Discovery of a novel adjuvant for oral vaccine formulations

CASTRO, CELESTE PUEBLAS; CORIA, LORENA; BRUNO LAURA; SAPOSNIK, LUCAS; PHILIPPE HERMAND; STÉPHANE TEMMERMAN; KARINA A. PASQUEVICH; CASSATARO JULIANA

Mar del Plata

Congreso; Reunión Conjunta de Sociedades de Biociencias SAIC ? SAI ? FAIC - SAFI; 2022

SAIC SAI FAIC

In our laboratory, we have shown that U-Omp19 from Brucella spp. is an oral vaccine adjuvant because it can inhibit gastrointestinal proteases while it induces adaptive immune responses. To our knowledge there are no other reports describing the use of protease inhibitors from bacteria as vaccine adjuvants. Thus, to discover new oral adjuvants we performed an in-silico and in vivo screening of different bacterial protease inhibitors where Ecotin from Salmonella spp. was selected as a candidate.Here, we evaluate if this protease inhibitor could be used as an adjuvant for oral vaccines. For this aim, we orally immunized BALB/c or C57BL/6 mice with two different viral antigens (Ags) simultaneously or both co-administered with Ecotin.When co-administered with the Ags, Ecotin induced a sustainable specific IgA response in feces compared to the administration of Ags alone (p