In Vivo Efficacy of Neuropeptide S on the Expression of Cytokines Indeced by Influenza A Virurs in Ducks

摘要

Neuropeptide S(NPS)is involved in severe pathological processes.Direct evidence showed NPS regulates the secretion of proinflammatory cytokines in pigs.This study investigated the effect of NPS on the secretion of inflammatory cytokines in ducks with H9N2 infection via intramuscular injection with NPS or NPS receptor(NPSR)antagonist.The ducks received 15 nM NPS or 10 nM NPSR antagonist in saline.Samples were collected to analyze the expression levels of IL-1β,IL-6,TNF-α,IFN-α,NPS,and the H9N2 gene NP by RT-PCR and real time RT-PCR;samples were fixed to observe the histopathological changes by hematoxylin-eosin staining.Serial blood samples were collected(every 30 min,starting 1 h before injections and lasting until 2 h after injections)to measure the serum levels of IL-1β,IL-6,TNF-α,and IFN-αby ELISA.Semiquantitative RT-PCR confirmed that the expression of NPS mRNA was increased in H9N2 infection group.Morphological data showed NPS treatment could reverse the pathological changes in the duck bursa induced by H9N2 infection.Both the results of real time quantitative RT-PCR and ELISA methods showed NPS and NPSR antagonist treatments could significantly regulate the expression of IFN-α,but not of IL-1β,IL-6 and TNF-α;meanwhile,the levels of increased IFN-α and decreased NP were further prompted by NPS,and NPSR antagonist revered.Conclusion,NPS is involved in the innate immunity response to H9N2 infection via the IFN-αpathway in ducks in vivo.These results indicate NPS affects the immune homeostasis and provides an alternative for anti-H9N2 drugs.