Structural Elements of a Protein Antigen Determine Immunogenicity of the Embedded MHC Class I-Restricted T Cell Epitope

摘要: Substantial effort has been invested into optimization of vector structure, DNA formulation, or delivery methods to increase the effectiveness vaccines. In contrast, it only insufficiently explored how higher order structure an antigenic protein influences immunogenicity embedded epitopes in vivo. Potent CD8 + T cell responses specific for a single immunogenic epitope are induced upon electrovaccination with plasmid encoding full-length heavy chain human HLA-Cw3 molecule. Contrary expectations, minimal construct, which provoked substantial release IFN-γ from CTLs vitro, did not induce significant response Systematically altered variants Cw3 molecule were thus tested both vivo and vitro determine structural parts responsible this discrepancy. complementation experiments participation trans -acting helper was ruled out. Successive C-terminal truncations, human/mouse domain swap variants, subdomain modifications defined α3 region HLA membrane anchoring as critical elements. Based on these data, refined constructs engineered that triggered very high responses. The most advanced variant consisted adenoviral leader, epitope, domain, 16 aa transmembrane domain. When tumor Ag incorporated one performer constructs, protection against melanoma metastases attained vaccination. Thus, elements can dominantly influence These also markedly improve unrelated Ags may form basis new generation