Swine virus-specific cytotoxic cells producing IFNγ under different conditions of virus antigenic stimulation

摘要

Flow cytometry is a useful tool to determine both the phenotype and function of immune cells during vaccination and viral infection. Since cytokine release is a hallmark of cell activation, detection of intracellular interferon (IFN)γ in cytotoxic CD8α+ cells under physiological conditions and after Aujeszky’s Disease Virus (ADV)- or Porcine Circovirus type 2 (PCV2)-swine interaction was carried out. Blood samples were collected from healthy 10-month-old pigs, ADV- or PCV2-vaccinated pigs, and PCV2-infected pigs; the levels of total IFNγ+ and CD8α+IFNγ+ cells were evaluated after PMA-ionomycin and virus-specific in vitro stimulation. High CD8α+IFNγ+ cell levels were detected in adult pigs, whereas lower virus-specific cell fractions were observed after ADV or PCV2 vaccination as well as after PCV2 natural infection due to restricted activation. Such results support the use of cytokine intracellular staining to monitor virus-specific cell-mediated immunity.