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

Maternal and Perinatal Center, and. Department of Microbiology and Immunology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
Journal of Clinical Investigation (Impact Factor: 13.22). 01/2001; 106(11):1409-15. DOI: 10.1172/JCI10396
Source: PubMed


We recently discovered an emerging neonatal infectious disease, neonatal toxic shock syndrome-like (TSS-like) exanthematous disease (NTED), which is induced by a superantigen, TSS toxin-1 (TSST-1), produced by methicillin-resistant Staphylococcus aureus (MRSA). Here, we analyzed the activation and the response of TSST-1-reactive Vss2(+) T cells in NTED patients during the acute and recovery phases and in asymptomatic infants exposed to MRSA. In the acute phase, Vss2(+) T cells were anergic to stimulation with TSST-1 and underwent marked expansion, but by 2 months after disease onset, their numbers had declined to about 10% of the control level. Although the percentage of Vss2(+) T cells in the ten asymptomatic neonatal MRSA carriers was within the control range, these individuals could be divided into two groups on the basis of Vss2(+) T-cell activation. Vss2(+)CD4(+) T cells from three of these infants (Group 1) highly expressed CD45RO and were anergic to TSST-1, whereas in the other seven asymptomatic neonatal MRSA carriers (Group 2), these cells expressed CD45RO at the control level and were highly responsive to stimulation with TSST-1. The serum anti-TSST-1 IgG Ab titer was negligible in the four NTED patients in the acute phase and the three asymptomatic neonatal MRSA carriers in Group 1, but it was high in the seven asymptomatic carriers in Group 2. We suggest that maternally derived anti-TSST-1 IgGs helps to suppress T-cell activation by TSST-1 and protects infants from developing NTED.

Download full-text


Available from: Ken'ichi Imanishi,
  • Source
    • "NTED has been observed in over 70% of the major neonatal care units in Japan, although the condition has not been described elsewhere except for a single case in France [6] [19] [20]. The condition resolves spontaneously without antibiotic therapy in full-term neonates, but most preterm neonates develop severe symptoms, with two deaths in the latter group reported to date [6] [19]. Treatment involves supportive measures and, in the case of premature neonates, antistaphylococcal antibiotics. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Over the last several decades, a number of previously known or newly described species of gram-positive bacteria have emerged as important human pathogens, particularly in industrialized countries. These microbes have demonstrated an impressive ability to produce an array of striking infectious diseases never before seen or only infrequently encountered in the past. Despite aggressive therapeutic intervention, many of these conditions portend significant morbidity and mortality. Diseases caused by members of the Staphylococcus and Streptococcus genera have figured prominently in this regard, with Staphylococcus aureus, S. epidermidis, Streptococcus pyogenes, and other beta-hemolytic streptococci being regarded as the most important species. This review focuses on the clinical and microbiologic aspects of key emerging infections caused by this group of microorganisms.
    Clinics in Laboratory Medicine 10/2004; 24(3):587-603, v. DOI:10.1016/j.cll.2004.05.007 · 1.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Excessive release of proinflammatory cytokines mediates the toxic effect of superantigenic staphylococcal exotoxins (SE). Baicalin, a flavone isolated from the Chinese herb Scutellaria baicalensis Georgi and used in China to treat infectious diseases, inhibited SE-stimulated T-cell proliferation (by 98%) and production of interleukin 1beta, interleukin 6, tumor necrosis factor, interferon gamma, monocyte chemotactic protein 1, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta mRNA and protein by human peripheral blood mononuclear cells. These data suggest that baicalin may be therapeutically useful for mitigating the pathogenic effects of SE by inhibiting the signaling pathways activated by superantigens.
    FEBS Letters 07/2001; 500(1-2):52-5. DOI:10.1016/S0014-5793(01)02584-4 · 3.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a high accuracy robust position controller for linear permanent magnet synchronous servo motor in which, the H<sub>∞</sub> control theory is applied to design a feedback controller so as to guarantee the robust stability and performance of the closed-loop system. Linear feedback control theory is applied to make up the position feedback loop being gradually stable. An IP controller with high response ability for reference signals under the higher integral gain and high restraint ability for load disturbance is applied to improve the performance of the closed loop system. Based on a nominal model of the plant, an IP controller is designed in order to meet the position systems performance requirements. As a result, the controller not only guarantees system robustness, but also guarantees system following performance. The simulation results show that the controller presented in this paper is reasonable and effective.
    Advanced Motion Control, 2002. 7th International Workshop on; 02/2002
Show more