title: Targeting antigens to an invariant epitope of the MHC Class II DR molecule potentiates the immune response to subunit vaccines.
abstract: Recombinant subunit and peptidic vaccines in general present a reduced immunogenicity in vaccinated individuals with respect to the whole pathogen from which they derived. The generation of strong immune responses to these vaccines requires the use of potent adjuvants, high antigen doses and repetitive vaccinations. In this report, we document the enhanced antibody response obtained against two recombinant subunit vaccines by means of targeting to antigen-presenting cells by a recombinant single chain antibody. This antibody, named APCH1, recognizes an epitope of MHC Class II DR molecule preserved in different animal species, including humans. We showed that vaccinal antigens translationally fused to APCH1 antibody and produced by recombinant baculoviruses in insect larvae (Trichoplusia ni), elicited an increased antibody response in comparison with the same antigens alone or fused to a carrier molecule. These results suggest that targeting of antigens to this invariant MHC Class II epitope has immunopotentiating effects that could circumvent the reduced potency of peptidic or subunit vaccines, opening the possibility of widespread application of APCH1 as a new adjuvant antibody of general use.
authors.affiliation: Departamento de Biotecnología, INIA, Autovía A6 Km7, 28040 Madrid, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Gil
authors.forename: Mariano
authors.initials: M
authors.lastname: Pérez-Filgueira
authors.forename: María G
authors.initials: MG
authors.lastname: Barderas
authors.forename: Carlos
authors.initials: C
authors.lastname: Pastor-Vargas
authors.forename: Covadonga
authors.initials: C
authors.lastname: Alonso
authors.forename: Fernando
authors.initials: F
authors.lastname: Vivanco
authors.forename: José M
authors.initials: JM
authors.lastname: Escribano
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D000939:Epitopes / Q000276:immunology* / Q000378:metabolism; D006684:HLA-DR Antigens / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007915:Lepidoptera; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D057127:Single-Chain Antibodies / Q000378:metabolism; D022223:Vaccines, Subunit / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000939:Epitopes; D006684:HLA-DR Antigens; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic