Porcine reproductive and respiratory syndrome virus induces CD4+CD8+CD25+Foxp3+ regulatory T cells (Tregs)

Abstract

The aim of this study was to analyze the regulatory T cells (Tregs) induced by the porcine reproductive and respiratory syndrome virus (PRRSV) in pigs. Serum, blood, tonsil, and mediastinal lymph nodes' samples were obtained at different time post-infection (dpi). The frequencies of CD4(+)CD8(-)CD25(+)Foxp3(+), CD4(+)CD8(+)CD25(+)Foxp3(+), or CD4(-)CD8(+)CD25(+)Foxp3(+) phenotypes were determined in PBMC and lymph node cells, and cells producing IL-10 or TGF-β were analyzed. PRRSV increased the number of CD4(+)CD8(+)CD25(+)Foxp3(+) cells at 14 dpi, whereas CD4(+)CD8(-)CD25(+)Foxp3(+) remained constant until 28 dpi. Positive correlation exists between viremia and induced regulatory cells. CD4(+)CD8(+)CD25(+)Foxp3(+)-induced Treg cells were consistently observed in lymphoid tissues. Analysis of IL-10- and TGF-β-producing cell demonstrated that in response to PRRSV, CD4(+)CD8(-)Foxp3(low) and CD4(+)CD8(+)Foxp3(high) cells increase moderately the proportion of IL-10(+) cells. TGF-β was only observed in the CD4(+)CD8(+)Foxp3(high) population after PRRSV stimulation. In conclusion, PRRSV infection increases the frequency of Tregs with the phenotype CD4(+)CD8(+)CD25(+)Foxp3(high) and produces TGF-β.

The effects of dietary deoxynivalenol (DON) on selected blood biochemical and hematological parameters in pre-pubertal gilts

“…This inhibitory effect could be caused by the "escape" of signal molecules, such as NO and DON, from stimulation of the local and general immune system. A similar situation is observed when Treg cells are induced by pathogens (Silva-Campa et al 2012) during chronic infections, which could be regarded as a case of food tolerance (Maresca and Fantini 2010). Our findings seem to suggest that low (below NOAEL) doses of DON could deliver therapeutic effects (Alassane-Kpembi et al 2013).…”

The effect of selected environmental Fusarium mycotoxins on the ovaries in the female wild boar (Sus scrofa)

“…Clinical intoxication levels are not proportional to the ingested dose, which is consistent with the low-dose hypothesis proposed by Vandenberg et al (2012). The induction of regulatory T cells (Tregs) is one of the mechanisms used by pathogens to escape the immune response (Silva-Campa et al 2012). The above is observed during chronic or permanent infections of low intensity, and it could be regarded as a form of nutritional adaptation.…”

Evaluation of the proliferative activity of immunocompetent cells in the jejunal and iliac lymph nodes of prepubertal female wild boars diagnosed with mixed mycotoxicosis

“…The immune system of boars is probably more tolerant to low mycotoxin doses, or such doses do not provoke a response to toxic substances ingested in small amounts with feed, in accordance with the Tregs hypothesis (25); this is because wild boars are omnivorous scavengers which do not eat a monodiet. Therefore, the species can tolerate widely varying levels of undesirable substances, including mycotoxins, at least in initial stages of exposure, as at the dose levels applied in our study, the exposure period of 7 d was very short not only for PFWBs.…”