Effects of respiratory syncytial virus infection on the levels of host translational initiation factors

Abstract

Respiratory Syncytial Virus (RSV) is a leading cause of respiratory infection primarily in children. Presently, there are no effective vaccines available whereas current treatments are only limited to relieve the signs and symptoms. Currently, the development of RSV antivirals and vaccines are much more focused on viral attachment and RNA transcription and few information are produced on the effect of RSV infection on host translation initiation factors. Therefore, this study aimed to analyse the level of translational initiation factors (eIF4A, eIF4E, eIF4G) in RSV-infected cells, in which they play a major role as the translation control target. Time course infection study was carried out at 0, 24, 48, 72, 96, 120 hours at Multiplicity of Infection 1 (MOI 1) to determine virus growth curve and level of host proteins. Findings of the study demonstrated that the virus particles were detected in the supernatant as early as 12 hours post infection (hpi) and the titre was found to increase drastically after 48 hpi before reaching the highest concentration at 72 hpi. However, RSV titre started to reduce both out-cellular and in-cellular between 96 hpi to 108 hpi, due to the latent period of RSV infection. In addition, eIF4G and eIF4E levels were found to be maintained throughout the infection. However, eIF4A levels decreased during early infection before increased at a later stage of infection. This finding shows that the eIF4G and eIF4E are probably required in synthesizing the viral proteins. The reduction of eIF4A level, however, primarily suggests that this helicase factor might be very crucial in the early stage of the RSV replication.