Biology subjects
Publications and source records attributed to Gorska, S..
We present a novel protocol for intranasal colonization of germ-free mice with human nasal microbiota, coupled with an optimized DNA extraction method for murine nasal samples compatible with 16S rRNA sequencing. This protocol may facilitate investigation of the functional roles and causal effects of nasal microbial communities in chronic rhinosinusitis and antimicrobial resistance.
Extracellular vesicles (EVs) are key mediators of bacterial communication and adaptation to environmental stress. Their size, cargo, and surface charge are influenced by several factors, including environmental conditions, bacterial physiology, and isolation methods, and are highly strain-specific. Herein, we investigated how exposure to bile, a physiological component of the gut environment, affects the production and properties of EVs released by the probiotic strain Lactiplantibacillus plantarum NCIMB 8826. Through ultracentrifugation followed by size-exclusion chromatography (SEC), we isolated highly purified L. plantarum EVs (LpEVs) and characterized them according to the Minimal Information for Studies of Extracellular Vesicles guidelines. SEC purification significantly reduced the contents of contaminating proteins and peptidoglycans, improving the compositional purity of the isolated EVs. Compared with the parent bacteria, purified LpEVs exhibited distinct surface lipid profiles and zeta potential as well as remarkable stability across varying pH levels, elevated NaCl concentrations, and increasing detergent challenges. Under bile stress, the bacteria released larger LpEVs enriched in bile metabolism-related proteins, suggesting vesicle-mediated adaptation. Fourier-transform infrared spectroscopy further revealed bile-induced molecular alterations in LpEVs that differed from those in the parent bacteria. These findings highlight bacterial EVs as dynamic environmental communicators that respond to stress and may modulate host-microbe interactions before detectable changes occur in the bacterial cells.
Allergies have become a growing problem and the number of cases is increasing yearly. Administration of postbiotics, well-defined bacterial molecules, is gaining attention as a novel and promising strategy to ameliorate the allergic burden. The BAP1 polysaccharide (PS) of Bifidobacterium adolescentis CCDM 368, was previously characterized by us regarding its structure and in vitro immunomodulatory properties. Here, to decipher the effect of BAP1 on immune system development, it was intranasally (i.n.) administered to germ-free mice. We observed increased IgA in bronchoalveolar lavage (BAL) fluid, decreased CCL2 production, and higher Rorc gene expression in the lung. The intranasal administration of BAP1 reduced lung inflammation and decreased eosinophils numbers in BAL in the ovalbumin-induced allergy mouse model. Moreover, BAP1 decreased OVA-specific IgE levels in sera and Th2-related cytokines in OVA-stimulated splenocytes and lung cells. Finally, increased Rorc and inhibited Il10 gene expression were observed in lung tissue indicating their possible role in BAP1 function. Our findings support and expand on our previous in vitro and ex vivo studies by demonstrating that BAP1, with a unique chemical structure, induces a specific immunomodulatory effect in the host and could be potentially used for alleviating allergic diseases. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/613063v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@16e1d1eorg.highwire.dtl.DTLVardef@39dbe0org.highwire.dtl.DTLVardef@928dd0org.highwire.dtl.DTLVardef@19c8a60_HPS_FORMAT_FIGEXP M_FIG C_FIG