Streptococcal 5′-Nucleotidase A (S5nA), a Novel Streptococcus pyogenes Virulence Factor That Facilitates Immune Evasion

Zheng, Lisa; Khemlani, Adrina Hema J.; Lorenz, Natalie; Loh, Jacelyn M. S.; Langley, Ries J.; Proft, Thomas

doi:10.1074/jbc.m115.677443

Cited by 39 publications

(60 citation statements)

References 41 publications

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“…Unexpectedly, both ENuc and 5Nuc demonstrated the ability to convert calf thymus DNA and NET DNA into deoxyadenosine as directly detected by rpHPLC. This mechanism differs from that observed in other pathogens such as Staphylococcus aureus and Streptococcus pyogenes because these pathogens possess NET-cleaving nucleases in addition to 5=-nucleotidases (20,22,23). In this study, S. equi subsp.…”

Section: Discussionmentioning

confidence: 68%

“…Extracellular 5=-nucleotidases, such as AdsA of Staphylococcus aureus, produce adenosine, which is an immunomodulatory molecule (20,21). However, Thammavongsa and colleagues noted cooperation between AdsA and a nuclease, facilitating the production of deoxyadenosine through the degradation of NET DNA.…”

Section: Discussionmentioning

confidence: 99%

“…The recombinant E. coli was incubated at 37°C until the exponential growth phase was reached, and then protein expression was induced for 6 h with the addition of 0.1 mM isopropyl-␤-Dthiogalactopyranoside (Sigma-Aldrich). Cells were harvested, washed, and suspended in ice-cold binding buffer (20 …”

Section: Methodsmentioning

confidence: 99%

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Extracellular Nucleases of Streptococcus equi subsp. zooepidemicus Degrade Neutrophil Extracellular Traps and Impair Macrophage Activity of the Host

Guo

Fan

2017

Appl Environ Microbiol

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The pathogen Streptococcus equi subsp. zooepidemicus is associated with a wide range of animals, including humans, and outbreaks frequently occur in pigs, equines, and goats. Thus far, few studies have assessed interactions between the host immune system and S. equi subsp. zooepidemicus and how these interactions explain the wide host spectrum of S. equi subsp. zooepidemicus. Neutrophils, the first line of innate immunity, possess a defense mechanism called neutrophil extracellular traps (NETs), which primarily consist of DNA and granule proteins that trap bacteria via charge interactions. Extracellular nucleases play important roles in the degradation of the DNA backbone of NETs. Here, two related extracellular nucleases, nuclease and 5=-nucleotidase (named ENuc and 5Nuc, respectively, in this study), were identified as being encoded by the SESEC_RS04165 gene and the SESEC_RS05720 gene (named ENuc and 5Nuc, respectively), and three related gene deletion mutant strains, specifically, the single-mutant ⌬ENuc and ⌬5Nuc strains and the double-mutant ⌬ENuc ⌬5Nuc strain, were constructed. The ⌬ENuc and ⌬5Nuc single-mutant strains and the ⌬ENuc ⌬5Nuc double-mutant strain demonstrated lower virulence than wild-type S. equi subsp. zooepidemicus when the mouse survival rate was evaluated postinfection. Furthermore, wild-type S. equi subsp. zooepidemicus more frequently traversed the bloodstream and transferred to other organs. Wild-type S. equi subsp. zooepidemicus induced fewer NETs and was able to survive in NETs, whereas only 40% of the ⌬ENuc ⌬5Nuc double-mutant cells survived. S. equi subsp. zooepidemicus degraded the NET DNA backbone and produced deoxyadenosine, primarily through the action of ENuc and/or 5Nuc. However, the double-mutant ⌬ENuc ⌬5Nuc strain lost the ability to degrade NETs into deoxyadenosine. Deoxyadenosine decreased RAW 264.7 cell phagocytosis to 40% of that of normal macrophages.IMPORTANCE Streptococcus equi subsp. zooepidemicus causes serious bacteremia in its hosts. However, little is known about how S. equi subsp. zooepidemicus interacts with the host innate immune system, particularly innate cells found in the blood. S. equi subsp. zooepidemicus is capable of evading NET-mediated killing via the actions of its potent extracellular nucleases, ENuc and 5Nuc, which directly degrade the NET DNA backbone to deoxyadenosine. In previous studies, other pathogens have required the synergism of nuclease and 5=-nucleotidase to engage in this self-protective process; however, ENuc and 5Nuc both possess nuclease activity and 5=-nucleotidase activity, highlighting the novelty of this discovery. Furthermore, deoxyadenosine impairs phagocytosis but not the intracellular bactericidal activity of macrophages. Here we describe a novel mechanism for S. equi subsp. zooepidemicus extracellular nucleases in NET degradation, which may provide new insights into the pathogen immune evasion mechanism and the prevention and treatment of bacterial disease.

