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 study the effects of simple portal hypertension on the endotoxin levels in serum and intestinal mucosa of rats. Methods A total of 16 rats were divided into the blank control group (4 rats) and the model groups (3-day group, 7-day group and 10-day group, 4 rats in each group). The rat model of partial portal vein ligation was established in the model groups, and samples of blood and jejunum, ileum and colon of the rats were taken on the 3rd, 7th and 10th days, respectively. Changes in the serum endotoxin levels were detected by ELISA. Histopathological changes of the intestinal tissues were examined by HE staining. Results The rat model of partial portal vein ligation was successfully established in all the model groups. The serum levels of endotoxin on the 3rd, 7th and 10th days in the model groups were not significantly different from that in the normal control group. Damages of different intestinal segments were not serious on the 3rd day after modeling. However, on the 7th day after modeling, there were some sowllen and damaged intestinal villi in the intestinal mucosa of each intestinal segment, and the connection between the epithelial cells and the lamina propria was broken, compared with that at 3 days after modeling. In addition, there were obvious damages in the intestinal mucosa and lamina propria on the 10th day, compared with that at 3 d and 7 d after modeling. Conclusions In the case of normal liver function, portal hypertension can cause intestinal mucosal damages within a short period of time, but the amount of endotoxin produced by intestine does not exceed the processing capacity of the liver and thus does not cause an increase in the serum endotoxin level.

Objective BALB/c mutant curly mice and normal BALB/c mice were genetically detected by microsatellite DNA marker analysis to detect the differential microsatellite loci between BALB/c mutant curly mice and normal mice.Methods 38 microsatellite DNA loci were selected and their variation in the BALB/c mutant curly mice, BALB/c mutant hairless mice and normal BALB/c mice were detected by multiplex fluorescence PCR and STR scanning genotyping.Results There were 27 the same microsatellite loci between the 38 microsatellite loci in BALB/c mutant curly mice and normal mice,and there were 11 differential loci, with a mutation rate of 28.9%(11/38). There were 30 the same sites between BABL/c mutant hairless mice and normal mice,and there were 8 different loci,with a mutation rate of 21.1%(8/38). There were also 12 differential loci between BABL/c mutant curly mice and hairless mice. Conclusions BALB/c mutant curly mice have a higher mutation rate and are significantly higher than those of hairless mice,demonstrating that the mutations in curly mice and hairless mice are two completely different mutations. These results provide reliable theoretical data for the future study and development of BALB/c mutant curly mice.