Itakura, YukariYukariItakuraMatsuno, KeitaKeitaMatsunoIto, AsakoAsakoItoGerber, Markus DanielMarkus DanielGerberLiniger, MatthiasMatthiasLinigerFujimoto, YuriYuriFujimotoTamura, TomokazuTomokazuTamuraKameyama, Ken-IchiroKen-IchiroKameyamaOkamatsu, MasatoshiMasatoshiOkamatsuRuggli, NicolasNicolasRuggliKida, HiroshiHiroshiKidaSakoda, YoshihiroYoshihiroSakoda2024-10-052024-10-052020-01-15https://boris-portal.unibe.ch/handle/20.500.12422/55129Classical swine fever viruses (CSFVs) do typically not show cytopathic effect (CPE) in cell culture, while some strains such as vaccine strain the GPE- induce CPE in the swine kidney-derived CPK-NS cell line cultured in serum-free medium. These latter strains commonly lack Npro-mediated inhibition of type-I interferon (IFN) induction. In order to explore the molecular mechanisms of GPE--induced CPE, we analyzed the cellular pathways involved. In CPK-NS cells infected with the attenuated-vaccine-derived vGPE- strain, both, apoptosis and necroptosis were induced. Necroptosis was type-I IFN-dependent and critical for visible CPE. In contrast, the parental virulent vALD-A76 strain did not induce any of these pathways nor CPE. We used reverse genetics to investigate which viral factors regulate these cell-death pathways. Interestingly, a mutant vGPE- in which the Npro function was restored to inhibit type-I IFN induction did not induce necroptosis nor CPE but still induced apoptosis, while an Npro-mutant vALD-A76 incapable of inhibiting type-I IFN production induced necroptosis and CPE. Although Erns of CSFV is reportedly involved in controlling apoptosis, apoptosis induction by vGPE- or apoptosis inhibition by vALD-A76 were independent of the unique amino acid difference found in Erns of these two strains. Altogether, these results demonstrate that type-I IFN-dependent necroptosis related to non-functional Npro is the main mechanism for CPE induction by vGPE-, and that viral factor(s) other than Erns may induce or inhibit apoptosis in vGPE- or vALD-A76 infected CPK-NS cells, respectively.enApoptosis Classical swine fever virus Necroptosis Type-I interferon600 - Technology::630 - Agriculture500 - Science::570 - Life sciences; biologyarticle10.7892/boris.1454213171520410.1016/j.virusres.2019.197809