The Important Role of Lipid Raft-Mediated Attachment in the Infection of Cultured Cells by Coronavirus Infectious Bronchitis Virus Beaudette Strain

Guo, Huichen; Huang, Mei; Yuan, Quan; Wei, Yanquan; Gao, Yuan; Mao, Lejiao; Gu, Lingjun; Tan, Yong Wah; Zhong, Yanxin; Liu, Dingxiang; Sun, Shiqi

To determine the effect of lipid rafts on IBV genome replication, Vero cells treated with MβCD or mevastatin after IBV infection were collected at different time points to evaluate the level of viral RNA copies. IBV RNA copies were determined by semi-quantitative RT-PCR with specific primers. The RNA level represents the IBV genome copies after IBV replication. Fig 4A and 4B show that RNA copies, including negative-strand genomic RNA (gRNA) and negative and positive subgenomic RNA (sgRNA) were evaluated by semi-quantitative RT-PCR. The results showed that the viral RNA levels increased over time after IBV infection. Notably, both gRNA and sgRNA exhibited rapid increases in RNA levels regardless of drug treatment, indicating that drug-induced lipid raft disruption could not suppress IBV viral genome replication. The RNA levels of drug-treated Vero cells decreased at each time point after IBV infection compared with the control, suggesting that drug treatment may affect IBV virion entry into cells during the early stages of infection. These results demonstrated that lipid rafts may function in the early stages of virion entry into cells, but do not affect viral genome replication.