Nano-particulate platforms for vaccine delivery to enhance antigen-specific CD8+ T cell response

Vaccines remain the most effective way to protect populations against deathly infectious diseases. Several disadvantages associated with the traditional vaccines that use whole pathogens have led to the development of alternative strategies that use recombinant subunit vaccines. Subunit vaccines are, in general, safer than whole pathogens. Subunit vaccines lag in immunogenicity. To enhance immunogenicity, the subunit antigen is usually supplemented with adjuvants that stimulate the innate immune system as a means to steer the quality and intensity of the adaptive immune response. Of the new class of adjuvants being investigated are particle-based platforms such as virus-like particles, liposomes, and polymeric nanoparticles that present antigen in ways reminiscent of pathogen. Such platforms offer several advantages that include co-delivery of antigen along with innate immune stimulators in highly immunogenic format. By delivering antigen to the cross-presentation pathway, particulate-based systems elicit robust CD8⁺ T cell responses. Here we describe our recent efforts to synthesize, characterize, and validate two different, promising nanoparticle-based delivery systems. They demonstrate their potential to induce antigen-specific CD8⁺ T cell responses, essential in clearing viral infection and eradicating tumors.