Redirecting cytomegalovirus immunity to treat tumors

A peptide vaccine that activates immune response to latent CMV infection could help treat cancer in CMV-infected individuals. In a xenograft mouse model of lung cancer and latent CMV infection, intratumoral injection of CMV peptide epitopes designed to be presented on MHCI increased tumor T cell infiltration, delayed tumor growth and increased survival compared with vehicle. Also in the model, sequential vaccination with MHCI CMV peptide epitopes and epitopes designed to be presented on MHCII increased long-term survival and decreased tumor growth, completely clearing tumors in a subset of mice. In a mouse model of immunologically cold melanoma and latent CMV infection, intratumoral injection of the MHCI and MHCII epitopes delayed tumor growth and increased survival compared with vehicle. Next steps include testing the approach in a wider range of immunologically hot and cold tumor models...