Potent dendritic cell vaccine loaded with latent membrane protein 2A (LMP2A)

Epstein-Barr virus (EBV), a potential oncogenic herpesvirus, has been found to be associated with several malignancies. It's critical to elicit cellular immunity of the body to fight against EBV-associated tumor development. Using dendritic cells (DCs) loaded with latent membrane protein 2A (LMP2A) to elicit T cell response against tumor may be one of the most direct and safest immunotherapy approaches. The present study aimed to develop DCs-based cancer vaccine (DC loaded with LMP2A protein) and study its biological characteristics and immune functions. Purified LMP2A protein was extracted from a cell line L929/LMP2A stably expressing LMP2A. LMP2A could be loaded on DCs with no significant changes of the DC surface markers and cytomorphology. The percentage of DCs loaded with LMP2A was above 80%. LMP2A-loaded DCs markedly enhanced the proliferation of antigen-specific CD8+ T and CD4+ T cells by 3H-TdR incorporation assay. Besides, the specific cytotoxicity of the CTLs against LMP2A target cells was also significantly increased. These results indicated that DC-based vaccine loaded with virus antigen could elicit potent CTL response and provide a foundation for further study on the DC-based immunotherapy for nasopharygeal carcinoma and other EBV associated tumors.