Streptococcus pneumoniae
Molecular Pathogenesis | SpotlightStreptococcus pneumoniae Elaborates Persistent and Prolonged Competent State during Pneumonia-Derived SepsisThe competence regulon of pneumococcus regulates both genetic transformation and virulence. However, competence induction during host infection has not been examined. By using the serotype 2 strain D39, we transcriptionally fused the firefly luciferase (luc) to competence-specific genes and spatiotemporally monitored the competence development in a mouse model of pneumonia-derived sepsis. In contrast to the universally reported...
Host Response and InflammationInterleukin 17 Receptor E (IL-17RE) and IL-17C Mediate the Recruitment of Neutrophils during Acute Streptococcus pneumoniae PneumoniaNeutrophils contribute to lung injury in acute pneumococcal pneumonia. The interleukin 17 receptor E (IL-17RE) is the functional receptor for the epithelial-derived cytokine IL-17C, which is known to mediate innate immune functions. The aim of this study was to investigate the contribution of IL-17RE/IL-17C to pulmonary inflammation in a mouse model of acute Streptococcus...
Molecular PathogenesisDprA-Dependent Exit from the Competent State Regulates Multifaceted Streptococcus pneumoniae VirulenceStreptococcus pneumoniae (pneumococcus) causes multiple infectious diseases. The pneumococcal competence system facilitates genetic transformation, spreads antibiotic resistance, and contributes to virulence. DNA-processing protein A (DprA) regulates the exit of pneumococcus from the competent state. Previously, we have shown that DprA is important in both bacteremia...
Microbial Immunity and Vaccines | SpotlightA Novel, Multiple-Antigen Pneumococcal Vaccine Protects against Lethal Streptococcus pneumoniae ChallengeCurrent vaccination against Streptococcus pneumoniae uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from S....
Host Response and InflammationThe Pneumococcal Surface Proteins PspA and PspC Sequester Host C4-Binding Protein To Inactivate Complement C4b on the Bacterial SurfaceComplement is a critical component of antimicrobial immunity. Various complement regulatory proteins prevent host cells from being attacked.
Microbial Immunity and Vaccines | SpotlightScreening for Th17-Dependent Pneumococcal Vaccine Antigens: Comparison of Murine and Human Cellular Immune ResponsesConjugate vaccines against Streptococcus pneumoniae have significantly reduced the incidence of diseases caused by the serotypes included in those vaccines; however, there is still a need for vaccines that confer serotype-independent protection. In the current study, we have constructed a library of conserved surface proteins from...
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsDesialylation of Platelets by Pneumococcal Neuraminidase A Induces ADP-Dependent Platelet HyperreactivityPlatelets are increasingly recognized to play a role in the complications of Streptococcus pneumoniae infections. S. pneumoniae expresses neuraminidases, which may alter glycans on the platelet surface.
- Bacterial InfectionsNovel Immunoprotective Proteins of Streptococcus pneumoniae Identified by Opsonophagocytosis Killing Screen
The success of polysaccharide conjugate vaccines represents a major advance in the prevention of pneumococcal disease, but the power of these vaccines is limited by partial spectrum of coverage and high cost. Vaccines using immunoprotective proteins are a promising alternative type of pneumococcal vaccines.
- Cellular Microbiology: Pathogen-Host Cell Molecular Interactions | SpotlightEnzymatic Hydrolysis of Pneumococcal Capsular Polysaccharide Renders the Bacterium Vulnerable to Host Defense
Despite a century of investigation, Streptococcus pneumoniae remains a major human pathogen, causing a number of diseases, such as pneumonia, meningitis, and otitis media. Like many encapsulated pathogens, the capsular polysaccharide (CPS) of S. pneumoniae is a critical component for colonization...