Dietary conjugated linoleic acid and its effect on immune response in pigs infected with the porcine reproductive and respiratory syndrome virus

• We evaluated the effect of dietary CLA on immune response in PRRSV infected pigs.
• Dietary CLA boost the TNF-α production in pigs infected with PRRSV.
• Inflammation mediators and PPAR-γ were not affected by CLA in infected pigs.

The aim of this study was to evaluate the effects of dietary conjugated linoleic acid (CLA) on immune response in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). A total of 18 pigs 4 weeks of age were allocated to 3 treatments, 6 per treatment: 0% CLA, 1% CLA, and 2% CLA. Serum IL-1β, IL-6 and TNF-α; lymphocyte proliferation; and IL-2, IFN-γ, IL-10, IL-4 and IL-12 in PBMCs were evaluated. NF-κB, COX2, iNOS and PPAR-γ mRNA were also evaluated. No differences were observed among treatment groups in most of the in vivo cytokine profiles; only TNF-α production was increased in infected pigs in the CLA-supplemented groups. The cytokine profile in vitro was not affected by CLA supplementation. CLA decreased the proliferation of PBMCs stimulated with PRRSVs. Inflammation mediators and PPAR-γ were not affected by CLA in infected pigs. CLA did not improve the immune response of PRRSV infected pigs.