Effect of moxifloxacin and human beta-defensin 2 on ICAM-1 and cytokines expression in human lung epithelial cell line

Abstract number: 1733_1258

Tufano M., Paoletti I., Perfetto B., Iovene M., Tudisco L., Donnarumma G.

Interaction of pathogenic bacteria with airway epithelium is usually an essential step in the infectious process. Epithelia in the human airways, from the nasal aperture to the alveoli, are covered in a protective film of fluid containing a number of antimicrobial proteins.

Antimicrobial peptides have been identified as key elements in the innate host defence against infection. Defensins are single chain strongly cationic peptides of molecular weight 3000–4500 and are one of the most extensively studied classes of antimicrobial peptides. In the airways, the antimicrobial peptide human beta-defensin 1 (HBD1) is constitutively expressed by epithelia at low levels while the related peptide human beta-defensin 2 (HBD2) is predominantly induced at sites of inflammation.

A number of antibiotics have been found to have significant immunomodulatory properties both in vitro and in vivo in animal models. Moxifloxacin (MXF) is a fluoroquinolone with activities against both Gram-positive and Gram-negative bacteria. It has been suggested that MXF has inhibitory and stimulatory effects on the immune system. Our data demonstrate that HBD2 stimulation produces a remarkable increase of ICAM-1 protein expression, but does not induce proinflammatory cytokines expression. In contrast, the costimulation with MXF/HBD2 induces a different production of proinflammatory cytokines (IL-8, IL-1 and IL-6). Moreover, the adhesion of PMN to airway epithelium is increased over either baseline when stimulated with HBD2 or with MXF/HBD2. These data indicate that the association of MXF/HBD2 can play a crucial role during the infectious processes determining a balanced release of proinflammatory cytokines and adhesion molecules, possessing chemotactic activity for neutrophils.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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