The aim of this study was to investigate the regulatory roles of distinct signaling cascades within the death receptor pathway in host cell apoptosis induced by Eimeria tenella (E. tenella); to this end, primary chicken embryo cecal epithelial cell culture, gene silencing, enzyme-linked immunosorbent assay (ELISA), Hoechst–Annexin V/PI apoptosis staining, hematoxylin–eosin (HE) staining, and quantitative real-time polymerase chain reaction (qRT-PCR) were employed. At 4, 24, 72, and 120 h post-inoculation (hpi) with E. tenella sporozoites, the proportion of apoptosis in six treatment groups Group C, Group T0 (E. tenella infection group), Group T1 (E. tenella + Fas SiRNA), Group T2 (E. tenella + TRAIL SiRNA), Group T3 (E. tenella + TNFR1 SiRNA), and Group T4 (E. tenella + NC SiRNA) and the dynamic changes in Fas cell surface death receptor (Fas), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), tumor necrosis factor receptor 1 (TNFR1), TNF receptor-associated death domain (TRADD), Fas-associated death domain (FADD), and death domain-associated protein (Daxx) expression and caspase-8 activity in the cells were determined. The results demonstrated that, from 4 to 120 hpi, the Fas and TNFR1 mRNA expression levels in Group T0’s host cells were significantly higher than those in Group C (p TNFR1 signaling pathway > TRAIL signaling pathway.
Xu et al. (Thu,) studied this question.