Repeated administration of hepatitis C virus core-encoding plasmid to mice does not necessarily increase the immune response generated against this antigen.
DNA immunization is a promising approach in generating immune responses to infectious pathogens in many different animal models. In an effort to augment 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 intramuscularly injected with an expression plasmid encoding a truncated variant comprising amino acids 1-176 of the HCV core protein. The highest anti-core antibody titres (1:3700) were detected in mice inoculated with 50-100 microg of core-encoding plasmid. Additionally, we demonstrated that antibody levels induced by a single injection of DNA could be further increased by boosting with a second injection of DNA three weeks after primary immunization. However, administration of additional doses or lengthening of the resting period between inoculations resulted in similar or even weaker anti-core antibody responses. A similar anti-(HCV core) lymphoproliferative response was also detected in animals that had the highest level of anti-core antibodies. These results indicate that, in clinical trials, vaccination regimen might be a critical factor in generating optimal anti-(HCV core) immune responses after genetic immunization.
Dueñas-Carrera
S
S
HCV Department, Vaccine Division, Centro de Ingeniería Genética y Biotecnología, P.O. Box 6162, Havana City, Cuba.
Alvarez-Lajonchere
L
L
Alvarez
J C
JC
Ramos
T
T
Pichardo
D
D
Morales
J
J
D000818:Animals; D002455:Cell Division / Q000276:immunology; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000096:biosynthesis; D018936:Hepatitis C Antigens / Q000235:genetics* / Q000276:immunology; D007111:Immunity, Cellular; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D013601:T-Lymphocytes / Q000166:cytology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D014765:Viral Vaccines