TLR2-mediated NF-κB signaling pathway is involved in PPV1-induced apoptosis in PK-15 cells

Porcine parvovirus 1 (PPV1) mainly induces severe reproductive failure in pregnant swine, and causes huge economic losses to the swine industry. Cell apoptosis induced by PPV1 infection has been identified the major cause of reproductive failure. However, the molecular mechanism was not fully elucidated. In this study, the potential mechanism of PPV1 induced apoptosis in PK-15 cells was investigated. Our results showed that PPV1 induced apoptosis in PK-15 cells. Further studies revealed toll-like receptor 2 (TLR2) was involved in the PPV1-mediated apoptosis. TLR2 siRNA significantly decreased the apoptosis. Finally, our study showed NF-kappa B was activated by TLR2 during PPV1-induced apoptosis. The activation of NF-kappa B signaling was demonstrated by the phosphorylation of p65, p65 nuclear translocation and degradation of inhibitor of kappa B alpha (IKB alpha). Together, these results provided evidence that the recognition between PPV1 and PK-15 cells was mainly through TLR2, and then induction of the NF-kappa B signaling pathway activation, which further induces apoptosis. Our study could provide information to understand the molecular mechanisms of PPV1 infection.