Streptococcus pneumoniae endopeptidase O induces trained immunity and confers protection against various pathogenic infections.

Antibiotic resistance and the surge of infectious diseases during the pandemic present significant threats to human health. Trained immunity emerges as a promising and innovative approach to address these infections. Synthetic or natural fungal, parasitic and viral components have been reported to induce trained immunity.

Protein sensors combining both on-and-off model for antibody homogeneous assay.

Protein sensors based on allosteric enzymes responding to target binding with rapid changes in enzymatic activity are potential tools for homogeneous assays. However, a high signal-to-noise ratio (S/N) is difficult to achieve in their construction. A high S/N is critical to discriminate signals from the background, a phenomenon that might largely vary among serum samples from different individuals.

Inactivation of Transcriptional Regulator FabT Influences Colony Phase Variation of Streptococcus pneumoniae.

Streptococcus pneumoniae is an opportunistic pathogen that can alter its cell surface phenotype in response to the host environment. We demonstrated that the transcriptional regulator FabT is an indirect regulator of capsular polysaccharide, an important virulence factor of Streptococcus pneumoniae. Transcriptome analysis between the wild-type D39s and D39Δ mutant strains unexpectedly identified a differentially expressed gene encoding a site-specific recombinase, PsrA.

Biomineralization improves the stability of a protein vaccine at high temperatures.

Protein vaccines have been the focus of research for vaccine development due to their safety record and facile production. Improving the stability of proteins is of great significance to the application of protein vaccines. Based on the proteins pneumolysin and DnaJ of , biomineralization was carried out to prepare protein nanoparticles, and their thermal stability was tested both and .

Endopeptidase O Promotes the Clearance of and via SH2 Domain-Containing Inositol Phosphatase 1-Mediated Complement Receptor 3 Upregulation.

Increasing evidences demonstrate that microorganism and their products protect against bacterial and viral pathogens through various mechanisms including immunomodulation. endopeptidase O (PepO), a pneumococcal virulence protein, has been proven to enhance the phagocytosis of and by macrophages in our previous study, where we detected the down regulation of SH2 domain-containing inositol phosphatase 1 (SHIP1) and the up regulation of complement receptor 3 (CR3) in PepO-stimulated macrophages. In the present study, using SHIP1 over-expression plasmid and CR3 siRNA, we proved that the down regulation of SHIP1 and the up regulation of CR3 mediate the enhanced phagocytosis of and by PepO-stimulated macrophages.

Combination of Detoxified Pneumolysin Derivative ΔA146Ply and Berbamine as a Treatment Approach for Breast Cancer.

Increasing evidence demonstrates that microorganisms and their products can modulate host responses to cancer therapies and contribute to tumor shrinkage via various mechanisms, including intracellular signaling pathways modulation and immunomodulation. Detoxified pneumolysin derivative ΔA146Ply is a pneumolysin mutant lacking hemolytic activity. To determine the antitumor activity of ΔA146Ply, the combination of ΔA146Ply and berbamine, a well-established antitumor agent, was used for breast cancer therapy, especially for triple-negative breast cancer.

PepO promotes host anti-infection defense via autophagy in a Toll-like receptor 2/4 dependent manner.

Macrophage is essential for host anti-bacterial defense by directly eliminating invading microbes and inducing a series of immune reactions. Here we identified a protein, PepO, as a TLR2/TLR4 bi-ligand. We found that PepO enhances macrophage unspecific phagocytosis and bactericidal activity, which is related to the induction of autophagy in macrophage, for the inhibition of autophagy significantly decreased the phagocytosis and bactericidal activity of PepO-treated macrophage.

Progranulin Decreases Susceptibility to in Influenza and Protects against Lethal Coinfection.

coinfection is a major cause of mortality in influenza pandemics. Growing evidence shows that uncontrolled immune response results in severe tissue damage and thereby promotes death in coinfection. Progranulin (PGRN) is widely expressed in immune and epithelial cells and exerts anti-inflammatory role in many diseases.

Pneumococcal LytR Protein Is Required for the Surface Attachment of Both Capsular Polysaccharide and Teichoic Acids: Essential for Pneumococcal Virulence.

The LytR-Cps-Psr family proteins are commonly present in Gram-positive bacteria, which have been shown to implicate in anchoring cell wall-related glycopolymers to the peptidoglycan. Here, we report the cellular function of SPD_1741 (LytR) in and its role in virulence of pneumococci. Pneumococcal Δ mutants have been successfully constructed by replacing the gene with cassette.

Double signal enhancement strategy based on rolling circle amplification and photoinduced electron transfer for ultrasensitive fluorometric detection of methylated DNA.

The authors describe a novel assay for the detection of methylated DNA site. Rolling circle amplification and CdSe/ZnS quantum dots with high fluorescence efficiency are applied in this method. The CdSe/ZnS quantum dots act as electron donors, and hemin and oxygen (derived from hydrogen peroxide act as acceptors in photoinduced electron transfer.