¹Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

Correspondence: Jacek Hawiger, Department of Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Avenue South, A-5321 Medical Center North, Nashville, Tennessee 37232-2363, USA. E-mail: jacek.hawiger@vanderbilt.edu

Received 9 June 2008; Accepted 20 January 2009; Published online 3 March 2009.

Abstract

Acute lung inflammation is a potentially life-threatening complication of infections due to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), a worldwide emerging pathogen, which causes necrotizing pneumonia and acute respiratory distress syndrome (ARDS). MRSA virulence factors encompass immunotoxins termed superantigens that contribute to lung inflammation. In this study, we demonstrate that staphylococcal enterotoxin B (SEB)-induced lung inflammation is attenuated by a cell-penetrating peptide nuclear import inhibitor of nuclear factor (NF)-B and other stress-responsive transcription factors (SRTFs). This inhibitor suppressed production of a wide spectrum of cytokines and chemokines induced by direct SEB airway exposure. Consequently, trafficking of neutrophils, monocytes/macrophages, and lymphocytes to the bronchoalveolar space was significantly reduced while vascular injury, manifested by increased permeability and protein leakage, was attenuated. Moreover, induction of systemic proinflammatory cytokines and chemokines in response to direct SEB airway exposure was reduced. Thus, intracellular delivery of a nuclear import inhibitory peptide suppresses respiratory and systemic expression of key mediators of lung inflammation evoked by SEB.