Virus-Like Particles as vaccine antigens and adjuvants: application to chronic disease, cancer immunotherapy and infectious disease preventive strategies

Existing vaccines are mainly limited to the microorganisms we are able to culture and produce and/or to those whose killing is mediated by humoral responses. It has been more difficult to develop vaccines capable to induce functional cellular responses needed to prevent or cure chronic diseases. Several results suggest that specific enhancement of T-cell responses is nevertheless possible in persistently infected patients to treat chronic diseases including cancer. This work presents preclinical and clinical results obtained using virus like particles (VLPs) as a vaccine platform. VLPs based on envelope, membrane or nucleocapsid microbial proteins are able to stimulate mucosal as well as systemic immunity and induce a strong immune response after nasal or systemic administration in mice, non human primates and humans. In addition, the immune response obtained is biased in a Th1 direction. VLPs were able to potentiate humoral and cellular immune responses against several viral and cancer antigens as measured by LPA and IFN-γ ELISPOT assays. Studies in animals and humans with nasal and systemic formulations show that it is possible to induce functional immune responses against HBV, HCV, dengue as well as against prostate and cervical cancers.