title: Built-in adjuvanticity of genetically and protein-engineered chimeric molecules for targeting of influenza A peptide epitopes.
abstract: Highly purified, subunit, or synthetic viral antigens are known to be weakly immunogenic and potentate only the antibody, rather than cell-mediated immune responses. An alternative approach for inducing protective immunity with small viral peptides would be the direct targeting of viral epitopes to the immunocompetent cells by DNA vaccines encoding antibody fragments specific to activating cell surface co-receptor molecules. Here, we are exploring as a new genetic vaccine, a DNA chimeric molecule encoding a T and B cell epitope-containing influenza A virus hemagglutinin peptide joined to sequences encoding a single-chain variable fragment antibody fragment specific for the costimulatory B cell complement receptors 1 and 2. This recombinant DNA molecule was inserted into eukaryotic expression vector and used as a naked DNA vaccine in WT and CR1/2 KO mice. The intramuscular administration of the DNA construct resulted in the in vivo expression of an immunogenic chimeric protein, which cross-links cell surface receptors on influenza-specific B cells. The DNA vaccination was followed by prime-boosting with the protein-engineered replica of the DNA construct, thus delivering an activation intracellular signal. Immunization with an expression vector containing the described construct and boosting with the protein chimera induced a strong anti-influenza cytotoxic response, modulation of cytokine profile, and a weak antibody response in Balb/c mice. The same immunization scheme did not result in generation of influenza-specific response in mice lacking the target receptor, underlining the molecular adjuvant effect of receptor targeting.
authors: Laboratory of Experimental Immunology, Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 26, 1113, Sofia, Bulgaria.
authors: Nikola S
authors: NS
authors: Kerekov
authors: Iva I
authors: II
authors: Ivanova
authors: Nikolina M
authors: NM
authors: Mihaylova
authors: Maria
authors: M
authors: Nikolova
authors: Jozsef
authors: J
authors: Prechl
authors: Andrey I
authors: AI
authors: Tchorbanov
mesh_terms: D016475:3T3 Cells; D000276:Adjuvants, Immunologic; D000818:Animals; D000954:Antigens, Surface / Q000276:immunology; D002460:Cell Line; D045744:Cell Line, Tumor; D016207:Cytokines / Q000097:blood; D000939:Epitopes / Q000276:immunology*; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G; D009980:Influenza A virus; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology*; D015202:Protein Engineering; D051381:Rats; D011956:Receptors, Cell Surface / Q000276:immunology; D017464:Receptors, Complement 3d / Q000276:immunology; D057127:Single-Chain Antibodies / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000954:Antigens, Surface; C513105:Cr1l protein, rat; D016207:Cytokines; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007074:Immunoglobulin G; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D017464:Receptors, Complement 3d; D057127:Single-Chain Antibodies; D019444:Vaccines, DNA