Frontiers in Microbiology (Jun 2021)

RIPK3-Dependent Necroptosis Limits PRV Replication in PK-15 Cells

  • Hongchao Gou,
  • Hongchao Gou,
  • Hongchao Gou,
  • Hongchao Gou,
  • Zhibiao Bian,
  • Zhibiao Bian,
  • Zhibiao Bian,
  • Zhibiao Bian,
  • Rujian Cai,
  • Rujian Cai,
  • Rujian Cai,
  • Rujian Cai,
  • Pinpin Chu,
  • Pinpin Chu,
  • Pinpin Chu,
  • Pinpin Chu,
  • Shuai Song,
  • Shuai Song,
  • Shuai Song,
  • Shuai Song,
  • Yan Li,
  • Yan Li,
  • Yan Li,
  • Yan Li,
  • Zhiyong Jiang,
  • Zhiyong Jiang,
  • Zhiyong Jiang,
  • Zhiyong Jiang,
  • Kunli Zhang,
  • Kunli Zhang,
  • Kunli Zhang,
  • Kunli Zhang,
  • Dongxia Yang,
  • Dongxia Yang,
  • Dongxia Yang,
  • Dongxia Yang,
  • Chunling Li,
  • Chunling Li,
  • Chunling Li,
  • Chunling Li

DOI
https://doi.org/10.3389/fmicb.2021.664353
Journal volume & issue
Vol. 12

Abstract

Read online

Pigs infected by pseudorabies virus (PRV) display necrotic pathology in multiple organs. The mechanism by which PRV induces cell death is still unclear. Recently, necroptosis was identified as a programmed process dependent on the receptor interacting protein kinase 3 (RIPK3) and mixed lineage kinase-like protein (MLKL). In this study, we demonstrated that PRV induced RIPK3-dependent necroptosis in PK-15 cells. The data showed that PRV infection caused cell death with Propidium Iodide (PI)-positive staining. Transmission electron microscopy analysis indicated plasma membrane disruption in PRV-infected cells. A pan-caspase inhibitor did not prevent PRV-induced necrotic cell death. Western blot analysis indicated that caspase-3 and caspase-8 were not cleaved during PRV infection. Although the transcription of tumor necrosis factor-alpha (TNF-α) was increased by PRV infection, RIPK1 was shown to be not involved in PRV-induced necrotic cell death by use of its specific inhibitor. Further experiments indicated that the phosphorylation of RIPK3 and MLKL was upregulated in PRV-infected cells. Stable shRNA knockdown of RIPK3 or MLKL had a recovery effect on PRV-induced necrotic cell death. Meanwhile, viral titers were enhanced in RIPK3 and MLKL knockdown cells. Hence, we concluded that initiation of necroptosis in host cells plays a limiting role in PRV infection. Considering that necroptosis is an inflammatory form of programmed cell death, our data may be beneficial for understanding the necrotic pathology of pigs infected by PRV.

Keywords