Serum from mice immunized with EP67 ovalbumin (OVA) contained high OVA-specific antibody (Ab) titers [IgG1, IgG2a (IgG2b), IgG2b].
In comparison with mice immunized with only OVA, human HNP-1, HBD1 and HBD2 induced significantly higher OVA-specific serum IgG, including IgG1 and IgG2b subtypes (Brogden et al., 2003).
In the former, there were significantly lower levels of OVA-specific IgG2a and significantly higher OVA-specific IgE levels than in the latter.
They found that the s.c. adjuvant-free protocol resulted in significantly higher OVA-specific IgE and significantly lower OVA-specific IgG1 levels than the i.p. adjuvant protocol.
Comparison of adjuvant-free i.p. and s.c. sensitization routes revealed that s.c. sensitization resulted in significantly higher OVA-specific IgE antibody production (see Table 1).
Also in sensitized mice using the s.c. adjuvant-free Protocol 1C, BALB/c mice expressed higher OVA-specific IgG1 titres than C57BL/6 mice (2546 ± 434 vs. 337 ± 91 ng/mL, respectively, P<0.01).
As expected, observation of OVA-specific antibody titres from OVA-sensitized and -challenged mice demonstrated that the s.c. adjuvant-free protocol (Protocol 1C) resulted in significantly higher OVA-specific IgE and significantly lower OVA-specific IgG1 levels than the i.p. adjuvant protocol (Protocol 2A).
Interestingly, assessment of strain differences revealed that in OVA-sensitized mice, the BALB/c strain consistently produced higher OVA-specific IgE antibody titres than the C57BL/6 strain regardless of whether the adjuvant Protocol 2A (42 ± 7 vs. 6 ± 2 ng/mL, respectively, P<0.001) or adjuvant-free Protocol 1C (95 ± 11 vs. 24 ± 8 ng/mL, respectively, P<0.001) was used.
In addition, we observed that DNA vaccine delivered by intramuscular injection followed by electroporation and DNA vaccine delivered by gene gun both generated higher OVA-specific CD8+ T cell immune responses at a higher dose of DNA (2 ug) compared to a lower dose of DNA (50 ng).
In order to produce high quality ova the females must undergo physiological adaptations that initiate further gamete development and maturation.
