Abstract:
Respiratory Syncytial Virus (RSV) is a leading cause of respiratory infections primarily in children. Presently, there are no effective vaccines able to fight the RSV infection, instead of treatments that tend to be limited in relieving the signs and symptoms only. Currently, the development of RSV antivirals and vaccines is much more focused on viral attachment and RNA transcription and there are few information regarding the effect of RSV infection on host translation initiation factors. Therefore, this study aimed to analyze the level of translational initiation factors (eIF4A, eIF4E, eIF4G) in RSV-infected cells, in which they play major role as translation control target. Human Epithelial type-2 (HEp-2) cells were optimized and observed for the morphological changes in RSV-infected cells in which involved with the formation of multinucleated cells (syncytia) and disintegration of the cellular membrane. Following these, the time course infection were carried out at 0, 24, 48, 72, 96, 120 h at MOI 1 and the virus titer was determined using TCID50 method. Based on the growth curve of RSV in the HEp-2 cells, it clearly showed that the entry of RSV into the HEp-2 cells were initiated between 12 hpi to 36 hpi, whereas at 48 hpi, RSV started to synthesis their viral proteins as the new viral particles were found to increase gradually until 72 hpi. However, between 96 hpi to 108 hpi, RSV titer started to reduce both out-cellular and in-cellular due to the latent period of RSV infection. Level of proteins was determined by immunoprecipitation Western Blotting. From this analysis we found, there were no changes on the level of eIF4G and eIF4E during the RSV infection. This finding suggests that, the translation initiation factor; eIF4G as scaffold protein and eIF4E, known as cap binding protein might not be cleaved during the RSV infection. However, we found that eIF4A have shown a reduction at 24 hpi, primarily suggesting that this helicase factor ofeIF4A might be very useful in the RSV replication. With that, in future, confirmatory study should be done to determine the functional requirement of these initiation factors (eIF4A, eIF4E, eIF4G).
