Streptococcus pyogenes is a group A streptococcus (GAS) and an important human pathogen that causes a variety of diseases. Streptococcal pyrogenic exotoxin B (SPE B) and streptolysin S (SLS) are important virulence factors involved in GAS infection, but it is not clear which one is more virulent. Using an air pouch infection model, the wild-type strain NZ131, its isogenic mutants, and complementary mutants were used to examine the effects of SPE B and SLS on GAS infection. The results of the skin lesion and mouse mortality assays showed that although SPE B and SLS had a synergistic effect on GAS infection, SPE B played a more important role in local tissue damage while SLS had a more prominent effect on mouse mortality. Surveys of the exudates from the air pouch revealed that the expression of inflammatory cytokines was significantly inhibited in the sagB/speB-double-mutant JM4-infected mice. Furthermore, in vivo and in vitro studies showed that the isogenic mutant strains were more susceptible to the immune cell killing than the wild-type strain and that the sagB/speB-double-mutant JM4 was the most sensitive among these strains. Moreover, infection with the sagB/speB-double-mutant JM4 strain caused the least amount of macrophage apoptosis compared to infection with the wild-type NZ131 and the other complementary strains, which express only SPE B or SLS or both. Taken together, these results indicate that both SPE B and SLS contributed to GAS evasion from immune cell killing, local tissue damage, and mouse mortality.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s00430-012-0241-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Designing tannic acid-polyethyleneimine-modified electrode and novel affinity peptide for β-lactoglobulin detection in milk.
Food Chem
March 2024
Basic Research Laboratory, Department of Food Science and Technology, Chung-Ang University, 4726 Seodong-daero, Anseong 17546, Republic of Korea. Electronic address:
Harmful substances that cause food allergies can pose a significant threat to consumers along with food safety. According to the World Health Organization (WHO), approximately 10 % of the global population is currently affected by food allergies. Therefore, there is an urgent need for the development of more accurate and precise biosensors capable of detecting these hazardous substances including beta-lactoglobulin.
View Article and Find Full Text PDFEvaluation and Quantification of Natural Strigolactones from Root Exudates.
Methods Mol Biol
August 2021
Utsunomiya University, Utsunomiya, Japan.
Strigolactones (SLs) in the root exudates can be detected by germination assays with root parasitic weed seeds, but precise and accurate evaluation and quantification are possible only by chemical analysis with the liquid chromatography-tandem mass spectrometry (LC-MS/MS). Here we describe methods for root exudate collection, sample preparation, and LC-MS/MS analysis of SLs.
View Article and Find Full Text PDFConformational switching of the pseudokinase domain promotes human MLKL tetramerization and cell death by necroptosis.
Nat Commun
June 2018
The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.
Necroptotic cell death is mediated by the most terminal known effector of the pathway, MLKL. Precisely how phosphorylation of the MLKL pseudokinase domain activation loop by the upstream kinase, RIPK3, induces unmasking of the N-terminal executioner four-helix bundle (4HB) domain of MLKL, higher-order assemblies, and permeabilization of plasma membranes remains poorly understood. Here, we reveal the existence of a basal monomeric MLKL conformer present in human cells prior to exposure to a necroptotic stimulus.
View Article and Find Full Text PDFApplication of the C3-binding motif of streptococcal pyrogenic exotoxin B to protect mice from invasive group a streptococcal infection.
PLoS One
February 2016
Department of Pathology, E-DA Hospital, Kaohsiung City, Taiwan.
Article Synopsis
- Group A streptococcus (GAS) is a harmful bacteria that uses exotoxins like streptococcal pyrogenic exotoxin B (SPE B) to invade the body and evade the immune system by cleaving complement 3 (C3).
- Research identified specific regions on SPE B that bind to human C3, with the C-terminal domain and two distinct binding motifs playing key roles in this interaction.
- Immunization with these C3-binding motifs in combination with peptides from another exotoxin, streptolysin S, effectively reduced death rates and skin lesions in mice infected with invasive GAS strains, suggesting a potential subunit vaccine approach against serious GAS infections.
Synergistic effects of streptolysin S and streptococcal pyrogenic exotoxin B on the mouse model of group A streptococcal infection.
Med Microbiol Immunol
August 2012
Institute of Biotechnology and Chemical Engineering, I-Shou University, Kaohsiung City, Taiwan.
Streptococcus pyogenes is a group A streptococcus (GAS) and an important human pathogen that causes a variety of diseases. Streptococcal pyrogenic exotoxin B (SPE B) and streptolysin S (SLS) are important virulence factors involved in GAS infection, but it is not clear which one is more virulent. Using an air pouch infection model, the wild-type strain NZ131, its isogenic mutants, and complementary mutants were used to examine the effects of SPE B and SLS on GAS infection.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!