tailieunhanh - Báo cáo y học: "Upregulation of a novel eukaryotic translation initiation factor 5A (eIF5A) in dengue 2 virus-infected mosquito cells"

Upregulation of a novel eukaryotic translation initiation factor 5A (eIF5A) in dengue 2 virus-infected mosquito cells | Shih et al. Virology Journal 2010 7 214 http content 7 1 214 VIROLOGY JOURNAL RESEARCH Open Access Upregulation of a novel eukaryotic translation initiation factor 5A eIF5A in dengue 2 virus-infected mosquito cells Yu-Tzu Shih1 Chao-Fu Yang1 Wei-June Chen1 2 Abstract Background Dengue virus a mosquito-borne flavivirus is the etiological agent of dengue fever dengue hemorrhagic fever and dengue shock syndrome. It generally induces apoptosis in mammalian cells but frequently results in persistent infection in mosquito cells. That mechanism remains to be explored. In turn a genomic survey through subtractive hybridization PCR-select cDNA subtraction was conducted in order to find gene s that may play a role in interactions between the virus and its host cells. Results Through this technique we identified a novel eukaryotic translation initiation factor 5A eIF5A which is upregulated in Aedes albopictus-derived C6 36 cells infected by the type 2 dengue Den-2 virus. The full-length of the identified eIF5A gene consisted of 1498 bp of nucleotides with a G C content and it possessed a higher similarity and shorter evolutionary distance with insects than with other organisms. Upregulation of eIF5A in response to Den-2 virus infection was validated at both the RNA and protein levels. This phenomenon was also observed by confocal microscopy. In addition cell death obviously occurred when eIF5A activity was inhibited in C6 36 cells even when they were infected by the virus. However viral multiplication was not obviously affected in infected C6 36 cells when eIF5A activity was reduced. Conclusions Taken together we postulated that eIF5A plays a role in preventing mosquito cells from death in response to Den-2 viral infection thus facilitating continued viral growth and potential persistent infection in mosquito cells. It would be worthwhile to further investigate how its downstream factors or cofactors contribute to this phenomenon of dengue infection. .