Hypothalamus-pituitary-adrenal axis involves in anti-viral ability through regulation of immune response in piglets infected by highly pathogenic porcine reproductive and respiratory syndrome virus

Abstract

BackgroundThe highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has been responsible for several viral attacks in the Asian porcine industry, since the first outbreak in China in 2006. During the early stages of the HP-PRRSV infection, high levels of proinflammatory cytokines are noted in the host peripheral blood, which are accompanied by severe lesions in the lungs and immune system organs; these are considered as the greatest contributors to the overall disease burden. We hypothesized that the anti-PRRSV response in piglets might be mediated by the hypothalamus-pituitary-adrenal (HPA) axis, which led to a decrease in the psycho-neuroendocrinological manifestation of HP-PRRSV etiology via immune response regulation.ResultsWe investigated the regulation of the HPA axis in HP-PRRSV-infected piglets that were treated with 1 mg/kg body weight (b. w.)/day mifepristone (RU486) or 2 mg/kg b.w./day dexamethasone (DEX). Both RU486 and DEX enhanced the disease status of the piglets infected by the HP-PRRSV HuN4 strain, resulting in high mortality and more severe pathological changes in the lungs.ConclusionsHP-PRRSV infection activates the HPA axis, and artificial regulation of the immune-endocrine system enhances disease severity in HP-PRRSV-infected piglets. Thus, DEX and RU486 should be avoided in the clinical treatment of HP-PRRS.Electronic supplementary materialThe online version of this article (10.1186/s12917-018-1414-3) contains supplementary material, which is available to authorized users.

Effects of Injectable Administration of Dexamethasone Alone or in Combination with Vitamin E/Se in Newborn Low Birth Weight Piglets

“…As for the IM administration of both dexamethasone and vitamin E/Se combination in our study at the first 3 days of life, the use of dexamethasone could improve the growth of LBW piglets due to its beneficial effects on their digestive capability, metabolism, and reaction to stress [ 29 , 33 , 51 ]. In a recent study, it was reported that the use of dexamethasone in piglets infected by highly pathogenic PRRSV (HP-PRRSV) increases the disease severity and should be avoided in the clinical treatment of HP-PRRS [ 52 ]. In our study at an endemically PRRSV-infected farm, similar results were noticed using dexamethasone, as a significant reduction in growth performance and a high frequency of clinical findings were noticed in LBW piglets with IM administration of dexamethasone alone for the first 3 days of life.…”