the CHO glycosylation machinery, a CHO cell line producing recombinant human interferon- gamma (IFN) was transformed to replace the endogenous pseudogene with a functional copy of the enzyme alpha2,6-sialyltransferase (alpha2,6-ST). Both the parental and the modified CHO cell line were propagated in serum-free batch culture with or without 1 mM sodium butyrate. Although Na-butyrate inhibited cell growth, IFN concentration was increased twofold. The IFN sialylation status was determined using linkage specific sialidases and HPLC. Under non- induced conditions, IFN expressed by alpha2,6-engineered cells contained 68% of the total sialic acids in the alpha2,6- conformation and the overall molar ratio of sialic acids to IFN was 2.3. Sodium butyrate addition increased twofold the molar ratio of total sialic acids to IFN and 82% of total sialic acids on IFN were in the alpha2,6-conformation. In contrast, no effect of the sodium butyrate was noticed on the sialylation of the IFN secreted by the alpha2,6-ST deficient parental cell line. This study deals for the first time with the effect of Na-butyrate on CHO cells engineered to produce human like sialylation.
authors.affiliation: Laboratoire des Sciences du Génie Chimique, CNRS-ENSIC, 1, rue Grandville, BP 451, 54001, Nancy Cedex, France.
authors.forename: D
authors.initials: D
authors.lastname: Lamotte
authors.forename: L
authors.initials: L
authors.lastname: Buckberry
authors.forename: L
authors.initials: L
authors.lastname: Monaco
authors.forename: M
authors.initials: M
authors.lastname: Soria
authors.forename: N
authors.initials: N
authors.lastname: Jenkins
authors.forename: J M
authors.initials: JM
authors.lastname: Engasser
authors.forename: A
authors.initials: A
authors.lastname: Marc