Coupling of Immunostimulants to Live Cells through Metabolic Glycoengineering and Bioorthogonal Click Chemistry

Abstract

The present study investigated the potential of metabolic glycoengineering followed by bioorthogonal click chemistry for introducing into cell-surface glycans different immunomodulating molecules. Mouse tumor models EG7 and MC38-OVA were treated with Ac4GalNAz and Ac4ManNAz followed by ligation of immunostimulants to modified cell-surface glycans of the living cells through bioorthogonal click chemistry. The presence of covalently bound oligosaccharide and oligonucleotide immunostimulants could be clearly established. The activation of a reporter macrophage cell line was determined. Depending on the tumor cell line, covalently and noncovalently bound CpG activated the macrophages by between 67 and 100% over controls. EG7 cells with covalently attached immunostimulants and controls were injected subcutaneously into C57BL/6 mice. All tumor cells subjected to the complete treatment with control molecules formed tumors like nontreated cells confirming cell viability. However, when CpG oligonucleotide was linked to cell-surface glycans, tumor growth was slowed significantly (60% reduction, n = 10, by covalently bound CpG compared to noncovalently bound CpG, n = 10). When mice that had not developed large tumors were challenged with unmodified EG7 cells, no new tumors developed, suggesting protection through the immune system.

Phillygenin attenuates inflammatory responses and influences glucose metabolic parameters by inhibiting Akt activity

“…15,16 Since its introduction, the concept of the click reaction has enabled the study of biomolecules, such as glycans and proteins, in real time in living systems without cellular toxicity. 17,18 In addition, a shing-rod strategy is also one of promising methods applicable for target identication of natural products. 19 This prompted us to explore natural products using the effective approaches of molecular imaging and shing-rod strategy.…”

Advanced Bottom‐Up Engineering of Living Architectures

“…Unsurprisingly, glycoengineering represents an enabling technology for various biomedical applications, namely, both live cell, and extracellular vesicle labeling/tracking, drug‐based cancer theranostics, as well as cell‐based chemo‐ and immunotherapies . Despite an impressive body of literature on these recent advances, tissue engineering concepts exploiting this biomachinery phenomenon are still at their youth.…”

“…Importantly, this can allow allocation of typically nonadherent cell lines (e.g., immune cells) in bottom‐up assemblies of heterogenous cell‐rich building blocks as it will be further discussed. Alternatively, coupling of immunostimulants to live cells has recently been reported via a glycoengineering strategy . The concept of incorporating immune cells in engineered assemblies, i.e., immunoengineering, is on the forefront of developing clinically relevant immunomodulatory tissues .…”

“Clicking” Gene Therapeutics: A Successful Union of Chemistry and Biomedicine for New Solutions

“…These cells were found to be able to stimulate macrophages in vitro , and when injected into mice, resulted in significantly smaller tumor sizes, than the control cells. Additionally, when mice were re-challenged with unmodified cells, no new tumors developed, suggesting broad protection from immune system targeting of the tumor 9 .…”