Baculovirus AcMNPV induces type I interferons and NK/NKT cells-mediated protection against foot-and-mouth disease virus in mice

CACCIABUE, MARCO; MOLINARI, PAULA; MOLINA, GUIDO NICOLÁS; TABOGA, OSCAR; GISMONDI, MARÍA INÉS

ANTIVIRAL RESEARCH

ELSEVIER SCIENCE BV

Año: 2020 vol. 180

0166-3542

Foot-and-mouth disease is a viral illness that affects cloven-hoofed animals causing serious economic losses.Inactivated vaccines against its causative agent, foot-and-mouth disease virus (FMDV), require approximatelyseven days to induce protection. Therefore, antiviral strategies are needed to provide earlier protection and tostop the spread of this highly contagious virus during outbreak situations. In this way, our group has previouslydemonstrated that the baculovirus (BV) Autographa californica multiple nucleopolyhedrovirus (AcMNPV), aninsect virus with immunostimulant effects, induces a nonspecific antiviral status that protects C57BL/6 miceagainst a lethal challenge with FMDV A/Arg/01 at 3 hours or 3 days post inoculation. In this work, we studiedthe immunological mechanisms involved in this protection. Firstly, we compared the protection elicited byAcMNPV in wild type mice and in knock-out mice lacking the subunit IFNAR1 of the receptor for type I interferons(IFNs). Our results showed that type I IFNs are key to prevent the death of the animals after the FMDVchallenge. On the other hand, we evaluated the role of NK and NKT cells by depleting these cell subsets with anti-NK1.1 monoclonal antibody. These cells proved to be necessary for the induction of IFN-γ by AcMNPV and toprevent the onset of a severe disease after the FMDV challenge. We propose BV as a novel tool for the developmentof antiviral strategies because of the high levels of IFNs induced and the NK/NKT cells-mediated immuneresponse elicited.