FLAGELLIN H7 AS A POTENTIAL VACCINE COMPONENT TO PREVENT H EMOLYTIC UREMIC SYNDROME

ALAN MAURO BERNAL; FERNANDO NICOLÁS SOSA; MARÍA FLORENCIA TODERO; MÓNICA VERMEULEN; DANIELA ROMINA MONTAGNA; ROMINA JIMENA FERNÁNDEZ-BRANDO; MARÍA VICTORIA RAMOS; AGUSTINA ERREA; MARTIN RUMBO; MARINA PALERMO

Mar del Plata

Congreso; Joint Meeting SAIC SAI&FAIC SAFIS 2022; 2022

SAIC SAI FAIC & SAFIS

Argentina has the highest global incidence of hemolyticuremic syndrome (HUS), a systemic complication secondaryto Escherichia coli O157:H7 (EHEC) infections.Local humoral response plays a key role in controlling intestinalcolonization of EHEC and preventing HUS. Thus,the objective of this work was to analyze the ability offlagellin H7 (H7) to induce a local protective response.For this, BALB/c mice were intranasally immunized with3 doses of purified H7 (10 μg/mouse) at 10-day intervals.At different times, stools and serum samples were takento analyze the levels of anti-H7 antibodies by ELISA. 21days post 3 rd immunization (dp3i) we studied ex vivothe specific proliferation of CFSE-stained lymphocytesfrom spleen (S) and lung-draining lymph nodes (LN) ofimmunized mice versus controls. The production of cytokineswas measured in the proliferation supernatantsto determine Th1/Th2/Th17 profile. To assess protection,immunized and control mice were challenged orally with10 5 colony-forming units of EHEC 21 dp3i. We observedsignificant levels of IgG and IgA anti-H7 in plasma and feces,respectively, in immunized mice at all times evaluatedfrom the 7th day after the 2 nd dose (p