Isolation, Sequence Analysis Of PRRSV And Influence Of Annexin A2and Hsp27Protein On PRRSV-infection

Porcine reproductive and respiratory syndrome(PRRS) caused by porcinereproductive and respiratory syndrome virus（PRRSV）, which is a worldwide swinedisease, with the financial damage of the swine producing area. In this study, wehave isolated and purified PRRSV from the disease tissue. Further，89PRRSVisolates in China during2007to2012were selected from GenBank. Evolutionarycharacteristics of these isolates were analyzed based on the sequences of Nsp2andORF5. The genetic variations of the isolates were also compared to sixrepresentative strains. The results showed that the deduced amino acid sequencesanalysis of89PRRSV isolates revealed that HP-PRRSV isolates, with adiscontinuous30-aa deletion in Nsp2region, were the dominating virus during2007-2012in China. Due to the extensive use of the representative vaccine strains,recombination event was occurred. Three isolates, HH08, DY, and YN-2010, weremore closely related to vaccine strains. Both YN-2011and DY were the evolutionaryproducts of recombination events between SP and CH-1R.The results of the presentstudy might be useful for epidemiology of PRRSV.It was reported that Annexin A2and HSP27protein may participate in theassembly of viral particles during PRRSV infecting. Moreover, HSP27may inhibitthe apoptotic in the early infected cells and increase the time of viral replication. Inthis study, Annexin A2and HSP27down-regulated cells were constructed andcharacteristics of PRRSV infection were studied. The results showed that PRRSVwas significantly decreased in Annexin A2or HSP27down-regualted cells. BothAnnexin A2and HSP27may play an important role in PRRSV infection. It alsoprovides a new way for the development of vaccines.