Porcine circovirus type 2 increases IL-1β and IL-10 production via the MyD88?NF-κB signaling pathway in porcine alveolar macrophages in vitro
Junyuan Han, Shuxia Zhang, Yaqun Zhang, Mengmeng Chen, Yingjun Lv*
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
Correspondence to: Tel: +86-25-8439-5316; Fax: +86-25-8439-8669; E-mail: shuxia@njau.edu.cn
Received: December 4, 2015; Revised: March 17, 2016; Accepted: June 8, 2016; Published online: July 25, 2016.
Abstract
Porcine alveolar macrophages represent the first line of defense in the porcine lung after infection with porcine circovirus type 2 (PCV2) via the respiratory tract. However, PCV2 infection impairs the microbicidal capability of PAMs and alters cytokine production and/or secretion. Currently, the reason for the imbalance of cytokines has not been fully elucidated and the regulatory mechanisms involved are not clear. Here, we investigated the expression levels and regulation of IL-1β and IL-10 in PAMs following incubation with PCV2 in vitro. Both levels of IL-1β and IL-10 increased in PAM supernatants, and the distribution of NF-κB p65 staining in the nucleus, the expression of MyD88 and p-IκB in the cytoplasm and the DNA-binding activity of NF-κB increased after incubation with PCV2, while the expression of p65 in the cytoplasm of PAMs decreased. However, when PAMs were co-incubated with PCV2 and small interfering RNA targeting MyD88, these effects were reversed. Additionally, mRNA expression levels of Toll-like receptor (TLR)-2, -3, -4, -7, -8 and -9 were increased when PAMs were incubated with PCV2. These findings showed that PCV2 induced increased IL-1β and IL-10 production in PAMs, and these changes in expression were relative to the TLR?MyD88?NF-κB signaling pathway.
Keywords: IL-1β, IL-10, NF-κB, PCV2, porcine alveolar macrophage


© 2016 The Korean Society of Veterinary Science.