Mechanism of Uncoating of Influenza B Virus in MDCK Cells: Action of Chloroquine
“Exposure of influenza B virus-infected MDCK cells to chloroquine at the time of infection resulted in significant inhibition of infection.”
“It is likely that chloroquine prevents the uncoating of influenza B virus by increasing the lysosomal pH above the critical value required for inducing fusion between the virus envelope and the lysosomal membrane.”
“The normal pH inside the lysosomes was around 5-6. This value was within the pH range optimal for the haemolysis reaction by influenza B virus. When chloroquine was added to the culture, the lysosomal pH rapidly increased to 6-5, which is above the critical value required for haemolysis by influenza B virus.”
“These findings indicate that extracellular chloroquine is essential for the maintenance of elevated pH inside the lysosomes.”
“These results suggest that chloroquine inhibits infection by acting
at a replicative step preceding primary transcription of the virus genome. Similar conclusions have also been reported for the effect of another lipophilic amine, amantadine, on influenza A viral replication.”
“Actinomycin D completely inhibited the growth of influenza B virus in MDCK cells when added within 2 h after infection, as observed with influenza A virus.”
“Chloroquine inhibits infection by acting at a step preceding the primary transcription of the influenza B virus genome”
“Further experiments were carried out to confirm that elevation of the lysosomal pH by chloroquine is responsible for its inhibition of infection.”
https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-64-5-1149