Designing multifunctional recombinant vaccines: an engineering strategy based on innovative epitope prediction-guided splicing

Background: Recombinant subunit vaccines leveraging pathogen-derived components are pivotal for disease prevention. Nonetheless, application of these vaccines still faces challenges such as low immunogenicity and a short half-life. Additionally, selecting appropriate antigens presents a significant barrier in recombinant vaccine design. Methods: Here, we applied a novel approach to address these challenges by developing recombinant vaccines targeting LMP2A. We employed in silico epitope prediction and splicing to create epitope enrichment regions (EERs) in conjunction with the TLR4 agonist hEDA to enhance immunogenicity and the immunoglobulin G1 (IgG1) Fc fragment to prolong persistence. Results: This multifaceted strategy enhances antigen uptake by antigen-presenting cells, eliciting major histocompatibility complex (MHC) allele-dependent T-cell responses against targeted epitopes. Compared with split-component candidates, these innovatively designed vaccines demonstrate superiority in inducing the development of IFN-γ(+) antigen-specific T cells, along with elevated humoral and cellular immune responses, and exhibit significantly enhanced antitumor efficacy in both preventive and therapeutic models. Furthermore, optimized vaccine treatment synergistically inhibits tumor growth when combined with the administration of immune checkpoint inhibitors, leading to significantly prolonged survival. Conclusion: This novel design strategy offers advances for the development of multifunctional recombinant vaccines and represents a promising platform for cancer immunotherapy and applications in other diseases.