Different Group A Streptococcus pili lead to varying proinflammatory cytokine responses and virulence.

The human pathogen Streptococcus pyogenes, or Group A Streptococcus (GAS), is associated with a variety of diseases ranging from mild skin and soft tissue infections to invasive diseases and immune sequelae such as rheumatic heart disease. We have recently reported that one of the virulence factors of this pathogen, the pilus, has inflammatory properties and strongly stimulates the innate immune system. Here we used a range of nonpathogenic Lactococcus lactis gain-of-function mutants, each expressing one of the major pilus types of GAS, to compare the immune responses generated by various types of fully assembled pili.

Expanding strain coverage of a group A Streptococcus pilus-expressing Lactococcus lactis mucosal vaccine.

Group A Streptococcus (GAS) is a human pathogenic bacterium that can trigger a wide range of diseases, including the autoimmune diseases acute rheumatic fever and rheumatic heart disease, causing major morbidity and mortality in many low- and middle-income countries. Primary intervention programs have had limited success thus far, and a licensed vaccine has yet to be developed. The pilus of GAS is known to be involved in host cell adhesion, biofilm formation and immune evasion.

The Cell Wall Deacetylases Spy1094 and Spy1370 Contribute to Virulence.

, or Group A Streptococcus (GAS), is a strictly human pathogen that causes a wide range of diseases, including skin and soft tissue infections, toxic shock syndrome and acute rheumatic fever. We have recently reported that Spy1094 and Spy1370 of serotype M1 are N-acetylglucosamine (GlcNAc) deacetylases. We have generated and gene deletion mutants in and gain-of-function mutants in .

A multivalent T-antigen-based vaccine for Group A Streptococcus.

Pili of Group A Streptococcus (GAS) are surface-exposed structures involved in adhesion and colonisation of the host during infection. The major protein component of the GAS pilus is the T-antigen, which multimerises to form the pilus shaft. There are currently no licenced vaccines against GAS infections and the T-antigen represents an attractive target for vaccination.

A Mouse Nasopharyngeal Colonization Model for Group A Streptococcus.

Group A Streptococcus (GAS) often exists as an asymptomatic colonizer of the upper respiratory tract in humans. Unsurprisingly, a high proportion of symptomatic infections caused by GAS include pharyngitis. While not usually life-threatening, these infections cause significant morbidity and economic burden/loss of productivity, and can have downstream life-threatening autoimmune consequences.

Assays to Analyze Adhesion of Group A Streptococcus to Host Cells.

The critical first step of Group A Streptococcus (GAS) pathogenesis is adhesion to the host pharyngeal and skin epithelial cell surfaces (Brouwer et al., FEBS Lett 590:3739-3757, 2016). Host-cell adhesion assays provide a straightforward model to study these host-pathogen interactions.

Publisher Correction: Mucosal vaccination with pili from Group A Streptococcus expressed on Lactococcus lactis generates protective immune responses.

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Streptococcus pyogenes nuclease A (SpnA) mediated virulence does not exclusively depend on nuclease activity.

Background: Streptococcus pyogenes, or Group A Streptococcus (GAS), is a human pathogen that causes a wide range of diseases, including pharyngitis, necrotizing fasciitis and toxic shock syndrome. The bacterium produces a large arsenal of virulence factors, including the cell wall-anchored Streptococcus pyogenes nuclease A (SpnA), which facilitates immune evasion by degrading the DNA backbone of neutrophil extracellular traps. SpnA consists of a C-terminal endo/exonuclease domain and a N-terminal domain of unknown function.

Mucosal vaccination with pili from Group A Streptococcus expressed on Lactococcus lactis generates protective immune responses.

The human pathogen Group A Streptococcus (GAS) produces pili that are involved in adhesion and colonisation of the host. These surface-exposed pili are immunogenic and therefore represent an attractive target for vaccine development. The pilus is encoded in the genomic region known as the fibronectin-collagen-T-antigen (FCT)-region, of which at least nine different types have been identified.