Rapid synchronization of hepatitis C virus infection by magnetic adsorption.

Hepatitis C virus (HCV) entry into target cells is thought to be a multistep process involving several cellular factors. However, their precise role during virus entry is unclear. Investigation of the mechanisms of HCV entry, such as the order of intervention by the cellular receptors, requires synchronizing infections. This study describes a new method involving magnetic adsorption of virus to nanoparticles to synchronize infection, which can be adapted to both HCV pseudoparticles and cell culture infectious HCV. By combining these particles with negatively or positively charged magnetic nanoparticles it was possible to adsorb them onto target cells under a magnetic field in only 2min. This resulted in greater efficiency of virus adsorption to cells, and increased the infectivity of cell culture infectious virus, as compared to the standard protocol involving incubation of the virus with cells at 4 degrees C for 1h, or to a standard infection at 37 degrees C. Furthermore, magnetic adsorption respected the natural entry route of the virus, making this system suitable to study the early stages of HCV infection.