College of Animal Science and Technology, Shanxi Agricultural University, Taigu 030801, China.
Poult Sci. 2019 Oct 1;98(10):4384-4390. doi: 10.3382/ps/pez218.
The present study aims to investigate the similarities and differences between the host cells apoptosis induced by virulent line of Eimeria tenella (Tsx) and precocious line (PTsx), which can provide a theoretical basis for the study of drugs and vaccines against coccidiosis. HE staining, Hoechst 33342/AnnexinV-FITC/PI composite staining, and ELISA were used to detect the infection rate, apoptosis rate, and Caspase-3 enzyme activity of host cells infected by PTsx or Tsx, respectively. The apoptotic rates and Caspase-3 absorbance of the inoculation groups were lower (P < 0.05 or P < 0.01) than those of the control group at 4 h, whereas the apoptotic rates and Caspase-3 absorbance of the inoculation groups were higher (P < 0.05 or P < 0.01) than those of the control groups at 24 to 120 h. At the same inoculation dose, there was no significant difference in the infection rate, apoptosis rate or Caspase-3 absorbance between Tsx groups and PTsx groups after E. tenella inoculation for 4 to 72 h (P > 0.05). However, these indicators of PTsx groups were lower (P < 0.01) than those of the same dose inoculated Tsx groups at 120 h. The apoptosis rates of cecal and glandular epithelial cells in the inoculated groups were higher (P < 0.01) than those in the control group after inoculated E. tenella 5 D in vivo, and the apoptosis rates of cecal and glandular epithelial cells in PTsx group was lower (P < 0.01) than that in the same dose inoculated Tsx group. These observations indicate that both Tsx and PTsx inhibit host cell apoptosis in the early development of E. tenella, induce host cell apoptosis in the middle and late stages, and the apoptosis-inducing effect on host cells increases with increasing dose. However, when the same dose of oocysts was inoculated, the amount of apoptosis induced by PTsx in late development was less than Tsx.
本研究旨在探讨柔嫩艾美耳球虫强毒株（Tsx）和早熟株（PTsx）诱导宿主细胞凋亡的异同，为球虫病药物和疫苗的研究提供理论依据。分别采用 HE 染色、Hoechst 33342/AnnexinV-FITC/PI 复合染色和 ELISA 法检测 PTsx 和 Tsx 感染宿主细胞的感染率、凋亡率和 Caspase-3 酶活性。接种组在 4 h 时的凋亡率和 Caspase-3 吸光度低于对照组（P<0.05 或 P<0.01），而在 24120 h 时的凋亡率和 Caspase-3 吸光度高于对照组（P<0.05 或 P<0.01）。在相同的接种剂量下，接种柔嫩艾美耳球虫后 472 h，Tsx 组和 Ptsx 组的感染率、凋亡率或 Caspase-3 吸光度无显著差异（P>0.05）。然而，在 120 h 时，PTsx 组的这些指标均低于相同剂量接种 Tsx 组（P<0.01）。接种柔嫩艾美耳球虫后 5 d 时，实验组盲肠和腺胃上皮细胞的凋亡率均高于对照组（P<0.01），PTsx 组的凋亡率均低于相同剂量接种 Tsx 组（P<0.01）。这些观察结果表明，Tsx 和 Ptsx 在柔嫩艾美耳球虫早期发育过程中均抑制宿主细胞凋亡，在中晚期诱导宿主细胞凋亡，且随着剂量的增加，对宿主细胞的凋亡诱导作用增强。然而，当接种相同剂量的卵囊时，PTsx 在后期发育中诱导的凋亡量小于 Tsx。
