Inhibition of cytomegalovirus infection and photothermolysis of infected cells using bioconjugated gold nanoparticles

Human cytomegalovirus (CMV) is a herpesvirus that causes major health problems in neonates as well as in immunocompromised individuals. At present, a vaccine is not available for CMV infection and the available antiviral drugs suffer from toxicity, poor efficacy and resistance. Here, we chemically conjugated a monoclonal antibody raised against CMV surface glycoprotein (gB) with gold nanoparticles (GNP) and characterized the potential of this gB-GNP conjugate for antiviral activity against CMV. The gB-GNP blocks viral replication, virus-induced cytopathogenic effects and virus spread in cell culture without inducing cytotoxicity. High concentrations of gB-GNP that coat the surface of virus particles block virus entry, whereas lower concentrations block a later stage of virus life cycle. Also, cells treated with gB-GNP gain resistance to CMV infection. In addition, infected cells when bound to gB-GNP can be selectively lysed after exposing them to specific wavelength of laser (nanophotothermolysis). Thus, we have not only designed a potential antiviral strategy that specifically blocks CMV infection at multiple stages of virus life cycle, but we have also characterized a technique that can potentially be useful in eliminating CMV infected cells from donor tissue during transplant or transfusion.