AbISCO® compared to other adjuvants

To prove the efficacy of the AbISCO® adjuvants a comparison with other adjuvants was performed. AbISCO® adjuvant generated the highest antibody titers when inducing antibody response to ovalbumin. AbISCO® adjuvant also induced the highest proliferation index and also gave consistently high production levels of IFN-γ, IL-4 and IL-5.

Antibody response to ovalbumin in mice.

Female Balb/c mice (18-20 g) were immunized with 10 µg ovalbumin formulated with different adjuvants. All adjuvants were handled according to manufacturers’ instructions. Eight mice per group were immunized s.c. at the base of the tail at weeks 0 and 4. The mice were bled at weeks 3 and 6 and the sera tested for ovalbumin-specific IgG and ovalbumin-specific IgG2a subclass antibodies. Control mice were immunized identically but without adjuvant.
Figure 1 shows that while all adjuvants tested were efficient in inducing antibody response to ovalbumin, AbISCO®-100 generated the highest titers.

For the IgG2a response after primary and booster administrations, AbISCO®-100 and TiterMax Gold were highly efficacious. Both induced more than one log higher ovalbumin-specific IgG2a titers than FIA, for example. Once again, however, AbISCO®-100 gave the highest response. Note that Alum did not induce a significant IgG2a response at all.

Antigen-specific proliferation and cytokine production in spleen cell cultures from mice immunized with ovalbumin formulated in different adjuvants.

Mice were immunized as described above and spleens were removed within 2 weeks of the second bleeding. Spleen cells were stimulated in vitro with 100 µg/ml ovalbumin. After 72 hours in culture, supernatants were tested for cytokines (IFN-γ, IL-4 and IL-5). Antigen-specific proliferation was measured with the BrdU ELISA after 41 h of culture.
Figure 2 shows that the highest proliferation index was induced in mice immunized with ovalbumin formulated with AbISCO®-100 adjuvant. Cells from this group of mice also produced high levels of IFN-γ. High production levels of both IL-4 and IL-5 matched this IFN-γ response. In comparison, the other adjuvant formulations did not display this broad cellular response; i.e. they induced only low levels of IFN-γ, IL-4 and IL-5 production.

Some recent findings with other animals

Animal Antigen Observations Ref.
Cats Herpes virus Virus neutralizing antibodies; Proliferating T-cellsReduced virus shedding; lower amounts and during shorter time compared to controls after viral challenge 1
Seal Herpes virus Virus neutralizing antibodies; Proliferating T-cells 1
Cynomolgus macaques Influenza Long-lasting immunity against homologous challenge infection 2
Rhesus monkeys HIV and SIV Antigen-specific cellular immunity; IFN-γ production and CTL; Protection against challenge infection 3
Pigs Rotavirus Oral vaccination; High titers of protecting IgG and IgA antibodies; After viral challenge, high protection rates against virus shedding and diarrhea 4
Sheep Influenza Intranasal vaccination; High levels of antibody 5

References:

1. Martina et al., 2003. Vaccine 21, 2433-2440.
2. Rimmelzwaan et al., 2002. Vaccine 20, 158-163.
3. Mooij et al., 2004. J. Virol. 78, 3333-3342.
4. Nguyen et al., 2003. Vaccine 21, 4059-4070.
5. Coulter et al., 2002. Vaccine 21, 946-949.