• Archives of Pharmacal Research
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• v.20 no.5
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• pp.396-403
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• 1997

In order to direct the form of the immune response in an antigen-specific manner, we constructed a fusion protein (OVA/IL12) that contained the T cell-dependent antigen, ovalbumin (OVA), covalently linked to murine interleukin-12 (IL-12). The OVA/IL12 protein was produced in a baculovirus expression system and was purified by anti-OVA immunoaffinity chromatography. The purified OVA/ILI2 protein displayed potent IL-12 bioactivity in an IL-12 proliferation assay. BALB/c mice immunized with the OVA/IL12 protein produced increased quantities of anti-OVA IgG2a antibody compared with mice immunized with recombinant OVA alone. Lymph node cells from the immunized mice with the OVA/IL12 protein produced large amounts of IFN-,Y when restimulated in vitro with OVA, while those from mice immunized with the OVA protein produced little or no IFN-.gamma.. In contrast, immunization with a mixture of OVA and free recombinant IL-12 also induced IFN-.gamma. production, which was not OVA-specific. These studies indicate that the OVA/IL12 fusion protein can induce OVA-specific, Th1-dominated immune responses, and that the covalent linkage of OVA and IL-12 confines the effect of IL-12 to OVA-specific cells.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.764-772
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• 2017

Fertilized hen eggs are rich in a variety of bioactive ingredients. In this study, we aimed to obtain an antioxidant protein from fertilized eggs and the radical scavenging abilities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (${\bullet}OH$), superoxide anion ($O^{2-}{\bullet}$) were used to evaluate the antioxidant activity of the purified protein. During 20 d of incubation, the radical scavenging ability of protein extracted from fertilized eggs exhibited significantly differences and the protein on day 16 showed higher antioxidant capacity. Based on this, the antioxidant protein of the samples on day 16 were isolated for the follow-up study. With a molecular weight 43.22 kDa, the antioxidant protein was purified by Diethylaminoethyl cellulose -52 (DEAE-52) column and Sephadex G-100. The LC-MS analysis showed that the purified protein molecular weight was 43.22 kDa, named D2-S. The sequence of amino acids was highly similar to ovalbumin and the coverage reached to 84%. The purified protein showed a radical scavenging rate of $52.34{\pm}3.27%$ on DPPH and $63.49{\pm}0.25%$ on ${\bullet}OH$, respectively. Furthermore, the C-terminal amino acid sequence was NAVLFFGRCVSP, which was consistent with the sequence of ovabumin. These results here indicated that purified protein may be a potential resource as a natural antioxidant.