EXTRACELLULAR VESICLES DERIVED FROM ANTIGEN PRESENTING CELLS PULSED WITH INACTIVATED FOOT AND MOUTH DISEASE VIRUS EXPRESS A HIGH LEVEL OF VIRAL PROTEINS AND INDUCE A SPECIFIC ANTIVIRAL RESPONSE.

WALDNER C, ; FERELLA A; COCOZZA F; SAMPEDRO P; MENAY F ; ELISEI A; MONGINI C

Congreso; 10 annual Meeting ISEV2021 VIRTUAL; 2021

Foot and mouth disease (FMD) is a worldwide economically important infectioncaused by FMD-virus (FMDV).The main strategy for the control is vaccinationwith FMDV chemically inactivated with binary ethylenimide (FMDVi). In FMDVinfection and in vaccination, the B cell response plays a major role by providingneutralizing/protective antibody in both animal models and natural hosts. EVssecreted by antigen presenting cells (APC) participate in the activation of B andT cells through the presentation of native antigen membrane associated (to Bcells) or by transferring MHC-peptide complexes (to T cells) and even completeantigen from DCs.We aimed to evaluate the immune properties of EVs derived from APC pulsedwith FMDVi in a murine model. APC differentiated from bone marrow cellsinternalized FMDVi labelled with FITC after incubation for 60 min. EVs wereisolated after 24h from APC pulse with FMDVi. By flow cytometry EVsexpressed the EVs (CD9, CD81, CD63) and APC markers (MHC-II and CD86).Remarkably, FMDV antigens were expressed on >89% EVs.We demonstrated that EVs-FMDVi induced specific proliferation in vitro insplenocytes sensitized with FMDVi, EVs-FMDVi induced specific B cell (16.05%± 0.61 p