Different hepatitis C virus nonstructural protein 3 (Ns3)-DNA-expressing vaccines induce in HLA-A2.1 transgenic mice stable cytotoxic T lymphocytes that target one major epitope.
The immunogenicity of the Hepatitis C virus (HCV) nonstructural protein 3 (NS3) was investigated using different DNA-based strategies and a preclinical mouse model transgenic for the HLA-A2.1 molecule. Plasmids expressing NS3 either as a wild-type protein, as a fusion with murine lysosome-associated-membrane protein-1 specific sequences, or under the control of the Semliki Forest virus replicase were evaluated in vitro and in vivo. All plasmids were shown to express the expected size protein. These 3 NS3-expressing vaccines induced overall comparable levels of CTLs when measured at different times postvaccination although mice injected with the NS3-LAMP expressing plasmid showed a particularly homogeneous and overall vigorous response (specific lysis ranged from 60% to 90 % for an E:T ratio of 33.3:1 with a mean CTL precursor frequency of 1:2.10(5) cells). Out of the four HLA-A2.1-restricted NS3 epitopes previously described in HCV infected patients (aa 1073-1081, aa 1406-1415; aa 1169-1177 and aa 1287-1296), the NS3-DNA generated CTLs were predominantly targeted at the aa 1073-1081 epitope. Peptide-based immunization showed that the mouse repertoire was intact for all epitopes tested except one (aa 1287-1296). In conclusion, the 3 NS3-DNA vaccines although based on different mode of action, shared a comparable efficacy at inducing CTL. Surprisingly, the breadth of such response was restricted to a single, major epitope.
Brinster
C
C
Unité Mixte CNRS BioMérieux UMR 2142, Lyon, France.
Muguet
S
S
Lone
Y C
YC
Boucreux
D
D
Renard
N
N
Fournillier
A
A
Lemonnier
F
F
Inchauspé
G
G
D016475:3T3 Cells; D000818:Animals; D000917:Antibody Formation; D000939:Epitopes / Q000276:immunology*; D005260:Female; D015789:HLA-A2 Antigen / Q000032:analysis* / Q000235:genetics; D007114:Immunization; D007371:Interferon-gamma / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008822:Mice, Transgenic / Q000235:genetics; D013601:T-Lymphocytes / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000276:immunology*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000939:Epitopes; D015789:HLA-A2 Antigen; D007371:Interferon-gamma; D019444:Vaccines, DNA; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases