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To discuss the antiviral activity of IFN-α-IL-18 fusion protein, IFN-α,IL-18 and the fusion gene IFN-α-IL-18 was cloned into the downstream of the promoter AOX1 of the yeast expression vector pPICZ-αA to construct the recombinant plasmids pPICZ-IFN-α, pPICZ-IL-18 and pPICZ-IFN-α-IL-18. The recombinant plasmids was transformed into P. Pastoris X-33 strain by electroporation after pPICZ-IFN-α-IL-18, pPICZ-IFN-α was linearized by Pme I enzyme. The expression protein was expressed under the induction of 1% methanol,and detected by SDS-PAGE and Western-blot. The biological activity of the expression products was determined by the lymphocyte transformation test initially, and was the anti-IBDV effect of the expression products evaluated by embryonic vaccinated. The results showed that the expression products existed in supernatant, and its molecular weight was about 22 000, 23 000 and 43 000, the expression products IL-18 and IFN-α-IL-18 had a distinct transformation for chicken lymphocyte(P<0. 05). IFN-α-IL-18 fusion protein can significantly inhibit the amplification of IBDV (P < 0.01), IFN-α and IL-18 showed the obvious anti-IBDV activity of (P < 0.05). The study builta foundation for study on the function of IFN-α-IL-18 fusion protein and the exploration of the role in controlling viral diseases in chicken. [ABSTRACT FROM AUTHOR]

The article focuses on the study which investigates the construction and identification of Salmonella typhimurium SL1334 mutant strain (SL1344ΔcrpΔasd). The said mutant strain was constructed through the two-step method that was introduced by the transduction of recombinant suicide plasmid. The study shows that the mutant strain could be considered as a potential oral vaccine vector to express foreign antigen.

The article explores the expression and construction of mature chicken interleukin-18 (MCh1L-18) in Pichia pastoris. The MCh1L-18 is reconstructed using the technique of site-specific mutagenesis. The constructed plasmid is transformed into Pichia pastoris X-33 to obtain a high expression transformant. It was found that the MCh1L-18 has a strong antigen immune reactions.

The present study focused on establishing the effects of interferon-gamma (IFN-γ) on interleukin-18 (IL-18) expression patterns and pregnancy outcomes in pregnant rats. Pregnant rats at the post-implantation stage were randomized into control, low IFN-γ (L-IFN-γ) and high IFN-γ groups (H-IFN-γ) that received normal saline, 100 IU/g of IFN-γ and 500 IU/g of IFN-γ vaginal muscular injection, respectively. The effects of IFN-γ on IL-18 expression and pregnancy outcomes were assessed systematically using several methods, including immunohistochemistry streptavidin-perosidase (SP), image pattern analysis, enzyme-linked immune-sorbent assay (ELISA), whole blood count (WBC) count, microscopy and visual observation. IL-18 was detected in the uteri of all pregnant rats, and mainly distributed in the endometrium, decidual cells, vascular endothelium and myometrium. Immunohistochemistry and image pattern analyses revealed significantly lower IL-18 expression in the H-IFN-γ group compared to the L-IFN-γ and control groups (p<0.01), indicating that high doses of IFN-γ induce downregulation of IL-18 in the uterus of pregnant rats. ELISA results disclosed that IL-18 expression in peripheral blood of the H-IFN-γ group was lower than that of the L-IFN-γ group (p<0.05), and significantly reduced compared to the control group (p<0.01). Moreover, the number of peripheral leukocytes in the H-IFN-γ group was significantly higher than those in the control and L-IFN-γ groups (p<0.01). Morphology analysis showed no evident differences between the L-IFN-γ and control groups. However, for the H-IFN-γ group, uterine mucosa bleeding, necrosis and excoriation were observed using microscopy. Visual observation revealed marroon, swelling, crassitude and no embryo in the uterus, which are obvious indicators of abortion. These results indicate that IFN-γ plays a regulatory role in IL-18 expression in the uterus and peripheral blood of pregnant rats at the post-implantation stage. Moreover, high levels (500 IU/g) of IFN-γ influence normal pregnancy at the early stages in rats by downregulating IL-18 expression in the uterus and peripheral blood and increasing the number of peripheral leukocytes, consequently triggering termination of pregnancy.

MicroRNAs (miRNAs) are endogenous small non-protein coding RNAs that play important regulatory roles in animals and plants by binding to target transcripts for cleavage or translational repression. The miR-9a is very conservative in animals from flies to humans. Studies indicated that miR-9a is involved in the regulation of neurogenesis in animals. In our study, the baculovirus expression system was used to transcribe a recombinant vector containing miR-9a for further analysis the function ofmiR-9a. The sequence ofpre-miR-9a from silkworm DNA was first cloned into the donor pFastBac. The enhanced green fluorescent protein (EGFP) was used as reporter gene. The recombinant donor plasmid pFastBac-miR-9a was transformed into E.coli DH10Bac/AcNPV forming Bacmid-9a which was transfected into insect cells with cational lipofectin. The transcription of mature miR-9a was detected by Real-time PCR. The results show the recombinant Bacmid-9a was successfully constructed and effectively transcribed miR-9a in infected Sf21 insect cells.

Aim: Expression and analysis of recombinant chicken IL-18 in Pichia pastoris., Methods: Chicken IL-18 mature peptide gene was amplified from the recombinant plasmid pMD18-T-ChIL-18 by PCR, and was subcloned into Pichia pastoris expression vector pPICZalphaA to construct the recombinant plasmid pPICZalphaA-ChIL-18. After identified by restriction enzymes digestion analysis, PCR and DNA sequencing, the recombinant plasmid was transformed into Pichia pastoris X-33.Then choosing the multi-copy recombinant strains to be induced for expression.Then the bioactivity of rchIL-18 was analysed by Western blot, ELISA and MTT after purified by Sephadex G-100 column., Results: The chicken IL-18 with the immunogenicity was secreted by Pichia pastoris. It could induce T lymphocytes proliferation and secreting IFN-gamma in vitro., Conclusion: The chicken IL-18 with obvious biological activity is secreted by Pichia pastoris X-33.