[Experimental study of immunization of mice with hepatitis C virus genetic vaccine constructs].
OBJECTIVE
To inquire into the immune responses to expression protein in mice immunized with genetic vaccine of hepatitis C virus (HCV) and lay a foundation for HCV genetic vaccine development in future.


METHODS
The gene fragments coding C and most E regions of HCV-II type were inserted into pCD-SRalpha(1) of eukaryotic expression vector and formed genetic vaccine constructs of pCD-HCV(1) and then was injected into the quadriceps muscles of Balb/c mice. The serum anti-HCV level of mice was tested by ELISA and peripheral blood mononuclear cell (PBMC) proliferative responses to HCV antigens were detected by (3)H-TdR incorporation method (cpm).


RESULTS
The serum antibody level reached to 0.71 +/- 0.08 - 0.77 +/- 0.06 (A value, the same below) after genetic vaccine pCD-HCV(1) (100 microg/mouse) were inoculated into the mice (n = 12) three or four times while blank vector pCD-SRalpha(1) could not induce the mice (n = 8) to generate antibody response in same way. After the antibody levels in mice (n = 8) immunized by pCD-HCV(1) had ascended to peak value (0.71), there was no trend of descending during the following 18 weeks of detection (0.68 +/- 0.06 - 0.75 +/- 0.07). Specific fragment of HCV cDNA identified by polymerase chain reaction (PCR) from DNA extracted from the muscles of the mice after pCD-HCV(1) had been inoculated three months. PBMC proliferative responses to HCV synthetic peptides CP(9) and gene recombinant antigens C, E(1) in the mice immunized with pCD-HCV(1) were detected and its stimulation indexes (SI) were 4.07 +/- 1.58, 3.88 +/- 0.70 and 3.69 +/- 1.13 respectively and there was a significant difference (P < 0.001) as compared with that of PBMC in mice immunized with pCD-SRalpha(1).


CONCLUSIONS
These investigations demonstrated that genetic vaccine constructs made of HCV structural region can induce Balb/c mice to generate antibody and PBMC proliferative responses to HCV antigens via DNA immunization.
Dou
J
J
Institute of Infectious Disease, The First Affiliated Hospital of Zhejiang University, Hangzhou 310003.
Liu
K
K
Chen
Z
Z
Wo
J
J
Liu
Y
Y
Xu
C
C
Chen
M
M
Jin
J
J
He
N
N
D000818:Animals; D049109:Cell Proliferation; D016174:Hepacivirus / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D018936:Hepatitis C Antigens / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D014761:Viral Hepatitis Vaccines / Q000276:immunology*
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014761:Viral Hepatitis Vaccines