Protein glycosylation has already become a hot issue and nodus in glycoprotein expression and its application in biotherapeutic field. Manipulations and studies of glycosylation cannot be achieved by traditional genetic approaches. With years of experience and first-in-class technologies, Creative Biolabs has successfully developed several effective strategies to provide a series of cell line glycoengineering services. In short, we have the capacity of producing glycoprotein with human glycans in either research quantities or large scale for industrial applications.
Recombinant glycoproteins have shown different biological properties based on their glycan profiles. Monoclonal antibodies (mAbs) glycosylation is particularly important for pharmacokinetics and immunogenicity of recombinant glycoprotein therapeutics. Thereby, different cell line glycoengineering strategies have been developed not only to improve cell’s specific productivity but also to adapt their glycosylation profiles for increased therapeutic activity. Notably, the host cell line used to produce glycoprotein has a strong influence on the glycosylation because different host systems may express various repertoire of glycosylation enzymes and transporters that contribute to specificity and heterogeneity in glycosylation profiles. Thus, cell line glycoengineering is an essential process for the synthesis of desired glycoprotein no matter which production system you choose.
Protein glycosylation includes the covalent addition of glycans to the amino group of the hydroxy group of a serine or threonine (O-linked) or an asparagine (N-linked). There are diverse genetic approaches used in different cell lines for glycoengineering, such as modulate the sialylation patterns through overexpression of sialyltransferases and other glycosyltransferases, alter sialylation including manipulation of sialic acid biosynthetic pathways and inhibition of sialidases, the glycosylation site insertion and manipulation of glycan heterogeneity to produce desired glycoforms for diverse biotechnology applications. Knockdown, overexpression, knockout and knockin by precision genome editing are the most commonly used techniques to change the activity of glycosyltransferases and increase or decrease the precursors involved in the N-glycosylation process.
Several production systems have been exploited to prepare recombinant glycoprotein. The race to engineer Escherichia coli to perform glycosylation is gathering pace. The successful functional transfer of an N-glycosylation pathway from Campylobacter jejuni to Escherichia coli in 2002 can be considered as the crucial first engineering step. Among the mammalian-based expression systems, Chinese hamster ovary (CHO) cells especially genetically modified CHO is by far, the most commonly used cell line. Some recombinant glycoproteins could be also produced in yeast, which can also divide rapidly and generate high yields. Insect cells have been also widely used for the production of heterologous proteins, ranging from cytosolic enzymes to membrane-bound proteins. As for plant, since there is no risk for viral or prion contamination, many therapeutically interesting proteins such as cytokines, hormones, growth factors, antibodies, and antigens have been quite successfully produced in plants.
Fig.1 Expression systems used for glycoprotein production (Lalonde, 2017).
With Ph.D. level scientists and over a decade of experience, Creative Biolabs has successfully established promising platforms for cell line glycoengineering and the production of glycosylated protein with improved characteristics that are tailored to meet your R&D timeline and budget. Please contact us for more information and a detailed quote.