Gene 3 induzido pelo vírus Epstein-Barr (EBI3) atua como regulador negativo da resposta imune frente à infecção por Neospora caninum

Abstract

Neospora caninum is a protozoan of apicomplexa phylum widespread around the world, that infects several species of mammals and birds and canids act as its definitive host. The infec-tion possess high economic importance due to the induction of abortion in bovine and neuro-muscular disease in dogs. Although, the number of information in the literature is limited exit evidence pointing on the essential role of the innate immune response against N. caninum, triggering an efficient adaptive response leading to infection control. The EBI3 gene codifies a glycoprotein which participates in two heterodimers formation, which are IL35 when com-bined with IL12p35 and IL27 when joined with IL27p28. Previous studies reported that IL27 can present distinct functions during infections by intracellular parasites. Considering the im-portance of this molecule during the infection by other pathogens, this study aimed to evalu-ate the importance of EBI3 during the infection by N. caninum using knockout mice. Follow-ing this premise, it was observed that EBI3 regulates negatively the early production of effec-tors molecules NO and ROS in the local of initial infection meanwhile promote the reduction of cytokines essential to induction of Th1 profile and production of total IgG and its’s sub-classes. Additionally, it was possible to observe that animals genetically deficient in the pro-duction of EBI3 (EBI3-/-) presented an enhanced survival and body weight recovery and a reduced parasite burden during the chronic phase of infection associated with increased in-flammation in the brain when compared to wild type mice. In conclusion, our results demon-strated that EBI3 is a negative regulator of the immune response against the infection by N. caninum.