Wong, S. S. W. | Search bioRxiv

bioRxiv2026

In vivo experimental model of β-glucan-induced innate immune memory

SUMMARYInnate immune memory is the ability of innate immune cells to develop a recallable, epigenetically imprinted response after an initial stimulus, enabling them to mount differential responses upon restimulation. Here, we present a detailed protocol of {beta}-glucan preparation, and its in vivo application to modulate innate immune memory in mice through repeated intraperitoneal (IP) injections. This approach results in enhanced hematopoiesis and bone marrow specific myeloid bias, key hallmarks of in vivo innate immune memory responses. For complete details on the use and execution of this protocol, please refer to Hassan et al. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=184 SRC="FIGDIR/small/705736v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@d41c3aorg.highwire.dtl.DTLVardef@18939cdorg.highwire.dtl.DTLVardef@31e879org.highwire.dtl.DTLVardef@956f6b_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIPreparation of {beta}-glucan for in vivo experiments. C_LIO_LIIn vivo modulation of innate immune memory through repeated intraperitoneal {beta}-glucan injections in mice. C_LIO_LIModulation of innate immune memory is assessed by enhanced bone marrow hematopoiesis and GMP production. C_LI

immunology↗

bioRxiv2020

New insights into Cryptococcus extracellular vesicles suggest a new structural model and an antifungal vaccine strategy

Whereas extracellular vesicle (EV) research has become commonplace in different biomedical fields, this field of research is still in its infancy in mycology. Here we provide a robust set of data regarding the structural and compositional aspects of EVs isolated from the fungal pathogenic species Cryptococcus neoformans, C. deneoformans and C. deuterogattii. Using cutting-edge methodological approaches including cryogenic electron microscopy and cryogenic electron tomography, proteomics, and flow cytometry, we revisited cryptococcal EV features and suggest a new EV structural model, in which the vesicular lipid bilayer is covered by mannoprotein-based fibrillar decoration, bearing the capsule polysaccharide as its outer layer. About 10% of the EV population is devoid of fibrillar decoration, adding another aspect to EV diversity. By analyzing EV protein cargo from the three species, we characterized the typical Cryptococcus EV proteome. It contains several membrane-bound protein families, including some Tsh proteins bearing a SUR7/PalI motif. The presence of known protective antigens on the surface of Cryptococcus EVs, resembling the morphology of encapsulated virus structures, suggested their potential as a vaccine. Indeed, mice immunized with EVs obtained from an acapsular C. neoformans mutant strain rendered a strong antibody response in mice and significantly prolonged their survival upon C. neoformans infection.

microbiology↗