Targeting of hepatitis C virus core protein for MHC I or MHC II presentation does not enhance induction of immune responses to DNA vaccination.
We analyzed different vaccine approaches aimed at enhancing CD4(+)- and CD8(+)-dependent responses against hepatitis C virus (HCV) core antigen. Specific DNA vectors expressing various forms of the core in fusion with the ubiquitin or the lysosome-associated membrane protein (LAMP) were generated. These expressed the full-length wildtype core; the full-length core expressed as a covalent fusion with the ubiquitin; the full-length core expressed as a noncovalent fusion with the ubiquitin and containing a N-stabilizing or N-destabilizing residue; and the full-length core expressed as a fusion with the LAMP sequence. In vitro expression levels of the different plasmids differed by as much as tenfold. After injection into mice, none of the plasmids yielded a detectable antibody response, whereas core-specific cytotoxic T-lymphocyte (CTL) activity could be observed with all plasmids as long as 21 weeks postimmunization. No increase in CTL activity (ranging from 7% to 34% specific lysis) was observed with the ubiquitin-fusion-expressed core antigens compared with the wildtype core. The lowest CTL activity (< 5% specific lysis) was observed with the LAMP fusion. This vector was nonetheless unable to induce a detectable proliferative response. Screening of 10 different putative CTL peptide epitopes failed to reveal newly targeted epitopes when the core-fusion plasmids were used compared with the wildtype core-expressing plasmid. These data underline the difficulty in optimizing anti-core cellular immune response using molecular targeting strategies in DNA-based vaccination.
Vidalin
O
O
INSERM U271-151, Lyon, France.
Tanaka
E
E
Spengler
U
U
Trépo
C
C
Inchauspé
G
G
D000818:Animals; D017951:Antigen Presentation; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D018604:Epitope Mapping; D005260:Female; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D006526:Hepatitis C / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D018936:Hepatitis C Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014452:Ubiquitins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014758:Viral Core Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000235:genetics / Q000276:immunology
D015703:Antigens, CD; D016207:Cytokines; D018936:Hepatitis C Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D014452:Ubiquitins; D019444:Vaccines, DNA; D014758:Viral Core Proteins; D014761:Viral Hepatitis Vaccines; C069130:nucleocapsid protein, Hepatitis C virus