Comparison of immune response in mice sensitized to an animal allergen, Can f 1, and to a food allergen, ovalbumin.

Can f 1 belongs to the lipocalin superfamily and is considered to be an animal allergen. The immune response induced by Can f 1 in mice was compared with that induced by ovalbumin (OVA), a typical food allergen. Female BALB/c and C57BL/6 mice (6 weeks of age) were subcutaneously injected with Can f 1 or OVA with or without aluminum hydroxide (Alum) three times with intervals of two weeks. Serum levels of total IgE or antigen-specific IgE and production of IL13 and IFNγ from splenocytes were analyzed. Immunization with Can f 1 or OVA increased serum levels of both total IgE and antigen-specific IgE significantly irrespective of Alum. These results indicate that Can f 1 and OVA were able to induce allergic sensitization in mice. Splenocyte production of IL13 in mice immunized with Can f 1 or OVA with and without Alum were significantly increased after stimulation with each antigen. However, IL13 levels in the mice immunized with Can f 1 with Alum were significantly lower than those immunized without Alum. Increases in IFNγ levels after stimulation with Can f 1 or OVA were not remarkable. No influence of genetic backgrounds of BALB/c and C57BL/6 mice was found. Although Can f 1 induced Th2 type immune responses as was also the case for immunization with OVA, an inhibitory effect of Alum on induction of IL13 was observed only in mice immunized with Can f 1. These results suggest that the immune mechanism for allergic sensitization with Can f 1 is different from that with OVA.