Figure 4.

A simulation model describes the mechanisms of PCV2 ORF3-induced apoptosis (Pan et al., 2018). On the one hand, the PCV2 ORF3 protein induces apoptosis through the death receptor pathway via the activation of caspase 8 and caspase 3. On the other hand, the interaction of the ORF3 protein and pPirh2 causes the accumulation of p53 and then upregulates factors downstream of p53 to induce apoptosis. The ORF4 protein inhibits apoptosis by suppressing the activation of ORF3. And by interacting with FHC, which has been suggested to prevent cells from undergoing apoptosis induced by a variety of stimuli, it can ultimately suppress apoptosis by inhibiting the production of ROS.