Human neutrophil response to Shiga toxin

KEITELMAN, IRENE; GALLETI, MAURICIO; OSTROWSKI, MATIAS; TREVANI, ANALIA; CAROLINA MAIUMI SHIROMIZU; GUZMAN, MAURICIO; PEREYRA GERBER, PEHUEN; RAMOS, MARIA V.; SABBIONE FLORENCIA; MIGLIO, MAXIMILIANO; JANCIC, CAROLINA; PALERMO M

Mar del Plata

Congreso; SAIC - SAI - SAFIS 2018; 2018

SAI - SAIC

Shiga-toxin-producing E coli (STEC) infections can cause hemolytic uremic syndrome (HUS), a life-threatening condition. These non-invasive bacteria colonize the intestine where they release the Shiga toxin (Stx) which after reaching the blood stream and binding to Gb3Cer receptor, causes the characteristic events of the hemolytic uremic syndrome: hemolytic anemia, thrombocytopenia and renal failure. Recently, it has been proposed that Stx is transported in circulation in extracellular vesicles (EV) released by leukocytes and platelets. Neutrophilia is a typical finding in patients with HUS, and elevated neutrophil counts are considered a poor prognostic factor. The aim of this research is to determine if neutrophils (PMN) produce EV in response to Stx2 and to analyze its effects. 107 PMN isolated from human peripheral blood from healthy donors were incubated with Stx2 (0.1 µg/ml) or with vehicle for 4hs. Afterwards, supernatants were centrifugated at 16000 x g for 30 min to obtain the EV (EV-Stx or EV-Veh). Later, we studied their cytotoxic effect on VERO cells, as a parameter to determine the presence of Stx2 in the EV. The viability percentage of VERO cells cultured for 48hs with EV-Stx or EV-Veh was 83±X% and 69±X %, respectively (n=6; p