Mann-Delany, O. | Search bioRxiv

bioRxiv2026

Cell Surface Sialoglycan Engineering Through Exogenous mRNA

All human cells display a dense matrix of structurally diverse glycans that often terminate in monosaccharides belonging to the sialic acid family of sugars. While these sialoglycans are now recognized as critical regulators of human immunity, there is a lack of technologies that provide precise, transient control over their biosynthesis and presentation on a live cell surface. Here, we addressed this unmet need by developing an mRNA-based platform for delivery of transcripts coding for the enzymes that assemble sialoglycans - sialyltransferases - to human cells. We demonstrated that mRNA coding for the 2-6-specific sialyltransferase ST6Gal1 produced active, Golgi-resident enzyme that potentiated levels of 2-6-sialoglycans on the surface of human cell lines. Increased presentation of these sialoglycans was transient and tracked with the degradation kinetics of the delivered mRNA. Importantly, this approach minimally perturbed other classes of glycans and did not broadly alter physiological transcriptional networks beyond those involved in cellular responses to exogenous RNA. Similar on-target effects were observed for the O-linked 2-6-specific sialyltransferase ST6GalNAc4; however, the effects from mRNA coding for the 2-3-specific sialyltransferases ST3Gal1 and ST3Gal4 were more complex. Taken together, this mRNA platform provides a framework for cellular sialoglycoengineering endeavours, where precise and reversible control over glycocalyx composition is desired.

bioengineering↗

bioRxiv2023

Pathogenic IgE-fated B cell memory retains functional plasticity

Long-lived immunoglobulin (Ig) E responses against innocuous environmental and dietary antigens (Ags) are maintained by an IgG1-dominant memory B cell (MBC) compartment primed for IL-4 responsiveness. The plasticity of the MBC compartment destined for IgE class switch recombination (CSR), however, remains poorly understood. In this work, we report a critical IL-4/IL-13 dependency for the pathogenic IgE fate of type 2-polarized MBCs. Initiating a recall response in the absence of IL-4/IL-13 signaling diminished the type 2 MBC phenotype in mice and humans and, in mice, permitted the emergence of long-lived Ag-specific IgG2c+ MBCs. The divergence to a type 1-like response was dependent on IFN-{gamma} signaling and arose from both unswitched and class-switched Ag-specific B cells in vivo. This reprogrammed fate was sustained even beyond therapeutic intervention, revealing fundamental insight into the plasticity of the allergen-specific MBC response. One Sentence SummaryB cell responses to allergens can be reprogrammed away from a pathogenic fate through IL-4/IL-13 signaling blockade.

immunology↗