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Mediators of Inflammation
Volume 2014, Article ID 468285, 13 pages
http://dx.doi.org/10.1155/2014/468285
Research Article

The Impact of Staphylococcus aureus-Associated Molecular Patterns on Staphylococcal Superantigen-Induced Toxic Shock Syndrome and Pneumonia

1Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA
2Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
3Division of Infectious Diseases, Mayo Clinic, Rochester, MN 55905, USA
4Department of Immunology and Division of Infectious Diseases, Mayo Clinic College of Medicine, 200 First Street, SW, Rochester, MN 55905, USA

Received 30 January 2014; Revised 25 March 2014; Accepted 29 March 2014; Published 12 June 2014

Academic Editor: Ronald Gladue

Copyright © 2014 Ashenafi Y. Tilahun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Staphylococcus aureus is capable of causing a spectrum of human illnesses. During serious S. aureus infections, the staphylococcal pathogen-associated molecular patterns (PAMPs) such as peptidoglycan, lipoteichoic acid, and lipoproteins and even intact S. aureus, are believed to act in conjunction with the staphylococcal superantigens (SSAg) to activate the innate and adaptive immune system, respectively, and cause immunopathology. However, recent studies have shown that staphylococcal PAMPs could suppress inflammation by several mechanisms and protect from staphylococcal toxic shock syndrome, a life-threatening systemic disease caused by toxigenic S. aureus. Given the contradictory pro- and anti-inflammatory roles of staphylococcal PAMPs, we examined the effects of S. aureus-derived molecular patterns on immune responses driven by SSAg in vivo using HLA-DR3 and HLA-DQ8 transgenic mice. Our study showed that neither S. aureus-derived peptidoglycans (PGN), lipoteichoic acid (LTA), nor heat-killed Staphylococcus aureus (HKSA) inhibited SSAg-induced T cell proliferation in vitro. They failed to antagonize the immunostimulatory effects of SSAg in vivo as determined by their inability to attenuate systemic cytokine/chemokine response and reduce SSAg-induced T cell expansion. These staphylococcal PAMPs also failed to protect HLA-DR3 as well as HLA-DQ8 transgenic mice from either SSAg-induced toxic shock or pneumonia induced by a SSAg-producing strain of S. aureus.