B. parapertussis suppresses proinflammatory citoquines-mediated NETs-induction released by epithelial cells during infection.

GORGOJO, JUAN PABLO; LAMBERTI, YANINA; OVIEDO, JUAN MARCOS; RODRIGUEZ, MARIA EUGENIA

Mar del Plata

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Inmunología (SAI).; 2016

Sociedad Argentina de Inmunología (SAI).

Recent studies demonstrated that B. pertussis (Bp) has theability to inhibit neutrophil extracellular traps (NETs) formationin response to the proinflamatory stimulus of IL-8. However,this cytoquine is a weak inducer of NETs. Moreover, in ourhands, IL-8 alone does not induce significant NETosis even atsupraphysiological concentrations (1000 ng/ml). Since, Bp mightbe exposed to a more complex, usually stronger NETs-inducerstimulus in vivo, we here investigated the interaction of Bp wi thepithelial cells and its relevance in NETs production. We usedthe 16HBE14o- epithelial cell line derived from human bronchialepithelium, which retains differentiated epithelial morphologyfeatures and functions. We found that 16HBE14o- epithelialcells secrete IL-8, IL-6 and TNF-á in response to Bp infection,as determined by ELISA. By mean of DNA labeling withpropidium iodide, antibodies against NET-associated proteins,and fluorescence microscopy we observed that conditionedmedium, obtained after incubation of bacteria with 16HBE14ocells,induced NETs release. Our results show that the NETsinducerstimulus associated to bacterial infection of epithelialcells can be inhibited by Bp. This effect proved dependent onCyaA-mediated ROS inhibition activity as determined by blockingantibodies against this toxin. These results show that Bp isable to control this essential neutrophil bactericidal mechanism even in a complex proinflammatory environment. Together withprevious results these data highlight the role of CyaA in Bp evasionof the immune response against this bacterium.