Ganguillet, S. | Search bioRxiv

bioRxiv2023

Surface crosslinking of virus-like particles increases resistance to proteases, low pH and mechanical stress for mucosal applications

AbstractVirus-like particles (VLPs) are emerging as nano-scaffolds in a variety of biomedical applications including the delivery of vaccine antigens to mucosal surfaces. These soft, colloidal, and proteinaceous structures (capsids) are nevertheless susceptible to mucosal environmental factors which limit their usefulness. We addressed this issue by crosslinking multiple capsid surface reactive residues using polyethylene glycol tethers. Surface crosslinking enhanced the colloidal stability and mechanical strength of VLPs against low pH, proteases, and mechanical agitation, while it did not interfere with function as vaccine. Chemical crosslinking thus offers a viable means to enhance the resilience of VLPs in mucosal applications.

biophysics↗

bioRxiv2022

Gasdermin D is the only Gasdermin that provides non-redundant protection against acute Salmonella gut infection

Gasdermins (GSDMs) share a common functional domain structure and are best known for their capacity to form membrane pores. These pores are hallmarks of a specific form of cell death called pyroptosis and mediate the secretion of pro-inflammatory cytokines such as interleukin 1{beta} (IL1{beta}) and interleukin 18 (IL18). Thereby, Gasdermins have been implicated in various immune responses against cancer and infectious diseases such as acute Salmonella Typhimurium (S.Tm) gut infection. However, to date, we lack a comprehensive functional assessment of the different Gasdermins (GSDMA-E) during S.Tm infection in vivo. Here, we have performed littermate-controlled oral S.Tm infections to investigate the impact of all murine Gasdermins. While GSDMA, -C and -E appear dispensable, we show that GSDMD (i) restricts S.Tm loads in the gut tissue and systemic organs, (ii) controls gut inflammation kinetics, and (iii) prevents epithelium disruption by 72h of the infection. Full protection requires GSDMD expression by both bone-marrow-derived lamina propria cells and intestinal epithelial cells (IECs). In vivo experiments, 3D- and 2D-enteroid infections further show that infected IEC extrusion proceeds also without GSDMD, but that GSDMD controls the permeabilization and morphology of the extruding cells and affects extrusion kinetics. As such, this work identifies a non-redundant multipronged role of GSDMD in mucosal tissue defence against a common enteric pathogen. HIGHLIGHTSO_LIGasdermin D restricts Salmonella Typhimurium (S.Tm) translocation across the gut tissue, controls gut inflammation kinetics, and prevents epithelium disruption by 72h of the infection. C_LIO_LIGasdermins A, C and E appear dispensable for protection against acute S.Tm gut infection. C_LIO_LIGasdermin D in bone-marrow-derived lamina propria cells and intestinal epithelial cells complement each other to suppress gut tissue S.Tm loads. C_LIO_LIGasdermin D is not required for extrusion of infected intestinal epithelial cells but drives their permeabilization and affects qualitative features of the extrusion process. C_LI

immunology↗