Cytokine and C-Reactive Protein Profiles Induced by Porcine Circovirus Type 2 Experimental Infection in 3-Week-Old Piglets

Abstract

The purpose of this study was to determine serum profiles of cytokines at a protein level and Creactive protein (CRP) during the development of postweaning multisystemic wasting syndrome (PMWS) in experimentally inoculated pigs. Levels of serum IFN-alpha, IL-6, IL-10, and CRP were examined for a 35-day period in 10 piglets experimentally infected with PCV2 at 3 weeks of age. Four of the infected piglets developed severe PMWS at 14 to 21 days post-infection (d.p.i.) and died prior to termination of the experiment. The remaining six PCV2-infected piglets experienced transient fever, but did not display overt clinical signs of PMWS and were considered as subclinically infected. A bioassay was used to detect IL-6 and ELISAs were used to detect IFN-alpha, IL-10, and CRP. There were no significant differences in cytokine or CRP expression from 0 to 7 d.p.i. between the PMWS-affected and the subclinically infected piglets. Levels of IL-10 and CRP were elevated from 10 and 14 d.p.i. respectively in the PMWS-affected piglets compared to the subclinically infected piglets. There were no significant differences in IFN-alpha and IL-6 expression between the PMWS-affected piglets and the subclinically infected piglets. The present study shows that elevated levels of serum CRP and IL-10 were associated with PCV2-infected piglets that subsequently developed severe PMWS. This may help to provide further insight into the immunoaetiogenesis of this syndrome.

Effects of porcine circovirus type 2 and pseudorabies vaccine co-inoculation on regulatory cytokine mRNA expression in pig peripheral blood mononuclear cells

“…Many studies have revealed that the induction of IL-10 upregulation is one of the basic characteristics of PCV2 (Darwich et al, 2003a;Segalés et al, 2004;Stevenson et al, 2006;Darwich et al, 2008). Our study further confirmed this phenomenon.…”

Porcine circovirus type 2-induced interleukin-10 modulates recall antigen responses

“…Previous studies (Darwich et al, 2003a, b;Hasslung et al, 2005;Stevenson et al, 2006) have shown that PCV2 may substantially alter unspecific cytokine responses and suggested that IL-10 might be one of the mechanisms by which these alterations take place. Based on these previous ex vivo and in vitro studies, the role of PCV2-induced IL-10 in immune disorders in PMWS could not be precisely determined.…”

“…Also, elevated systemic IL-10 mRNA levels have been reported in PMWSaffected pigs (Sipos et al, 2004); however, contradictory results on IL-10 mRNA levels have been described elsewhere (Sipos et al, 2005). In a recent report, serum IL-10 was associated with PCV2-infected piglets that subsequently developed PMWS (Stevenson et al, 2006). Non-replicating PCV2 can persist in dendritic cells (DCs) without affecting myeloid DC differentiation or antigen uptake and presentation (Vincent et al, 2005).…”

“…There is evidence that IL-10 may contribute to the development of PMWS. Thus, Stevenson et al (2006) reported that PMWS pigs show elevated levels of IL-10 in serum and Darwich et al (2008) showed that, in subclinically PCV2-infected pigs, a transient IL-10 response correlates with the viraemic phase of infection. Our in vitro results show that PCV2 induces IL-10, which in turn partially suppresses the IFN-c secretion stimulated by the PRV recall antigen.…”

Haptoglobin serum concentration is a suitable biomarker to assess the efficacy of a feed additive in pigs

“…Thus, increased serum levels of APPs have been reported in pigs experimentally infected with porcine reproductive and respiratory syndrome (PRRS) virus, porcine circovirus type 2, different serotypes of Actinobacillus pleuropneumoniae and Streptococcus suis (Heegaard et al, 1998;Asai et al, 1999;Hulten et al, 2003;Diaz et al, 2005;Sorensen et al, 2006;Stevenson et al, 2006). Serum APPs also increase in pigs naturally infected with A. pleuropneumoniae and in field cases of a Yolanda Saco and Lorenzo Fraile equally contributed to this paper.…”