Streptococcal pyrogenic exotoxin C (SPE C) is a superantigen produced by many strains of Streptococcus pyogenes that (along with streptococcal pyrogenic exotoxin A) is highly associated with streptococcal toxic shock syndrome (STSS) and other invasive streptococcal diseases. Based on the three-dimensional structure of SPE C, solvent-exposed residues predicted to be important for binding to the TCR or the MHC class II molecule, or important for dimerization, were generated. Based on decreased mitogenic activity of various single-site mutants, the double-site mutant Y15A/N38D and the triple-site mutant Y15A/H35A/N38D were constructed and analyzed for superantigenicity, toxicity (lethality), immunogenicity, and the ability to protect against wild-type SPE C-induced STSS. The Y15A/N38D and Y15A/H35A/N38D mutants were nonmitogenic for rabbit splenocytes and human PBMCs and nonlethal in two rabbit models of STSS, yet both mutants were highly immunogenic. Animals vaccinated with the Y15A/N38D or Y15A/H35A/N38D toxoids were protected from challenge with wild-type SPE C. Collectively, these data indicate that the Y15A/N38D and Y15A/H35A/N38D mutants may be useful as toxoid vaccine candidates.
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http://dx.doi.org/10.4049/jimmunol.165.4.2306 | DOI Listing |
Curr Issues Mol Biol
December 2024
Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
Abrin, a toxin of the rosary pea plant (), has been implicated as causing an autoimmune demyelinating disease in humans, but the exact mechanisms responsible for the induction of these demyelinating conditions are still unknown. Certain superantigen microbial toxins such as Staphylococcus enterotoxin type A, type D, type E or streptococcal pyrogenic exotoxin type C also lead to various diseases including autoimmune disorders of the nervous system. Here, the effect of abrin toxin on the immune reaction was studied in human CD4 T-cell lines, and its inhibition of protein synthesis in kidney cells.
View Article and Find Full Text PDFJ Antimicrob Chemother
December 2024
Department of Medical Laboratory Science, I-Shou University, Kaohsiung City, Taiwan.
Objectives: Group A Streptococcus (GAS) results in invasive diseases. Our published studies show that AR-12 can directly kill GAS. However, AR-12 is toxic to the human microvascular endothelial cells (HMEC-1 cells) even at its MIC.
View Article and Find Full Text PDFJ Conserv Dent Endod
September 2024
Department of Restorative Dental Sciences, Faculty of Dentistry, Al Baha University, Al Baha, Saudi Arabia.
Background: Dental caries, commonly known as tooth decay is a widespread oral health problem mainly attributed to the activity of cariogenic bacteria, such as and species. Tooth Mousse, containing remineralizing agents, herbal and fluoride containing toothpaste with antimicrobial agents have been developed to target cariogenic bacteria. Herbal, fluoride toothpaste, and Tooth Mousse are commonly prescribed to prevent, reduce, and control dental caries.
View Article and Find Full Text PDFPathog Dis
February 2024
School of Science & Technology, University of New England, NSW, Australia.
Post-streptococcal glomerulonephritis (PSGN) is primarily associated with preceding group A streptococcal skin or throat infections, now mainly observed in economically disadvantaged communities. This condition significantly predisposes individuals to later-life chronic kidney disease and concurrent renal complications, with the elderly experiencing increased severity and less favourable outcomes. Streptococcal pyrogenic exotoxin B and nephritis-associated plasmin receptor are identified nephritogenic antigens (nephritogens).
View Article and Find Full Text PDFOpen Forum Infect Dis
August 2024
School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
M1 is associated with current surges in invasive infection globally, partly due to increased production of superantigen streptococcal pyrogenic exotoxin A. We show that M1 is now the dominant invasive 1 lineage in Aotearoa New Zealand and is genomically related to community infections, suggesting that measures that effectively prevent group A pharyngitis in children could reduce invasive disease.
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