Effect of the pre-exposition of rats' airways with staphylococci enterotoxin type B (SEB) on pulmonary allergic inflammation

Abstract

Introduction: The staphylococci enterotoxin (SEs) are produced and secretedby some kind of Staphylococcus aureus. The asthma is a disease characterized by a chronicinfl ammatory response of the airways. The systemic administration of SEB in rabbits causesa pulmonary infl ammation characterized by leukocytes infi ltration, endothelium damage andincrease of vascular permeability. Materials and Methods: Rats were submitted to a protocolthat they were sensitized with ovalbumin (OVA) and after 14 days they received a nasal instillationof PBS or SEB or LPS. After 4 hours the rats received a new nasal instillation of PBS or OVAand after 24 hours the bronchoalveolar lavage (BAL) were obtained. The total and differentialcount was done and the results were submitted to a statistical analysis. Results: The neutrophilinfl ux was larger in those animals that received SEB and OVA than those animals that receivedonly SEB or only OVA. In those animals that received LPS, the levels of TNF-α were larger inanimals submitted to the protocol of allergic infl ammation caused by OVA. Conclusion: Thepre-administration of SEB or LPS promoted a neutrophil infl ux, but not an eosinophil infl ux.SEB and LPS seems to act of different mechanism in the neutrophil infl ux.