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Section: Discussionmentioning

confidence: 68%

Section: Discussionmentioning

confidence: 99%

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Extracellular Nucleases of Streptococcus equi subsp. zooepidemicus Degrade Neutrophil Extracellular Traps and Impair Macrophage Activity of the Host

Guo

Fan

2017

Appl Environ Microbiol

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“…Several streptococcal 5′‐NTs have been functionally characterized , including ecto‐5′‐nucleotidase (Nt5e) from S. sanguinis (Fan et al, ), Ecto‐5‐nucleoside diphosphate phosphohydrolase (NudP) from S. agalactiae (Firon et al, ), streptococcal 5′‐nucleotidase A (S5nA) from S. pyogenes (Zheng et al, ), S5nAi from S. iniae (Soh, Loh, & Proft, ), S. suis adenosine synthase (Ssads) (Liu et al, ) and S. equi subsp. zooepidemicus 5′‐nucleotidase (5Nuc; Ma, Guo, & Fan, ).…”

Section: ′‐Nucleotidases In Streptococcimentioning

confidence: 99%

“…There are also differences between the 5′‐NTs regarding substrate specificity for other nucleosides and metal‐ion requirements. Hydrolysis of other nucleoside monophosphates (GMP, CMP, TMP) was shown for NudP, S5nA and S5nAi (Firon et al, ; Soh et al, ; Zheng et al, ), in contrast to the S. aureus AdsA which only recognizes AMP and GMP, but not CMP and TMP. Furthermore, enzymatic activities for individual substrates also differ.…”

Section: ′‐Nucleotidases In Streptococcimentioning

confidence: 99%

Cell wall‐anchored 5′‐nucleotidases in Gram‐positive cocci

Soh

Loh

Proft

2020

Molecular Microbiology

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5′‐nucleotidases (5′‐NTs) are enzymes that catalyze the hydrolysis of nucleoside monophosphates to produce nucleosides and phosphate. Since the identification of adenosine synthase A (AdsA) in Staphylococcus aureus in 2009, several other 5′‐NTs have been discovered in Gram‐positive cocci, mainly in streptococci. Despite some differences in substrate specificity, pH range and metal ion requirements, all characterized 5′‐NTs use AMP and ADP, and in some cases ATP, to produce the immunosuppressive adenosine, which dampens pro‐inflammatory immune responses. Several 5′‐NTs are also able to use dAMP as substrate to generate deoxy‐adenosine which is cytotoxic for macrophages. A synergy between 5′‐NTs and exonucleases which are commonly expressed in Gram‐positive cocci has been described, where the nucleases provide dAMP as a cleavage product from DNA. Some of these nucleases produce dAMP by degrading the DNA backbone of neutrophil extracellular traps (NETs) resulting in a “double hit” strategy of immune evasion. This Micro Review provides an overview of the biochemical properties of Gram‐positive cell wall‐anchored 5′‐NTs and their role as virulence factors. A potential use of 5′‐NTs for vaccine development is also briefly discussed.

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