The highly virulent PRRSV isolate strain HN-1/06 was cultivated on Marc-145. To study the viral entry mechanisms, the GP5 gene of PRRSV isolate was amplified by RT-PCR and cloned into pcDNA3.0 to generate the expressing plasmid pcDNA-GP5. pcDNA-GP5 was transfected into 293T by the calcium phosphate precipitation method. Analysis of flow cytometry confirmed that the GP5 proteins were expressed in surface of the 293T cells. Then 293T cells were transfected with pcDNA-GP5, pHIT60 and pHIT111 plasmids to generate pseudotyping virus. The pseudotyping virus supernatant was harvested 48 hours post-transfection and was detected by Western blotting and infection assay. Western blotting indicated that the GP5 glycoproteins were incorporated into the retroviral pseudotyped virus. Infection assay showed that the pseudotyped virus infected 293T and Mark-145 cell. The pseudotyped virus could be used to further study infectious mechanism of PRRSV.
Animals ; Cell Line ; Cloning, Molecular ; Endothelial Cells ; cytology ; metabolism ; virology ; Leukemia Virus, Murine ; genetics ; metabolism ; Mice ; Porcine respiratory and reproductive syndrome virus ; chemistry ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; Transfection ; Viral Envelope Proteins ; biosynthesis ; genetics ; Virion ; genetics ; metabolism

Objective:To investigate the mechanism of crossed cerebellar diaschisis(CCD) induced by supratentorial tumors and the characteristics of 18F-FDG PET/CT imaging. Methods:Eighty-six patients with supratentorial tumors who underwent 18F-FDG PET/CT whole-body imaging from January 2017 to June 2021 were retrospectively analyzed.Placement, number, size, SUVmax, CT values, relationship with basal ganglia, edema, and cerebellar asymmetry index (AI) were observed and recorded.The imaging differences between patients with CCD and patients without CCD were compared, and the correlations between SUVmax, maximum diameter and cerebellar AI were analyzed.SPSS 21.0 software was used for statistical analysis.Chi-square test, independent sample t-test and Pearson correlation analysis were used for data statistics. Results:Among the 86 patients, 14 were patients with CCD and 72 were patients without CCD.The incidence of CCD was 16.3%.There were statistically significant differences in whether the primary lesions involved the basal ganglia region between patients with CCD and patients without CCD ( χ2=7.637, P=0.006). The cerebellar AI ((0.27±0.09), (0.05±0.02), t=6.847, P=0.003)and maximum diameter of primary lesions((3.98±1.09)cm, (2.36±1.61)cm, t=2.011, P=0.040) in patients with CCD were both larger than those in patients without CCD.There was a significant positive correlation between cerebellar AI and the maximum diameter of primary lesions in patients with CCD ( r=0.375 P=0.028). Conclusion:18F-FDG PET/CT imaging can assist in the diagnosis of crossed cerebellar diaschisis.The primary lesion of supratentorial tumor involving the basal ganglia is more likely to cause crossed cerebellar diaschisis, and the size of the primary lesion is correlated with cerebellar AI.