Synchronous infection of SIV and HIV in vitro for virology, immunology and vaccine-related studies

The development of an HIV vaccine will require a more precise understanding of the immunological and virological underpinnings of HIV infection. Magnetofection, the process of magnetizing HIV by coupling it to ferrous nanoparticles and coordinating infection using a magnetic field, synchronizes the viral replication cycle at attachment while recapitulating the events of natural infection. Although spinoculation also concentrates virus onto target cells to increase infection, it does not synchronize infection. The synchronization of HIV infection in vitro facilitates the study of events in the viral replication cycle and the antiviral immune response on timelines previously impossible. Furthermore, by infecting a high percentage of cells in a short time frame, magnetofection increases the throughput of in vitro assays. Once a virus stock is generated, magnetofection of target cells is rapid, requiring only 1-2 h. Here we present a detailed protocol for this assay and review its applications for studying the immune response to HIV.