Repeated administration of hepatitis C virus core-encoding plasmid to micedoes not necessarily increase the immune response generated against this antigen
S. Duenas-carrera et al., Repeated administration of hepatitis C virus core-encoding plasmid to micedoes not necessarily increase the immune response generated against this antigen, BIOT APP B, 33, 2001, pp. 47-51
DNA immunization is a promising approach in generating immune responses to
infectious pathogens in many different animal models. In an effort to augme
nt the anti-[hepatitis C virus (HCV) core] immune response, generated after
DNA immunization, the importance of vaccination regimen regarding dose and
boosting was investigated in the present study. Balb/c mice were intramusc
ularly injected with an expression plasmid encoding a truncated variant com
prising amino acids 1-176 of the HCV core protein. The highest anti-core an
tibody titres (1:3700) were detected in mice inoculated with 50-100 mug of
core-encoding plasmid. Additionally, we demonstrated that antibody levels i
nduced by a single injection of DNA could be further increased by boosting
with a second injection of DNA three weeks after primary immunization. Howe
ver, administration of additional doses or lengthening of the resting perio
d between inoculations resulted in similar or even weaker anti-core antibod
y responses. A similar anti-(HCV core) lymphoproliferative response was als
o detected in animals that had the highest level of anti-core antibodies. T
hese results indicate that, in clinical trials, vaccination regimen might b
e a critical factor in generating optimal anti-(HCV core) immune responses
after genetic immunization.