ENTEROHEMORRHAGIC Escherichia coli O157:H7 STIMULATES HUMAN NEUTROPHILS TO RELEASE NEUTROPHIL EXTRACELLULAR TRAPS (NETS)

SHIROMIZU, CAROLINA MAIUMI; MIGLIO RODRIGUEZ, MAXIMILIANO S.; RAMOS, M.VICTORIA; TREVANI, ANALÍA S.; KEITELMAN, IRENE A.; FUENTES, FEDERICO; JANCIC, CAROLINA C.; SABBIONE, FLORENCIA; BRUBALLA, ANDREA; GALLETI, JEREMIAS G.; PALERMO, MARINA

Tucumán

Congreso; LXVII Reunión científica anual de la Sociedad Argentina de Inmunología; 2019

SAI

Shiga toxin (Stx)-producing Escherichia coli (STEC) can cause diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). These non-invasive bacteria colonize the intestine where they release Stx, which after reaching the bloodstream causes the events of the HUS.Neutrophilia and neutrophil infiltration of gastrointestinal tissues are found in these patients. We previously demonstrated that Stx induces NETosis. Our aim was to determine if in response to STEC neutrophils also release NETs, which in the gut might contribute to bacterial entrapment and killing but also to increase inflammation.We isolated human blood neutrophils and co-cultured them without or with E.coli O157:H7(E.coli Stx+) or with the isogenic strain incapable to produce Stx (E.coli Stx-) at MOI 1 or 10. By immunostaining and confocal microscopy we determined that both strains stimulated the release of DNA which colocalized with myeloperoxidase (MPO) (n=3). DNA and MPO levels were significantly higher than the basal condition when neutrophils were stimulated with bothbacterial strains (DNA n=6, p