Imunologic response in pigs with naturally acquired postweaning multisystemic wasting syndrome

The composition of peripheral blood leukocyte populations was studied in 10-week-old pigs with naturally acquired postweaning multisystemic wasting syndrome. Twenty PMWS diseased pigs were selected from the farm with evidenced PMWS and ten clinically healthy pigs were selected from the farm without history of PMWS as a control group. Pigs from both groups were seronegative for porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), and Aujeszky's disease virus (ADV). For the triple labeling flow cytometric analysis PBMC were incubated with mAb against porcine CD3, CD4, CD8 and SWC3. A lower proportions of CD3+CD4-CD8+ CTLs, CD3− CD4− CD8+ NK cells and CD3+SWC3+ monocytes was notable in PMWS diseased pigs. In diseased pigs an increase in proportions and numbers of CD3+CD4+CD8- Th and CD3+CD4− CD8− /low γ δ T cells was recorded. Porcine circovirus type 2 (PCV2) infection clearly induced an immunossuppresion by inhibiting leukocyte subsets of direct antiviral response.