Subversion of interleukin-1-mediated host defence by a nasal carrier strain of Staphylococcus aureus.
Staphylococcus aureus, a major source of nosocomial and community-acquired infections, has a nasal carriage rate exceeding 25% in the human population. To elucidate host-pathogen interactions pertaining to nasal carriage, we examined the role of interleukin-1 (IL-1) in the colonization of human nasal epithelial cells (NEC) by a nasal carrier strain and a non-carrier strain of S. aureus. Using an organotypic model of the nasal epithelium, we observed that inoculation with a non-carrier strain of S. aureus induced production of IL-1 from NEC, but the expression of this cytokine was significantly reduced when NEC were inoculated with a carrier strain. Moreover, both IL-1alpha and IL-1beta significantly decreased the growth of the nasal carrier strain of S. aureus (P < 0.001, n = 17 to n = 25); however the growth of the non-carrier strain was unaffected. Interestingly, it was found that several nasal carrier strains of S. aureus form quorum-dependent biofilms, which can be partially inhibited when preincubated with IL-1alpha. Taken together these data suggest that, although nasal carrier strains of S. aureus are sensitive to IL-1, they display a significant colonization advantage by both preventing the host from expressing IL-1 and elaborating a protective biofilm.
Quinn
Gerry A
GA
Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
Tarwater
Patrick M
PM
Cole
Alexander M
AM
D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D002353:Carrier State / Q000276:immunology*; D002460:Cell Line; D054884:Host-Pathogen Interactions / Q000187:drug effects / Q000276:immunology; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000276:immunology / Q000494:pharmacology; D016753:Interleukin-10 / Q000276:immunology / Q000494:pharmacology; D053582:Interleukin-1alpha / Q000276:immunology* / Q000494:pharmacology; D053583:Interleukin-1beta / Q000276:immunology* / Q000494:pharmacology; D009297:Nasal Mucosa / Q000276:immunology* / Q000382:microbiology; D013203:Staphylococcal Infections / Q000276:immunology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000494:pharmacology
C508609:IL10 protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10