Streptococcal DNase B Is Immunologically Identical to Superantigen SpeF but Involves Separate Domains

Eriksson, Anna; Eriksson, B.; Holm, Stig E.; Norgren, Mari

doi:10.1128/cdli.6.1.133-136.1999

Cited by 18 publications

(14 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These results indicate that under the tested conditions, NucA is the major DNase of GBS strain NEM316. Subsequently, to evaluate only the role of nuclease activity of NucA in vivo we performed studies using the nucA H148A mutant since this strain produces the protein but without any activity and it has been reported that some nucleases can also display antigenic properties (Ferrieri et al, 1980;Eriksson et al, 1999;Sriskandan et al, 2000).…”

Section: Fig 3 Effects Of Concentration Of Mgcl2 Andmentioning

confidence: 99%

Nuclease A (Gbs0661), an extracellular nuclease of Streptococcus agalactiae, attacks the neutrophil extracellular traps and is needed for full virulence

Derré-Bobillot

Cortes-Perez

Yamamoto

et al. 2013

Molecular Microbiology

View full text Add to dashboard Cite

SummaryMost bacteria of the genus Streptococcus are opportunistic pathogens, and some of them produce extracellular DNases, which may be important for virulence. Genome analyses of Streptococcus agalactiae (GBS) neonate isolate NEM316 revealed the presence of seven genes putatively encoding secreted DNases, although their functions, if any, are unknown. In this study, we observed that respiration growth of GBS led to the extracellular accumulation of a putative nuclease, identified as being encoded by the gbs0661 gene. When overproduced in Lactococcus lactis, the protein was found to be a divalent cation-requiring, pH-stable and heat-stable nuclease that we named Nuclease A (NucA). Substitution of the histidine 148 by alanine reduced nuclease activity of the GBS wild-type strain, indicating that NucA is the major nuclease ex vivo. We determined that GBS is able to degrade the DNA matrix comprising the neutrophil extracellular trap (NET). The nucA H148A mutant was impaired for this function, implicating NucA in the virulence of GBS. In vivo infection studies confirmed that NucA is required for full infection, as the mutant strain allowed increased bacterial clearance from lung tissue and decreased mortality in infected mice. These results show that NucA is involved in NET escape and is needed for full virulence.

show abstract

Section: Fig 3 Effects Of Concentration Of Mgcl2 Andmentioning

confidence: 99%

Nuclease A (Gbs0661), an extracellular nuclease of Streptococcus agalactiae, attacks the neutrophil extracellular traps and is needed for full virulence

Derré-Bobillot

Cortes-Perez

Yamamoto

et al. 2013

Molecular Microbiology

View full text Add to dashboard Cite

show abstract

“…Antisera produced against MF were not able to neutralize the mitogenic activity of this MF preparations. But these antisera blocked the DNase activity of MF previously reported [3,10]. MF (SDBII) preparations from the strain C203S only showed VL2 speci¢city.…”

Section: Discussionmentioning

confidence: 73%

“…Characteristic for MF the VL8 activity was suggested. The ability to slit DNA was reported as a second biological activity for it [3,10]. MF is considered to be an important pathogenicity factor involved in the sequelae of group A streptococcal infections such as shock and autoimmunity [2,13].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Basic streptococcal superantigens (SPEX/SMEZ or SPEC) are responsible for the mitogenic activity of the so-called mitogenic factor (MF)

Gerlach

2001

FEMS Immunology and Medical Microbiology

View full text Add to dashboard Cite

The mitogenic factor (MF) of group A streptococci has been reported to be a superantigen stimulating human T cells carrying Vbeta2, 4 and 8 and has been designated streptococcal pyrogenic exotoxin F (SPEF). MF was also shown to possess DNase activity. Here we have purified MF from culture supernatants of different Streptococcus pyogenes strains. Surprisingly, the MF preparations from different strains showed different Vbeta specificities depending on the expression of SPEC or SMEZ3 by the producing strain. Their mitogenic activity decreased upon further purification. In addition, the mitogenic activity could be only neutralized by antibodies against the basic streptococcal superantigens SPEC or SPEX (SMEZ3) but not by antibodies against MF itself although the latter were able to neutralize completely the DNase activity of MF. We found that streptodornase type B (SDB) was expressed in two molecular forms (SDBI and SDBII), differing only by one additional N-terminal arginine at SDBI. MF was found identical to the enzyme SDBII but is devoid of superantigenic properties and should no longer be called a superantigen or a pyrogenic exotoxin.

show abstract

“…The zinc-dependent homodimer of SED uses a lysine as one of the ligands, a rather unusual ligand, which has been observed in aminopeptidases [44,45]. Furthermore, SpeF has been reported to have a heat resistant nuclease activity and was recently shown to be immunologically identical to DNAse B [6,16]. However, the nuclease and superantigenic activities were found to involve separate domains of the protein [6].…”

Section: Introductionmentioning

confidence: 99%

The superantigenic activity of streptococcal pyrogenic exotoxin B is independent of the protease activity

Eriksson

Norgren

1999

FEMS Immunology &Amp; Medical Microbiology

Self Cite

View full text Add to dashboard Cite

The nature of the mitogenic activity of pyrogenic streptococcal exotoxin B, also known as streptococcal cysteine protease, has been debated in the literature. Streptococcal exotoxin B has been shown to cleave interleukin-1beta precursor and create biologically active interleukin-1beta, a major cytokine mediating inflammation and shock. This activity could mimic the mitogenicity and cytokine release induced by superantigens in lymphocyte stimulating experiments. In this study, the protease activity of streptococcal exotoxin B was irreversibly inhibited by covalent binding of a tripeptide and the superantigenic properties of streptococcal exotoxin B were found not to be influenced by this inactivation. Native as well as protease-inactivated streptococcal exotoxin B was shown to stimulate T-cell proliferation without a need of metabolically active antigen presenting cells. Furthermore, streptococcal exotoxin B-induced T-cell proliferation was shown to require HLA-DQ since addition of HLA-DQ monoclonal antibodies totally inhibited the mitogenic activity of streptococcal exotoxin B, indicating that streptococcal exotoxin B, as other superantigens, makes direct contact with the T-cell receptor via HLA class II. The aim of this study was to characterize the relationship between the proteolytic and superantigenic properties of streptococcal exotoxin B.

show abstract

Streptococcal DNase B Is Immunologically Identical to Superantigen SpeF but Involves Separate Domains

Cited by 18 publications

References 22 publications

Nuclease A (Gbs0661), an extracellular nuclease of Streptococcus agalactiae, attacks the neutrophil extracellular traps and is needed for full virulence

Nuclease A (Gbs0661), an extracellular nuclease of Streptococcus agalactiae, attacks the neutrophil extracellular traps and is needed for full virulence

Basic streptococcal superantigens (SPEX/SMEZ or SPEC) are responsible for the mitogenic activity of the so-called mitogenic factor (MF)

The superantigenic activity of streptococcal pyrogenic exotoxin B is independent of the protease activity

Contact Info

Product

Resources

About