Humoral and
cellular immune responses are currently induced against
hepatitis C virus (HCV) core following
vaccination with core-encoding
plasmids. However, the anti-core
antibody response is frequently weak or
transient. In this
paper, we evaluated the effect of different additives and
DNA-
protein combinations on the anti-core
antibody response. BALB/c
mice were intramuscularly injected with an expression
plasmid (pIDKCo), encoding a C-terminal truncated variant of the HCV core
protein, alone or combined with CaCl2, PEG 6000,
Freund's adjuvant, sonicated calf
thymus DNA and a recombinant core
protein (Co.120). Mixture of pIDKCo with PEG 6000 and
Freund's adjuvant accelerated the development of the anti-core Ab response. Combination with PEG 6000 also induced a
bias to
IgG2a subclass predominance among anti-core
antibodies. The
kinetics,
IgG2a/
IgG1 ratio and
epitope specificity of the anti-core
antibody response elicited by Co.120 alone or combined with pIDKCo was different regarding that induced by the pIDKCo alone. Our data indicate that the
antibody response induced following
DNA immunization can be modified by formulation
strategies