Bacterial Superantigens—Mechanism of T Cell Activation by the Superantigens and Their Role in the Pathogenesis of Infectious Diseases

Uchiyama, Takehiko; Yan, Xiao‐Jie; Imanishi, Ken’ichi; Yagi, Junji

doi:10.1111/j.1348-0421.1994.tb01772.x

Cited by 91 publications

(73 citation statements)

References 81 publications

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“…As a result, large amounts of cytokines are released, causing systemic symptoms such as shock, pancytopenia, and multi-organ failure. 16) Our results demonstrated that significantly lower platelet count, higher catecholamine administration, and higher SOFA score were observed in patients infected with TABC, suggesting severe sepsis or septic shock in patients with MRSA bacteremia. Thus, SAgT induced systemic symptoms that potentially caused poor patient prognosis.…”

Section: Discussionmentioning

confidence: 66%

“…S. aureus is known to produce various virulence factors, 14) such as toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SEs), which are superantigenic toxins (SAgT) associated with severe infections. 11,15,16) A previous study reported that TSST-1 and SEC1 caused shock when intravenously injected into an animal model. 17) In addition, recent experimental study showed that SAgT play a critical role in the development and progression of S. aureus infective endocarditis and sepsis.…”

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confidence: 99%

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Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia

Maeda

Shoji

Shirakura

et al. 2016

Biological & Pharmaceutical Bulletin

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It is well known that methicillin-resistantVancomycin (VCM) has been the standard treatment for MRSA infections for over 50 years. The area under the concentration-time curve [AUC/minimum inhibitory concentration (MIC) ratio] is a representative parameter of the pharmacokinetics-pharmacodynamics (PK-PD) of VCM.3) The Infectious Diseases Society of America recommends a target AUC/ MIC>400 for the treatment of severe MRSA infections. 4)However, this is often difficult to achieve for MRSA strains with high VCM MICs, thus increasing the risk of insufficient therapeutic response. Previous meta-analyses have attempted to address the association between MIC and clinical outcomes. [5][6][7] In contrast to these studies, a recent meta-analysis examining 8291 episodes reported no differences in the risk of death between patients with S. aureus high and low VCM MICs. 8) These results highlight the current lack of consensus regarding the relationship between VCM MICs and the prognosis of patients with MRSA infections.Our previous study measured MICs at 0.25 µg/mL intervals using the broth microdilution method and found that VCM MICs≥1.5 µg/mL affected the prognosis for MRSA bacteremia. 9) However, there were no significant differences in VCM AUC/MIC and clinical prognosis between the groups.The pathological mechanism of S. aureus infections includes infectious pathogenicity such as pneumonia, cellulitis, osteomyelitis, and infective endocarditis as well as toxic pathogenicity such as food poisoning and toxic shock syndrome.10,11) Several virulence factors have been reported to be associated with the clinical outcomes of MRSA infections. The expression of major virulence factors, such as Panton-Valentine leukocidin (PVL), is known to be correlated with higher mortality in community-associated MRSA infections. 12,13) We believe that toxic pathogenicity is closely associated with patient prognosis. S. aureus is known to produce various virulence factors, 14) such as toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SEs), which are superantigenic toxins (SAgT) associated with severe infections. 11,15,16) A previous study reported that TSST-1 and SEC1 caused shock when intravenously injected into an animal model. 17) In addition, recent experimental study showed that SAgT play a critical role in the development and progression of S. aureus infective endocarditis and sepsis.18) However, the association between SAgT and the prognosis of patients with MRSA bacteremia has not been sufficiently studied. Therefore, here we aimed to examine the effects of staphylococcal virulence factors on the prognosis of patients with MRSA bacteremia.

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Section: Discussionmentioning

confidence: 66%

mentioning

confidence: 99%

Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia

Maeda

Shoji

Shirakura

et al. 2016

Biological & Pharmaceutical Bulletin

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“…PBMCs were isolated by Ficoll-Conray density-gradient centrifugation, as described previously (20,21). To examine the percentage of Vβ2 + T cells (reactive with TSST-1) or Vβ3 + T cells (reactive with staphylococcal enterotoxin B; SEB) (7,8), PBMCs were stained with several combinations of adequate PC5-, FITC-, or PE-conjugated mAb's and examined by three-color flowcytometry analysis using a EPICS XL flow cytometer (Coulter Corp.), as described previously (20,21).…”

Section: Methodsmentioning

confidence: 99%

Immunopathophysiological aspects of an emerging neonatal infectious disease induced by a bacterial superantigen

Takahashi

Kato²,

Imanishi³

et al. 2000

J. Clin. Invest.

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“…Production of superantigens and of heat shock proteins (HSPs) is closely associated with changing host responses [1][2][3][6][7][8]21,22,26,27) . This study was designed to evaluate the significance of infections by M. salivarium and M. orale in HIV(‫)ם‬ patients.…”

Section: Mycoplasma Salivarium and Mycoplasma Oralementioning

confidence: 99%

Heat shock protein of Mycoplasma salivarium and Mycoplasma orale strains isolated from HIV-seropositive patients.

Chattin-Kacouris

Ishihara

Miura

et al. 2002

Bull. Tokyo Dent. Coll.

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It has been suggested that infection by some mycoplasma species can act as possible cofactors in the acceleration of immunodeficiency in HIV-infected patients. The present study was designed to examine infections by oral mycoplasma species in HIV-seropositive (HIV(‫))ם‬ patients. Mycoplasma salivarium and Mycoplasma orale were isolated from 59.5% and 16.7% of 42 HIV(‫)ם‬ patients, respectively. Non-M. salivarium and non-M. orale species were isolated from 40.5% of saliva samples from the HIV(‫)ם‬ group and 20.8% of those from 24 HIV-seronegative (HIV(‫))מ‬ subjects, respectively. Although the production of superantigen by human peripheral lymphocytes in the isolated mycoplasma species from HIV(‫)ם‬ and HIV ‫)מ(‬ subjects was evaluated, none of the examined mycoplasma strains, including ATCC strains of M.salivarium, M. orale, Mycoplasma buccae and Mycoplasma penetrans, were found to produce superantigen. Production of heat shock proteins (HSPs) by isolated mycoplasma strains was examined by immunoblotting using monoclonal antibodies against Helicobacter pylori HSP60. It was found that all the strains of M. salivarium, M.orale, and unidentified mycoplasma species isolated from HIV(‫)ם‬ and HIV(‫)מ‬ groups produced heat shock proteins. HSP production by oral mycoplasma may play a role in the immunomodulation of HIV(‫)ם‬ patients.

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Bacterial Superantigens—Mechanism of T Cell Activation by the Superantigens and Their Role in the Pathogenesis of Infectious Diseases

Cited by 91 publications

References 81 publications

Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia

Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia

Immunopathophysiological aspects of an emerging neonatal infectious disease induced by a bacterial superantigen

Heat shock protein of Mycoplasma salivarium and Mycoplasma orale strains isolated from HIV-seropositive patients.

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