Replication of Adeno-Associated Virus in Murine Fibroblasts with Mouse Adenovirus Provided Helper Functions

by Bhrigu, Vipul

The adeno-associated virus (AAV) replicates to high titer when host cell are coinfected with a helper virus. Here we analyzed the coinfection of AAV and mouse adenovirus (MAV-1) in murine fibroblasts. We observed that MAV-1 coinfected 3T3 cells produced approximately 10-40 fold less AAV DNAse resistant particles (DRP) than Hela cells. Levels of AAV DNA replication were approximately 30 fold less in 3T3 cells as compared to Hela cells coinfected with human adenovirus (Ad-5). A study of these lower levels of infection in 3T3 cells compared to Hela cells revealed that receptor binding and internalization of AAV in 3T3 and Hela cells was comparable. However, AAV did not enter into the nucleus of 3T3 cells as efficiently as it does in Hela cells. Furthermore, viral DNA replication levels of AAV DNA were found to be lower in 3T3 cells than Hela cells even after transfection of proviral plasmid indicating a defect in support for the AAV DNA replication as well in 3T3 cells as compared to Hela cells.