Comparative Immunogenicity in Rabbits of the Polypeptides Encoded by the 5′ Terminus of Hepatitis C Virus RNA

Figure 5

Anti-HCV core immune response induced by single and repeated immunizations with synthetic gene encoding core aa 1–152 (DNAcore152). Rabbits were regularly bled; PBMCs were isolated and subjected to stimulation with HCV core-derived peptides and recombinant HCV core aa 1–152. Stimulation indexes (SI) observed after double priming (week 4) (a); boosting of T-cell response in rabbits receiving multiple injections of DNAcore152 illustrated by stimulation indexes exhibited by PBMCs of rabbits 101 and 102 before and after boost 5 at weeks 54 and 56, respectively (b); dynamics of antibody response to HCV core aa 1–152 in rabbits receiving repeated injections of DNAcore152 (c). All antigen stimulation tests were performed in triplicate; SI values represent an average with standard deviation. Test results were discarded if radioactivity incorporation values demonstrated by mitogen PHA were below 1000 counts per minute and if stimulation indexes in response to PHA were below 2. HCV core-specific antibodies response represent an average optical density exhibited by sera of each of the rabbits collected at given time points in two ELISA runs with standard deviations. OD of sera of rabbits immunized with empty vector DNA collected at the same time points did not exceed the optical density of 0.3 (data not shown).

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