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Comparative Analysis of Immune Responses in Pigs to High and Low Pathogenic Porcine Reproductive and Respiratory Syndrome Viruses Isolated in China
Author(s) -
Han Z.,
Liu Y.,
Wang G.,
He Y.,
Hu S.,
Li Y.,
Shi W.,
Wu J.,
Wang S.,
Liu H.,
Cai X.
Publication year - 2015
Publication title -
transboundary and emerging diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.392
H-Index - 63
eISSN - 1865-1682
pISSN - 1865-1674
DOI - 10.1111/tbed.12190
Subject(s) - porcine reproductive and respiratory syndrome virus , immune system , biology , cytokine , immunology , immunity , virus , virology , respiratory system , highly pathogenic , interferon , interleukin , interleukin 10 , influenza a virus subtype h5n1 , anatomy
Summary The CH ‐1a and HuN4 strains of porcine reproductive and respiratory syndrome virus ( PRRSV ) show different pathogenicities in pigs. To understand host immune responses against these viruses, we investigated the dynamic changes in cytokine levels produced in peripheral blood of piglets infected with the highly pathogenic PRRSV HuN4 strain or the CH ‐1a strain. Clinical signs, virus loads and serum cytokine levels [interferon( IFN )‐α, Interleukin ( IL )‐1, TNF ‐α, IL ‐6, IL ‐12, IFN ‐γ, IL ‐10 and TGF ‐β] were tested. The results showed that while piglets developed effective cellular immune responses against CH ‐1a infection, those infected with HuN4 displayed ineffective cellular immunity, organ lesions and persistent elevated levels of immunoregulatory cytokines ( IL ‐10 and TGF ‐β), which delayed the development of PRRSV ‐specific immune responses. These results demonstrated that HuN4 infection induced higher cytokine levels than that of CH ‐1a infection induced. The changes in inflammatory cytokines intensified the inflammatory reaction and damaged the tissues and organs.