Metabolic glycoengineering bacteria for therapeutic, recombinant protein, and metabolite production applications

Abstract

Metabolic glycoengineering is a specialization of metabolic engineering that focuses on using small molecule metabolites to manipulate biosynthetic pathways responsible for oligosaccharide and glycoconjugate production. As outlined in this article, this technique has blossomed in mammalian systems over the past three decades but has made only modest progress in prokaryotes. Nevertheless, a sufficient foundation now exists to support several important applications of metabolic glycoengineering in bacteria based on methods to preferentially direct metabolic intermediates into pathways involved in lipopolysaccharide, peptidoglycan, teichoic acid, or capsule polysaccharide production. An overview of current applications and future prospects for this technology are provided in this report.

Living functional hydrogels generated by bioorthogonal cross-linking reactions of azide-modified cells with alkyne-modified polymers

“…To assess the utility of CxGels in regenerative medicine, LifeAct-GFP-expressing N 3 (+)C2C12 cells suspended in bAlg-DBCO solution were injected into severe skeletal muscle defects in the hind limbs of mice (Supplementary Fig. 23 ) and functional recovery was evaluated using a grip-strength meter 24 . We also performed this muscle injury study using two appropriate negative controls: treatment with bAlg/Ca 2+ physical gels encapsulating LifeAct-GFP-expressing N 3 (+)C2C12 cells, and no treatment (PBS injection).…”

A bioorthogonal chemistry approach to detect the K1 polysialic acid capsule in Escherichia coli

“…Experiments in which the bacteria were labelled with SiaNAz and SiaNAl generally exhibited a lower fluorescence intensity when compared to ManNAz and ManNAl, which came as a surprise. Indeed, these microbial cells are generally thought to be able to scavenge, process and install Sia derivatives but to metabolize ManNAc very slowly 35,36 , although this is highly species dependent. ManNAz led to the most efficient labelling.…”

“…The noticeable difference in intensity between ManNAz and ManNAl tagging indicates that the azide handle may be more compatible with the metabolic network overall, or that the alkyne moiety might induce toxicity during the metabolic incorporation step. Distinct uptake and/or metabolisms should account for differences in labelling efficiency between ManNAc or Sia derivatives bearing the same chemical tag (e.g., ManNAz and SiaNAz) 36 .…”

Improving Immunotherapy Through Glycodesign

“…(A) Glycolipids, exemplified by bacterial structures such as LPS contain the Lipid A, and inner core, an outer core, and the O-antigen, which varies based on species and strain [ Salmonella enterica Serotype Typhi is show ( 160 )]. (B) LPS glycans contains a variety of non-mammalian monosaccharides, which contributes to their immunogenicity and provokes sepsis [ (A,B) are adapted from Saeui et al ( 161 )]. (C) Medicinal chemistry efforts have exploited the Lipid A structure to create anti-inflammatory analogs [three are shown, from Piazza et al ( 162 )] that are promising anti-sepsis agents.…”

“…Glycoengineering falls into two main approaches: genetic and metabolic; we will discuss specific examples of both approaches while describing general strengths and drawbacks to each approach. Although glycoengineering strategies are being developed for many production platforms [bacteria ( 161 ), yeast ( 335 ), plants ( 336 ), insects ( 337 )], we will focus our discussion on mammalian cells used to produce the vast majority of today's immunotherapeutics.…”