Modulation of the Immune Response to DNA Vaccine Encoding
Gene of 8-kDa Subunit of Echinococcus granulosus Antigen B
Using Murine Interleukin-12 Plasmid in BALB/c Mice
Abstract
Background: The current study was designed to evaluate immune responses induced
by DNA vaccines encoding 8-kDa subunit of antigen B (HydI) of Echinococcus granulosus
and murine interleukin 12 (IL-12) as genetic adjuvants in BALB/c mice.
Methods: Expression plasmid pcDNA3.1 containing HydI (pcHyd1) as vaccine along
with the murine interleukin 12 (pcMIL12) as adjuvant were used. Thirty-five mice in
the five experimental groups received PBS, empty pcDNA3.1, pcHydІ, pcMIL-12, and
pcHydІ+ pcMIL-12 in days zero, 14th and 28th. Two weeks after the last immunization,
evaluation of the immune response was performed by evaluating the proliferation of
splenic lymphocytes, IFN-γ and IL-4, determination of IgG isotyping titer.
Results: Mice that received the pcHydI+pcMIL12 exhibited higher levels of lymphocyte
proliferation compared to mice that received the pcHydI alone (P<0.001), and produced significantly more IFN-γ in comparison to other groups (P< 0.001). In addition,
they produced significantly less IL-4 than mice receiving the PBS and the empty
plasmid (P<0.023). The IgG2a levels were clearly higher in pcHydI+pcMIL12 group in
comparison with the groups of pcHydI alone, empty plasmid, and PBS. In contrast,
IgG1 was elevated in the group of pcHydI.
Conclusion: Co-delivery of IL-12 with DNA encoding 8-kDa subunit of antigen B
was effective significantly in inducing the immune response in mice
