Morphogenesis and proliferative rule of porcine transmissible gastroenteritis virus in porcine intestinal epithelial cells

To gain a better understanding of the replication, proliferation and infection characteristics of porcine transmissible gastroenteritis virus (TGEV) in porcine intestinal epithelial cells (IECs), this study established a cell model of IECs infected with the Chongqing (CQ) strain of TGEV. The morphogenesis and proliferative rule of TGEV in porcine IECs were investigated using transmission electron microscopy, indirect immunofluorescence assays and real-time fluorescence quantitative PCR. Observations under the TEM indicated that the enveloped viral particles were roughly spherical, with diameters of between 80 and 120 nm. The virions entered porcine IECs by membrane fusion and the mature viruses in the vacuoles were transported to the cell membrane before release. The results also showed that from 0 to 12 h after TGEV infection of porcine IECs, the intracellular viral RNA content did not change significantly. Logarithmic growth occurred from 12 to 36 h, after which it gradually decreased. Moreover, the extracellular RNA content began to rise at 24 h after inoculation and then reduced gradually at approximately 48 h. This study provided a theoretical foundation for further study on the infection characteristics of TGEV in target cells.