O-GalNAc glycosylation affects the immunogenicity of the receptor-binding domain (RBD) of SARS-CoV-2 spike protein

High soluble expression and characterization of human GalNAc transferase T2 and T11 in Escherichia coli

The efficient expression of soluble glycosyltransferases from mammalian sources in Escherichia coli (E. coli) remains a significant challenge, often resulting in misfolding and the formation of inclusion bodies. In this study, we investigated strategies to enhance the solubility and catalytic activity of human GalNAc-T2 and GalNAc-T11, two O-glycosyltransferases involved in O-glycosylation of glycoproteins. We found that fusion with maltose-binding protein (MBP) and cellulase catalytic domain (Cel-CD), which led to majority of the fusion proteins being soluble, could increase the solubility of the recombinant proteins. Enzyme activity assays revealed that the fusion glycosyltransferase exhibited significantly higher catalytic efficiency than non-fused enzymes. In addition, the influence of GalNAc-T11 lectin domain on substrate specificity was also determined. The presence of lectin domain had no influence on the recognition of specific substrate and the specific activity of GalNAc-T11. This work offers an efficient approach for the large-scale production of human glycosyltransferases with enhanced bioactivity, highlighting its potential for glycosylation engineering of glycoprotein drugs.

Impact of glycosylation on viral vaccines

Glycosylation is the most prominent modification important for vaccines and its specific pattern depends on several factors that need to be considered when developing a new biopharmaceutical. Tailor-made glycosylation can be exploited to develop more effective and safer vaccines; for this reason, a deep understanding of both glycoengineering strategies and glycans structures and functions is required. In this review we discuss the recent advances concerning glycoprotein expression systems and the explanation of glycans immunomodulation mechanisms. Furthermore, we highlight how glycans tune the immunological properties among different vaccines platforms (whole virus, recombinant protein, nucleic acid), also comparing commercially available formulations and describing the state-of-the-art analytical technologies for glycosylation analysis. The whole review stresses the aspect of glycoprotein glycans as a potential tool to overcome nowadays medical needs in vaccine field.

Therapeutic synthetic and natural materials for immunoengineering

Immunoengineering is a rapidly evolving field that has been driving innovations in manipulating immune system for new treatment tools and methods. The need for materials for immunoengineering applications has gained significant attention in recent years due to the growing demand for effective therapies that can target and regulate the immune system. Biologics and biomaterials are emerging as promising tools for controlling immune responses, and a wide variety of materials, including proteins, polymers, nanoparticles, and hydrogels, are being developed for this purpose. In this review article, we explore the different types of materials used in immunoengineering applications, their properties and design principles, and highlight the latest therapeutic materials advancements. Recent works in adjuvants, vaccines, immune tolerance, immunotherapy, and tissue models for immunoengineering studies are discussed.

Recent advances in chemical synthesis of O-linked glycopeptides and glycoproteins: An advanced synthetic tool for exploring the biological realm

Glycoproteins play crucial roles in various biological processes. To investigate the relationship between glycan structure and function, researchers have employed various chemical methods to precisely synthesize homogeneous O-glycoproteins. This review summarizes the recent progress of their synthetic strategies, highlighting the significant advancements in this area.

Unravelling the Mystery of COVID-19 Pathogenesis: Spike Protein and Cu Can Synergize to Trigger ROS Production

The COVID-19 pandemic has had a devastating impact on global health, highlighting the need to understand how the SARS-CoV-2 virus damages the lungs in order to develop effective treatments. Recent research has shown that patients with COVID-19 experience severe oxidative damage to various biomolecules. We propose that the overproduction of reactive oxygen species (ROS) in SARS-CoV-2 infection involves an interaction between copper ions and the virus's spike protein. We tested two peptide fragments, Ac-ELDKYFKNH-NH2 (L1) and Ac-WSHPQFEK-NH2 (L2), derived from the spike protein of the Wuhan strain and the β variant, respectively, and found that they bind Cu(II) ions and form a three-nitrogen complexes at lung pH. Our research demonstrates that these complexes trigger the overproduction of ROS, which can break both DNA strands and transform DNA into its linear form. Using A549 cells, we demonstrated that ROS overproduction occurs in the mitochondria, not in the cytoplasm. Our findings highlight the importance of the interaction between copper ions and the virus's spike protein in the development of lung damage and may aid in the development of therapeutic procedures.